Article

Two-level cervical disc arthroplasty versus anterior cervical discectomy and fusion: 10-year outcomes of a prospective, randomized investigational device exemption clinical trial

Authors:
  • The Orthopedic Center of St. Louis
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Abstract

Objective: The authors assessed the 10-year clinical safety and effectiveness of cervical disc arthroplasty (CDA) to treat degenerative cervical spine disease at 2 adjacent levels compared to anterior cervical discectomy and fusion (ACDF). Methods: A prospective, randomized, controlled, multicenter FDA-approved clinical trial was conducted comparing the low-profile titanium ceramic composite-based Prestige LP Cervical Disc (n = 209) at two levels with ACDF (n = 188). Ten-year follow-up data from a postapproval study were available on 148 CDA and 118 ACDF patients and are reported here. Clinical and radiographic evaluations were completed preoperatively, intraoperatively, and at regular postoperative follow-up intervals for up to 10 years. The primary endpoint was overall success, a composite variable that included key safety and efficacy considerations. Ten-year follow-up rates were 86.0% for CDA and 84.9% for ACDF. Results: From 2 to 10 years, CDA demonstrated statistical superiority over ACDF for overall success, with rates at 10 years of 80.4% versus 62.2%, respectively (posterior probability of superiority [PPS] = 99.9%). Neck Disability Index (NDI) success was also superior, with rates at 10 years of 88.4% versus 76.5% (PPS = 99.5%), as was neurological success (92.6% vs 86.1%; PPS = 95.6%). Improvements from preoperative results in NDI and neck pain scores were consistently statistically superior for CDA compared to ACDF. All other study effectiveness measures were at least noninferior for CDA compared to ACDF through the 10-year follow-up period, including disc height. Mean angular ranges of motion at treated levels were maintained in the CDA group for up to 10 years. The rates of grade IV heterotopic ossification (HO) at the superior and inferior levels were 8.2% and 10.3%, respectively. The rate of severe HO (grade III or IV) did not increase significantly from 7 years (42.4%) to 10 years (39.0%). The CDA group had fewer serious (grade 3-4) implant-related or implant/surgical procedure-related adverse events (3.8% vs 8.1%; posterior mean 95% Bayesian credible interval [BCI] of the log hazard ratio [LHR] -0.92 [-1.88, -0.01]). The CDA group also had statistically fewer secondary surgical procedures at the index levels (4.7%) than the ACDF group (17.6%) (LHR [95% BCI] -1.39 [-2.15, -0.61]) as well as at adjacent levels (9.0% vs 17.9%). Conclusions: The Prestige LP Cervical Disc, implanted at two adjacent levels, maintains improved clinical outcomes and segmental motion 10 years after surgery and is a safe and effective alternative to fusion.Clinical trial registration no.: NCT00637156 (clinicaltrials.gov).

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... Methodological quality assessment of the 11 eligible studies is shown in Fig. 2. Nine studies 28,[30][31][32][33][34][35][36][37] were adequately randomized, but 1 study 29 did not provide detailed information of randomization, and 1 study 38 failed to achieve adequate randomization. Only 4 studies 30,32,33,35 provided a clear statement regarding avoiding allocation concealment. ...
... In addition, all included RCT 28-38 failed to achieve blinding to patients and care providers due to the specialty of this kind of trial. The patients were informed immediately after surgery about the type of surgical procedure they had been underwent, and care providers were aware of which kind of surgery was to be performed during surgery 28,[30][31][32][33][34][35][36][37] . Almost all the studies described the dropout rate and 2 studies 28,29 with a followup rate below 70% were considered as having high risk of bias. ...
... Of all the parameters identified for meta-analysis, 6 studies compared overall success 28,29,31,34,37,38 and NDI success 28 36,37 . ...
Article
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Objective: Whether cervical disc arthroplasty (CDA) is superior to anterior cervical discectomy and fusion (ACDF) remains controversial, especially in relation to long-term results. The present study aimed to evaluate the long-term safety and efficiency of CDA and ACDF for cervical disc disease. Methods: We performed this study according to the Cochrane methodology. An extensive search was undertaken in PubMed, Embase, and Cochrane databases up to 1 June 2019 using the following key words: "anterior cervical fusion," "arthroplasty," "replacement" and "artificial disc". RevMan 5.3 (Cochrane, London, UK) was used to analyze data. Safety and efficiency outcome measures included the success rate, functional outcome measures, adverse events (AE), adjacent segment degeneration (ASD), secondary surgery, and patients' satisfaction and recommendation rates. The OR and MD with 95% confidence interval (CI) were used to evaluate discontinuous and continuous variables, respectively. The statistically significant level was set at P < 0.05. Results: A total of 11 randomized controlled trials with 3505 patients (CDA/ACDF: 1913/1592) were included in this meta-analysis. Compared with ACDF, CDA achieved significantly higher overall success (2.10, 95% CI [1.70, 2.59]), neck disability index (NDI) success (1.73, 95% CI [1.37, 2.18]), neurological success (1.65, 95% CI [1.24, 2.20]), patients' satisfaction (2.14, 95% CI [1.50, 3.05]), and patients' recommendation rates (3.23, 95% CI [1.79, 5.80]). Functional outcome measures such as visual analog score neck pain (-5.50, 95% CI [-8.49, -2.52]) and arm pain (-3.78, 95% CI [-7.04, -0.53]), the Short Form-36 physical component score (SF-36 PCS) (1.93, 95% CI [0.53, 3.32]), and the Short Form-36 mental component score (SF-36 MCS) (2.62, 95% CI [0.95, 4.29]), revealed superiority in the CDA group. CDA also achieved a significantly lower rate of symptomatic ASD (0.46, 95% CI [0.34, 0.63]), total secondary surgery (0.50, 95% CI [0.29, 0.87]), secondary surgery at the index level (0.46, 95% CI [0.29, 0.74]), and secondary surgery at the adjacent level (0.37, 95% CI [0.28, 0.49]). However, no significant difference was found in radiological success (1.35, 95% CI [0.88, 2.08]), NDI score (-2.88, 95% CI [-5.93, 0.17]), total reported AE (1.14, 95% CI [0.92, 1.42]), serious AE (0.89, 95% CI [0.71, 1.11]), device/surgery-related AE (0.90, 95% CI [0.68, 1.18]), radiological superior ASD (0.63, 95% CI [0.28, 1.43]), inferior ASD (0.45, 95% CI [0.19, 1.11]), and work status (1.33, 95% CI [0.78, 2.25]). Furthermore, subgroup analysis showed different results between US and non-US groups. Conclusion: Our study provided further evidence that compared to ACDF, CDA had a higher long-term clinical success rate and better functional outcome measurements, and resulted in less symptomatic ASD and fewer secondary surgeries. However, worldwide multicenter RCT with long-term follow up are still needed for further evaluation in the future.
... Incidence of heterotopic ossification (HO) was reported in 34 studies [15][16][17][18][19]21,22,[24][25][26][27][28]30,32,33,[35][36][37]39,40,[44][45][46][47]49,50,52,55,58,60,[62][63][64]74 . Heterotopic ossification was reported in TDA patients as a grade (0 through 4) according to the McAfee classification system or as absent versus present. ...
... The majority of studies assessed and reported clinical outcome using neck disability index (NDI), visual analog scale (VAS) neck and/or arm pain, SF-36 physical component summary (PCS) or mental component summary (MCS), and Japanese Orthopaedic Association (JOA) scores 1,[15][16][17][18][19]21,[23][24][25][26][27][28][29][30]32,34,35,[37][38][39][40][41][42][43][44][46][47][48][51][52][53][54][55][56][59][60][61][62]64,65,74,76 . These are patient-reported outcomes in which patients complete a questionnaire to rank their pain on items such as personal care, lifting, headaches, concentration, etc. ...
... Overall, the combined rates of reoperation for any reason for TDA and ACDF were 5.6% and 7.8%, respectively (P=0.06). However, while many studies included in this systematic review reported significantly lower TDA secondary surgery rates 1,19,21,30,[41][42][43]60,65 , many also reported lower rates in ACDF, or insignificant differences between the two groups 16,20,23,27,33,43,53,55 . This may be due to differences in follow-up times, patient inclusion criteria, or limited ACDF patient data for comparison to TDA. ...
Article
Background: Reviews of total disc arthroplasty (TDA) performance have focused on prospective randomized controlled trials (RCTs), excluding potentially important clinical information reported by others. The goal of the present study was to perform a comprehensive review, including both RCTs and non-randomized cohorts with more than five years of clinical outcome. We further explored the differences in outcome between prospective RCT and non-randomized, including retrospective studies. Methods: A systematic literature review was performed following PRISMA guidelines. Inclusion criteria were: clinical follow-up ≥ 5 years with quantitative clinical and radiographic outcome. All studies that met these criteria, including retrospective and non-randomized studies, were included, for a total of 62 studies. As anterior cervical discectomies and fusion (ACDF) was included as a control group in the majority of the studies, comparisons between TDA and ACDF were conducted. Results: Overall, there was a statistically significant difference between the rates of secondary surgeries reported for prospective RCTs and all other studies, with reoperation rates of 5.4% for prospective RCT studies v. 7.5% in all others (P<0.01). Including all studies, the reoperation rate for TDA patients was 5.6% and for fusion patients (included as control groups), 7.8%, (P=0.06). Overall, the reported incidence of adjacent segment degeneration was 26.2% in TDA patients and 43.9% in fusion patients (P<0.001). Conclusions: These findings demonstrated the need for including all available data to assess the current outcomes of cervical disc arthroplasty and account for potential biases.
... 5 Two-level uses of CDA have been approved for certain artificial discs by the US FDA and other regulatory agencies worldwide. Although the occurrence of HO by each treated level in 2-level uses may be similar to that in single-level uses, 6,15 the rate of HO on a patient basis (for either the superior or inferior level or both levels) can be expected to be higher in 2-level use. Recently published data for the Prestige LP disc used at 2 levels in a clinical trial showed severe HO (grade III or IV) at 10 years' follow-up, with an incidence at either the superior or inferior level or both levels of 39.0% compared with an additional recently published result of a 28.5% incidence of HO in a single-leveluse clinical trial of the Prestige LP disc. ...
... Recently published data for the Prestige LP disc used at 2 levels in a clinical trial showed severe HO (grade III or IV) at 10 years' follow-up, with an incidence at either the superior or inferior level or both levels of 39.0% compared with an additional recently published result of a 28.5% incidence of HO in a single-leveluse clinical trial of the Prestige LP disc. 5,6 This slightly greater incidence in 2-level CDA provides an opportunity for unique insights regarding the clinical implications of HO, with a chance to examine the relationships between HO severity and clinical outcomes. ...
... Results of the clinical trial at 2, 7, and 10 years of follow-up have been published. 6,7,10 The current study was performed as a subgroup analysis using the data accrued from the 209 patients who were implanted with the Prestige LP discs in that clinical trial and followed in the PAS. The specific study design, methods, and procedures for the clinical study have been described in the previous publications, including inclusion and exclusion criteria and definitions of all outcome measures, but the methods relevant to the current study are briefly summarized below. ...
Article
Objective: The authors sought to assess the impact of heterotopic ossification (HO) on clinical outcomes and angular range of motion (ROM) after cervical disc arthroplasty (CDA) performed with the Prestige LP Cervical Disc (Prestige LP disc) at 2 levels. Methods: HO was assessed and graded from 0 to IV for increasing severity on lateral neutral radiographs at each visit in 209 patients who underwent implantation of Prestige LP discs at 2 cervical levels in a clinical trial with extended 10-year follow-up. ROM was compared by using HO grade, and clinical outcomes were compared between HO subgroups (grade 0-II vs III/IV) based on HO severity at 2 and 10 years after surgery. Results: The grade III/IV HO incidence at either or both index levels was 24.2% (48/198) at 2 years and 39.0% (57/146) at 10 years. No statistical difference was found in overall success; neurological success; or Neck Disability Index (NDI), neck pain, arm pain, or SF-36 Physical Component Summary (PCS) scores between the HO subgroups (grade 0-II vs III/IV) at either 2 or 10 years. The cumulative rate of possible implant-related adverse events (AEs) was higher in patients having grade III/IV HO at 2 years (56.3%) and 10 years (47.8%) compared with those having grade 0-II HO at 2 years (24.4%) and 10 years (17.9%), specifically in 2 subcategories: spinal events and HOs reported by the investigators. No statistical difference was found between the HO subgroups in possible implant-related serious AEs or secondary surgeries at the index or adjacent levels. The average angular ROMs at index levels were lower in subjects with higher-grade HO at 2 and 10 years. The average ROMs at the superior level were 8.8°, 6.6°, 3.2°, and 0.3°, respectively, for the HO grade 0/I, II, III, and IV groups at 10 years, and 7.9°, 6.2°, 3.7°, and 0.6°, respectively, at the inferior level. Conclusions: Radiographically severe (grade III or IV) HO after CDA with the Prestige LP disc at 2 levels did not significantly affect efficacy or safety outcomes (severe AEs or secondary surgeries). However, severe HO, particularly grade IV HO, significantly limited ROM, as expected.
... Cervical disc replacement (CDR) is growing in popularity for the treatment of cervical spine pathology [1,2]. Multiple studies over the last 10 years demonstrate that CDR is comparable or superior to anterior cervical discectomy and fusion (ACDF), especially in terms of symptom relief, preserved range of motion, and a lower rate of revision surgery [1,3,4]. ...
... Cervical disc replacement (CDR) is growing in popularity for the treatment of cervical spine pathology [1,2]. Multiple studies over the last 10 years demonstrate that CDR is comparable or superior to anterior cervical discectomy and fusion (ACDF), especially in terms of symptom relief, preserved range of motion, and a lower rate of revision surgery [1,3,4]. Additionally, CDR can eliminate the 10% risk of nonunion, a potential complication of ACDF [3]. ...
... Pseudarthrosis rates vary vastly in the literature; 7 to 60% of patients who undergo an ACDF develop a nonunion [3,6,8]. Common nonunion side effects include recurrent neck pain, return of radiculopathy, and the need for additional surgery [1,3,4,6]. Revision surgical approaches are revision fusion through ACDF, posterior fusion, or a combined approach [3]. ...
Article
Full-text available
Introduction Cervical disc replacement (CDR) has become prevalent in the treatment of cervical pathology. CDR is an appealing option for several reasons, including improvement of symptoms, preservation of range of motion, and the absence of risk for nonunion – a complication of an anterior cervical decompression and fusion (ACDF) surgery. In this case series, we explore the use of CDR to treat cervical nonunion. Methods Four patients, ages 50 to 64, presented to one surgeon with symptomatic cervical nonunion. Three of the four patients possessed risk factors for further nonunion and were therefore considered especially well-suited to a CDR rather than a revision ACDF. X-ray, MRI, and CT were used to confirm the presence of nonunion and to determine the architectural feasibility of replacing the level with a cervical disc arthroplasty. Six total nonunion levels were present in four patients (two levels in two patients and one level in two patients). Each of the nonunion levels was successfully treated with a revision decompression and CDR. Results Postoperatively, all four patients experienced improvement of nonunion symptoms. Neck Disability Index improved on average by 75% (preoperative score 51% to postoperative score 13%). Flexion-extension X-rays were available in three patients, which showed an increase in average range of motion from 2 degrees to 7 degrees at the revised levels. Conclusion The series describing four successful cases expands the current literature and provides support for future investigation into CDR as a treatment for cervical nonunion. We propose CDR as a viable option to treat symptomatic cervical nonunion and restore range of motion in patients without significant arthrosis and with preserved endplate architecture.
... Prestige-LP is one of the most commonly used artificial discs currently. Gornet et al. 17,18 have demonstrated that Prestige-LP CDR can effectively relieve patients' symptoms and preserve the ROM at 10-year follow-up. Compared with ACDF, Prestige-LP CDR showed lower prevalence of ASD and reoperation during long-term follow-up. ...
... Compared with ACDF, Prestige-LP CDR showed lower prevalence of ASD and reoperation during long-term follow-up. [17][18][19][20] However, the cervical sagittal alignment and its impacts on clinical outcomes after Prestige-LP CDR has been rarely studied. ...
Article
Full-text available
Purpose Cervical sagittal balance plays important roles in transmitting the load of the head and maintaining global spinal balance. This study aimed to identify the association of cervical sagittal alignment with adjacent segment degeneration (ASD) and heterotopic ossification (HO) after Prestige-LP cervical disc replacement (CDR). Methods We enrolled 132 patients who underwent one-level Prestige-LP CDR with 2–10 years of follow-up. Cervical sagittal alignment parameters, including the degree of C2–C7 lordosis (CL), functional spinal unit angle (FSUA), sagittal vertical axis (SVA),, and T1 slope (T1s), were measured. ASD and HO were evaluated at the last follow-up. Unpaired t tests and logistic regression analysis were used to identify the associations of cervical sagittal alignment with ASD and HO. Results We found that patients who developed ASD showed significantly lower FSUA (2.1° vs. −1.4°, p < 0.001) and T1s values (28.4° vs. 25.5°, p = 0.029) after surgery. Similarly, the postoperative CL was significantly better in patients without ASD or HO (18.0° vs. 14.4°, p = 0.043). The decrease in the T1s at the last follow-up was significantly larger in the patients with ASD (−11.0° vs. −3.2°, p = 0.003), HO (−6.7° vs. −2.7°, p = 0.050), and ASD or HO (−7.0° vs. −0.8°, p < 0.001) than in those without ASD or HO. Multivariate logistic regression analysis showed that both the FSUA and T1s are associated with ASD and that the degree of CL is associated with postoperative complications. Conclusion The results imply that maintaining cervical sagittal alignment after Prestige-LP CDR is important.
... A total of 4,087 patients were included. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] Follow-up rates, when documented, varied from 54% to 92%, with the exception of the study by Walraevens et al. 8 which had only 26 of 89 patients with a follow-up at 8 years (29.2%). All the information extracted from the studies are summarized in Table 1. ...
... All the information extracted from the studies are summarized in Table 1. [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25][26][27] ...
Article
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Objective: To perform a systematic literature review on revision surgeries at the index level after cervical disc arthroplasty (CDA) failure. Methods: A systematic literature review was performed according to the PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) guidelines. Prospective studies on patients who required a secondary surgery after CDA failure were included for analysis. The minimum follow-up for these studies was 5 years. Results: Out of 864 studies in the original search group, a total of 20 studies were included. From a total of 4,087 patients, 161 patients required a reoperation at the index level. A total of 170 surgeries were performed, as some patients required multiple surgeries. The most common secondary procedures were anterior cervical discectomy and fusion (ACDF) (68%, N = 61) and posterior cervical fusion (15.5%, N = 14), followed by other reoperation (13.3%, N = 12). The associated outcomes for those who required a revision surgery were rarely mentioned in the included literature. Conclusion: The long-term revision rate at the index level of failed CDA surgery was 3.9%, with a minimum 5-year follow-up. ACDF was the most commonly performed procedure to salvage a failed CDA. Some patients who required a new surgery after CDA failure may require a more extensive salvage procedure and even subsequent surgeries.
... e United States Food and Drug Administration investigational device exemption trial documented that 10 years following two adjacent level cervical disc arthroplasty (CDA), patients continued to show clinical improvement and preservation of motion at the operated levels. [1] Imaging Cervical dynamic X-rays showed a loss of the normal cervical lordosis with a congenital KFS fusion at the C7-T1 level; dynamic studies confirmed no instability at that level [ Figure 1]. In addition, the MR revealed bilateral, right greater than left, neuroforaminal stenosis at the C5-C6 and C6-C7 levels, without accompanying significant central stenosis [ Figure 2]. ...
... Gornet and Lanman's multicenter data demonstrated the superiority of two-level CDA over ACDF at 10 postoperative years; the overall success was 80.4% for CDA versus 62.2% for ACDF. [1] Postoperatively, the patient's radiographs showed excellent movement of the segments treated. ...
Article
Full-text available
Background Klippel-Feil syndrome (KFS) is defined by multiple abnormal segments of the cervical spine with congenital synostosis of two or more cervical vertebrae. KFS patients who demonstrate progressive symptomatic instability and/or neurologic sequelae are traditionally managed with operative decompression and arthrodesis. Case Description A 44-year-old female with chronic neck pain and radiculopathy and a C7-T1 KFS presented with adjacent segment degenerative disc disease at the C5-6 and C6-7 levels. She was successfully managed with a two-level cervical disc arthroplasty (CDA). Conclusion Patients with KFS and disease at two contiguous, adjacent levels (e.g., cervical disc disease) may be safely and effectively managed with two-level CDA.
... 1 In recent series, CDR has been shown to result in better immediate post-operative range of motion and improved long-term outcomes compared to ACDF. [2][3][4][5][6][7][8][9] In addition, there is evidence suggesting lower rates of adjacent segment degeneration with CDR compared with ACDF. 7,10,11 For patients with myelopathy, both ACDF and CDR are known to be effective long-term treatment options. ...
Article
Full-text available
Objective: Cervical disc replacement (CDR) is an effective long-term treatment for both cervical radiculopathy and myelopathy. However, there may be unique differences in the early postoperative clinical improvement for patients with and without myelopathy. In addition, previous studies using CDR to treat cervical myelopathy were underpowered to determine risk factors for relatively postoperative medical complications. Methods: Two different cohorts were studied. A local cohort of patients undergoing CDR by a single surgeon was utilized to study the early postoperative course of clinical improvement. In addition, a national cohort of patients undergoing CDR in the 2015 and 2016 National Surgical Quality Improvement Program database was utilized to study differences in postoperative medical complications after CDR. Patients with a preoperative diagnosis of cervical myelopathy were identified in both cohorts, and perioperative outcomes and complications were compared to patients without myelopathy. Results: A total of 43 patients undergoing CDR were included in the institutional cohort, of those 16 patients (37% of cohort) had a preoperative diagnosis of cervical myelopathy. A total of 3,023 patients undergoing CDR were included in the national cohort, of those 411 (13% of cohort) had a preoperative diagnosis of cervical myelopathy. In the institutional cohort, the nonmyelopathy group had a lower initial Neck Disability Index (NDI) and saw a faster improvement in NDI by 2 weeks postoperative. However, at 24 weeks there was no significant difference between groups in terms of NDI. Interestingly, only the nonmyelopathy cohort had a significant improvement in modified Japanese Orthopaedic Association score by 6 weeks (p<0.05). In the national cohort, myelopathy was associated with longer operative time and length of stay (p<0.05). However, there was no significant difference in perioperative complications (p>0.05) between myelopathy and nonmyelopathy patients. Conclusion: Significant improvements in NDI, visual analogue scale (VAS)-arm pain, and VAS-neck pain are seen in both myelopathy and nonmyelopathy populations undergoing CDR by 6 weeks postoperatively. However, nonmyelopathy populations improve faster by 2 weeks postoperatively. In the national cohort analysis, medical complications were similarly low in both myelopathy and nonmyelopathy groups.
... From spinal fusion to artificial disc implantation, these advancements have brought great benefits, allowing preservation of spinal motion and flexibility after intervertebral discectomy [20]. A disc prosthesis is the best alternative to arthrodesis, especially since this, in addition to congenital fusion, accentuates the biomechanical disturbances of the cervical spine and exposes the adjacent segments to early degeneration [21] [22] [23] [24]. However, the decision to perform an arthrodesis or arthroplasty is difficult, as the natural history of KFS is poorly understood. ...
... Cervical disc arthroplasty (CDA) has been recognized as a safe and effective alternative to anterior cervical discectomy and fusion (ACDF) for patients with cervical myelopathy and radiculopathy caused by disc herniation or spondylosis. [1][2][3][4][5] Many midterm to long-term reports of multicenter prospective randomized controlled trials have demonstrated the effectiveness of CDA in maintaining neurological improvement and preservation of segmental mobility. [6][7][8][9] The potential to alleviate adjacent segment degeneration (ASD) with CDA has also been suggested but still needs long-term data for corroboration. ...
Article
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BACKGROUND Heterotopic ossification (HO) is a well-documented complication of cervical disc arthroplasty (CDA), although it rarely causes adverse clinical effects. Despite high-grade HO possibly limiting segmental mobility, it is reportedly seldom associated with symptoms. OBSERVATIONS The authors report a case of a 46-year-old male patient who underwent hybrid CDA and anterior cervical discectomy and fusion for 3-level cervical disc herniation that caused myeloradiculopathy. The surgery was successful; the patient experienced nearly complete recovery postoperatively. The follow-up images, including computed tomography and magnetic resonance imaging scans, showed satisfactory decompression at the indexed levels without residual osteophytes or ossification of the posterior longitudinal ligament. However, 10 years later, the patient presented with symptomatic compressive myelopathy caused by severe HO that prompted a secondary surgery. LESSONS Although it is generally reported in the literature that HO is clinically innocuous, in this patient, it gradually and progressively developed and caused myelopathy, requiring a secondary surgery. Symptomatic HO can be expected over time, and patients with a high risk of HO deserve long-term follow-up after CDA. Further investigations are warranted to corroborate these risk factors, including multilevel calcified disc herniation, severe spondylosis, and suboptimal placement of the device during primary CDA surgery.
... 1,2 Randomized controlled trials have demonstrated good symptom relief, low reoperation rates, and high patient satisfaction using CDR. [3][4][5][6][7] Heterotopic ossification (HO) is a feared complication of CDR because it can immobilize the artificial disc. [8][9][10] However, the mechanism of HO is unclear. ...
Article
Background: Heterotopic ossification (HO) is a potential and severe complication of cervical disc replacement (CDR). However, the underlying mechanism of CDR and its association with preoperative disc height loss (DHL) and postoperative degree of distraction (PDD) remain unclear. We hypothesized that DHL and PDD could predict HO after CDR. Methods: Data were obtained from 127 patients who underwent single-level CDR with a minimum follow up of two years. DHL and adjusted degree of distraction (ADD) were obtained from lateral radiographs and HO was evaluated at the last follow up appointment. Receiver operating characteristic (ROC) curves were calculated to verify the diagnostic value of DHL and ADD in predicting HO. Results: Both DHL and ADD were significantly larger in the HO group than the non-HO group (P<0.05). DHL ≥ 24.97% increased the risk of HO by 5 times (P=0.003, 95% CI: 1.62-15.49), and ADD ≥ 36.67% increased the risk of HO by 3.87 times (P<0.001, 95% CI: 1.81-8.27). A combined DHL and ADD (combined parameter) cut-off of 60.36 had a sensitivity of 87.18%, specificity of 67.35%, and area under the curve of 0.77 for predicting HO. Conclusions: DHL and ADD are associated with the development of HO after CDR. The cut-off value of DHL may narrow the criteria for CDR with the aim of reducing HO formation. The combined parameter may help surgeons to select the most suitable implant height to reduce the prevalence of HO.
... Anterior cervical discectomy and fusion (ACDF) is a classic treatment for multilevel cervical spondylosis, although it has some limitations involving the pseudarthrosis and degeneration of adjacent segments [1,2] . In recent decades, with the development of nonfusion surgery, the efficacy and safety of using artificial cervical disc replacement (CDR) for single-level or multilevel cervical degenerative disc diseases has been demonstrated by several prospective studies from the United States Food and Drug Administration and by some meta-analyses [3][4][5][6][7][8] . In contrast to ACDF, CDR has the advantages of preserving the segmental range of motion (ROM) at a surgical level, preventing the acceleration of degeneration in adjacent segments, and avoiding complications such as nonunion or pseudoarthrodesis [9,10] . ...
Article
Background: Multilevel artificial cervical disc replacement and anterior hybrid surgery have been introduced as reliable treatments for multilevel cervical degenerative disc disease. Surgical techniques are important for resolving patients' symptoms and maintaining the normal functioning of cervical implants. However, the use of inappropriate surgical strategies could lead to complications such as implant migration and neurological deficit. In this paper, we summarize our surgical strategies used in multilevel cervical disc replacement and hybrid surgery into five major notes. Case summary: We share the key notes and our surgical procedures in the form of four typical case presentations. All patients were diagnosed with cervical degenerative disc disease with myelopathy or radiculopathy and needed multilevel cervical spine surgery. The first case demonstrated that index levels indicating the presence of highly serious spinal cord compression required a prioritized decompression. The second case demonstrated that the disc replacement should be performed before fusion in cervical hybrid surgery. The third and forth cases demonstrated that a top-down implantation sequence was needed in continuous two-level cervical disc replacement. The symptoms of all patients were significantly relieved after surgery. Conclusion: We hope that our surgical strategies can help improve the performance and outcomes of multilevel cervical spine surgery.
... The vertebral artery runs through the transverse foramina of the cervical spine, from C5 to C2, and then runs posterolaterally to enter C1 transverse foramen. The artery will then line the vertebral artery groove, [42][43][44][45] RCT USA 275/265 43.5 Nabhan et al. (2007Nabhan et al. ( , 2011 [46,47] RCT [48][49][50][51][52][53][54] RCT USA 103/106 42.5 ...
Article
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Introduction: Since the landmark publication by Smith and Robinson, approaches to the cervical spine anteriorly have undergone many modifications and even additions. Nevertheless, at its core, the anterior approach remains an elegant and efficient approach to deal with majority of cervical spine pathologies including the degenerative cervical spine. Methodology: For this review, we searched for all major cases series and randomized control trials of anterior cervical approaches using the PubMed databases. Articles having the details of clinical variables and outcomes were tabulated and analyzed. Results: A total of 9 case series for transoral, 7 case series for transmanubrial, 19 case series for anterior cervical discectomy and fusion (ACDF), 6 studies for ACDF versus posterior cervical foraminotomy, 37 case series for ACDF versus arthroplasty, and 7 studies for ACDF versus anterior cervical corpectomy and fusion have been included. The majority of the case series suggested that the anterior cervical procedures have good clinical outcomes. The upper cervical spine approached by the transoral route had good outcomes in ventral compressive pathologies, with morbidity of cerebrospinal fluid leak in 7% of patients. The midcervical spine approached by ACDF had better clinical outcomes equivalent to the majority of modifications even in multiple-level pathologies. The transsternal approach had provided greater access and stability to the cervicothoracic junction with minimal morbidity. Conclusion: The anterior cervical approach can address the majority of cervical pathologies. They provide adequate corridor from craniovertebral junction to T4 with minimal morbidity, thus providing a good clinical outcome.
... The aim of this study was to determine whether ADR surgery resulted in better long-term clinical outcomes than fusion surgery after anterior decompression in patients with degenerative cervical radiculopathy and to investigate with MRI whether ADR surgery prevented ASP at 10 years. Because none of the larger open-label randomized controlled trials had long-term follow-up MRI data at 10 years postoperatively, [5][6][7][8] there are still insufficient data to support the view that ADR devices prevent ASP. ...
Article
OBJECTIVE Artificial disc replacement (ADR) is designed to preserve motion and thus protect against adjacent-segment pathology (ASP) and act as an alternative treatment to fusion surgery. The question remains, how well do ADR devices perform after 10 years of follow-up compared with fusion surgery in terms of patient satisfaction, sustainability, and protection against ASP? METHODS This was the 10-year follow-up study of 153 participants who underwent ADR or fusion surgery after anterior decompression due to cervical degenerative radiculopathy (ISRCTN registration no. 44347115). Scores on the Neck Disability Index (NDI), EQ-5D, and visual analog scale for neck and arm pain were obtained from the Swedish Spine Registry and analyzed using ANCOVA. Information about secondary surgical procedures was collected from medical records and presented as Kaplan-Meier curves. MRI and flexion-extension radiography were performed, and ASP was graded according to the Miyazaki classification system. RESULTS Ten participants were lost to follow-up, which left 143 participants (80 underwent ADR and 65 underwent anterior cervical discectomy and fusion). There were no differences between groups in terms of patient-reported outcome measures (10-year difference in NDI scores 1.7 points, 95% CI −5.1 to 8.5, p = 0.61). Nineteen (24%) participants in the ADR group compared with 9 (14%) in the fusion group underwent secondary surgical procedures. The higher reoperation rate of the ADR group was mainly due to 11 female participants with device loosening. The rates of reoperation due to ASP were similar between groups, which was confirmed with MRI assessment of ASP that also showed no differences between the groups (p = 0.21). CONCLUSIONS This was the first 10-year follow-up study to compare ADR with fusion surgery and to provide MRI information for the assessment of ASP. The authors found no benefit of ADR over fusion surgery after anterior decompression for cervical degenerative radiculopathy.
... Results of these studies, some with 10 years of follow-up, have shown clinical improvement of patients treated with disc replacement, as assessed by the JOA and NDI scores with no differences in complication rates to patients treated for radiculopathy or to patients treated with ACDF. [44][45][46] Furthermore, a recent systematic review comparing ACDF with cage and plate, ACDF with stand-alone cage, and cervical disc replacement found no differences in NDI scores and in sagittal alignment. As such, and while cervical disc prostheses are not traditionally considered lordosis-producing devices, the amount of lordosis achieved is comparable to that which is achieved with ACDF. ...
Article
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Study Design Literature Review (Narrative). Objective To introduce the number 10 research priority for Degenerative Cervical Myelopathy: Individualizing Surgery. Methods This article summarizes the current recommendations and indications for surgery, including how known prognostic factors such as injury time, age, disease severity, and associated comorbidities impact surgical outcome. It also considers key areas of uncertainty that should be the focus of future research. Results While a small proportion of conservatively managed patients may remain stable, the majority will deteriorate over time. To date, surgical decompression is the mainstay of treatment, able to halt disease progression and improve neurologic function and quality of life for most patients. Whilst this recognition has led to recommendations on when to offer surgery, there remain many uncertainties including the type of surgery, or timing in milder and/or asymptomatic cases. Their clarification has the potential to transform outcomes, by ensuring surgery offers each individual its maximum benefit. Conclusion Developing the evidence to better guide surgical decision-making at the individual patient level is a research priority for Degenerative Cervical Myelopathy.
... [2,3] Several randomized controlled trials comparing the safety and efficiency of CDR with anterior cervical discectomy and fusion have proven the noninferiority of CDR. [4][5][6][7][8] In addition, studies showed that both 1-level and 2-level CDR is more cost-effective in long-term follow-up. [9,10] Therefore, CDR has been widely used in recent years. ...
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Background: Cervical disc replacement (CDR) has been widely used as an effective treatment for cervical degenerative disc diseases in recent years. However, the cost of this procedure is very high and may bring a great economic burden to patients and the health care system. It is reported that outpatient procedures can reduce nearly 30% of the costs associated with hospitalization compared with inpatient procedures. However, the safety profile surrounding outpatient CDR remains poorly resolved. This study aims to evaluate the current evidence on the safety of outpatient CDR METHODS:: Four English databases were searched. The inclusion and exclusion criteria were developed according to the PICOS principle. The titles and abstracts of the records will be screened by 2 authors independently. Records that meet the eligibility criteria will be screened for a second time by reading the full text. An extraction form will be established for data extraction. Risk of bias assessment will be performed by 2 authors independently using Cochrane risk of bias tool or Newcastle-Ottawa scale. Data synthesis will be conducted using Stata software. Heterogeneity among studies will be assessed using I test. The funnel plot, Egger regression test, and Begg rank correlation test will be used to examine the publication bias. Results: The results of this meta-analysis will be published in a peer-review journal. Conclusion: This will be the first meta-analysis that compares the safety of outpatient CDR with inpatient CDR. Our study will help surgeons fully understand the complications and safety profile surrounding outpatient CDR. OSF REGISTRATION NUMBER:: doi.org/10.17605/OSF.IO/3597Z.
... The rate of symptomatic ASD after ACDF requiring surgery has been reported to be 16% after 10 years for single-level ACDF, 2 and 18% after 2-level ACDF. 3 There is not yet good long-term data on rate of symptomatic ASD requiring surgery after 3-level ACDF. However, there are some retrospective data suggesting that the radiographic rate of ASD after 3-level ACDF can be as high as 40%. ...
Article
Objective: Pseudarthrosis and adjacent segment degeneration (ASD) are two common complications after multi-level anterior cervical discectomy and fusion (ACDF). We aim to identify the potential biomechanical factors contributing to pseudarthrosis and ASD following three-level ACDF using a cervical spine finite-element model (FEM). Methods: A validated cervical spine FEM from C2 to C7 was used to study the biomechanical factors in cervical spine intervention. The FEM model was used to simulate a three-level ACDF with intervertebral spacers and anterior cervical plating with screw fixation from C4 to C7. The model was then constrained at the inferior nodes of the T1 vertebra, and physiological loads were applied at the top vertebra. The pure moment load of 2 Nm was applied in flexion, extension, and lateral bending. A follower axial force of 75 N was applied to reproduce the weight of the cranium and muscle force, was applied using standard procedures. The motion-controlled hybrid protocol was utilized to comprehend the adjustments in the spinal biomechanics. Results: Our cervical spine FEM demonstrated that the cranial adjacent level (C3-4) had significantly more increase in range of motion (+90.38%) compared to the caudal adjacent level at C7-T1 (+70.18%) after C4-7 ACDF, indicating that the cranial adjacent level has more compensatory increase in ROM than the caudal adjacent level, potentially predisposing it to earlier ASD. Within the C4-7 ACDF construct, the C6-7 level had the least robust fixation during fixation compared to C4-5 and C5-6, as reflected by the smallest reduction in ROM compared to intact spine (-71.30% vs -76.36% and -77.05%, respectively), which potentially predisposes the C6-7 level to higher risk of pseudarthrosis. Conclusion: Biomechanical analysis of C4-7 ACDF construct using a validated cervical spine FEM indicated that the C3-4 has more compensatory increase in ROM compared to C7-T1, and C6-7 has the least robust fixation under physiological loads. These findings can help spine surgeons to predicate the areas with higher risks of pseudarthrosis and ASD, and thus developing corresponding strategies to mitigate these risks and provide appropriate pre-operative counseling to patients.
... Due to the development of individual therapy and precision medicine, anterior cervical discectomy and fusion (ACDF), which is considered a traditional surgery, has been partly replaced by cervical disc arthroplasty (CDA) [1][2][3][4] Hybrid surgery (HS), a combination of ACDF and CDA, has also been used for the treatment of multilevel cervical degenerative disc disease (CDDD). Many studies have indicated that HS is a safe, effective and reliable surgical procedure [5][6][7][8][9]. ...
Article
Full-text available
Introduction: According to the different numbers and locations of cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF), three-level hybrid surgery (HS) has many constructs. The purpose of the present study was to introduce a classification system for three-level HS and compare the two types with each other and with ACDF. Methods: A retrospective study was conducted involving patients with three-level cervical degenerative disc disease (CDDD) who underwent ACDF or HS in our hospital between June 2012 and May 2019. According to the different numbers and locations of ACDFs and CDAs, we classified the three-level HS into two types (type I: one-level CDA and two-level ACDF, and type II: two-level CDA and one-level ACDF). The differences of clinical and radiological outcomes were compared with each other and with three-level ACDF. Results: A total of 108 patients were analyzed. The Neck Disability Index (NDI) of the ACDF group at 3 months postoperatively was significantly higher than that in the type I and type II groups (p < 0.05). The cervical lordosis was significantly lower in the ACDF group than that in the type I and II groups at 3 days, 6, 12 months postoperatively and the final follow-up (p < 0.05). The range of motion (ROM) of the total cervical spine decreased significantly in all three groups at 3, 6, and 12 months postoperatively and at the final follow-up (p < 0.05). The ACDF group was observed with the most severe loss of ROM of the total cervical spine, followed by the type I group. The type II group could preserve the most ROM of the total cervical spine. The ROM of adjacent segments increased most in the ACDF group, followed by the type I group. Conclusions: Compared with ACDF, three-level HS may yield a faster recovery rate and superior radiological outcomes, such as a superiority in maintaining the cervical curvature and ROM of the total cervical spine and a smaller increase in the ROM of adjacent segments. The advantages were most remarkable in the type II group.
Article
OBJECTIVE. The purpose of this article is to provide a review of the imaging of spine fixation hardware. CONCLUSION. As the prevalence of neck and back pain continues to increase, so does the number of surgical procedures used to treat such pain. Accordingly, new techniques and hardware designs are used, and the hardware will be seen on postoperative imaging. It is critical that radiologists understand the appropriate imaging modalities for the assessment of spine fixation hardware, recognize the normal imaging appearance of such hardware, and be able to detect hardware-related complications.
Article
Background: Anterior cervical discectomy and fusion (ACDF) is an effective treatment for cervical spondylosis. A limitation of ACDF is the risk of adjacent-segment degeneration (ASD), owing to arthrodesis of a motion segment. Cervical disc arthroplasty (CDA) has hence garnered significant attention; yet, compelling evidence of reduction in ASD requiring surgery is lacking. This systematic review and meta-analysis sought to compare long-term longitudinal adjacent-level operation rates with CDA versus ACDF. Methods: An electronic literature search was conducted. Eligible studies were multi-center randomized controlled trials (RCTs) comparing CDA with ACDF for one- or two-level symptomatic cervical spondylosis. The primary outcome was adjacent-level operation. Index-level reoperation was a secondary outcome. Outcomes were evaluated at 1-year intervals from the index operation to last reported follow-up by random-effects meta-analyses. Results: Eleven RCTs met criteria. For one-level spondylosis, there was no difference in the rate of adjacent-level operation between CDA (2.3%) and ACDF (3.6%) at 2 years. However, a large difference favoring CDA became evident at 5 years and persisted at 7 years (4.3% vs. 10.8%, P<0.001). Significantly fewer patients who underwent CDA required index-level reoperation at all time points out to 7 years (5.2% vs. 12.7%, P<0.001). Similar to one-level operations, there was no significant difference in adjacent-level operations with two-level CDA (1.7%) versus two-level ACDF (3.4%) at 2 years. At 7 years, a significant difference favoring CDA became apparent (5.1% vs. 10.0%, P=0.014). Two-level CDA resulted in fewer index-level reoperations out to 7 years (4.2% vs. 13.5%, P<0.001). Conclusions: In this meta-analysis, the short-term rate of adjacent-level operation was similar with CDA or ACDF. However, around 5 years, a statistically significant divergence emerged, where the rate of adjacent-level surgery rose steeply for ACDF. Index-level reoperations were less frequent with CDA in both the short- and long-term. These data indicate CDA may have a superior longevity to ACDF with regard to need for subsequent adjacent-level operation.
Article
Background context: Cervical disc replacement (CDR) has increased in popularity over the past decade based on published outcomes from FDA IDE studies with narrowly defined inclusion and exclusion criteria. A low rate of complications was noted in these studies. The broader complication profile for CDR in widespread clinical practice has yet to be described. Purpose: To outline the complications reported to the FDA regarding commonly used CDR products STUDY DESIGN/SETTING: Retrospective database review PATIENT SAMPLE: Nationwide database of reported complications related to CDR products from patients across the country OUTCOME MEASURES: Complications related to CDR METHODS: We queried the MAUDE database and Alternative Summary Reporting (ASR) data files submitted between January 2005 to March 2020. The complications listed for seven FDA-approved CDR implants were analyzed. The entries in the databases were cataloged for complication type, date of entry, source of report, and whether the investigation was "complete". Reports that had too little information to extract relevant data were excluded. Results: There were 1,517 entries identified in the MAUDE database. After removal of duplicate entries and entries without sufficient information, there were 1,347 entries analyzed. The top 5 complications were (1) migration of implant (338 entries, 25.2%) (2) insertion problem/failure (312 entries, 23.3%) (3) neck pain (203 entries, 15.2%) (4) heterotopic ossification (108 entries, 8.1%) and (5) radiculopathy (90 entries, 8.1%). The number of analyzed implant-related MAUDE entries and most common implant-related complication for each implant was 209 entries for insertion problem/failure for Mobi-C; 158 entries for migration of implant for ProDisc-C; 154 entries for insertion problem/failure for Bryan cervical disc; 130 entries for migration of implant for Prestige cervical disc; 49 entries for migration of implant for PCM cervical disc; 12 entries for migration of implant for M6 and 10 entries for migration of implant for Secure-C. Only 263 entries (19.5%) were deemed "complete". Most entries were from the manufacturer/company representative/distributor (923 entries, 70%). There were no entries related to cervical disc replacement devices within the ASR data. Conclusion: The MAUDE database highlights complications related to CDR implants that may not be emphasized in currently published studies. It is important to understand this broad complication profile for CDR to ensure safe utilization of this new technology.
Article
Study design: This was a post hoc analysis of a prospective FDA-IDE study. Objective: The purpose of this study is to determine the effectiveness of a 2-level anterior cervical discectomy and fusion (ACDF) or cervical disk arthroplasty (CDA) at relieving headaches associated with cervical radiculopathy or myelopathy at 10 years postoperative. Background: To our knowledge, there is no large, prospective study that has examined the efficacy of cervical spine surgery for relieving headaches associated with radiculopathy or myelopathy at 10 years postoperative. Materials and methods: This was a post hoc analysis of a prospective FDA-IDE study for the Prestige LP versus ACDF for radiculopathy or myelopathy due to 2 levels. Preoperatively and out to 10 years, their Neck Disability Index documented if they had headaches (0: no headaches; 1: infrequent slight; 2: infrequent moderate; 3: frequent moderate; 4: frequent severe; 5: nearly constant). Results: Three hundred ninety-seven patients were randomized to CDA (209) or ACDF (188). Preoperatively 86% had headaches and 55.9% (52.2% of CDA, 60.1% of ACDFs) had frequent moderate, severe, or nearly constant headache (grades 3-5). By 6 weeks postoperative, 64.4% had headaches and only 12.5% had grades 3-5 headaches (9.3% of CDA and 16% of ACDFs). The benefit lasted to the 10-year follow-up such that 60.3% had any headaches and 16.8% had grades 3-5 headaches (10.9% CDA; 24.3% ACDF). Conclusions: These results suggest that 86% of patients with radiculopathy or myelopathy complain of headaches preoperatively, with 55.9% having frequent or constant, moderate to severe headaches (grades 3-5). By 6 weeks postoperative, only 12.5% had grades 3-5 headaches. At 10-year follow-up, 16.8% had grades 3-5 headaches. Both arthroplasty and ACDF are often effective at alleviating headaches associated with radiculopathy or myelopathy.
Article
Background In a standard surgical operating room, advanced imaging is projected on a separate monitor screen away from the surgical field of view. This setup requires surgeons to repeatedly shift their attention between the operative field and a screen. Such movement may result in a disruption of focus that can extend surgical time, cause physical strain, and lead to surgical errors. A potential solution to this inefficiency in the surgical workflow is to use a heads-up display (HUD) to mirror what is being displayed. A HUD projects preoperative or intraoperative imaging over the surgical field, allowing surgeons to visualize both as they perform surgery. Case Description We performed a single-level arthroplasty for a patient with right-sided disc herniation at C6-7. A HUD was used by the lead surgeon to continuously view intraoperative X-rays without needing to repeatedly turn away from the surgical field while placing Caspar pins into the C6 and C7 vertebral bodies, and malleating trials and the artificial disc into the disc space. Conclusions Following surgery, the patient experienced resolution of his preoperative right arm and hand paresthesia and regained full strength. This case describes the novel use of the Moverio BT-35E Smart Glasses (Epson Inc, Suwa, Japan) HUD during a spine procedure.
Article
Background: Heterotopic ossification (HO) and anterior bone loss (ABL) are two complications in cervical disc replacement (CDR), which have impacts on the clinical outcomes. Physiologically, bone formation (HO) and bone loss are two sides of bone remodeling. However, clinically, some patients occurred anterior HO (AHO) after CDR, while other patients occurred ABL. Is there any factor in determining the fate of the vertebral bone in the anterior region? Is ABL the opposite of AHO? This study aims to answer the above questions. Methods: Seventy patients with one-level Prestige-LP CDR were retrospectively reviewed and were divided into AHO group or ABL group. Radiological outcomes, including cervical lordosis, sagittal vertical axis (SVA), functional spine unit (FSU) angle, disc angle, range of motion (ROM), implant migration, subsidence, adjacent segment degeneration (ASD) were evaluated. Patient-reported clinical outcomes were also evaluated. Results: AHO group showed significantly lower disc angle after surgery (0.9±4.2˚), compared to ABL group (6.7±4.7˚) (p<0.001). The preoperative segmental ROM was significantly higher in AHO group (10.2±3.3˚) than that in ABL group (8.2±3.7˚) (p=0.042). No correlation was observed between clinical outcomes and the presence of anterior bone remodeling. Both groups maintained cervical alignment and FSU angle during long-term follow-up. No significant difference was found in the endplate preparation, implant subsidence, migration, or ASD rate between the two groups. Conclusions: The differences in the disc angle showed the role of mechanical load in the anterior bone remodeling. Combined the results with the basic concepts of bone remodeling, ABL may be the opposite of AHO.
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Background: Multiple studies have highlighted the motion-sparing benefits of single-level cervical disc arthroplasty (CDA) compared with anterior cervical discectomy and fusion (ACDF). However, few studies have reviewed multilevel ACDF versus CDA. Several recent studies have midterm and even long-term data available comparing 2-level ACDF versus CDA. Methods: We reviewed 3 reports from 2 large randomized, prospective Food and Drug Administration investigational drug exemption trials looking at 2-level CDA versus ACDF, which provide the bulk of the available midterm to long-term, high-level evidence for the topic. We also present several smaller and/or shorter-term studies. Results: One 5-year study showed that, while both CDA and ACDF showed significant improvement in patient-reported outcome scores, CDA demonstrated greater improvement in Neck Disability Index (NDI) scores than ACDF (mean = -37 versus mean = -28, P = .0003), were more likely to be satisfied (96.4% versus 89.5%, P = .04), had fewer secondary surgeries (4% versus 16.2%, P = .0003), had fewer adjacent level reoperations (3.1% versus 11.4%), and developed less adjacent segment degeneration (50.7% versus 90.5%, P < .0001). Adverse events occurred more frequently with ACDF (8.6% versus 4.4%).Similarly, Lanman et al [Lanman TH, Burkus JK, Dryer RG, Gornet MF, McConnell J, Hodges SD. Long-term clinical and radiographic outcomes of the Prestige LP artificial cervical disc replacement at 2 levels: results from a prospective randomized controlled clinical trial. J Neurosurg Spine. 2017;27(1):7-19] showed that, at 7 years, while both groups demonstrated improvement in patient-reported outcomes, CDA had greater improvement in regard to NDI, neck pain, and Short Form (36) Physical Component Summary scores (each P < .001), had higher rates of satisfaction (94.8% versus 92.6%), had lower rate of secondary surgery at treated levels (4.2% versus 14.7%), and had a lower, albeit not statistically significant, rate of secondary surgeries at adjacent levels (6.5% versus 12.5%). Adverse events were more common with ACDF (7.2% versus 3.2%).More recently, Gornet et al [Gornet MF, Lanman TH, Burkus JK, et al. Two-level cervical disc arthroplasty versus anterior cervical discectomy and fusion: 10-year outcomes of a prospective, randomized investigational device exemption clinical trial. J Neurosurg Spine. 2019;31:508-518.] in 2019 reported 10-year data from the same clinical trial as the Lanman et al report comparing 2-level CDA (209 patients) versus ACDF (188 patients). With >84% follow-up for both groups at 10 years, they found that CDA demonstrated a statistically significantly improved rate of overall success (84% versus 62%) as compared with ACDF. Greater improvements were seen in several other outcome measures for CDA, including NDI, neurological success, and neck pain scores. The CDA group had a lower rate of serious implant-related adverse events and demonstrated a lower rate of needing a secondary surgery at an adjacent level, 9% versus 18% in the ACDF group. Conclusions: Results of 2 large randomized trials suggest similar-to-improved patient reported outcomes for multilevel CDA versus ACDF maintained out to midterm to long-term follow-up of 5-10 years, with lower rates of revision surgery at index and adjacent levels and lower rates of serious adverse device-related events. Level of evidence: 5. Clinical relevance: Comparison of the safety and efficacy of multi-level cervical disc arthroplasty and cervical discectomy and fusion.
Article
Biomechanical studies have demonstrated that cervical fusion results in increased motion and intradiscal pressures at adjacent levels. Cervical disc arthroplasty (CDA) is an alternative treatment for cervical radiculopathy and myelopathy resulting from degenerative disc disease. By maintaining segmental motion, surgeons hope to avoid some of the primary drawbacks of anterior cervical discectomy and fusion (ACDF), such as pseudoarthrosis and adjacent segment disease. First introduced in the 1960s, CDA has evolved over the years with changes to implant geometry and materials. Early devices produced suboptimal outcomes, but more recent generations of implants have shown long-term outcomes rivaling or even surpassing those of ACDF. In this article, the rationale for CDA as well as the history of such devices is reviewed.
Article
Background: Anterior bone loss (ABL) is a relatively easily neglected condition after cervical disc replacement (CDR). Whether this phenomenon is a radiological anomaly or a complication remains controversial. Several studies have reported the clinical characteristics of ABL and speculated on the pathogenic mechanism based on a certain type of artificial disc, while the overall understanding of ABL is lacking. Aim: To describe the prevalence, impacts, and risk factors of ABL after CDR. Methods: We searched the PubMed, Cochrane Library, and Excerpta Medica databases using the terms "bone loss" or "bone remodeling" or "bone absorption" or "osteolysis" or "implant loosening" or "implant migration" or "hypersensitivity" or "hyperreactivity", "cervical disc replacement" or "cervical disc arthroplasty" or "total disc replacement". Eligible manuscripts on the prevalence and impacts of ABL were reviewed by the authors. Data extraction was performed using an established extraction form. The results of the included studies were described narratively. Results: Six studies met the inclusion and exclusion criteria. One was a prospective study and the others were retrospective studies. A total of 440 patients with 536 segments were included. The artificial cervical discs included Bryan, Baguera-C, Discocerv, and Mobi-C. The prevalence of ABL ranged from 3.13% to 91.89%, with a combined overall prevalence of 41.84%. ABL occurred within 6 mo and stopped 12 mo after surgery. Several cases were noted to have a self-healing process. Severe ABL resulted in segmental kyphosis, implant subsidence, and persistent neck pain. ABL may be related to heterotopic ossification. Multilevel surgery may be one of the risk factors for ABL. Conclusion: ABL is a common condition after CDR. The underlying mechanisms of ABL may include stress concentration and injury to nutrient vessels. ABL should be considered a complication after CDR as it was associated with neck pain, implant subsidence, and heterotopic ossification.
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Introduction To date, there is no consensus on which anterior surgical technique is more cost-effective in treating cervical degenerative disc disease (CDDD). The most commonly used surgical treatment for patients with single- or multi-level symptomatic CDDD is anterior cervical discectomy with fusion (ACDF). However, new complaints of radiculopathy and/or myelopathy commonly develop at adjacent levels, also known as clinical adjacent segment pathology (CASP). The extent to which kinematics, surgery-induced fusion, natural history and progression of disease play a role in the development of CASP remain unclear. Anterior cervical discectomy with arthroplasty (ACDA) is another treatment option that is thought to reduce the incidence of CASP by preserving motion in the operated segment. While ACDA is often discouraged, as the implant costs are higher while the clinical outcomes are similar to ACDF, preventing CASP might be a reason for ACDA to be a more cost-effective technique in the long-term. Methods and analysis In this randomized controlled trial, patients will be randomized to receive ACDF or ACDA in a 1:1 ratio. Adult patients with single- or multi-level CDDD and symptoms of radiculopathy and/or myelopathy will be included. The primary outcome is cost-effectiveness and cost-utility of both techniques from a healthcare and societal perspective. Secondary objectives are the differences in clinical and radiological outcomes between the two techniques, as well as the qualitative process surrounding anterior decompression surgery. All outcomes will be measured at baseline, and every six months until four years post-surgery. Discussion High-quality evidence regarding the cost-effectiveness of both ACDA and ACDF is lacking; to date, there are no prospective trials from a societal perspective. Considering the ageing of the population and the rising healthcare costs, there is an urgent need for a solid clinical cost-effectiveness trial addressing this question.
Article
Introduction: Cervical laminoplasty (LP) and laminectomy with fusion (LF) are common operations used to treat cervical spondylotic myelopathy. Conflicting data exist regarding which operation provides superior patient outcomes while minimizing the risk of complications. This study evaluates the trends of LP compared with LF over the past decade in patients with cervical myelopathy and examines long-term revision rates and complications between the two procedures. Methods: Patients aged 18 years or older who underwent LP or LF for cervical myelopathy from 2010 to 2019 were identified in the PearlDiver Mariner Database. Patients were grouped independently (LP versus fusion) and assessed for association with common medical and surgical complications. The primary outcome was the incidence of LP versus LF for cervical myelopathy over time. Secondary outcomes were revision rates up to 5 years postoperatively and the development of complications attributable to either surgery. Results: In total, 1,420 patients underwent LP and 10,440 patients underwent LF. Rates of LP (10.5% to 13.7%) and LF (86.3% to 89.5%) remained stable, although the number of procedures nearly doubled from 865 in 2010 to 1,525 in 2019. On matched analysis, LP exhibited lower rates of wound complications, surgical site infections, spinal cord injury, dysphagia, cervical kyphosis, limb paralysis, incision and drainage/exploration, implant removal, respiratory failure, renal failure, and sepsis. Revision rates for both procedures at were not different at any time point. Conclusion: From 2010 to 2019, rates of LP have not increased and represent less than 15% of posterior-based myelopathy operations. Up to 5 years of follow-up, there were no differences in revision rates for LP compared with LF; however, LP was associated with fewer postoperative complications than LF. Level of evidence: Level III retrospective cohort study.
Article
Introduction: Cervical radiculopathy (CR) is commonly treated by spine surgeons, with surgical options including anterior cervical diskectomy and fusion (ACDF) and cervical disk replacement (CDR). CDR is a motion-sparing alternative to ACDF and was approved by the US FDA in 2007. CDR utilization has increased because evidence has emerged demonstrating its long-term efficacy. Despite CDR's efficacy, studies have suggested that socioeconomic factors may influence which patients undergo CDR versus ACDF. Our objective was to determine whether gender, racial, and ethnic disparities exist in the utilization of CDR versus ACDF for CR. Methods: Patients age ≥18 years undergoing elective CDR or ACDF for CR between 2017 and 2020 were identified in the Vizient Clinical Database. Proportions of patients undergoing CDR and ACDF, as well as their comorbidities, complications, and outcomes, were compared by sex, race, and ethnicity. Bonferroni correction was done for multiple comparisons. Results: A total of 7,384 patients, including 1,427 undergoing CDR and 5,957 undergoing ACDF, were reviewed. Black patients undergoing surgical treatment of CR were less likely to undergo CDR than ACDF, had a longer length of stay, and had higher readmission rates, while Hispanic patients had higher complication rates than non-Hispanic patients. Discussion: Important racial and ethnic disparities exist in CR treatment. Interventions are necessary to ensure equal access to spine care by reducing barriers, such as underinsurance and implicit bias. Level of evidence: IV (Case Series).
Article
BACKGROUND Cervical disc replacement (CDR) is an increasingly used alternative to fusion for symptomatic cervical disc disease. While more studies have suggested favorability of CDR over fusion procedures, limited data exist regarding implant fatigability. Here, the authors present a unique and previously unreported failure of the M6-C prosthesis causing spinal cord injury. OBSERVATIONS A 49-year-old female with history of cervical degenerative disease and prior C4–7 M6-C arthroplasty presented 9 years later after a minor fall from standing. She endorsed bilateral hand numbness ascending to forearms and shoulders, with dysesthesias and weakness. Imaging showed fractured arthroplasty penetrating the spinal cord. Revision surgery found a ruptured arthroplasty annulus with metal piece piercing the spinal cord. Partial C4 and C5 corpectomy was performed to remove the integrated fins of the arthroplasty and inspect the cord and dura. This was reconstructed with a corpectomy cage and plate. The patient made an excellent recovery, with improvement in her weakness and resolution of her sensory symptoms. LESSONS Possibility of fatigue-related failures presenting years after implantation have only been infrequently reported but can be catastrophic for patients. The authors encourage further discussions in this area, increased counseling with patients, and recommend a patient registry to better document adverse events.
Article
Background Cervical disc arthroplasty (CDA) using Prestige LP disc has been widely used for cervical degenerative disease. Postoperative shell angle (SA) is the angle between the upper and lower prosthesis endplate and previous studies have reported a significant correlation between prosthesis SA with postoperative biomechanical stress. Due to the lack of reference range in SA, a larger discrepancy exists in postoperative SA among the patients after CDA with Prestige LP disc. Methods A total of 160 patients who had been subjected to single level CDA with Prestige-LP were enrolled. SA was defined the angle between the upper and lower prosthesis endplate and patients were assigned into parallel (SA 0°−3°) and lordotic (SA > 3°) groups according to the immediate postoperative SA. Patients were followed up for a mean duration of 27.78 ± 5.13 months. Clinical, radiographic and complication data were compared among groups. Results 90 patients were assigned in the parallel group while 70 patients were included in the lordotic group. The mean immediate postoperative SA in the parallel and lordotic groups were 1.64 ± 0.08° and 4.88 ± 1.20°, respectively (p < 0.05). FSU angle in the parallel group at 1 year and last follow-up were 2.6 ± 2.1° and 2.1 ± 2.0°, respectively, with a change value of − 0.68 ± 2.28°. In the lordotic group, FSU angle at 1 year and last follow-up were 3.3 ± 2.5° and 3.1 ± 2.2°, respectively, with a change value of 0.70 ± 1.43°. At 1 year, the FSU angle in the parallel group was significantly low than in the lordotic group (p < 0.05). Besides, average intervertebral space heights (ISH) at 6 months, 1 year and last follow-up were 6.81 ± 0.38 mm, 6.79 ± 0.3 7 mm, 6.78 ± 0.36 mm in the parallel group and 6.64 ± 0.24 mm, 6.32 ± 0.19 mm, 6.30 ± 0.19 mm in the lordotic group, respectively (all p < 0.05). There were no significant differences in clinical outcomes and complications between the groups (p > 0.05). Conclusions Immediate postoperative SA has no significant effects on clinical outcomes and complications after CDA with Prestige-LP. However, it has a positive correlation with postoperative FSU angle and a negative correlation with ISH maintenance.
Article
Purpose: Anterior cervical discectomy and fusion (ACDF) surgery is commonly performed to treat cervical degenerative disc disease (CDDD). The lost of range of motion (ROM) is also found after ACDF, which contributes to degenerate in adjacent segment disease (ASD). Artificial cervical disc replacement (ACDR), an alternative to ACDF, is developed to preserve the ROM and reduce ASD. This article aims to compare the outcomes between ACDR and ACDF in the short-, mid-, and long-term. Methods: Databases including Cochrane, Embase, PubMed, and Web of Science were searched. Only RCTs were included in this meta-analysis, and the search strategy followed the requirements of the Cochrane Handbook. The strength of evidence was assessed using GRADE. Two reviewers independently assessed the methodological quality of each included study and extracted the relevant data. Results: Thirty prospective RCTs were included. Prolonged operative duration, better overall success, neurological success, and NDI success rates were found in ACDR group in all follow-up periods, with lower dysphagia/dysphonia during short-term follow-up. Moreover, a lower ASD was found in ACDR group during long-term follow-up and overall analysis, with lower reoperation rates in all follow-up periods. Comparable length of hospital stay and blood loss were found in both groups. Moreover, ASD was similar in short- and mid-term follow-ups, while dysphagia/dysphonia incidence was similar in mid- and long-term follow-ups. The incidence of implant events was comparable in all follow-up periods (p > 0.05). Conclusions: ACDR is as effective as ACDF and superior for some success rates. Disc replacement can reduce the risk of dysphagia/dysphonia, ASD, and re-operation.
Article
Objective The aim of this study was to assess rates of adjacent segment degeneration (ASDeg), adjacent segment disease (ASDis), and reoperation rates due to adjacent segment pathology in patients who have undergone anterior cervical discectomy and fusion (ACDF) versus cervical disc arthroplasty (CDA). Methods A comprehensive search of randomized controlled trials was performed in PubMed from 2012 to 2019. Relevant studies included were assessed for quality using the Cochrane Beck Review Group guidelines. Rates of ASDeg, ASDis, and reoperation due to adjacent segment pathology were extracted and included in the final analysis. A random effects and fixed effects model was run among studies that showed high and low heterogeneity, respectively. Results A total of 19 studies were included in the final analysis, comprising 4,655 total patients. Overall, ACDFs reported significantly higher rates of ASDeg (19.7% vs 14.4%; p<0.001), ASDis (6.1% vs. 3.8%; p<0.001), and reoperation rates (6.1% vs 3.1%; p<0.001) compared to CDAs, which was further corroborated in fixed-effects analysis. When stratified by length of follow-up, a significant difference was seen in ASDeg, ASDis, and reoperation rates of studies with follow-up of 12-48 months versus more than 48 months, with the exception of ASDeg rates in the CDA cohort. Conclusions Our study shows CDA results in significantly lower ASDeg, ASDis, and reoperation rates. While CDA may be a viable alternative to ACDF, further long-term studies are warranted to ensure consistency and establish longevity of our findings.
Article
Background The availability of diverse and sophisticated surgical options to treat spine conditions is compounded by the scarcity of high-level evidence to guide decision-making. Although studies on discrete treatments are frequently published, little information is available regarding real-world surgical practice. We intended to survey spine surgeons to assess clinical management of common spine diagnosis in day-to-day settings. Methods An online survey was distributed among neurosurgeons and orthopaedic surgeons worldwide. The obtained assessment of common surgical practice is contextualized in a review of the best available evidence. Results The survey was answered by more than 310 members of several European, Australasian, and South African professional societies. The submitted responses translate a surgical practice generally grounded on evidence, favoring well-tried techniques, providing comprehensive treatment for the most severe diagnoses. Such practice comes mostly from neurosurgeons focused on spine surgery, practicing in teaching hospitals. Conclusion We believe that the pragmatic, day-to-day approach to spine conditions captured in the present survey offers an informative insight to involved surgeons.
Article
Study design: Retrospective Cohort Study OBJECTIVE.: To evaluate the safety of 2-level cervical disc replacement (CDR) in the outpatient setting. Summary of background data: Despite growing interest in CDR, limited data exists evaluating the safety of 2-level CDR in the outpatient setting. Methods: The National Surgical Quality Improvement Program (NSQIP) database was queried for all 2-level ACDF and CDR procedures between 2015-2018. Demographics, comorbidities, and 30-day postoperative complication rates of outpatient 2-level CDR were compared to those of inpatient 2-level CDR and outpatient 2-level ACDF. Radiographic data is not available in the NSQIP. Results: 403 outpatient CDR's were compared to 408 inpatient CDR's and 4134 outpatient ACDF's. Outpatient CDR patients were older and more likely to have pulmonary comorbidities compared to inpatient CDR (p < 0.03). Outpatient CDR patients were less likely to have an ASA class ≥ 2 and have hypertension compared to outpatient ACDF patients (p < 0.0001). Outpatient CDR had a lower 30-day readmission rate (0.5% vs. 2.5%, p = 0.02) and lower 30-day reoperation rate (0% vs. 1%, p = 0.047) compared to inpatient CDR. Outpatient CDR had a lower readmission rate (0.5% vs. 2.1%, p = 0.03) compared to outpatient ACDF but there was no difference in reoperation rates between the two procedures (0% vs. 0.8%, p = 0.07). Outpatient CDR had an overall complication rate of 0.2%, inpatient CDR had a complication rate of 0.9%, and outpatient ACDF had a complication rate of 1.3%. These differences were not significant. Conclusion: To our knowledge, this is the largest multicenter study examining the safety of 2-level outpatient CDR procedures. Outpatient 2-level CDR was associated with similarly safe outcomes when compared to inpatient 2-level CDR and outpatient 2-level ACDF. This suggests that 2-level cervical disc replacement can be performed safely in the outpatient setting. Level of evidence: 3.
Article
Degenerative disc disease and associated cervical spondylosis or stenosis are common conditions encountered in clinical practice. These conditions may cause progressive cervical radicular or myelopathic symptoms leading to significant impairment. Although anterior cervical discectomy and fusion (ACDF) has been a reliable surgical treatment of cervical myelopathy and radiculopathy, but limitations include loss of cervical range of motion, the concern for adjacent segment degeneration and disease, pseudoarthrosis, complications related to the choice of intervertebral graft, dysphagia, as well as standard anterior cervical approach risk. Cervical total disc arthroplasty has emerged as an alternative operative procedure to ACDF.
Article
Currently, the gold standard for the surgical treatment of cervical degenerative diseases is anterior cervical discectomy and fusion (ACDF) and laminoplasty (or laminectomy). However, unresolved problems include adjacent segment disease after ACDF and kyphosis after laminoplasty (or laminectomy). As a recent topic for cervical degenerative diseases, the new anterior technique, which is anterior cervical disc replacement (ACDR), has become available in Japan. ACDR is a relatively new motion-preserving procedure and is expected to prevent adjacent segment disease. Although good surgical results have been reported in Western and Asian countries except for Japan, where it has been introduced in advance. The long-term results in Japan are unknown, and careful follow-up is required. Cervical laminoplasty (or laminectomy) is indicated for cases with the preoperative alignment of lordosis or mild kyphosis. Despite the maintenance of preoperative alignment, some patients have poor postoperative surgery results. Therefore, the concept of cervical spine sagittal balance was proposed, as well as the thoracolumbar spine sagittal balance. The C2-C7 sagittal vertical axis, which indicates the anterior deviation of the cervical spine ; the chin-brow to vertical angle, which is an index of horizontal vision ; the T1 Slope, which is an index of cervical lordosis ; and cervical lordosis are used as the parameters of cervical spine sagittal balance. It is becoming an index for selecting surgical procedures.
Article
Background Context Cervical total disc arthroplasty (TDA) is an alternative procedure to anterior cervical discectomy and fusion (ACDF) that facilitates neural decompression while both preserving motion of the spinal unit and decreasing the risk for degenerative changes at adjacent segments. However, due to its more recent introduction in clinical practice and low complication rates, the modes by which TDA may fail remain to be described. Purpose This study sought to identify the modes and frequencies of cervical TDA failure in order to propose a novel classification system. Study Design Retrospective Cohort and Systematic Review Patient Sample Patients who underwent single or two-level TDA for cervical radiculopathy or myelopathy at a single institution and in the literature of medium and large prospective studies. Outcome Measures Cervical TDA failure, defined as subsequent surgical intervention at the index segment. Materials and Methods This study retrospectively reviewed patients who underwent single or two-level TDA for cervical radiculopathy or myelopathy at a single institution to identify the potential implant failure modes. A systematic review and meta-analysis of prospective data in the literature was then performed to further supplement failure mode identification and to describe the rates at which the various failure types occurred. Statistical analysis included between-group comparisons of Non-Failed and Failed patients and frequencies of each failure type among Failed patients. Results A retrospective review at our institution of 169 patients (201 levels) identified 8 failures, for a failure rate of 4.7%. Additionally, 7 patients were revised who had the primary surgery at an outside institution. The systematic review of 3976 patients (4525 levels) identified 165 (4.1%) additional failures. Using this data, six primary failure types were classified, with several subtypes. These include recurrent or persistent index-level stenosis (Type I); migration (Type II) presenting as gross extrusion (A) or endplate failure with subsidence/acute fracture (B); instability (Type III) due to mechanical loosening (A), septic loosening (B), or device fracture (C); device motion loss (Type IV) such as “locking” of the device in kyphosis; implantation error (Type V) due to malposition (A) or improper sizing (B); and wear (Type VI) either without osteolysis (A) or with wear-particle-induced osteolysis (B). Stenosis (Type I) was the most common mode of failure found both through retrospective review and in the literature. Conclusion Cervical TDA fails through six primary mechanisms. While rates of certain failures requiring subsequent surgical intervention are low, it is possible that these complications may become more prevalent upon further longitudinal observation. Thus, future application and validation of this classification system is warranted to evaluate how failure frequencies change over time and with larger patient samples.
Article
Introduction Cervical disc replacement (CDR) surgery is well established for the treatment of disc degeneration from C3-C7, but there is little data regarding the safety and efficacy of CDR at the cervicothoracic junction, C7-T1. CDR is an appealing option, in terms of range of motion preservation, symptom relief, and absence of risk for nonunion. Currently, C7-T1 CDR is not approved by the Food and Drug Administration, and the existing literature is limited to two case reports that describe the results of a combined two patients. This series explores whether C7-T1 CDR is a reasonable treatment and alternative to fusion. Methods We present a case series of seven consecutive patients who underwent CDR at C7-T1 by a single surgeon from January to December of 2019. There were five females and two males with an average age of 61.3 ± 6.4 years. Results Average follow up was 18.9 ± 2.5 months. The average postoperative NDI score was 22.6 % ± 14.0. We also recorded qualitative data regarding patient satisfaction and revision surgery status. There was one complication of disc subsidence following three months of complete pain resolution. The six other patients reported being very satisfied with their surgical outcome. Conclusion These seven cases dramatically increase the volume of data in the literature on clinical outcomes and patient satisfaction following CDR at the cervicothoracic junction. Additionally, the heterogeneity of cases shows the effectiveness of this treatment in many real-world cases. A greater volume of cases with longer follow up will be necessary to better establish long-term clinical success.
Article
BACKGROUND Short- and mid-term studies have shown the effectiveness of cervical disc arthroplasty (CDA) to treat cervical disc degeneration. OBJECTIVE To report the 10-yr outcomes of a multicenter experience with cervical arthroplasty for 1- and 2-level pathology. METHODS This was a prospective study of patients treated with CDA at 1 or 2 contiguous levels using the Mobi-C® Cervical Disc (Zimmer Biomet). Following completion of the 7-yr Food and Drug Administration postapproval study, follow-up continued to 10 yr for consenting patients at 9 high-enrolling centers. Clinical and radiographic endpoints were collected out to 10 yr. RESULTS At 10 yr, patients continued to have significant improvement over baseline Neck Disability Index (NDI), neck and arm pain, neurologic function, and segmental range of motion (ROM). NDI and pain outcomes at 10 yr were significantly improved from 7 yr. Segmental and global ROM and sagittal alignment also were maintained from 7 to 10 yr. Clinically relevant adjacent segment pathology was not significantly different between 7 and 10 yr. The incidence of motion restricting heterotopic ossification at 10 yr was not significantly different from 7 yr for 1-level (30.7% vs 29.6%) or 2-level (41.7% vs 39.2%) patients. Only 2 subsequent surgeries were reported after 7 yr. CONCLUSION Our results through 10 yr were comparable to 7-yr outcomes, demonstrating that CDA with Mobi-C continues to be a safe and effective surgical treatment for patients with 1- or 2-level cervical degenerative disc disease.
Article
Background context: Although highlighted in joint arthroplasty studies, long-term outcomes between differing biomaterial composites, such as metal-on-metal (MoM) and metal-on-plastic (MoP) in anterior cervical disc replacement (ACDR) have not been thoroughly investigated. Purpose: The purpose of this study was to evaluate the patient-reported clinical outcomes, overall reoperation rates, complications, and rates of ASD of MoM versus MoP artificial discs in two-level ACDR for the treatment of cervical DDD. Study design/setting: Meta-analysis and systematic review PATIENT SAMPLE: 980 patients (442 MoM, 538 MoP) across 7 studies OUTCOME MEASURES: Patient reported clinical outcomes (NDI, VAS-n, VAS-a), overall reoperation rates, complications and rates of ASD METHODS: A systematic search strategy of three electronic databases (PubMed, CINAHL Plus, and SCOPUS) was conducted utilizing terms related to two-level ACDR. All studies included had a sample size of >10 patients, had a minimum 5-year follow-up, and reported data on adjacent segment disease. Cadaver studies, non-English manuscripts, articles with less than 5-year follow-up and studies in which only single-level ACDR was investigated were excluded. A total of 7 studies were included in this analysis. Studies were analyzed for demographic data, clinical outcome scores (NDI, VAS-neck, and VAS-arm), overall reoperation rates, complications, and rates of ASD. A random-effects model of meta-analysis was used for groups that were determined to be heterogenous and a fixed-effects model was utilized for groups that were not. An overlap of 95% confidence intervals suggests no statistically significant difference at the p<0.05 level. Results: Seven studies were included with data on 980 patients (442 MoM, 538 MoP). The study population was 52.84% female, with a mean age of 48.01 years, and a mean follow-up of 85.66 months. The mean improvement in NDI was 34.42 (95% CI, 32.49-36.36) and 29.72 (95% CI, 27.15-32.29) for the MoM and MoP groups, respectively. The mean improvement in VAS-neck was 11.20 (95% CI, 10.69-11.70) and 8.78 (95% CI, 7.81-9.74) for the MoM and MoP groups, respectively. The mean improvement in VAS-arm was 10.73 (95% CI, 9.83-11.63) and 8.49 (95% CI, 7.59-9.39) for the MoM and MoP groups, respectively. 3.85% (95% CI, 2.40-6.10) of patients who underwent ACDR with a MoM implant required reoperation compared to 5.33% (95% CI, 3.68-7.65) of patients with a MoP implant. Heterotopic ossification and dysphagia were the most common complications in both groups. The MoM cohort showed a higher incidence of HO (72.62% vs. 21.07%), but a lower incidence of dysphagia (0.96% vs 16.31%) compared to the MoP cohort. The MoM cohort had a larger proportion of patients with ASD who underwent subsequent surgery at an adjacent level (7.89% MoM versus 1.91% MoP). Conclusions: Our present meta-analysis suggests that the use of MoM artificial discs in two-level ACDR results in superior clinical outcome score improvement, but higher rates of ASD requiring secondary surgery compared to MoP discs after a follow-up period of 5 years or more.
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Background Anterior cervical discectomy and fusion (ACDF) has been widely used in cervical spondylosis, but adjacent segment degeneration/disease (ASD) was inevitable. Cervical total disc replacement (TDR) could reduce the stress of adjacent segments and retard ASD in theory, but the superiority has not been determined yet. This analysis aimed that whether TDR was superior to ACDF for decreasing adjacent segment degeneration (ASDeg) and adjacent segment disease (ASDis). Methods A meta-analysis was performed according to the guidelines of the Cochrane Collaboration with PubMed, EMBASE, Cochrane Library and CBM (China Biological Medicine) databases. It included randomized controlled trials (RCTs) that reported ASDeg, ASDis, and reoperation on adjacent segments after TDR and ACDF. Two investigators independently selected trials, assessed methodological quality, and evaluated the quality of this meta-analysis using the grades of recommendation, assessment, development, and evaluation (GRADE) approach. Results Eleven studies with 2632 patients were included in the meta-analysis. The overall rate of ASD in TDR group was lower than ACDF group (OR = 0.6; 95% CI [0.38, 0.73]; P < 0.00001). Both the incidence of ASDeg and the reoperation rate were statistically lower in the TDR group than in the ACDF group (OR = 0.58, P < 0.00001; OR = 0.52, P = 0.01, respectively). Subgroup analysis was performed according to the follow-up time and trial site; the rate of ASDeg was lower in patients underwent TDR no matter the follow-up time, and TDR tended to increase the superiority across time. The rate of ASDeg was also lower with TDR both in the USA and China (P < 0.0001, P = 0.03, respectively). But the cost-effectiveness result might be prone to neither of the two surgery approaches. According to GRADE, the overall quality of this meta-analysis was moderate. Conclusions TDR decreased the rates of ASDeg and reoperation compared with that of ACDF, and the superiority may become more apparent over time. We cautiously and slightly suggest adopting TDR according to the GRADE but may not believe it excessively. Electronic supplementary material The online version of this article (10.1186/s13018-018-0940-9) contains supplementary material, which is available to authorized users.
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Introduction: Cervical disc arthroplasty (CDA) was developed as an alternative for anterior cervical discectomy and fusion (ACDF) for nerve root decompression. The rationale behind CDA was to help prevent adjacent segment degeneration which potentially may lead to additional surgery. Multiple randomized controlled trials have evaluated a myriad of disc arthroplasty devices over the past 10 years and provided data regarding clinical benefits and safety. Their long-term data, reporting results at 5-10 years, presents the opportunity to comment on the overall efficacy, safety and reported complications of these devices. This report reviews results of the Prestige, proDisc-C, Mobi-C Disc and various other arthroplasty devices and provides an overall report of the longest term available data and comparisons between devices. Areas Covered: This review summarizes previously published articles in a literature search using keywords: ‘cervical disc arthroplasty’, ‘cervical total disc replacement’, ‘anterior cervical decompression and fusion’, ‘anterior cervical arthrodesis’, ‘symptomatic degenerative disc disease’ and commercial names of devices. Expert Commentary: CDA, with the devices reviewed, resulted in favorable outcomes in comparison to ACDF for the treatment of symptomatic cervical degenerative disc disease (DDD) taking in to account the long-term functional recovery, adverse events, development of adjacent segment degeneration and subsequent surgical interventions.
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Cervical total disc replacement (cTDR) is still considered a developing technology, with widespread clinical use beginning in the early 2000s. Despite being relatively new to the marketplace, the literature surrounding cTDR is abundant. We conducted a thorough review of literature published in the United States (US) and outside the US to report the current global state of cTDR research and clinical use. Search criteria were restricted to publications with a clinical patient population, excluding finite element analyses, biomechanical studies, cadaver studies, surgical technique-specific papers, and case studies. US publications mostly encompass the results of the highly controlled Food and Drug Administration Investigational Device Exemption trials. The predominantly level I evidence in the US literature supports the use of cTDR at 1 and 2 surgical levels when compared to anterior cervical discectomy and fusion. In general, the outside the US studies typically have smaller patient populations, are rarely controlled, and include broader surgical indications. Though these studies are of lower levels of evidence, they serve to advance patient indications in the use of cTDR. Complications such as secondary surgery, heterotopic ossification, and adjacent segment degeneration also remain a focus of studies. Other external challenges facing cTDR technology include regulatory restrictions and health economics, both of which are beginning to be addressed. Combined, the evidence for cTDR is robust supporting a variety of clinical indications.
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OBJECTIVE Seven cervical total disc replacement (TDR) devices have received FDA approval since 2006. These devices represent a heterogeneous assortment of implants made from various biomaterials with different biomechanical properties. The majority of these devices are composed of metallic endplates with a polymer core. In this prospective, randomized multicenter study, the authors evaluate the safety and efficacy of a metal-on-metal (MoM) TDR (Kineflex|C) versus anterior cervical discectomy and fusion (ACDF) in the treatment of single-level spondylosis with radiculopathy through a long-term (5-year) follow-up. METHODS An FDA-regulated investigational device exemption (IDE) pivotal trial was conducted at 21 centers across the United States. Standard validated outcome measures including the Neck Disability Index (NDI) and visual analog scale (VAS) for assessing pain were used. Patients were randomized to undergo TDR using the Kineflex|C cervical artificial disc or anterior cervical fusion using structural allograft and an anterior plate. Patients were evaluated preoperatively and at 6 weeks and 3, 6, 12, 24, 36, 48, and 60 months after surgery. Serum ion analysis was performed on a subset of patients randomized to receive the MoM TDR. RESULTS A total of 269 patients were enrolled and randomly assigned to undergo either TDR (136 patients) or ACDF (133 patients). There were no significant differences between the TDR and ACDF groups in terms of operative time, blood loss, or length of hospital stay. In both groups, the mean NDI scores improved significantly by 6 weeks after surgery and remained significantly improved throughout the 60-month follow-up (both p < 0.01). Similarly, VAS pain scores improved significantly by 6 weeks and remained significantly improved through the 60-month follow-up (both p < 0.01). There were no significant changes in outcomes between the 24- and 60-month follow-ups in either group. Range of motion in the TDR group decreased at 3 months but was significantly greater than the preoperative mean value at the 12- and 24-month follow-ups and remained significantly improved through the 60-month period. There were no significant differences between the 2 groups in terms of reoperation/revision surgery or device-/surgery-related adverse events. The serum ion analysis revealed cobalt and chromium levels significantly lower than the levels that merit monitoring. CONCLUSIONS Cervical TDR with an MoM device is safe and efficacious at the 5-year follow-up. These results from a prospective randomized study support that Kineflex|C TDR as a viable alternative to ACDF in appropriately selected patients with cervical radiculopathy. Clinical trial registration no.: NCT00374413 (clinicaltrials.gov)
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Background: Cervical total disc replacement (TDR) is an increasingly accepted procedure for the treatment of symptomatic cervical degenerative disc disease. Multiple Level I evidence clinical trials have established cervical TDR to be a safe and effective procedure in the short-term. The objective of this study is to provide a long-term assessment of TDR versus anterior discectomy and fusion for the treatment of one- and two-level disc disease. Methods: This study was a continuation of a prospective, multicenter, randomized, US FDA IDE clinical trial comparing cervical TDR with the Mobi-C© Cervical Disc versus ACDF through 7 years follow-up. Inclusion criteria included a diagnosis of symptomatic cervical degenerative disc disease at one or two cervical levels. TDR patients were treated using a Mobi-C© artificial disc (Zimmer Biomet, Austin TX, USA). ACDF with allograft and anterior plate was used as a control treatment. Outcome measures were collected preoperatively and postoperatively at 6 weeks, at 3, 6, 12, 18 months, annually through 60 months, and at 84 months. Measured outcomes included Overall success, Neck Disability Index (NDI), VAS neck and arm pain, segmental range of motion (ROM), patient satisfaction, SF-12 MCS/PCS, major complications, and subsequent surgery rate. The primary endpoint was an FDA composite definition of success comprising clinical improvement and an absence of major complications and secondary surgery events. Results: A total of 599 patients were enrolled and treated, with 164 treated with one-level TDR, 225 treated with two-level TDR, 81 treated with one-level ACDF, and 105 treated with two-level ACDF. At seven years, follow-up rates ranged from 73.5% to 84.4% (overall 80.2%).The overall success rates of two level TDR and ACDF patients were 60.8% and 34.2%, respectively (p<0.0001). The overall success rates of one level TDR and ACDF patients were 55.2% and 50%, respectively (p>0.05). Both the single and two level TDR and ACDF groups showed significant improvement from baseline NDI scores, VAS neck and arm pain scores, and SF-12 MCS/PCS scores (p<0.0001). In the single level cohort, there was an increased percentage of TDR patients who reported themselves as "very satisfied" (TDR 90.9% vs ACDF 77.8%; p= 0.028). There was a lower rate of adjacent level secondary surgery in the single level TDR patients (3.7%) versus the ACDF patients (13.6%; p = 0.007).In the two level TDR group, the NDI success rate was significantly greater in the TDR group (TDR: 79.0% vs. ACDF: 58.0%; p=0.001). There was significantly more improvement in NDI change score at 7 years in the TDR patients versus ACDF. The TDR group had a significantly higher rate of patients who were "very satisfied" with their treatment compared to the ACDF group (TDR: 85.9% vs. ACDF: 73.9%). The rate of subsequent surgery at the index level was significantly lower in the TDR group compared to the ACDF group (TDR: 4.4% vs. ACDF: 16.2%; p=0.001). The rate of adjacent level secondary surgery was significantly lower in the two level TDR (4.4%) patients compared to the ACDF (11.3%; p=0.03) patients. In both single and two level cohorts, the percentage of patients with worse NDI (2.5%-3.8% of two level surgeries and 1.2%-2.5% of single level surgeries) or worse neck pain (5%-6.8% of the two level surgeries and 1.3% - 3.8% of the single level surgeries) was strikingly low in both groups but trended lower in the TDR patients. Conclusions: At seven years, the composite success analysis demonstrated clinical superiority of two level TDR over ACDF and non-inferiority of single level TDR versus ACDF. There were lower rates of secondary surgery and higher adjacent level disc survivorship in both groups. Both surgeries were remarkably effective in alleviating pain relative to baseline and the rate of patients with worse disability or neck pain was surprisingly low. Overall, greater than 95% of patients (from both groups) who underwent TDR and 88% of patients who underwent ACDF were "very satisfied" at seven years. The differences in clinical effectiveness of TDR versus ACDF becomes more apparent as treatment increases from one to two levels, indicating a significant benefit for TDR over ACDF for two-level procedures. Ethical standards: The Mobi-C Clinical Trial (ClinicalTrials.gov registration number: NCT00389597) was conducted at 24 sites in the US and was approved by the Institutional Review Board, Research Ethics Committee, or local equivalent of each participating site. Level of evidence: 1.
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Anterior cervical discectomy and fusion (ACDF) and total cervical disc replacement (TDR) are considered effective treatments for patients with cervical degenerative disc disease (CDDD). An indirect meta-analysis including 19 randomized controlled trials (5343 patients) was conducted to compare the clinical outcomes of ACDF with TDR. Primary outcomes including functional indicators (NDI [neck disability index] score, neurological success and patient satisfaction), secondary outcomes including surgical outcomes (operation time, blood loss and length of stay) and secondary surgical procedures (secondary surgery at an adjacent level, secondary surgery at the index level, secondary surgery at both levels, removal, reoperation, revision and supplemental fixation) were included in the study. TDR using the Bryan disc was associated with a greater improvement in NDI score than ACDF (MD = −5.574, 95% CrIs [credible intervals] −11.73–−0.219). For neurological success, the Bryan (odds ratio [OR] = 0.559, 95% CrIs 0.323–0.955) and Prestige (OR = 0.474, 95% CrIs 0.319–0.700) discs were superior to ACDF. However, no differences in the patient satisfaction rate were shown between TDR and ACDF. For patients with CDDD, ACDF using allograft and a plate is most effective for determining the surgical parameters. Moreover, TDR using the ProDisc-C, Mobi-C, Prestige and Bryan discs are good choices for improving functional outcomes and reducing secondary surgeries.
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Background Cervical disc replacement (CDR) has been developed as an alternative surgical procedure to anterior cervical discectomy and fusion (ACDF) for the treatment of single-level cervical degenerative disc disease. However, patients with multilevel cervical degenerative disc disease (MCDDD) are common in our clinic. Multilevel CDR is less established compared with multilevel ACDF. This study aims to compare the outcomes and evaluate safety and efficacy of CDR versus ACDF for the treatment of MCDDD. Methods A meta-analysis was performed for articles published up until August 2016. Randomized controlled trials (RCTs) and prospective comparative studies associated with the use of CDR versus ACDF for the treatment of MCDDD were included in the current study. Two reviewers independently screened the articles and data following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement. Results Seven studies with 702 enrolled patients suffering from MCDDD were retrieved. Patients who underwent CDR had similar operative times, blood loss, Neck Disability Index (NDI) scores, and Visual Analog Scale (VAS) scores compared to patients who underwent ACDF. Patients who underwent CDR had greater overall motion of the cervical spine and the operated levels than patients who underwent ACDF. Patients who underwent CDR also had lower rates of adjacent segment degeneration (ASD). The rate of adverse events was significantly lower in the CDR group. Conclusion CDR may be a safe and effective surgical strategy for the treatment of MCDDD. However, there is insufficient evidence to draw a strong conclusion due to relatively low-quality evidence. Future long-term, multicenter, randomized, and controlled studies are needed to validate the safety and efficacy of multilevel CDR.
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OBJECT This study compared the safety and efficacy of treatment with the PRESTIGE LP cervical disc versus a historical control anterior cervical discectomy and fusion (ACDF). METHODS Prospectively collected PRESTIGE LP data from 20 investigational sites were compared with data from 265 historical control ACDF patients in the initial PRESTIGE Cervical Disc IDE study. The 280 investigational patients with single-level cervical disc disease with radiculopathy and/or myelopathy underwent arthroplasty with a low-profile artificial disc. Key safety/efficacy outcomes included Neck Disability Index (NDI), Neck and Arm Pain Numerical Rating Scale scores, 36-Item Short Form Health Survey (SF-36) score, work status, disc height, range of motion, adverse events (AEs), additional surgeries, and neurological status. Clinical and radiographic evaluations were completed preoperatively, intraoperatively, and at 1.5, 3, 6, 12, and 24 months postoperatively. Predefined Bayesian statistical methods with noninformative priors were used, along with the propensity score technique for controlling confounding factors. Analysis by independent statisticians confirmed initial statistical findings. RESULTS The investigational and control groups were mostly similar demographically. There was no significant difference in blood loss (51.0 ml [investigational] vs 57.1 ml [control]) or hospital stay (0.98 days [investigational] vs 0.95 days [control]). The investigational group had a significantly longer operative time (1.49 hours vs 1.38 hours); 95% Bayesian credible interval of the difference was 0.01–0.21 hours. Significant improvements versus preoperative in NDI, neck/arm pain, SF-36, and neurological status were achieved by 1.5 months in both groups and were sustained at 24 months. Patient follow-up at 24 months was 97.1% for the investigational group and 84.0% for the control group. The mean NDI score improvements versus preoperative exceeded 30 points in both groups at 12 and 24 months. SF-36 Mental Component Summary superiority was established (Bayesian probability 0.993). The mean SF-36 PCS scores improved by 14.3 points in the investigational group and by 11.9 points in the control group from baseline to 24 months postoperatively. Neurological success at 24 months was 93.5% in the investigational group and 83.5% in the control group (probability of superiority ~ 1.00). At 24 months, 12.1% of investigational and 15.5% of control patients had an AE classified as device or device/surgical procedure related; 14 (5.0%) investigational and 21 (7.9%) control patients had a second surgery at the index level. The median return-to-work time for the investigational group was 40 days compared with 60 days for the control group (p = 0.020 after adjusting for preoperative work status and propensity score). Following implantation of the PRESTIGE LP device, the mean angular motion was maintained at 12 months (7.9°) and 24 months (7.5°). At 24 months, 90.0% of investigational and 87.7% of control patients were satisfied with the results of surgery. PRESTIGE LP superiority on overall success (without disc height success), a composite safety/efficacy end point, was strongly supported with 0.994 Bayesian probability. CONCLUSIONS This device maintains mean postoperative segmental motion while providing the potential for biomechanical stability. Investigational patients reported significantly improved clinical outcomes compared with baseline, at least noninferior to ACDF, up to 24 months after surgery.
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Background: Despite being considered the standard surgical procedure for symptomatic cervical disc disease, anterior cervical decompression and fusion invariably accelerates adjacent segment degeneration. Cervical total disc replacement is a motion-preserving procedure developed as a substitute to fusion. Whether cervical total disc replacement is superior to fusion remains unclear. Methods: We comprehensively searched PubMed, EMBASE, Medline, and the Cochrane Library in accordance with the inclusion criteria to identify possible studies. The retrieved results were last updated on December 12, 2014. We classified the studies as short-term and midterm follow-up. Results: Nineteen randomized controlled trials involving 4516 cases were identified. Compared with anterior cervical decompression and fusion, cervical total disc replacement had better functional outcomes (neck disability index [NDI], NDI success, neurological success, neck pain scores reported on a numerical rating scale [NRS], visual analog scales scores and overall success), greater segmental motion at the index level, fewer adverse events and fewer secondary surgical procedures at the index and adjacent levels in short-term follow-up (P < 0.05). With midterm follow-up, the cervical total disc replacement group indicated superiority in the NDI, neurological success, pain assessment (NRS), and secondary surgical procedures at the index level (P < 0.05). The Short Form 36 (SF-36) and segmental motion at the adjacent level in the short-term follow-up showed no significant difference between the two procedures, as did the secondary surgical procedure rates at the adjacent level with midterm follow-up (P > 0.05). Conclusions: Cervical total disc replacement presented favorable functional outcomes, fewer adverse events, and fewer secondary surgical procedures. The efficacy and safety of cervical total disc replacement are superior to those of fusion. Longer-term, multicenter studies are required for a better evaluation of the long-term efficacy and safety of the two procedures.
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Purpose: Cervical disc arthroplasty (CDA) was developed to treat cervical degenerated disc diseases with the advantages of preserving the kinematics of the functional spinal unit. However, the safety and reliability of multi-level CDA are still controverted when comparing to the single-level CDA. It has shown unclear benefits in terms of clinical results, functional recovery, heterotopic ossification, and the need for secondary surgical procedures. The purpose of this study is to estimate the effectiveness of multi-level cervical arthroplasty over single-level CDA for the treatment of cervical spondylosis and disc diseases. Methods: To compare the studies of multi-level CDA versus single-level CDA in patients with cervical spondylosis that reported at least one of the following outcomes: functionality, neck pain, arm pain, quality of life, reoperation and incidence of heterotopic ossification, electronic databases (Medline, Embase, Pubmed, Cochrane library, and Cochrane Central Register of Controlled Trials) were searched. No language restrictions were used. Two authors independently assessed the methodological quality of included studies and extracted the relevant data. Results: Out of Eight cohorts that were included in the study, four were prospective cohorts and the other four were retrospective. The results of the meta-analysis indicated that there was no significant difference in neck disability index scores, neck visual analog scale (VAS), arm VAS, morbidity of reoperation, heterotopic ossification, and parameters of living quality when comparing multi-level CDA with single-level CDA at 1 and 2 years follow-up postoperatively (p > 0.05). Conclusions: The meta-analysis revealed that the outcomes and functional recovery of patients performed with multi-level CDA are equivalent to those with single-level CDA, which suggests the multi-level CDA is as effective and safe as single-level invention for the treatment of cervical spondylosis. Nonetheless, more well-designed studies with large groups of patients are needed to provide further evidence for the benefit and reliability of multi-level CDA in the treatment of cervical disc diseases.
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The purpose of this retrospective analysis is to determine whether disc prosthesis replacement can be equivalent or superior compared with the disc interbody fusion. Between January, 2005 and June, 2011 we performed microdiscetomy by the anterior approach in 176 patients. We subdivided the total set of patients into two groups. Group A is made up of 84 patients in whom the prosthetic disc was implanted; Group B is made up of 92 patients in whom disc fusion was performed. In both groups, the radicular pain disappeared and the signs of spinal cord compression improved or remained stable. Patients of Group A required significantly fewer days of hospitalization and shorter absence from work, and had significant lower scores in the Neck Disability Index (NDI) at 12 months. Our experience demonstrates that the use of disc prosthesis is a safe and effective alternative to interbody fusion.
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Object: Cervical total disc replacement (TDR) is intended to treat neurological symptoms and neck pain associated with degeneration of intervertebral discs in the cervical spine. Anterior cervical discectomy and fusion (ACDF) has been the standard treatment for these indications since the procedure was first developed in the 1950s. While TDR has been shown to be a safe and effective alternative to ACDF for treatment of patients with degenerative disc disease (DDD) at a single level of the cervical spine, few studies have focused on the safety and efficacy of TDR for treatment of 2 levels of the cervical spine. The primary objective of this study was to rigorously compare the Mobi-C cervical artificial disc to ACDF for treatment of cervical DDD at 2 contiguous levels of the cervical spine. Methods: This study was a prospective, randomized, US FDA investigational device exemption pivotal trial of the Mobi-C cervical artificial disc conducted at 24 centers in the US. The primary clinical outcome was a composite measure of study success at 24 months. The comparative control treatment was ACDF using allograft bone and an anterior plate. A total of 330 patients were enrolled, randomized, and received study surgery. All patients were diagnosed with intractable symptomatic cervical DDD at 2 contiguous levels of the cervical spine between C-3 and C-7. Patients were randomized in a 2:1 ratio (TDR patients to ACDF patients). Results: A total of 225 patients received the Mobi-C TDR device and 105 patients received ACDF. At 24 months only 3.0% of patients were lost to follow-up. On average, patients in both groups showed significant improvements in Neck Disability Index (NDI) score, visual analog scale (VAS) neck pain score, and VAS arm pain score from preoperative baseline to each time point. However, the TDR patients experienced significantly greater improvement than ACDF patients in NDI score at all time points and significantly greater improvement in VAS neck pain score at 6 weeks, and at 3, 6, and 12 months postoperatively. On average, patients in the TDR group also maintained preoperative segmental range of motion at both treated segments immediately postoperatively and throughout the study period of 24 months. The reoperation rate was significantly higher in the ACDF group at 11.4% compared with 3.1% for the TDR group. Furthermore, at 24 months TDR demonstrated statistical superiority over ACDF based on overall study success rates. Conclusions: The results of this study represent the first available Level I clinical evidence in support of cervical arthroplasty at 2 contiguous levels of the cervical spine using the Mobi-C cervical artificial disc. These results continue to support the use of cervical arthroplasty in general, but specifically demonstrate the advantages of 2-level arthroplasty over 2-level ACDF. Clinical trial registration no.: NCT00389597 (ClinicalTrials.gov).
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Adjacent segment degeneration typically follows anterior cervical spine fusion. However, the primary cause of adjacent segment degeneration remains unknown. Therefore, in order to identify the loading effects that cause adjacent segment degeneration, this study examined the loading effects to superior segments adjacent to fused bone following anterior cervical spine fusion. The C3-C6 cervical spine segments of 12 sheep were examined. Specimens were divided into the following groups: intact spine (group 1); and C5-C6 segments that were fused via cage-instrumented plate fixation (group 2). Specimens were cycled between 20° flexion and 15° extension with a displacement control of 1°/second. The tested parameters included the range of motion (ROM) of each segment, torque and strain on both the body and inferior articular process at the superior segments (C3-C4) adjacent to the fused bone, and the position of the neutral axis of stress at under 20° flexion and 15° extension. Under flexion and Group 2, torque, ROM, and strain on both the bodies and facets of superior segments adjacent to the fused bone were higher than those of Group 1. Under extension and Group 2, ROM for the fused segment was less than that of Group 1; torque, ROM, and stress on both the bodies and facets of superior segments adjacent to the fused bone were higher than those of Group 1. These analytical results indicate that the muscles and ligaments require greater force to achieve cervical motion than the intact spine following anterior cervical spine fusion. In addition, ROM and stress on the bodies and facets of the joint segments adjacent to the fused bone were significantly increased. Under flexion, the neutral axis of the stress on the adjacent segment moved backward, and the stress on the bodies of the segments adjacent to the fused bone increased. These comparative results indicate that increased stress on the adjacent segments is caused by stress-shielding effects. Furthermore, increased stress and ROM of the adjacent segments after long-term bone fusion may accelerate degeneration in adjacent segment.
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The authors of previous in vitro investigations have reported an increase in adjacent-level intradiscal pressures (IDPs) and facet joint stresses following cervical spine fusion. This study was performed to compare adjacent-level IDPs and facet force following arthroplasty with the fusion model. Eighteen human cadaveric cervical spines were tested in the intact state for different modes of motion (extension, flexion, bending, and rotation) up to 2 Nm. The specimens were then divided into three groups: those involving the ProDisc-C cervical artificial disc, Prestige cervical artificial disc, and cervical fusion. They were load tested after application of instrumentation or surgery at the C6-7 level. During the test, IDPs and facet forces were measured at adjacent levels. In arthroplasty-treated specimens, the IDP showed little difference from that of the intact spine at both proximal and distal levels. In fusion-treated specimens, the IDP increased at the posterior anulus fibrosus on extension and at the anterior anulus fibrosus on flexion at the proximal level. At the distal level, the IDP change was not significant. The facet force changes were minimal in flexion, bending, and rotation modes in both arthroplasty- and fusion-treated spines. Significant changes were noted in the extension mode only. In extension, arthroplasty models exhibited significant increases of facet force at the treated level. In the fusion model the facet forces decreased at the treated segment and increased at the adjacent segment. The two artificial discs of the semiconstrained systems maintain adjacent-level IDPs near the preoperative values in all modes of motion, but with respect to facet force pressure tended to increase after arthroplasty.
Article
Study design: Prospective, randomized multicenter IDE Trial between May 2002 and October 2004. Objective: Report on the 10-year safety and efficacy of BRYAN® cervical disc (CDA). Summary of background data: Cervical disc arthroplasty (CDA) is a potential alternative for anterior cervical decompression and fusion (ACDF) with the hope that maintenance of motion may decrease the likelihood of adjacent segment disease. Methods: This is an analysis of a FDA investigation comparing CDA with ACDF for single level patients. Eligible patients were ≥ 21 years of age with symptomatic cervical disc disease who had failed conservative care. Patients were followed at regular intervals with the current data set at > 10 years. Protocol for overall success: ≥ 15- point improvement in NDI scores, maintenance or improvement in neurologic status, no serious adverse events related to implant or implant/surgical procedure, and no subsequent surgery or intervention classified as "failure." Results: At 10 year follow-up, 128 (CDA) and 104 (ACDF) patients were available for evaluation. Overall success rate was significantly higher for CDA group (81.3% vs. 66.3%; p = 0.005). The rate of second surgeries at adjacent levels was lower for CDA group (9.7% vs. 15.8%; p = 0.146). NDI scores improved significantly in CDA group (Δ38.3 vs. Δ31.1; p = 0.010). VAS neck and arm improved in the CDA group (Δ54.3 vs.Δ49.2; p = 0.119), (Δ58.1 vs. Δ51.6; p = 0.0.60) respectively. 4.1% of CDA patients and 4.9% of ACDF patients had serious adverse events related to study device. Mean angular motions at index level for BRYAN® disc and ACDF were 8.69° and 0.60° respectively. Conclusion: The CDA can preserve and maintain motion in long term compared to ACDF. There was a trend toward fewer adjacent segment surgeries for BRYAN® disc that did not reach significance. Significant improvement in CDA NDI scores may suggest better long-term success for CDA as compared to fusion. Level of evidence: 2.
Article
Background: This research was initiated to compare the long-term clinical safety and effectiveness of the selectively constrained SECURE-C (Globus Medical, Audubon, Pennsylvania) Cervical Artificial Disc to anterior cervical discectomy and fusion (ACDF). To preserve segmental motion, cervical total disc replacement (CTDR) was developed as an alternative to ACDF. Current CTDR designs incorporate constrained and unconstrained metal-on-metal or metal-on-polymer articulation with various means of fixation. Methods: Eighteen investigational sites participated in this prospective clinical trial; 380 patients were enrolled and treated in the investigational device exemption study. The first 5 patients treated at each site were nonrandomized and received the investigational SECURE-C device. Patients were randomized, treated surgically, and evaluated postoperatively at 6 weeks, 3 months, 6 months, 12 months, 24 months, and annually thereafter through 84 months postoperative. Results: Overall results for the randomized cohorts demonstrated statistical superiority of the investigational SECURE-C group over the control ACDF group at 84 months postoperative. SECURE-C showed clinically significant improvement in pain and function in terms of neck disability index and visual analog scale scores, and superiority in patient satisfaction was also achieved for patients treated with SECURE-C. Conclusion: Clinical study results indicated that the selectively constrained SECURE-C Cervical Artificial Disc is as safe and effective as ACDF. Long-term results from the Post Approval Study demonstrated that SECURE-C is statistically superior to ACDF in terms of overall success and patient satisfaction. Lower rates of subsequent index-level surgeries and device-related adverse events were observed in the SECURE-C group than in the ACDF group. The long-term, level 1 clinical evidence presented here is consistent with other reports supporting the safety and efficacy of cervical arthroplasty, and furthers advocacy for motion preservation as a viable alternative to fusion.
Article
Background: Heterotopic ossification (HO) is a known risk following cervical total disc replacement (CTDR) surgery, but the cause and effect of HO are not well understood. Reported HO rates vary, and few studies are specifically designed to report HO. The effects on outcomes, and the risk factors for the development of HO have been hypothesized and reported in small-population, retrospective analyses, using univariate statistics. Methods: Posthoc, multiple-phase analysis of radiographic, clinical, and demographic data for CTDR as it relates to HO was performed. HO was radiographically graded for 164 one-level and 225 two-level CTDR patients using the McAfee and Mehren system. Analysis was performed to correlate HO grades to clinical outcomes and to evaluate potential risk factors for the development of HO using demographics and baseline clinical measures. Results: At 7 years, 1-level clinically relevant HO grades were 17.6% grade 3 and 11.1% grade 4. Two-level clinically relevant HO grades, evaluated using the highest patient grade, were 26.6% grade 3 and 10.8% grade 4. Interaction between HO and time revealed significance for neck disability index (NDI; P = .04) and Visual Analog Scale (VAS) neck pain (P = .02). When analyzed at each time point NDI was significant at 48-84 months and VAS neck at 60 months. For predictors 2 analyses were run; odds ratios indicated follow-up visit, male sex, and preoperative VAS neck pain are related to HO development, whereas hazard ratios indicated male sex, obesity, endplate coverage, levels treated, and preoperative VAS neck pain. Conclusions: This is the largest study to report HO rates, and related outcomes and risk factors. To develop an accurate predictive model, further large-scale analyses need to be performed. Based on the results reported here, clinically relevant HO should be more accurately described as motion-restricting HO until a definitive link to outcomes has been established.
Article
OBJECTIVE The aim of this study was to assess long-term clinical safety and effectiveness in patients undergoing anterior cervical surgery using the Prestige LP artificial disc replacement (ADR) prosthesis to treat degenerative cervical spine disease at 2 adjacent levels compared with anterior cervical discectomy and fusion (ACDF). METHODS A prospective, randomized, controlled, multicenter FDA-approved clinical trial was conducted at 30 US centers, comparing the low-profile titanium ceramic composite-based Prestige LP ADR (n = 209) at 2 levels with ACDF (n = 188). Clinical and radiographic evaluations were completed preoperatively, intraoperatively, and at regular postoperative intervals to 84 months. The primary end point was overall success, a composite variable that included key safety and efficacy considerations. RESULTS At 84 months, the Prestige LP ADR demonstrated statistical superiority over fusion for overall success (observed rate 78.6% vs 62.7%; posterior probability of superiority [PPS] = 99.8%), Neck Disability Index success (87.0% vs 75.6%; PPS = 99.3%), and neurological success (91.6% vs 82.1%; PPS = 99.0%). All other study effectiveness measures were at least noninferior for ADR compared with ACDF. There was no statistically significant difference in the overall rate of implant-related or implant/surgical procedure–related adverse events up to 84 months (26.6% and 27.7%, respectively). However, the Prestige LP group had fewer serious (Grade 3 or 4) implant- or implant/surgical procedure–related adverse events (3.2% vs 7.2%, log hazard ratio [LHR] and 95% Bayesian credible interval [95% BCI] −1.19 [−2.29 to −0.15]). Patients in the Prestige LP group also underwent statistically significantly fewer second surgical procedures at the index levels (4.2%) than the fusion group (14.7%) (LHR −1.29 [95% BCI −2.12 to −0.46]). Angular range of motion at superior- and inferior-treated levels on average was maintained in the Prestige LP ADR group to 84 months. CONCLUSIONS The low-profile artificial cervical disc in this study, Prestige LP, implanted at 2 adjacent levels, maintains improved clinical outcomes and segmental motion 84 months after surgery and is a safe and effective alternative to fusion. Clinical trial registration no.: NCT00637156 (clinicaltrials.gov)
Article
OBJECTIVE The authors compared the efficacy and safety of arthroplasty using the Prestige LP cervical disc with those of anterior cervical discectomy and fusion (ACDF) for the treatment of degenerative disc disease (DDD) at 2 adjacent levels. METHODS Patients from 30 investigational sites were randomized to 1 of 2 groups: investigational patients (209) underwent arthroplasty using a Prestige LP artificial disc, and control patients (188) underwent ACDF with a cortical ring allograft and anterior cervical plate. Patients were evaluated preoperatively, intraoperatively, and at 1.5, 3, 6, 12, and 24 months postoperatively. Efficacy and safety outcomes were measured according to the Neck Disability Index (NDI), Numeric Rating Scales for neck and arm pain, 36-Item Short-Form Health Survey (SF-36), gait abnormality, disc height, range of motion (investigational) or fusion (control), adverse events (AEs), additional surgeries, and neurological status. Treatment was considered an overall success when all 4 of the following criteria were met: 1) NDI score improvement of ≥ 15 points over the preoperative score, 2) maintenance or improvement in neurological status compared with preoperatively, 3) no serious AE caused by the implant or by the implant and surgical procedure, and 4) no additional surgery (supplemental fixation, revision, or nonelective implant removal). Independent statisticians performed Bayesian statistical analyses. RESULTS The 24-month rates of overall success were 81.4% for the investigational group and 69.4% for the control group. The posterior mean for overall success in the investigational group exceeded that in the control group by 0.112 (95% highest posterior density interval = 0.023 to 0.201) with a posterior probability of 1 for noninferiority and 0.993 for superiority, demonstrating the superiority of the investigational group for overall success. Noninferiority of the investigational group was demonstrated for all individual components of overall success and individual effectiveness end points, except for the SF-36 Mental Component Summary. The investigational group was superior to the control group for NDI success. The proportion of patients experiencing any AE was 93.3% (195/209) in the investigational group and 92.0% (173/188) in the control group, which were not statistically different. The rate of patients who reported any serious AE (Grade 3 or 4) was significantly higher in the control group (90 [47.9%] of 188) than in the investigational group (72 [34.4%] of 209) with a posterior probability of superiority of 0.996. Radiographic success was achieved in 51.0% (100/196) of the investigational patients (maintenance of motion without evidence of bridging bone) and 82.1% (119/145) of the control patients (fusion). At 24 months, heterotopic ossification was identified in 27.8% (55/198) of the superior levels and 36.4% (72/198) of the inferior levels of investigational patients. CONCLUSIONS Arthroplasty with the Prestige LP cervical disc is as effective and safe as ACDF for the treatment of cervical DDD at 2 contiguous levels and is an alternative treatment for intractable radiculopathy or myelopathy at 2 adjacent levels. Clinical trial registration no.: NCT00637156 ( clinicaltrials.gov )
Article
Purpose: Cervical total disc replacement (TDR) has become an alternative to fusion (ACDF) in the surgical treatment of cervical radiculopathy with the promise of preserving motion in the affected segment and of avoiding accelerated degeneration of the adjacent levels. Nowadays there are numerous prospective, randomised and controlled studies comparing the clinical outcome of patients with both therapeutical options. Since cervical prostheses are much more expensive than cages it is crucial to compare the clinical benefit of both implants on the basis of a larger amount of patient data. Methods: A systematic data base search and study review identified 11 prospective, randomized and controlled studies that compared the clinical outcome after ACDF or TDR using at least the scores of NDI, VAS for neck pain and VAS for arm pain after a follow-up of at least 2 years. 2532 cases were included in the statistical analysis that compared the mean values of the clinical scores. Results: There were no statistically significant difference between the ACDF group and the TDR group in the clinical outcome scores (NDI, VAS neck, VAS arm) 2 years after surgery although some of the included studies found differences. Conclusion: ACDF and cervical TDR generate the same clinical results 2 years after surgery in regard to pain relief. Some of the included studies give proof of a better range of motion and less adjacent level degeneration in the TDR group. Thus, this more expensive option is only indicated in younger patients with soft-disc herniation.
Article
OBJECTIVE The purpose of this study was to report the outcome of a study of 2-level cervical total disc replacement (Mobi-C) versus anterior cervical discectomy and fusion (ACDF). Although the long-term outcome of single-level disc replacement has been extensively described, there have not been previous reports of the 5-year outcome of 2-level cervical disc replacement. METHODS This study reports the 5-year results of a prospective, randomized US FDA investigational device exemption (IDE) study conducted at 24 centers in patients with 2-level, contiguous, cervical spondylosis. Clinical outcomes at up to 60 months were evaluated, including validated outcome measures, incidence of reoperation, and adverse events. The complete study data and methodology were critically reviewed by 3 independent surgeon authors without affiliation with the IDE study or financial or institutional bias toward the study sponsor. RESULTS A total of 225 patients received the Mobi-C cervical total disc replacement device and 105 patients received ACDF. The Mobi-C and ACDF follow-up rates were 90.7% and 86.7%, respectively (p = 0.39), at 60 months. There was significant improvement in all outcome scores relative to baseline at all time points. The Mobi-C patients had significantly more improvement than ACDF patients in terms of Neck Disability Index score, SF-12 Physical Component Summary, and overall satisfaction with treatment at 60 months. The reoperation rate was significantly lower with Mobi-C (4%) versus ACDF (16%). There were no significant differences in the adverse event rate between groups. CONCLUSIONS Both cervical total disc replacement and ACDF significantly improved general and disease-specific measures compared with baseline. However, there was significantly greater improvement in general and disease-specific outcome measures and a lower rate of reoperation in the 2-level disc replacement patients versus ACDF control patients. Clinical trial registration no. NCT00389597 ( clinicaltrials.gov )
Article
OBJECTIVE Cervical total disc replacement (TDR) has been shown in a number of prospective clinical studies to be a viable treatment alternative to anterior cervical discectomy and fusion (ACDF) for the treatment of symptomatic degenerative disc disease. In addition to preserving motion, evidence suggests that cervical TDR may result in a lower incidence of subsequent surgical intervention than treatment with fusion. The goal of this study was to evaluate subsequent surgery rates up to 5 years in patients treated with TDR or ACDF at 1 or 2 contiguous levels between C-3 and C-7. METHODS This was a prospective, multicenter, randomized, unblinded clinical trial. Patients with symptomatic degenerative disc disease were enrolled to receive 1- or 2-level treatment with either TDR as the investigational device or ACDF as the control treatment. There were 260 patients in the 1-level study (179 TDR and 81 ACDF patients) and 339 patients in the 2-level study (234 TDR and 105 ACDF patients). RESULTS At 5 years, the occurrence of subsequent surgical intervention was significantly higher among ACDF patients for 1-level (TDR, 4.5% [8/179]; ACDF, 17.3% [14/81]; p = 0.0012) and 2-level (TDR, 7.3% [17/234]; ACDF, 21.0% [22/105], p = 0.0007) treatment. The TDR group demonstrated significantly fewer index- and adjacent-level subsequent surgeries in both the 1- and 2-level cohorts. CONCLUSIONS Five-year results showed treatment with cervical TDR to result in a significantly lower rate of subsequent surgical intervention than treatment with ACDF for both 1 and 2 levels of treatment. Clinical trial registration no.: NCT00389597 ( clinicaltrials.gov )
Article
One effect of rising health care costs has been to raise the profile of studies that evaluate care and create a systematic evidence base for therapies and, by extension, for health policies. All clinical trials and evaluative studies require instruments to monitor the outcomes of care in terms of quality of life, disability, pain, mental health, or general well-being. Many measurement tools have been developed, and choosing among them is difficult. This book provides comparative reviews of the quality of leading health measurement instruments and a technical and historical introduction to the field of health measurement, and discusses future directions in the field. This edition reviews over 100 scales, presented in chapters covering physical disability, psychological well-being, anxiety, depression, mental status testing, social health, pain measurement, and quality of life. An introductory chapter describes the theoretical and methodological development of health measures, while a final chapter reviews the current status of the field, indicating areas in which further development is required. Each chapter includes a tabular comparison of the quality of the instruments reviewed, followed by a detailed description of each instrument, covering its purpose and conceptual basis, its reliability and validity, alternative versions and, where possible, a copy of the scale itself. To ensure accuracy, each review has been approved by the original author of each instrument or by an acknowledged expert.
Article
A prospective, randomized, multicenter FDA IDE study using total disc replacement as surgical treatment of degenerative disc disease at one or two contiguous levels of the cervical spine. To evaluate the safety and effectiveness of total disc replacement at single or two contiguous levels through 48 months follow-up. Cervical total disc replacement has been shown to be a safe and effective alternative to anterior cervical discectomy and fusion at 24 months. Its motion preserving capabilities may avoid accelerating adjacent segment pathology and thereby lower the rate of associated complications. Patients were randomized in a 2:1 ratio (TDR:ACDF) at 24 sites. Ultimately, 164 patients received TDR at one level and 225 patients received TDR at two contiguous levels. An additional 24 patients (15 one-level, 9 two-level) were treated with TDR as training cases.Outcome measures included NDI, VAS neck and arm pain, SF-12 MCS/PCS, ROM, major complication rates, and secondary surgery rates. Patients received follow-up examinations at regular intervals through 4 years after surgery. Pre-operative characteristics were statistically similar for the one and two-level patient groups. Four year follow up rates were 83.1% (one-level) and 89.0% (two-level). There was no statistically significant difference between one and two-level TDR groups for all clinical outcome measures. Both TDR groups experienced significant improvement at each follow-up when compared to pre-operative scores. One case of migration was reported in the two-level TDR group. A four year post hoc comparison of one and two-level TDR patients concurrently enrolled in a 24 center, FDA IDE clinical trial indicated no statistical differences between groups in clinical outcomes, overall complication rates, and subsequent surgery rates.
Article
Object: The authors assess the long-term safety and efficacy of cervical disc replacement with the Prestige Cervical Disc in a prospective, randomized, multicenter trial at 7 years of follow-up. Methods: At 31 investigational sites, 541 patients with single-level cervical disc disease with radiculopathy were randomized to 1 of 2 treatment groups: 276 investigational group patients underwent anterior cervical discectomy and arthroplasty with the Prestige disc, and 265 control group patients underwent anterior cervical discectomy and fusion. Clinical outcomes included Neck Disability Index, the 36-Item Short-Form Health Survey, and neck and arm pain scores. Radiographs were assessed for angle of motion and fusion. Clinical and radiographic outcomes were evaluated preoperatively, intraoperatively, and at 1.5, 3, 6, 12, 24, 36, 60, and 84 months. Results: Of the 541 patients treated, 395 patients (73%; 212 investigational and 183 control patients) completed 7 years of clinical follow-up. Significant improvements achieved by 1.5 months in both groups were sustained at 7 years. In the investigational group, mean Neck Disability Index improvements from preoperative scores were 38.2 and 37.5 at 60 and 84 months, respectively. In the control group, the corresponding means were 33.8 and 31.9. The differences between the investigational and control groups at the 60-month and 84-month periods were significant (p = 0.014 and 0.002, respectively). The overall rates of maintenance or improvement in neurological status in the investigational group were significantly higher: 92.2% and 88.2% at 60 months and 84 months, respectively, compared with 85.7% and 79.7% in the control group (p = 0.017 and 0.011, respectively). At 84 months, the percentage of working patients in the investigational group was 73.9%, and in the control group, 73.1%. Postoperatively, the implant effectively maintained average angular motion of 6.67° at 60 months and 6.75° at 84 months. Cumulative rates for surgery at the index level were lower (p < 0.001) in the investigational group (11 [4.8%] of 276) when compared with the control group (29 [13.7%] of 265) (based on life-table method), and there were statistical differences between the investigational and control groups with specific regard to the rate of subsequent revision and supplemental fixation surgical procedures. Rates for additional surgical procedures that involved adjacent levels were lower in the investigational group than in the control group (11 [4.6%] of 276 vs. 24 [11.9%] of 265, respectively). Conclusions: Cervical disc arthroplasty has the potential for preserving motion at the operated level while providing biomechanical stability and global neck mobility and may result in a reduction in adjacent-segment degeneration. The Prestige Cervical Disc maintains improved clinical outcomes and segmental motion after implantation at 7-year follow-up. Clinical trial registration no. NCT00642876 ( ClinicalTrials.gov ).
Article
The safety and effectiveness of 2 implantation systems for single-segment cervical disk replacement-the Bryan Cervical Disc System (Medtronic Inc, Minneapolis, Minnesota) and the ACCEL system (Medtronic Inc)-have not been clinically compared. A prospective, nonrandomized controlled study in consecutive patients with a minimum 2-year follow-up was performed. Fifty patients with single-level cervical disk degeneration who responded poorly to conservative treatment and underwent Bryan Cervical Disc replacement were involved. Fifty patients were included (24 in group A [Bryan Cervical Disc System] and 26 in group B [ACCEL system]).The patients' visual analog scale scores, Neck Disability Index (NDI) scores, Short Form 36 (SF-36) scores, Odom scores, operative time, blood loss, and complications were compared. Patients' baseline statuses were similar (P>.05). Visual analog scale for neck and arm pain, NDI, and SF-36 were significantly improved postoperatively (P<.05) in both groups, and no clinical differences were found between the groups (P>.05). All Odom scores were better than good. Mean operative time and average blood loss in group A (173±42.5 minutes and 250±159.8 mL, respectively), were both significantly higher than the values in group B (137.5±19.3 minutes and 138.1±86.7 mL, respectively) (P<.05). Complications included intraoperative bleeding, temporary throat discomfort, and slight migration of the prosthesis; there was no significant difference in the total complication rates between the 2 groups (P>.05). The 2 implantation systems displayed equal clinical effectiveness and safety, but the ACCEL system appears to have the advantages of shorter operative time and less blood loss.
Article
The natural history of cervical degenerative disease with operative management has not been well described. Even with symptomatic and radiographic evidence of multilevel cervical disease, it is unclear whether single- or multilevel anterior cervical discectomy and fusion (ACDF) procedures produce superior long-term outcomes. To describe national trends in revision rates, complications, and readmission for patients undergoing single and multilevel ACDF. Administrative database study. Between 2006 and 2010, 92,867 patients were recorded for ACDF procedures in the Thomson Reuters MarketScan database. Restricting to patients with >24 months follow-up, 28,777 patients fulfilled our inclusion criteria, of which 12,744 (44%) underwent single-level and 16,033 (56%) underwent multilevel ACDFs. Revision rates and postoperative complications. We used the MarketScan database from 2006 to 2010 to select ACDF procedures based on Current Procedural Terminology coding at inpatient visit. Outcome measures were ascertained using either International Classification of Disease version 9 or Current Procedural Terminology coding. Perioperative complications were more common in multilevel procedures (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.2-1.6; p<.0001). Single-level ACDF patients had higher rates of postoperative cervical epidural steroid injections (OR, 0.88; 95% CI, 0.8-1.0; p=.01). Within 30 days after index procedure, the multilevel ACDF cohort was 1.6 times more likely to have undergone revision (OR, 1.6; 95% CI, 1.1-2.4; p=.02). At 2 years follow-up, revision rates were 9.13% in the single-level ACDF cohort and 10.7% for multilevel ACDFs (OR, 1.2; 95% CI, 1.1-1.3; p<.0001). In a multivariate analysis at 2 years follow-up, patients from the multilevel cohort were more likely to have received a surgical revision (OR, 1.1; 95% CI, 1.0-1.2; p=.001), to be readmitted into the hospital for any cause (OR, 1.2; 95% CI, 1.1-1.4; p=.007), and to have suffered complications (OR, 1.3; 95% CI, 1.1-1.5; p=.0003). In this study, we report rates of adverse events and the need for revision surgery in patients undergoing single versus multilevel ACDFs. Increasing number of levels fused at the time of index surgery correlated with increased rate of reoperations. Multilevel ACDF patients requiring additional surgery more often underwent more extensive revision surgeries.
Article
The purpose of this study was to determine long-term clinical outcomes in patients undergoing anterior cervical surgery in which a cervical disc prosthesis was used to treat single-level degenerative cervical disc disease. In this prospective, nonblinded study, 541 patients at 32 investigational sites were randomly assigned to 1 of 2 treatment groups. The results of the investigational group, in which patients received the Prestige disc prosthesis, were compared with those of the control group, in which patients underwent an instrumented interbody fusion. Data were collected preoperatively, intraoperatively, and at 1.5, 3, 6, 12, 24, 36, and 60 months postoperatively. To date, 271 patients have completed 5 years of clinical follow-up (144 investigational and 127 control patients). Significant improvements in Neck Disability Index (NDI) scores, Physical Component Summary scores of the 36-Item Short-Form Health Survey, and neck and arm pain scores were achieved by 1.5 months in both groups and sustained at 5 years. The mean NDI improvements from preoperative scores were 35.4, 36.3, and 38.4 at 24, 36, and 60 months, respectively, in the investigational group. The corresponding mean NDI improvements were 33.9, 31.3, and 34.1 in the control group. The intergroup differences at both 36 and 60 months were significant (p = 0.008 and 0.022, respectively). The overall rates of maintenance or improvement in neurological status in the investigational group were 91.6%, 92.8%, and 95.0%, respectively, at 24, 36, and 60 months compared with 83.6%, 83.2%, and 88.9% in the control group (p = 0.006, 0.004, and 0.051, respectively). The implant effectively maintained angular motion, averaging more than 7.3 degrees at 36 months and 6.5 degrees at 60 months after surgery. No implant migration was observed up to 60 months. There were statistically significant differences between the investigational and control groups with regard to the rate of revision and supplemental fixation surgical procedures performed subsequent to the index procedure. Additional surgical procedures for adjacent-segment disease were observed in both treatment groups. Rates for surgery at adjacent levels trended lower in the investigational group (8 patients [11 surgeries]) compared with those in the control group (13 patients [16 surgeries]), but the differences were not statistically significant (p = 0.376). Some of the second surgeries involved both index and adjacent levels. The Prestige disc maintains improved clinical outcomes and segmental motion after implantation at 5-year follow-up.
Article
A prospective, randomized, multicenter study of surgical treatment of cervical disc disease. To assess the safety and efficacy of cervical disc arthroplasty using a new arthroplasty device at 24-months follow-up. Cervical disc arthroplasty preserves motion in the cervical spine. It is an alternative to fusion after neurologic decompression, whereas anterior decompression and fusion provides a rigorous comparative benchmark of success. We conducted a randomized controlled multicenter clinical trial enrolling patients with cervical disc disease. Ultimately 242 received the investigational device (Bryan Cervical Disc), and 221 patients underwent a single-level anterior cervical discectomy and decompression and fusion as a control group. Patients completed clinical and radiographic follow-up examinations at regular intervals for 2 years after surgery. Analysis of 12- and 24-month postoperative data showed improvement in all clinical outcome measures for both groups; however, 24 months after surgery, the investigational group patients treated with the artificial disc had a statistically greater improvement in the primary outcome variables: Neck disability index score (P = 0.025) and overall success (P = 0.010). With regard to implant- or implant/surgical-procedure-associated serious adverse events, the investigational group had a rate of 1.7% and the control group, 3.2%. There was no statistical difference between the 2 groups with regard to the rate of secondary surgical procedures performed subsequent to the index procedure. Patients who received the artificial cervical disc returned to work nearly 2 weeks earlier than the fusion patients (P = 0.015). Two-year follow-up results indicate that cervical disc arthroplasty is a viable alternative to anterior cervical discectomy and fusion in patients with persistently symptomatic, single-level cervical disc disease.
Article
Cervical total disc replacement (TDR) is intended to address radicular pain and preserve functional motion between two vertebral bodies in patients with symptomatic cervical disc disease (SCDD). The purpose of this trial is to compare the safety and efficacy of cervical TDR, ProDisc-C (Synthes Spine Company, L.P., West Chester, PA), to anterior cervical discectomy and fusion (ACDF) surgery for the treatment of one-level SCDD between C3 and C7. The study was conducted at 13 sites. A noninferiority design with a 1:1 randomization was used. Two hundred nine patients were randomized and treated (106 ACDF; 103 ProDisc-C). Visual analog scale (VAS) pain and intensity (neck and arm), VAS satisfaction, neck disability index (NDI), neurological exam, device success, adverse event occurrence, and short form-36 (SF-36) standardized questionnaires. A prospective, randomized, controlled clinical trial was performed. Patients were enrolled and treated in accordance with the US Food and Drug Administration (FDA)-approved protocol. Patients were assessed pre- and postoperatively at six weeks, 3, 6, 12, 18, and 24 months. Demographics were similar between the two patient groups (ProDisc-C: 42.1+/-8.4 years, 44.7% males; Fusion: 43.5 +/- 7.1 years, 46.2% males). The most commonly treated level was C5-C6 (ProDisc-C: 56.3%; Fusion=57.5%). NDI and SF-36 scores were significantly less compared with presurgery scores at all follow-up visits for both the treatment groups (p<.0001). VAS neck pain intensity and frequency as well as VAS arm pain intensity and frequency were statistically lower at all follow-up timepoints compared with preoperative levels (p<.0001) but were not different between treatments. Neurologic success (improvement or maintenance) was achieved at 24 months in 90.9% of ProDisc-C and 88.0% of Fusion patients (p=.638). Results show that at 24 months postoperatively, 84.4% of ProDisc-C patients achieved a more than or equal to 4 degrees of motion or maintained motion relative to preoperative baseline at the operated level. There was a statistically significant difference in the number of secondary surgeries with 8.5% of Fusion patients needing a re-operation, revision, or supplemental fixation within the 24 month postoperative period compared with 1.8% of ProDisc-C patients (p=.033). At 24 months, there was a statistically significant difference in medication usage with 89.9% of ProDisc-C patients not on strong narcotics or muscle relaxants, compared with 81.5% of Fusion patients. The results of this clinical trial demonstrate that ProDisc-C is a safe and effective surgical treatment for patients with disabling cervical radiculopathy because of single-level disease. By all primary and secondary measures evaluated, clinical outcomes after ProDisc-C implantation were either equivalent or superior to those same clinical outcomes after Fusion.
Article
Injuries to the cervical spine, especially those involving the soft tissues, represent a significant source of chronic disability. Methods of assessment for such disability, especially those targeted at activities of daily living which are most affected by neck pain, are few in number. A modification of the Oswestry Low Back Pain Index was conducted producing a 10-item scaled questionnaire entitled the Neck Disability Index (NDI). Face validity was ensured through peer-review and patient feedback sessions. Test-retest reliability was conducted on an initial sample of 17 consecutive "whiplash"-injured patients in an outpatient clinic, resulting in good statistical significance (Pearson's r = 0.89, p less than or equal to .05). The alpha coefficients were calculated from a pool of questionnaires completed by 52 such subjects resulting in a total index alpha of 0.80, with all items having individual alpha scores above 0.75. Concurrent validity was assessed in two ways. First, on a smaller subset of 10 patients who completed a course of conservative care, the percentage of change on NDI scores before and after treatment was compared to visual analogue scale scores of percent of perceived improvement in activity levels. These scores correlated at 0.60. Secondly, in a larger subset of 30 subjects, NDI scores were compared to scores on the McGill Pain Questionnaire, with similar moderately high correlations (0.69-0.70). While the sample size of some of the analyses is somewhat small, this study demonstrated that the NDI achieved a high degree of reliability and internal consistency.(ABSTRACT TRUNCATED AT 250 WORDS)
Article
This retrospective study evaluated a single surgeon's series of patients treated by multilevel cervical disc excision (two or three levels), allograft tricortical iliac crest arthrodesis, and anterior instrumentation. The objective of this retrospective study was to compare fusion success and clinical outcome between multilevel Smith-Robinson interbody grafting and tricortical iliac strut graft reconstruction, both supplemented with anterior instrumentation in the cervical spine. The incidence of nonunion for cervical discectomy and fusion varies widely depending on the number of disc levels involved, type of bone graft used, and whether the anterior grafting is supplemented with instrumentation. An alternative to multilevel interbody fusion is corpectomy and strut grafting, in which the incidence of nonunion has been reported to be 27% with autograft and 41% with allograft. Sixty-four consecutive patients who underwent allograft tricortical iliac crest reconstruction and anterior cervical plating were studied. The average follow-up was 39 months. There were 38 patients in the discectomy and interbody grafting group and 26 patients in the corpectomy and strut graft reconstruction group. Pseudoarthrosis occurred in 42% of the anterior cervical interbody fusion patients and 31% of the corpectomy patients. Nonunion in two-level interbody fusions occurred in 36% of the patients as compared to 10% for patients with one-level corpectomies; while 54% of patients with three-level interbody fusions and 44% of patients with two-level corpectomies were noted to have pseudoarthrosis. Higher percentages of nonunion were noted in multilevel interbody grafting than in corpectomy with strut grafting and when more vertebral levels were involved. These radiographic and clinical findings underscore the shortcomings of multilevel anterior cervical allograft reconstruction with plating. Corpectomy may be the preferred method when multiple disc levels are fused. In addition, anterior corpectomy affords decompression of significant osteophytes in a safer and quicker manner. In retrospective studies, there is a need for long-term follow-up before accurate statements can be made about the study population.
Article
In vitro investigation of cervical adjacent level intradiscal pressures (IDPs) following a total disc replacement arthroplasty. The current in vitro study was undertaken to compare adjacent level IDPs and operative level kinematics following a cervical arthroplasty versus an arthrodesis procedure. Clinical data indicate the incidence of symptomatic transition syndrome to be as high as 3% annually following a cervical interbody arthrodesis. Recent developments in the motion preservation technology should, in theory, minimize transition syndrome at the adjacent levels. A total of 10 human cadaveric cervical spines were used in this investigation. Following intact analysis, all specimens were sequentially reconstructed at C5-C6 with 1) total disc replacement (TDR), 2) allograft dowel, and 3) allograft dowel + anterior cervical plate. Testing was performed in displacement control under axial rotation, flexion/extension, and lateral bending loading modes. IDPs were recorded at C4-C5 and C6-C7 whereas peak range of motion (ROM) and NZ were monitored at C5-C6 level. Similar IDPs were recorded between the intact condition and a TDR reconstruction at both adjacent levels under all loading modes (P > 0.05). However, the C4-C5 IDP values produced under flexion/extension testing for both arthrodesis treatments were significantly higher than the means obtained for the intact and disc replacement groups (P < 0.05). Similar intergroup differences were observed at the C6-C7 level; however, statistical significance was achieved during all three loading methods (P < 0.05). C5-C6 ROM analysis indicated a significantly lower ROM for both arthrodesis constructs compared with intact and TDR groups during flexion/extension testing (P < 0.05). No differences were recorded between the intact and the total disc replacement group under any loading conditions (P > 0.05). This is a first study to document that a cervical disc replacement arthroplasty procedure maintains adjacent level IDPs and reconstruction level kinematics near the preoperative values. Consequently, total disc replacement may provide an alternative to conventional surgical management of cervical discogenic pathology decreasing the incidence of symptomatic transition syndrome.
Article
The authors compared the incidence of radiologically documented changes and symptomatic adjacent-level cervical disc disease after single-level discectomy and subsequent cervical fusion or arthroplasty in two independent prospective clinical studies. The patients were treated with the Affinity Anterior Cervical Cage System or the Bryan Artificial Cervical Disc. In each study the patients were required to undergo serial cervical radiography preoperatively and 24 months postoperatively, as well as serial clinical evaluations including documentation of adverse events, neurological status, and results of the 36-item Short Form Health Survey. All serial radiographs were reviewed prior to evaluating the clinical symptoms for development of increasing or new adjacent degenerative disc disease (DDD). Subsequently, the clinical data were analyzed. For various reasons of exclusion, the cases analyzed in the Bryan disc-treated cohort consisted of 74 patients and in the Affinity system-treated cohort there were 158 patients. New anterior osteophyte formation or enlargement, increased narrowing of an interspace, new DDD, and calcification of the anterior longitudinal ligament were the radiological findings indicative of adjacent-level disease. Fusion was associated with a significant increase in x-ray film-based changes of adjacent-disc disease (p = 0.009, odds ratio [OR] 2.44). In the cage fusion series, the incidence of symptomatic adjacent-level DDD was statistically greater than that in the group treated with the artificial disc (p = 0.018), and the patients required a statistically greater number of medical treatments related to episodic symptoms of neck, shoulder, and arm pain attributed to new disc disease (p = 0.001, OR 35.8). In comparing these prospective studies the authors demonstrated that maintaining motion rather than fusion will prevent symptomatic adjacent-disc disease and will decrease adjacent-level radiological indicators of disease at a 24-month postoperative interval.