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Two-level cervical disc arthroplasty versus anterior cervical discectomy and fusion: 10-year outcomes of a prospective, randomized investigational device exemption clinical trial
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).
... of patients treated at a single level [19] and 80.4% when treated at two levels [20] J o u r n a l P r e -p r o o f Journal Pre-proof or "good", according to Odom"s criteria, ranged from 76% (single level group) [22] to 100% ...
... [23]. Statistically significant superiority of overall success compared to fusion was reported in the few studies that made this comparison [20,24] [21]. ...
... Mean reported NDIs range from 6.8 [21] to 14.80 (facet tropism group) [25] for TDRs that use ceramics for articulation, and from 5.77 [26] to 23.8 [27] for TDRs that use ceramics for osseointegration (0-50 scale, converted when reported differently). NDI scores of patients who received TDR were significantly lower, i.e. superior [20,21,24,28] or not statistically different [26], when compared to fusion outcomes. ...
Background
Ceramics are used in Total Disc Replacements (1) in articulating surfaces for their wear resistance and biocompatibility and (2) on endplates to promote osseointegration. They furthermore exhibit MRI and CT compatibility. These properties address main challenges associated with non-ceramic Total Disc Replacements i.e. wear, migration and postoperative imaging. While brittleness of ceramics caused fear of fracture in the past, improvements of ceramic materials were made and considerable clinical experience with ceramic Total Disc Replacements was gained. This review aims to assess the evidence on the use of ceramics in Total Disc Replacements and compare safety and effectiveness of ceramic Total Disc Replacements to spinal fusion and Total Disc Replacements in general.
Methods
We conducted a scoping review on the use of ceramics in Total Disc Replacements using Scopus, Web of Science and PubMed. The review includes 36 clinical, ex vivo and nonhuman in vivo, tribological and mechanical studies and case reports.
Findings
Ceramics are used in cervical Total Disc Replacements, with safety and efficacy comparable to non-ceramic Total Disc Replacements confirmed in clinical studies, with up to 10 and 3.3 years follow-up, for articulation and osseointegration applications, respectively. Clinical evidence shows that ceramic Total Disc Replacements (alike non-ceramic ones) restore segmental motion and result in non-inferior and possibly superior outcomes to spinal fusion. In vivo studies show osseointegration comparable to non-ceramic devices. Tribological studies suggest appropriate wear properties.
Interpretation
We found no indications of systematic problems with ceramic Total Disc Replacements. Ceramics are suitable materials for Total Disc Replacements.
... [41][42][43][44][45][46][47][48][49] For adjacent level surgery, 2 sets of citations reported on the same dataset, therefore we considered 5 unique studies. [50][51][52][53][54][55][56] For Analysis #1 (second surgery), the included studies were published between 2009 and 2020. For Analysis #2 (adjacent level surgery), the included studies were published between 2011 and 2019. ...
... 43,44 The remainder of studies in our second surgery analysis did not specify the number of operative levels. Analysis #2 considered 4 randomized controlled trials, [50][51][52][53][54] and 1 single-center retrospective cohort study. 55,56 Only 1 study reported survival curves for LAMP and PDIF, 55 therefore Analysis #2 only considered ACDF and ADR. ...
... All studies included patients with either diagnoses of radiculopathy or myelopathy with radiographic evidence of degenerative disc disease. Two studies focused on single level degenerative disease 51,52,54 , 1 on 2 adjacent level disease, 53 and 1 on either single or 2 level disease. 50 One study did not restrict number of levels operated in the index procedure. ...
Study Design
Systematic Review
Objectives
To conduct a meta-analysis on the survivorship of commonly performed cervical spine procedures to develop survival function curves for (i) second surgery at any cervical level, and (ii) adjacent level surgery.
Methods
A systematic review of was conducted following PRISMA guidelines. Articles with cohorts of greater than 20 patients followed for a minimum of 36 months and with available survival data were included. Procedures included were anterior cervical discectomy and fusion (ACDF), cervical disc arthroplasty (ADR), laminoplasty (LAMP), and posterior laminectomy and fusion (PDIF). Reconstructed individual patient data were pooled across studies using parametric Bayesian survival meta-regression.
Results
Of 1829 initial titles, 16 citations were included for analysis. 73 811 patients were included in the second surgery analysis and 2858 patients in the adjacent level surgery analysis. We fit a Log normal accelerated failure time model to the second surgery data and a Gompertz proportional hazards model to the adjacent level surgery data. Relative to ACDF, the risk of second surgery was higher with ADR and PDIF with acceleration factors 1.73 (95% CrI: 1.04, 2.80) and 1.35 (95% CrI: 1.25, 1.46) respectively. Relative to ACDF, the risk of second surgery was lower with LAMP with deceleration factor .06 (95% CrI: .05, .07). ADR decreased the risk of adjacent level surgery with hazard ratio .43 (95% CrI: .33, .55).
Conclusions
In cases of clinical equipoise between fusion procedures, our analysis suggests superior survivorship with anterior procedures. For all procedures, laminoplasty demonstrated superior survivorship.
... 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. ...
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.
... 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]. ...
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.
... Presently, results from 7 to 10 yr have been published on many of the CDA devices that are approved by the FDA for single-level 16,22-26 and 2-level treatment. 16,27,28 These studies consistently demonstrated superiority or noninferiority of CDA compared to ACDF, lower rates of secondary surgeries, low rates of serious AEs, and maintenance of motion. ...
... Other longterm studies of CDA reported adjacent level surgery occurring in 4.5% to 13.8% of patients, compared to rates of 16% to 24% in ACDF controls. 25,26,28,41 Long-term studies and meta-analyses estimate a cumulative incidence of adjacent level surgery ranging from 21% to 37% at 10 yr after ACDF. 7,[42][43][44][45] Recent studies have addressed the need to differentiate radiographic evidence of ASP from clinically symptomatic ASP, as well as identify the factors that lead to ASP and adjacent level surgeries after CDA. ...
... Our findings at 7 yr also reflect those reported earlier for grades 3/4 (1-level: 28.7%; 2-levels: 37.4%) with the Mobi-C device. 48 Similarly, Gornet et al 26,28 reported grade 3/4 HO of 28.6% and 39% in 1-and 2-level patients at 10 yr, while Mehren et al 40 reported grade 3/4 HO rates of 58% at 10 yr. Several studies have reported complete HO (grade 4) or solid fusion in approximately 11% of CDA patients at 7 yr. ...
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Graphical Abstract
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... 5 Clinical trials have shown noninferiority and potential superiority of CDA over ACDF for treating one-level and contiguous two-level CDDD, with 10-year outcomes demonstrating successful results. [6][7][8][9][10][11] Due to its motion-preservation capacity, CDA has been found to have superior patient outcomes for contiguous two-level CDDD, and a reduced reoperation rate at the adjacent level due to adjacent segment disease (ASDis). 6,9 Although patients with noncontiguous CDDD were not considered the optimal candidates for CDA, previous studies have not regarded noncontiguous CDDD as an absolute contraindication for CDA. ...
... [6][7][8][9][10][11] Due to its motion-preservation capacity, CDA has been found to have superior patient outcomes for contiguous two-level CDDD, and a reduced reoperation rate at the adjacent level due to adjacent segment disease (ASDis). 6,9 Although patients with noncontiguous CDDD were not considered the optimal candidates for CDA, previous studies have not regarded noncontiguous CDDD as an absolute contraindication for CDA. 12,13 Furthermore, some CDA clinical trials have included several patients with noncontiguous CDDD but have not analyzed the results separately. ...
Objective
The long‐term results of cervical disc arthroplasty (CDA) for noncontiguous cervical degenerative disc disease (CDDD) are still uncertain. Moreover, it is unclear whether CDA delays or avoids the degeneration of the intermediate segment (IS), leading to controversy in the field. Therefore, this study aimed to investigate the mid‐ to long‐term clinical and radiographic outcomes of CDA in treating noncontiguous CDDD and to explore whether the IS degenerated faster after CDA than other non‐surgically treated adjacent segments.
Methods
We retrospectively analyzed patients with noncontiguous CDDD who underwent CDA in our department between January 2008 and July 2018. The patients were divided into the CDA and hybrid surgery (HS) groups, and clinical and radiographic outcomes were evaluated at routine postoperative intervals. Clinical outcomes were assessed using the Japanese Orthopaedic Association (JOA), neck disability index (NDI), and visual analogue scale (VAS), while radiographic outcomes included cervical lordosis (CL), C2‐C7 range of motion (ROM), segmental ROM, and disc angle (DA) at the arthroplasty level. Complications were also evaluated.Pre‐ and postoperative values were compared using paired t ‐tests or Wilcoxon rank‐sum tests. Independent Student t ‐tests or Mann–Whitney U tests analyzed continuous data between CDA and HS groups, while chi‐square or Fisher exact tests assessed categorical data.
Results
Sixty‐four patients with noncontiguous CDDD, with 31 in the CDA group and 33 in the HS group, were evaluated. The mean follow‐up time was over 70 months. The most frequently involved levels were C4/5 and C5/6. Both groups showed significant improvements in JOA, NDI, and VAS values after surgery. Although CL was maintained, the CL in the CDA group was consistently lower than that in the HS group ( p < 0.05). There was a significant decrease in C2‐C7 ROM ( p < 0.05), but at the last follow‐up, the C2‐C7 ROM in the CDA group was greater than that in the HS group ( p < 0.05). At the last follow‐up, 44.3% of arthroplasty levels had developed heterotopic ossification (HO), and 48.45% had developed anterior bone loss (ABL). In addition, adjacent segment degeneration (ASDeg) was observed in the IS (22.7%), superior adjacent segment (20.6%)and inferior adjacent segment (21.9%).
Conclusion
CDA or CDA combined with fusion are viable treatments for noncontiguous CDDD, with satisfactory outcomes after mid‐to‐long‐term follow‐up. ASDeg is similar in non‐surgical segments after 70 months of follow‐up. ROM of the IS issimilar to preoperative levels, indicating CDA does not increase the risk of IS degeneration.
... Numerous studies support ADR having a comparable risk profile with superior clinical outcomes compared to anterior cervical discectomy and fusion (ACDF). [1][2][3] This is presumably due to less hypermobility and subsequent degeneration at the adjacent segment after preserving a functioning motion segment through arthroplasty. 4 This is supported by numerous large randomized clinical trials demonstrating significantly lower reoperation rates at the adjacent segment after both single-level 5,6 and 2-level ADR. ...
... 4 This is supported by numerous large randomized clinical trials demonstrating significantly lower reoperation rates at the adjacent segment after both single-level 5,6 and 2-level ADR. 1,7 In addition, ADR has been observed to have a lower reoperation rate at the index level. 8 In some cases, however, patients have persistent or recurrent radicular symptoms after ADR originating from the index level of the operation. ...
Background:
Patients may occasionally have persistent or recurrent radicular symptoms after cervical artificial disc replacement (ADR) for cervical spondylotic radiculopathy. We describe our approach using anterior cervical foraminotomy (ACF) to provide symptom relief in such patients without the need to convert to a fusion or remove the ADR implant.
Methods:
Our operative technique for ACF after cervical ADR begins by starting at the lateral edge of the ADR at the superior end plate of the inferior vertebral body. The ipsilateral uncovertebral joint is drilled with a combination of a high-speed burr and diamond-coated burr to minimize the risk of injury to the vertebral artery. The neuroforamen is entered after drilling through the posterior aspect of the uncinate process. The exiting cervical nerve root should be directly visualized, and a Kerrison rongeur may be used to trace along the nerve root laterally to remove any remaining uncinate osteophyte or process. We queried our internal database for patients with recurrent or new radicular pain following cervical ADR who underwent ACF. Clinical characteristics and outcomes were reported.
Results:
Five patients with recurrent radicular symptoms after ADR were reviewed. Two ACFs were performed at C5-6, and 2 were performed at C6-7. Four patients developed ipsilateral recurrent radicular symptoms, and only 1 patient developed contralateral new radicular symptoms. Three patients reported complete resolution of their new or recurrent radicular symptoms following ACF, and 2 patients reported only partial resolution. No patients required conversion to a fusion.
Conclusions:
In patients with recurrent symptoms of cervical spondylotic radiculopathy following ADR, ACF with uncovertebral joint resection can be used to provide direct foraminal decompression without the need for implant removal. This approach also preserves motion at the affected level, preserves cervical spinal stability, and prevents the need for spinal fusion.
Clinical relevance:
Patients with persistent or recurrent radicular symptoms after cervical ADR may achieve resolution of symptoms through a modified ACF technique.
Level of evidence: 4:
... Cervical disc replacements (CDRs) were designed with the intention to restore natural kinematics to patients that would typically undergo fusion surgery. [1][2][3][4][5] This patient population is relatively young, with an average age of 45.2 ± 5.2 years at the time of surgery, indicating that ideally, these devices should survive beyond 30 years. 6,7 While numerous CDR designs have been introduced over the past two decades, the majority have since been withdrawn from the market due to a failure to meet clinical expectation, with high complication rates such as adjacent segment degeneration, heterotopic ossification, and mechanical failures associated with potential revision surgeries. ...
Purpose
Composite models have become commonplace for the assessment of fixation and stability of total joint replacements; however, there are no comparable models for the cervical spine to evaluate fixation. The goal of this study was to create the framework for a tunable non‐homogeneous model of cervical vertebral body by identifying the relationships between strength, in‐fill density, and lattice structure and creating a final architectural framework for specific strengths to be applied to the model.
Methods
The range of material properties for cervical spine were identified from literature. Using additive manufacturing software, rectangular prints with three lattice structures, gyroid, triangle, zig‐zag, and a range of in‐fill densities were 3D‐printed. The compressive and shear strengths for all combinations were calculated in the axial and coronal planes. Eleven unique vertebral regions were selected to represent the distribution of density. Each bone density was converted to strength and subsequently correlated to the lattice structure and in‐fill density with the desired material properties. Finally, a complete cervical vertebra model was 3D‐printed to ensure sufficient print quality.
Results
Materials testing identified a relationship between in‐fill densities and strength for all lattice structures. The axial compressive strength of the gyroid specimens ranged from 1.5 MPa at 10% infill to 31.3 MPa at 100% infill and the triangle structure ranged from 2.7 MPa at 10% infill to 58.4 MPa at 100% infill. Based on these results, a cervical vertebra model was created utilizing cervical cancellous strength values and the corresponding in‐fill density and lattice structure combination. This model was then printed with 11 different in‐fill densities ranging from 33% gyroid to 84% triangle to ensure successful integration of the non‐homogeneous in‐fill densities and lattice structures.
Conclusions
The findings from this study introduced a framework for using additive manufacturing to create a tunable, customizable biomimetic model of a cervical vertebra.
... The results of surgical treatment in our historical control group were comparable to what is in the literature. However, our results using the algorithmic approach appear to be better than the results reported in the literature regarding anterior cervical procedures [19][20][21]. Our results using an algorithmic approach to indicate the promise of using our proposed algorithm for choosing the type of anterior cervical procedure in patients with two-level degenerative disease of the cervical spine. ...
Abstract
To analyze the efectiveness of an algorithmic anterior approach to the surgical treatment of patients with two-level cervical
degenerative disk disease based on the preoperative clinical and imaging parameters. The study included 244 patients with
two-level cervical degenerative disk disease. Three groups of patients were evaluated at 3 neurosurgical centers between
2016–2019. The prospective group (Group I, n=126) consisted of patients who were treated using an algorithm to decide
whether they should be treated with a two-level Total Disk replacement (TDR), Anterior Cervical Discectomy and Fusion
(ACDF) and hybrid technique. The control group (Group II, n=118) consisted of patients who underwent two-level anterior
decompression with TDR, ACDF and hybrid stabilization between 2005–2015. Visual Analogue Scale (VAS) neck pain,
VAS upper limbs pain, Neck Disability Index (NDI), SF-36, Macnab and Nurick scales were collected. Perioperative com�plications were identifed. At 2 years of follow up Group I had signifcantly better clinical outcomes based on VAS neck pain
score (p=0.02), VAS upper limbs pain (p=0.04), NDI score (p=0.02), SF-36 score (p=0.01), satisfaction with surgery
on the Macnab scale (p<0.001) and outcome of surgery based on Nurick scale (p<0.001). Complication rate was lower in
Group I, 6.3% compared to 24.6% in Group II, p=0.0001. The algorithmic anterior approach to the surgical treatment of
patients with two-level cervical degenerative disk disease resulted in signifcant improvement of functional outcomes and a
decrease in complications at a minimum 2 years of follow-up.
Keywords Cervical spine · Two-level degenerative disk disease · Total disk replacement · Anterior cervical discectomy and
fusion · Hybrid stabilization · Surgical algorithm
... Studies in the literature have concluded that the clinical outcomes of CDA and ACDF were very similar and that CDA could better preserve mobility at the indexed levels than ACDF, [30][31][32][33] but reports were elusive about patients with CSM. Also, it is well known that surgical procedures of both stabilization and decompression are effective for CSM. ...
Objective:
Anterior cervical discectomy and fusion (ACDF) is a standard surgical approach for cervical spondylotic myelopathy (CSM) caused by disc herniations. Although cervical disc arthroplasty (CDA) has become, in the past decade, a viable alternative to ACDF in selected patients, the differences among patients with CSM treated with CDA and ACDF remain elusive. The effectiveness of motion preservation devices in CSM is also unclear.
Methods:
Adult patients who underwent 1- or 2-level CDA or ACDF between 2007 and 2021 were retrospectively reviewed. Patients whose preoperative T2-weighted MRI demonstrated increased intramedullary signal intensity (IISI) were included and analyzed for the following: comparison of the length of IISI on pre- and postoperative MR images as well as range of motion (ROM) at the indexed levels between the CDA and ACDF groups. Measurement for clinical outcomes included the visual analog scale (VAS) of the arm and neck, the Neck Disability Index, and modified Japanese Orthopaedic Association scores. Perioperative clinical data were also compared between the two groups.
Results:
A total of 122 patients were allocated to the CDA group and 108 to the ACDF group, with mean follow-ups of 46.6 and 39.0 months, respectively. Patients in the CDA group were younger than those in the ACDF group (47.64 ± 12.40 vs 61.73 ± 12.25 years, p < 0.001) (mean ± SD). The ACDF group had more 2-level surgery compared to the CDA group (p = 0.002). Both groups had significant regression of IISI on postoperative MRI compared to that of preoperative imaging (CDA: 1.23 ± 0.84 to 0.28 ± 0.39 cm; ACDF: 1.07 ± 0.60 to 0.37 ± 0.42 cm; both p < 0.001). The decrease in the length of IISI was similar between the two groups (p = 0.058). The postoperative ROM was well preserved in the CDA group (superior to ACDF, which yielded minimal ROM postoperatively). Both the CDA and ACDF groups demonstrated improvement in Neck Disability Index and modified Japanese Orthopaedic Association scores at 24 months postoperatively. The CDA group had significant improvements on VAS scores, whereas the improvement did not reach significance for the ACDF group at 24 months postoperatively.
Conclusions:
Significant shortening of IISI on T2-weighted MRI was demonstrated after both CDA and ACDF. At 24 months postoperatively, all clinical outcomes demonstrated improvement after both strategies, except that the VAS score was not significantly improved for ACDF. Therefore, CDA is a safe and effective option for patients with MR-evident CSM.
... We only observed one reoperation after a direct neck trauma 7 years after the initial disc replacement. Reoperation rates in cervical arthroplasty for 10-year FU studies have been reported previously, ranging from 2 to 10.3%, depending on the study group and on the implant [10,11,[13][14][15][16][17] (Table 1). This low reoperation rate could be explained by each participating surgeon's indications for surgery, by the surgical technique that may differ from one implant to the other, but Lee et al. also suggested the importance of the implant design mimicking the natural centre of rotation during flexion and allowing wider distribution and lower contact pressure on the core [18]. ...
Purpose
We evaluated the long-term safety, mobility and complications of cervical total disc arthroplasty with the Baguera ® C prosthesis over 10 years.
Methods
We included 91 patients treated by arthroplasty for cervical degenerative disc disease. A total of 113 prostheses were implanted (50 one-level, 44 two-level and 19 hybrid constructs). They were assessed for complications, clinically, with NDI and SF-12 questionnaires and by independent radiologists for ROM, HO, disc height and adjacent level degeneration.
Results
No spontaneous migration, loss of fixation, subsidence, vascular complication or dislocation were observed. The reoperation rate was 1%. About 82.7% of the patients were pain free. About 9.9% were taking occasional grade I painkillers. Motricity and sensitivity were preserved in 98.8% and 96.3%. The NDI showed an average functional disability of 17.58%, 26% lower than preoperatively. The SF-12 scores were close to normal health. The average ROM at the treated level was 7.4°. Motion was preserved in 86.6%. Lack of motion was observed in 13.4%. Grades II and III H0 were present in 53.7% and 31.7%, respectively, Grade IV was present in 13.4%. Motion was preserved in 100% of the grades 0–III. The preoperative adjacent level disc height of 4.3 mm remained stable during all the follow-ups at 4.4 mm and 4.2 mm, respectively, at 5 and 10 years.
Conclusions
After 10 years, cervical arthroplasty with the Baguera ® C prosthesis presents excellent safety and functional results and low complications. Motion was preserved in 86.6%, with a 7.4° ROM. Although common, HO did not hinder motion. Adjacent disc height preservation confirms some adjacent level degeneration protection.
... In this figure, the most common complication was post-operative dysphagia. Re-operation rates for these procedures range from 9.13% to 11.1% in single-level cases and 17.6% in multi-level cases [16][17][18]. The re-operation rate for this study was only required for one case (0.43%). ...
Introduction
Anterior Cervical Discectomy and Fusion (ACDF) is the gold standard treatment for symptomatic cervical spondylosis refractory to analgesic medical management. Currently, there are numerous approaches and devices used; however, there is no single implant that is preferred for this procedure. The aim of this study is to evaluate the radiological outcomes of ACDF procedures performed in the regional spinal surgery centre in Northern Ireland. The results of this study will aid surgical decision-making, specifically with regard to the choice of implant. The implants that will be assessed in this study are the stand-alone polyetheretherketone (PEEK) cage (Cage) and the Zero-profile augmented screw implant (Z-P).
Methods
A total of 420 ACDF cases were reviewed retrospectively. Following exclusion and inclusion criteria, 233 cases were reviewed. In the Z-P group, there were 117 patients, with 116 in the Cage group. Radiographic assessment was carried out at the pre-operative stage, day one post-operation, and follow-up (> three months). Measured parameters included segmental disc height, segmental Cobb angle, and spondylolisthesis displacement distance.
Results
Patient characteristic features showed no significant difference between the two groups (p>0.05) and no significant difference in mean follow-up time (p=0.146). The Z-P implant was superior in increasing and maintaining disc height post-operatively (+0.4±0.94mm, 5.20±0.66mm) compared to the Cage (+0.1±1.00mm, 4.40±0.95mm) (p<0.001). Z-P was also more successful in restoring and maintaining cervical lordosis in comparison to the Cage group, as it had a significantly smaller kyphosis incidence (0.85% vs. 34.5%) at follow-up (p<0.001).
Conclusions
Results of this study show a more advantageous outcome in the Zero-profile group as it restores and maintains both disc height and cervical lordosis; it is also more successful in treating spondylolisthesis. This study advocates cautious endorsement of the use of the Zero-profile implant in ACDF procedures for symptomatic cervical disc disease.
... [3][4][5][6] However, heterotopic ossification (HO), a complication of CDR, is a cause for concern. Some studies [7][8][9] suggest that HO limits the ROM of the prosthesis, causing dysfunction and even becoming an "expensive fusion device." Therefore, HO may decrease the longevity of prostheses. ...
Study design:
Systematic review and meta-analysis.
Objective:
This study aimed to assess the incidence of heterotopic ossification (HO) 10 years after cervical disc replacement (CDR).
Summary of background data:
HO is a common complication after CDR and may limit the range of motion (ROM) of the artificial disc. As HO usually progresses slowly, long-term follow-up is required to better understand its incidence. In recent years, the increasing number of original articles reporting 10 year outcomes give us the opportunity to better understand the long-term incidence of HO.
Methods:
We searched PubMed, Medline, Embase, and Cochrane Library databases to identify eligible studies. The incidence of HO was pooled and subgroup analysis was performed. Meta-regression analyses were conducted to identify factors contributing to heterogeneity.
Results:
Eleven studies with at least 10 years of follow-up comprising 1,140 patients who underwent CDR were included. The pooled incidence of overall HO was 70% (95% CI: 60-81%) at 10 years postoperatively, 60% (95% CI: 44-75%) at 5 or 6 years postoperatively, and 50% (95% CI: 27-72%) at 1 or 2 years postoperatively. The pooled incidence of severe HO (grade 3 or 4) was 37% (95% CI: 29-45%), and mild HO (grade 1 to 2) was 30% (95% CI: 17-44%) at 10 years of follow-up. Pooled ROM decreased from 8.59° before surgery to 7.40° 10 years after surgery. Subgroup analysis showed that HO incidence differed according to the prosthesis type. Earlier publication was associated with a higher pooled incidence of severe HO in the meta-regression analysis.
Conclusion:
This is the first meta-analysis providing detailed information on the pooled 10-year incidence of HO after CDR. The incidence ofHO appears to increase with the length of follow-up.
Level of evidence:
III.
... Furthermore, the theoretical benefit of alleviating adjacent-segment disease (ASD) by CDA has also been demonstrated in the reports with long follow-ups. [13][14][15][16][17][18][19] These advantages were reportedly applicable for 1-and 2-level CDA. ...
OBJECTIVE
Cervical disc arthroplasty (CDA) has been recognized as a popular option for cervical radiculopathy or myelopathy caused by disc problems that require surgery. There have been prospective randomized controlled trials comparing CDA to anterior cervical discectomy and fusion (ACDF) for 1- and 2-level disc herniations. However, the indications for CDA have been extended beyond the strict criteria of these clinical trials after widespread real-world experiences in the past decade. This article provides a bibliometric analysis with a review of the literature to understand the current trends of clinical practice and research on CDA.
METHODS
The PubMed database was searched using the keywords pertaining to CDA in human studies that were published before August 2022. Analyses of the bibliometrics, including the types of papers, levels of evidence, countries, and the number of disc levels involved were conducted. Moreover, a systematic review of the contents with the emphasis on the current practice of multilevel CDA and complex cervical disc problems was performed.
RESULTS
A total of 957 articles published during the span of 22 years were analyzed. Nearly one-quarter of the articles (232, 24.2%) were categorized as level I evidence, and 33.0% were categorized as levels I or II. These studies clearly demonstrated the viability and effectiveness of CDA regarding clinical and radiological outcomes, including neurological improvement, maintenance, and preservation of segmental mobility with relatively low risks for several years postoperation. Also, there have been more papers published during the last decade focusing on multilevel CDA and fewer involving the comparison of ACDF. Overall, there was a clustering of CDA papers published from the US and East Asian countries. Based on substantial clinical data of CDA for 1- and 2-level disc diseases, the practice and research of CDA show a trend toward multilevel and complex disease conditions.
CONCLUSIONS
CDA is an established surgical management procedure for 1- and 2-level cervical disc herniation and spondylosis. The success of motion preservation by CDA—with low rates of complications—has outscored ACDF in patients without deformity. For more than 2-level disc diseases, the surgery shows a trend toward multiple CDA or hybrid ACDF–CDA according to individual evaluation for each level of degeneration.
... The baseline characteristics and 12-month outcome data were similar between the groups, except for slightly higher NDI and NRS-NP scores for the arthroplasty patients at baseline, as well as a lower number of operated levels. There is no current consensus about the use of arthroplasty vs fusion in patients with degenerative cervical disease [8,13,16,17,42,46]. One may question whether the results of the fusion group in our study can be generalized to the arthroplasty group since there are only 1% of arthroplasty patients in our cohort. ...
Purpose
By using data from the Norwegian Registry for Spine Surgery, we wanted to develop and validate prediction models for non-success in patients operated with anterior surgical techniques for cervical degenerative radiculopathy (CDR).
Methods
This is a multicentre longitudinal study of 2022 patients undergoing CDR surgery and followed for 12 months to find prognostic models for non-success in neck disability and arm pain using multivariable logistic regression analysis. Model performance was evaluated by area under the receiver operating characteristic curve (AUC) and a calibration test. Internal validation by bootstrapping re-sampling with 1000 repetitions was applied to correct for over-optimism. The clinical usefulness of the neck disability model was explored by developing a risk matrix for individual case examples.
Results
Thirty-eight percent of patients experienced non-success in neck disability and 35% in arm pain. Loss to follow-up was 35% for both groups. Predictors for non-success in neck disability were high physical demands in work, low level of education, pending litigation, previous neck surgery, long duration of arm pain, medium-to-high baseline disability score and presence of anxiety/depression. AUC was 0.78 (95% CI, 0.75, 0.82). For the arm pain model, all predictors for non-success in neck disability, except for anxiety/depression, were found to be significant in addition to foreign mother tongue, smoking and medium-to-high baseline arm pain. AUC was 0.68 (95% CI, 0.64, 0.72).
Conclusion
The neck disability model showed high discriminative performance, whereas the arm pain model was shown to be acceptable. Based upon the models, individualized risk estimates can be made and applied in shared decision-making with patients referred for surgical assessment.
... Anterior cervical discectomy and fusion (ACDF) is often described as the gold standard surgical technique for cervical radiculopathy. 3 Although the results of ACDF are considered favorable, the variability in outcomes and occurrence of adverse events underscores the importance of appropriate patient selection. 4,5 Prognostic factors provide important context to the process of clinical decision-making. 6 However, there is little prognostic evidence to guide patient selection for ACDF. ...
OBJECTIVE
Anterior cervical discectomy and fusion (ACDF) is often described as the gold standard surgical technique for cervical spondylotic radiculopathy. Although outcomes are considered favorable, there is little prognostic evidence to guide patient selection for ACDF. This study aimed to 1) describe the 24-month postoperative trajectories of arm pain, neck pain, and pain-related disability; and 2) identify perioperative prognostic factors that predict trajectories representing poor clinical outcomes.
METHODS
In this retrospective cohort study, patients with cervical spondylotic radiculopathy who underwent ACDF at 1 of 12 orthopedic or neurological surgery centers were recruited. Potential outcome predictors included demographic, health, clinical, and surgery-related prognostic factors. Surgical outcomes were classified by trajectories of arm pain intensity, neck pain intensity (numeric pain rating scales), and pain-related disability (Neck Disability Index) from before surgery to 24 months postsurgery. Trajectories of postoperative pain and disability were estimated with latent class growth analysis, and prognostic factors associated with poor outcome trajectory were identified with robust Poisson models.
RESULTS
The authors included data from 352 patients (mean age 50.9 [SD 9.5] years; 43.8% female). The models estimated that 15.5%–23.5% of patients followed a trajectory consistent with a poor clinical outcome. Lower physical and mental health–related quality of life, moderate to severe risk of depression, and longer surgical wait time and procedure time predicted poor postoperative trajectories for all outcomes. Receiving compensation and smoking additionally predicted a poor neck pain outcome. Regular exercise, physiotherapy, and spinal injections before surgery were associated with a lower risk of poor disability outcome. Patients who used daily opioids, those with worse general health, or those who reported predominant neck pain or a history of depression were at greater risk of poor disability outcome.
CONCLUSIONS
Patients who undergo ACDF for cervical spondylotic radiculopathy experience heterogeneous postoperative trajectories of pain and disability, with 15.5%–23.5% of patients experiencing poor outcomes. Demographic, health, clinical, and surgery-related prognostic factors can predict ACDF outcomes. This information may further assist surgeons with patient selection and with setting realistic expectations. Future studies are needed to replicate and validate these findings prior to confident clinical implementation.
... CASP occurs at an estimated cumulative rate of 1.6-4.2% per year after ACDF [16,17]; however, the incidence reported in literature varies widely [18][19][20][21]. Nevertheless, 50-75% of the patients that develop CASP require additional adjacent segment surgery [17,[22][23][24][25][26][27]. ...
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 remains 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 6 months until 4 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 aging of the population and the rising healthcare costs, there is an urgent need for a solid clinical cost-effectiveness trial addressing this question.
Trial registration
ClinicalTrials.gov NCT04623593. Registered on 29 September 2020.
... Our average NDI of 22.6 % approximately 1.5 years out from surgery is similar to the average NDI following 2-level CDR and ACDF at other levels of the cervical spine, as reported in a 10-year IDE follow-up study of the Prestige LP implant [16]. For the CDR group, Gornet et. ...
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.
... 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]. ...
Abstract 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
... 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%. ...
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.
... The value of d that we determined as acceptable in this study is significantly lower than respective values in sentinel studies of spinal literature. [9][10][11] In summary, we aimed to assess whether the risk difference between outpatient and inpatient surgery for any of the four outcomes was over 1.5%. ...
Objective:
Spine surgery represents an ideal target for healthcare cost reduction efforts, with outpatient surgery resulting in significant cost savings. With an increased focus on value-based healthcare delivery, lumbar decompression surgery has been increasingly performed in the outpatient setting when appropriate. The aim of this study was to compare clinical and patient-reported outcomes following outpatient and inpatient lumbar decompression surgery.
Methods:
The Quality Outcomes Database (QOD) was queried for patients undergoing elective one- or two-level lumbar decompression (laminectomy or laminotomy with or without discectomy) for degenerative spine disease. Patients were grouped as outpatient if they had a length of stay (LOS) < 24 hours and as inpatient if they stayed in the hospital ≥ 24 hours. Patients with ≥ 72-hour stay were excluded from the comparative analysis to increase baseline comparability between the two groups. To create two highly homogeneous groups, optimal matching was performed at a 1:1 ratio between the two groups on 38 baseline variables, including demographics, comorbidities, symptoms, patient-reported scores, indications, and operative details. Outcomes of interest were readmissions and reoperations at 30 days and 3 months after surgery, overall satisfaction, and decrease in Oswestry Disability Index (ODI), back pain, and leg pain at 3 months after surgery. Satisfaction was defined as a score of 1 or 2 in the North American Spine Society patient satisfaction index. Noninferiority of outpatient compared with inpatient surgery was defined as risk difference of < 1.5% at a one-sided 97.5% confidence interval.
Results:
A total of 18,689 eligible one- and two-level decompression surgeries were identified. The matched study cohorts consisted of 5016 patients in each group. Nonroutine discharge was slightly less common in the outpatient group (0.6% vs 0.3%, p = 0.01). The 30-day readmission rates were 4.4% and 4.3% for the outpatient and inpatient groups, respectively, while the 30-day reoperation rates were 1.4% and 1.5%. The 3-month readmission rates were 6.3% for both groups, and the 3-month reoperation rates were 3.1% for the outpatient cases and 2.9% for the inpatient cases. Overall satisfaction at 3 months was 88.8% for the outpatient group and 88.4% for the inpatient group. Noninferiority of outpatient surgery was documented for readmissions, reoperations, and patient-reported satisfaction from surgery.
Conclusions:
Outpatient lumbar decompression surgery demonstrated slightly lower nonroutine discharge rates in comparison with inpatient surgery. Noninferiority in clinical outcomes at 30 days and 3 months after surgery was documented for outpatient compared with inpatient decompression surgery. Additionally, outpatient decompression surgery performed noninferiorly to inpatient surgery in achieving patient satisfaction from surgery.
... 3,4 Many comparisons between ACDF and CDR have shown superiority of arthroplasty in long-term functional outcomes, rates of ASD, and frequency of additional surgeries for single-level 5-12 and two-level replacements. [13][14][15] Complications are low, with 0.8% vascular events and 4.7% short-term dysphagia. 16 Failures of CDR have mainly focused on the 32.5% incidence of heterotopic ossification that can limit the range of motion of the spinal segment and contribute to ASD. 17 Currently 15 different artificial discs are used worldwide, 18 with 7 having received Food and Drug Administration (FDA) approval. ...
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.
... 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. ...
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.
... 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. ...
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.
... 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 ...
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.
... 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. ...
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.
... 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. ...
Study design:
A meta-analysis of randomized controlled trials (RCTs).
Objective:
The aim of this study was to compare mid-term to long-term outcomes of cervical disk arthroplasty (CDA) with those of anterior cervical discectomy and fusion (ACDF) for the treatment of symptomatic cervical degenerative disk disease.
Summary of background data:
After ACDF to treat symptomatic cervical degenerative disk disease, the loss of motion at the index level due to fusion may accelerate adjacent-level disk degeneration. CDA was developed to preserve motion and reduce the risk of adjacent segment degeneration. Early-term to mid-term clinical outcomes from RCTs suggest noninferiority of CDA compared with ACDF, but it remains unclear whether CDA yields better mid-term to long-term outcomes than ACDF.
Materials and methods:
Two independent reviewers searched PubMed, Embase, and the Cochrane Library for RCTs with at least 60 months of follow-up. The risk ratio or standardized mean difference (and 95% CIs) were calculated for dichotomous or continuous variables, respectively.
Results:
Eighteen reports of 14 RCTs published in 2014-2023 were included. The pooled analysis demonstrated that the CDA group had a significantly greater improvement in neurological success and Neck Disability Index than the ACDF group. The ACDF group exhibited a significantly better improvement in the Short Form-36 Health Survey Physical Component Summary than the CDA group. Radiographic adjacent segment degeneration was significantly lower in the CDA group at 60- and 84-month follow-ups; at 120-month follow-up, there was no significant difference between the 2 groups. Although the overall rate of secondary surgical procedures was significantly lower in the CDA group, we did not observe any significant difference at 60-month follow-up between the CDA and ACDF group and appreciated statistically significant lower rates of radiographic adjacent segment degeneration, and symptomatic adjacent-level disease requiring surgery at 84-month and 108- to 120-month follow-up. The rate of adverse events and the neck and arm pain scores in the CDA group were not significantly different from those of the ACDF group.
Conclusions:
In this meta-analysis of 14 RCTs with 5- to 10-year follow-up data, CDA resulted in significantly better neurological success and Neck Disability Index scores and lower rates of radiographic adjacent segment degeneration, secondary surgical procedures, and symptomatic adjacent-level disease requiring surgery than ACDF. ACDF resulted in improved Short Form-36 Health Survey Physical Component Summary scores. However, the CDA and ACDF groups did not exhibit significant differences in overall changes in neck and arm pain scores or rates of adverse events.
Introduction
Artificial cervical disc replacement (ACDR) is a widely accepted surgical procedure in the treatment of cervical radiculopathy and myelopathy. However, some research suggests that ACDR may redistribute more load onto the facet joints, potentially leading to postoperative axial pain in certain patients. Earlier studies have indicated that facet tropism is prevalent in the lower cervical spine and can significantly increase facet joint pressure. The present study aims to investigate the changes in the biomechanical environment of the cervical spine after ACDR using different prosthese when facet tropism is present.
Methods
A C2-C7 cervical spine finite element model was created. Symmetrical, moderate asymmetrical (7 degrees tropism), and severe asymmetrical (14 degrees tropism) models were created at the C5/C6 level. C5/C6 ACDR with Prestige LP, Prodisc-C vivo, and Mobi-C were simulated in all models. A 75 N follower load and 1 N⋅m moment was applied to initiate flexion, extension, lateral bending, and axial rotation, and the range of motions (ROMs), facet contact forces(FCFs), and facet capsule stress were recorded.
Results
In the presence of facet tropism, all ACDR models exhibited significantly higher FCFs and facet capsule stress compared to the intact model. In the asymmetric model, FCFs on the right side were significantly increased in neutral position, extension, left bending and right rotation, and on both sides in right bending and left rotation compared to the symmetric model. All ACDR model in the presence of facet tropism, exhibited significantly higher facet capsule stresses at all positions compared to the symmetric model. The stress distribution on the facet surface and the capsule ligament in the asymmetrical models was different from that in the symmetrical model.
Conclusions
The existence of facet tropism could considerably increase FCFs and facet capsule stress after ACDR with Prestige-LP, Prodisc-C Vivo, and Mobi-C. None of the three different designs of implants were able to effectively protect the facet joints in the presence of facet tropism. Research into designing new implants may be needed to improve this situation. More attention should be paid to facet tropism when planning surgery and selecting implants.
New innovations within spine surgery continue to propel the field forward. These technologies improve surgeons’ understanding of their patients and allow them to optimize treatment planning both in the operating room and clinic. Additionally, changes in the implants and surgeon practice habits continue to evolve secondary to emerging biomaterials and device design. With ongoing advancements, patients can expect enhanced preoperative decision-making, improved patient outcomes, and better intraoperative execution. Additionally, these changes may decrease many of the most common complications following spine surgery in order to reduce morbidity, mortality, and the need for reoperation. This article reviews some of these technological advancements and how they are projected to impact the field. As the field continues to advance, it is vital that practitioners remain knowledgeable of these changes in order to provide the most effective treatment possible.
Cervical disk arthroplasty (CDA) is well-studied for 1-level and 2-level cervical pathology. There is an increasing trend towards its utilization for greater than 2-level disease as an alternative to the gold standard, anterior cervical discectomy and fusion (ACDF). The number of high-level, prospective studies or randomized trials regarding multilevel CDA is limited but continues to grow as the procedure gains popularity. In appropriately indicated patients with multilevel disease caused by disk herniations or spondylosis without extensive facet arthropathy, CDA shows promising results. Multilevel CDA should be avoided in patients with prior spinal trauma, significant degenerative spondylolisthesis with translation, arthrodesis without mobility, severely incompetent facet joints, ossification of the posterior longitudinal ligament, or kyphotic deformity. With overall similar risk profiles to ACDF but lower theoretical rates of pseudarthrosis and adjacent segment disease, multilevel CDA has been shown to preserve, or perhaps even increase, preoperative cervical range of motion. There are negligible differences in postoperative neck and arm pain, VAS scores, modified Japanese Orthopaedic Association scores, and Neck Disability Index scores when comparing multilevel CDA and ACDF. Despite current indications for multilevel CDA largely being based on single and 2-level data, careful patient selection is critical. Expansion of indications can be expected as literature continues to emerge regarding outcomes and complications in multilevel CDA, as well as with improvements in prosthesis design.
Objective
The purpose of this study was to assess the impact of facet tropism on the facet contact force and facet capsule strain after artificial cervical disc replacement (ACDR).
Methods
A finite element model was constructed from computed tomography (CT) scans of a 28-year-old male volunteer. Symmetrical, moderate asymmetrical (7 degrees tropism), and severe asymmetrical (14 degrees tropism) models were created at the C5/C6 level. C5/C6 ACDR was simulated in all models. A 75 N follower load and 1 N⋅m moment was applied to the odontoid process to initiate flexion, extension, lateral bending, and axial rotation, and the range of motions, facet contact forces, and facet capsule strains were recorded.
Results
In the severe asymmetrical model, the right-side FCF increased considerably under extension, right bending, and left rotation compared with the symmetrical model after C5/C6 ACDR. The ride-side FCFs of the severe asymmetrical model under extension, right bending, and left rotation were about 1.7, 3.1, and 1.8 times of those of the symmetrical model, respectively. The facet capsule strains of both the moderate and severe asymmetrical models increased significantly compared with those of the symmetrical model after C5/C6 ACDR. The left-side capsule strains of the severe asymmetrical model were 2.1, 2.4, 1.6, and 8.5 times of those of the symmetrical model under left bending, right bending, left rotation, and right rotation, respectively. The right-side capsule strains of the severe asymmetrical model were 6.3, 1.6, 3.7, and 2.2 times of those of the symmetrical model under left bending, right bending, left rotation, and right rotation, respectively. The stress distribution on the facet surface in the asymmetrical models was different from that in the symmetrical model.
Conclusions
The existence of facet tropism could considerably increase facet contact force and facet capsule strain after ACDR, especially under extension, lateral bending, and rotation. Facet tropism also could result in abnormal stress distribution on the facet joint surface and facet joint capsule. Such abnormality might be a risk factor for post-operative facet joint degeneration progression after ACDR, making facet tropism noteworthy when ACDR was considered as the surgical option.
Background:
Cervical disc arthroplasty replacement (CDA) was developed to avoid specific disadvantages of cervical fusion. The purpose of this paper is to provide 10-year follow-up results of an ongoing prospective study after CDA.
Methods:
384 patients treated using the Mobi-C (ZimVie, Troyes, France) were included in a prospective multicenter study. Routine clinical and radiological examinations were reported pre and postoperatively with up to 10-year follow-up. Complications and revision surgeries were also documented.
Results:
at 10 years showed significant improvement in all clinical outcomes (NDI, VAS for arm and neck pain, SF-36 PCS and MCS). Motion at the index level increased significantly over baseline (mean ROM=7.6° vs. 8° at 5 years and 6.0° preoperatively; P<0.001) and 71.3% of the implanted segments remained mobile (ROM>3°). Adjacent discs were also mobile at 10 years with the same mobility as preoperatively. At 10 years, 20.9% of the implanted segments demonstrated no heterotopic ossification (HO). Thirty-four patients (8.9%) experienced 41 adverse events, with or without reoperation during the 5 first years. We found only two additional surgeries after 5 years. We observed an increased percentage of working patients and a decrease in medication consumption. Regarding the overall outcome, 94% of patients were satisfied.
Conclusions:
Our 10-year results showed significant improvement in all clinical outcomes, with low rates of revision or failure. This experience in patients with long-term follow-up after CDA endorses durable, favorable outcomes in properly selected patients.
Objective
ACS-NSQIP PUF data from 2014 through 2019 were used to compare one- and two-level ACDF and cTDR with respect to: patient demographics, comorbidities, adverse events, and 30-day morbidity rates.
Methods
One- and two-level ACDF and cTDR patients were identified by CPT codes. Demographics, comorbidities, and adverse events were summarized. Unmatched cohorts were compared using Wilcoxon Rank Sum test for continuous variables, Pearson’s Chi Square test for categorical variables, and 30-day morbidity using inverse probability of treatment weighted (IPTW) log-binomial regression.
Results
ACS-NSQIP 2014 through 2019 PUF datasets represent 4,862,497 unique patients, identifying 13347 one-level, 6933 two-level ACDF, 3114 one-level, and 862 two-level cTDR patient cohorts. Statistically significant differences between cohorts are extensive: age, sex, race, admission status, patient origin, discharge disposition, emergent surgery, surgical specialty, ASA classification, wound class, operative time, hospital LOS, BMI, functional status, smoking, diabetes, dyspnea, COPD, CHF, HTN, renal failure, dialysis, cancer, steroid use, anemia, bleeding disorders, systemic sepsis, and number of concurrent comorbid conditions. IPTW log-binomial models, demonstrated increased risk of DVT/thrombophlebitis, pulmonary embolism, deep incisional SSI, pneumonia, and unplanned return to OR associated with ACDF while increased risk of CVA/stroke with neurological deficit and myocardial infarction associated with cTDR. The composite complications outcome favors cTDR over ACDF for 30-day morbidity. No mortalities occurred within the cTDR cohort.
Conclusions
Adjusting for demographics and comorbidities; ACDF has a higher average risk of adverse event. When ACDF and cTDR are equipoise, consideration for cTDR may be indicated in populations with higher rates of comorbid conditions.
Anterior cervical disc replacement (ACDR) using cervical artificial disc (CAD) has the advantage of maintaining the range of motion (ROM) at the surgical level, subsequently reducing the postoperative risk of adjacent disc disease. Following the approval for the clinical use in Japan, a post-marketing surveillance (PMS) study was conducted for two different types of CAD, namely, Mobi-C (metal-on-plastic design) and Prestige LP (metal-on-metal design). The objective of this prospective observational multicenter study was to analyze the first 2-year surgical results of the PMS study of 1-level ACDR in Japan. A total of 54 patients were registered (Mobi-C, n = 24, MC group; Prestige LP, n = 30, PLP group). Preoperative neurological assessment revealed radiculopathy in 31 patients (57.4%) and myelopathy in 15 patients (27.8%). Preoperative radiological assessment classified the disease category as disc herniation in 15 patients (27.8%), osteophyte in 6 patients (11.1%), and both in 33 patients (61.1%). The postoperative follow-up rates at 6 weeks, 6 months, 1 year, and 2 years after ACDR were 92.6%, 87.0%, 83.3%, and 79.6%, respectively. In both groups, patients' neurological condition improved significantly after surgery. Radiographic assessment revealed loss of mobility at the surgical level in 9.5% of patients in the MC group and in 9.1% of patients in the PLP group. No secondary surgeries at the initial surgical level and no serious adverse events were observed in either group. The present results suggest that 1-level ACDR is safe, although medium- to long-term follow-up is mandatory to further verify the validity of ACDR for Japanese patients.
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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.
Objective To evaluate dysphagia outcomes using the swallowing quality of life (SWAL-QOL) questionnaire between patients undergoing cervical disk arthroplasty (CDA) or anterior cervical discectomy and fusion (ACDF). Methods Patient-reported outcome measures (PROMs) were collected using SWAL-QOL, VAS, NDI, and SF-12 PCS. All measures were recorded preoperatively to 6-month postoperatively. Patients were grouped according to cervical procedure and instrumentation used. Differences in PROMs and SWAL-QOL domains were evaluated by t-test and one-way ANOVA with post-hoc testing, respectively. Simple linear regression was employed to evaluate the relationship between number of levels operated on and postoperative outcomes. Results 161 patients were included. CDA patients had significantly worse SWAL-QOL scores at 6-months. Preoperative VAS neck was significantly worse for patients who underwent either an ACDF procedure with a stand-alone cage or CDA as compared to patients who underwent an ACDF with anterior plating. At 6-months postoperatively, CDA patients reported a significantly worse “fatigue” score compared to ACDF patients. At 6-months postoperatively, ACDF patients reported a significantly better “sleep” scores compared to CDA patients with both recipients of an anterior plate and stand-alone cage reporting significantly better scores compared to the CDA cohort (p=0.024; p
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).
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.
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.
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.
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.
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.
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.
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.
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.
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.
Abstract 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
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.
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.
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)
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.
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.
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.
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.
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.
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.
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.
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).
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.
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.
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.
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.
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.
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)
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 )
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.
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 )
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 )
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.
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 exp