Article

Revision Rates After Single-Level Cervical Disc Arthroplasty Versus Anterior Cervical Discectomy and Fusion: An Observational Study With 5-Year Minimum Follow-Up

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Abstract

Study Design Retrospective Case-Control study. Objectives This study aimed to compare rates and risk factors for all-cause 5-year revisions for patients undergoing primary single-level cervical disc arthroplasty (CDA) versus Anterior Cervical Discectomy and Fusion (ACDF). Summary of Background Data Prospective studies have compared patient reported outcomes, adjacent segment degeneration, and long-term revisions between CDA and ACDF. Despite these high-level evidence studies, well-powered, large investigations have not been adequately reported. Patients and Methods A nationwide database was queried for patients undergoing primary single level CDA or ACDF for degenerative cervical spine pathology. Further inclusion criteria consisted of patients having a minimum of 5-year follow-up. Patients undergoing CDA were 1:5 ratio matched to patients undergoing ACDF by age, sex, comorbidities, and overall Elixhauser comorbidity index (ECI). Objectives were to compare the rates and risk factors of all-cause 5-year revisions for those undergoing single level CDA versus ACDF. Multivariate logistic regression models computed odds ratios (OR) of revisions within 5 years. P values less than 0.001 were significant. Results A total of 32,953 patients underwent single level CDA (N=5,640) or ACDF (N=27,313) with 5-Year minimum follow-up. The incidence of all cause revisions within 5 years were 1.24% for CDA and 9.23% for ACDF ( P <0.001). After adjustment, patients undergoing single level ACDF had significantly higher odds of all-cause revisions within 5 years (OR: 8.09; P <0.0001). Additional patient specific factors associated with revisions were a history of reported drug abuse (OR: 1.51; P <0.0001), depression (OR: 1.23; P <0.0001), cardiac arrythmias (OR: 1.21; P =0.0008), hypertension (OR: 1.20; P =0.0006), and tobacco use (OR: 1.18; P =0.0003). Conclusions In this study of nearly 33,000 single level cervical spine surgeries with minimum 5-year follow-up, all-cause revision rates were significantly lower for patients undergoing CDA. Surgeons may use this data to counsel patients regarding 5-year revisions following single level CDA or ACDF. Level of Evidence III.

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... 4 However, conventional ACDF internal fixation devices (cage plus plate) are still commonly used in clinical revision surgery (RS) for patients with secondary ASD after primary ACDF. 5 Although the use of single types of these conventional devices is wellestablished in revision surgeries, 5 they are less effective in improving the biomechanics of adjacent segments post-revision compared to a combination of multiple internal fixation devices. 2 they are not ideal for restoring normal biomechanical state of spine. The emerging zero-profile (Zero-P) device is being increasingly applied in ACDF. ...
... 2,3 The incidence of ASD after single-level ACDF is approximately 54%, most commonly occurring at C5/6 segment. 4 However, conventional ACDF internal fixation devices (cage plus plate) are still commonly used in clinical revision surgery (RS) for patients with secondary ASD after primary ACDF. 5 Although the use of single types of these conventional devices is wellestablished in revision surgeries, 5 they are less effective in improving the biomechanics of adjacent segments post-revision compared to a combination of multiple internal fixation devices. 2 they are not ideal for restoring normal biomechanical state of spine. The emerging zero-profile (Zero-P) device is being increasingly applied in ACDF. ...
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Background Tobacco smokers and companies are well aware that smoking increases the risks for cancers, vascular morbidity, and early mortality. This is a review of the plethora of adverse effects chronic smoking has on spinal tissues and spinal surgery. Methods Medline (PubMed) and Google Scholar databases were searched for pertinent literature through keywords related to smoking, spondylosis, and spinal surgery. Results Smoking accelerates spondylosis by impairing spinal tissue vascular supply through atherosclerosis and thrombosis, while inducing local hypoxia, inflammation, proteolysis, and cell loss. It, thus, compromises disc, cartilage, synovium, bone, and blood vessels. It can lead to early surgery, delayed wound healing, increased surgical site infection, failed fusion, more re-operations, and chronic spinal pain. Conclusion There is ample evidence to support surgeons’ declining to operate on chronic smokers. The need for immediate and permanent smoking cessation and its potential benefits should be emphasized for the patient considering or who has undergone spinal surgery.
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Importance: The coronavirus disease 2019 (COVID-19) pandemic and the policies to contain it have been a near ubiquitous exposure in the US with unknown effects on depression symptoms. Objective: To estimate the prevalence of and risk factors associated with depression symptoms among US adults during vs before the COVID-19 pandemic. Design, setting, and participants: This nationally representative survey study used 2 population-based surveys of US adults aged 18 or older. During COVID-19, estimates were derived from the COVID-19 and Life Stressors Impact on Mental Health and Well-being study, conducted from March 31, 2020, to April 13, 2020. Before COVID-19 estimates were derived from the National Health and Nutrition Examination Survey, conducted from 2017 to 2018. Data were analyzed from April 15 to 20, 2020. Exposures: The COVID-19 pandemic and outcomes associated with the measures to mitigate it. Main outcomes and measures: Depression symptoms, defined using the Patient Health Questionnaire-9 cutoff of 10 or higher. Categories of depression symptoms were defined as none (score, 0-4), mild (score, 5-9), moderate (score, 10-14), moderately severe (score, 15-19), and severe (score, ≥20). Results: A total of 1470 participants completed the COVID-19 and Life Stressors Impact on Mental Health and Well-being survey (completion rate, 64.3%), and after removing those with missing data, the final during-COVID-19 sample included 1441 participants (619 participants [43.0%] aged 18-39 years; 723 [50.2%] men; 933 [64.7%] non-Hispanic White). The pre-COVID-19 sample included 5065 participants (1704 participants [37.8%] aged 18-39 years; 2588 [51.4%] women; 1790 [62.9%] non-Hispanic White). Depression symptom prevalence was higher in every category during COVID-19 compared with before (mild: 24.6% [95% CI, 21.8%-27.7%] vs 16.2% [95% CI, 15.1%-17.4%]; moderate: 14.8% [95% CI, 12.6%-17.4%] vs 5.7% [95% CI, 4.8%-6.9%]; moderately severe: 7.9% [95% CI, 6.3%-9.8%] vs 2.1% [95% CI, 1.6%-2.8%]; severe: 5.1% [95% CI, 3.8%-6.9%] vs 0.7% [95% CI, 0.5%-0.9%]). Higher risk of depression symptoms during COVID-19 was associated with having lower income (odds ratio, 2.37 [95% CI, 1.26-4.43]), having less than $5000 in savings (odds ratio, 1.52 [95% CI, 1.02-2.26]), and exposure to more stressors (odds ratio, 3.05 [95% CI, 1.95-4.77]). Conclusions and relevance: These findings suggest that prevalence of depression symptoms in the US was more than 3-fold higher during COVID-19 compared with before the COVID-19 pandemic. Individuals with lower social resources, lower economic resources, and greater exposure to stressors (eg, job loss) reported a greater burden of depression symptoms. Post-COVID-19 plans should account for the probable increase in mental illness to come, particularly among at-risk populations.
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Objective: Whether cervical disc arthroplasty (CDA) is superior to anterior cervical discectomy and fusion (ACDF) remains controversial, especially in relation to long-term results. The present study aimed to evaluate the long-term safety and efficiency of CDA and ACDF for cervical disc disease. Methods: We performed this study according to the Cochrane methodology. An extensive search was undertaken in PubMed, Embase, and Cochrane databases up to 1 June 2019 using the following key words: "anterior cervical fusion," "arthroplasty," "replacement" and "artificial disc". RevMan 5.3 (Cochrane, London, UK) was used to analyze data. Safety and efficiency outcome measures included the success rate, functional outcome measures, adverse events (AE), adjacent segment degeneration (ASD), secondary surgery, and patients' satisfaction and recommendation rates. The OR and MD with 95% confidence interval (CI) were used to evaluate discontinuous and continuous variables, respectively. The statistically significant level was set at P < 0.05. Results: A total of 11 randomized controlled trials with 3505 patients (CDA/ACDF: 1913/1592) were included in this meta-analysis. Compared with ACDF, CDA achieved significantly higher overall success (2.10, 95% CI [1.70, 2.59]), neck disability index (NDI) success (1.73, 95% CI [1.37, 2.18]), neurological success (1.65, 95% CI [1.24, 2.20]), patients' satisfaction (2.14, 95% CI [1.50, 3.05]), and patients' recommendation rates (3.23, 95% CI [1.79, 5.80]). Functional outcome measures such as visual analog score neck pain (-5.50, 95% CI [-8.49, -2.52]) and arm pain (-3.78, 95% CI [-7.04, -0.53]), the Short Form-36 physical component score (SF-36 PCS) (1.93, 95% CI [0.53, 3.32]), and the Short Form-36 mental component score (SF-36 MCS) (2.62, 95% CI [0.95, 4.29]), revealed superiority in the CDA group. CDA also achieved a significantly lower rate of symptomatic ASD (0.46, 95% CI [0.34, 0.63]), total secondary surgery (0.50, 95% CI [0.29, 0.87]), secondary surgery at the index level (0.46, 95% CI [0.29, 0.74]), and secondary surgery at the adjacent level (0.37, 95% CI [0.28, 0.49]). However, no significant difference was found in radiological success (1.35, 95% CI [0.88, 2.08]), NDI score (-2.88, 95% CI [-5.93, 0.17]), total reported AE (1.14, 95% CI [0.92, 1.42]), serious AE (0.89, 95% CI [0.71, 1.11]), device/surgery-related AE (0.90, 95% CI [0.68, 1.18]), radiological superior ASD (0.63, 95% CI [0.28, 1.43]), inferior ASD (0.45, 95% CI [0.19, 1.11]), and work status (1.33, 95% CI [0.78, 2.25]). Furthermore, subgroup analysis showed different results between US and non-US groups. Conclusion: Our study provided further evidence that compared to ACDF, CDA had a higher long-term clinical success rate and better functional outcome measurements, and resulted in less symptomatic ASD and fewer secondary surgeries. However, worldwide multicenter RCT with long-term follow up are still needed for further evaluation in the future.
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Purpose: This meta-analysis of randomized controlled trials (RCTs) aims to evaluate the efficacy and safety in cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion (ACDF) for treating cervical degenerative disc diseases (CDDDs). Methods: The authors searched RCTs in the electronic databases (Cochrane Central Register of Controlled Trials, PubMed, EMBASE, Medline, Embase, Springer Link, Web of Knowledge, OVID and Google Scholar) from their establishment to march 2016 without language restrictions. We also manually searched the reference lists of articles and reviews for possible relevant studies. Researches on CDA versus ACDF in CDDDs were selected in this meta-analysis. The quality of all studies was assessed and effective data was pooled for this meta-analysis. Outcome measurements were surgical parameters (operative time, blood loss, and length of hospital stay), clinical indexes [neck disability index (NDI), neurological success, range of motion (ROM), Visual Analogue Score (VAS)], complications [the number of adverse events, adjacent segment disease (ASD), and reoperation]. Subgroup analysis, sensitivity analysis, and publication bias assessment were also performed, respectively. The meta-analysis was performed with software revman 5.3. Results: 37 articles (20 RCTs) with a total 4004 patients (2212 in the CDA and 1792 in the ACDF) met inclusion criteria. Eight types of disc prostheses were used in the included studies. Patients were followed up for at least 2 years in all the studies. No statistically significant differences were found between CDA and ACDF for blood loss [SMD -0.02; 95 % CI (-0.20, 0.17)], length of hospital stay [MD -0.06; 95 % CI (-0.19, 0.06)]. Statistical differences were found between operative time [MD 14.22; 95 % CI (6.73, 21.71)], NDI [SMD -0.27; 95 % CI (-0.43, -0.10)], neurological success [RR 1.13; 95 % CI (1.08, 1.18)], ROM [MD 6.72; 95 % CI (5.72, 7.71)], VAS of neck [SMD -0.40; 95 % CI (-0.75, -0.04)], VAS of arm [SMD -0.55; 95 % CI (-1.04, -0.06)], the rate of adverse events [RR 0.72 95 % CI (0.53, 0.96)], the rate of ASD [RR 0.62; 95 % CI (0.43, 0.88)], and reoperation [RR 0.50; 95 % CI (0.39, 0.63)]. Subgroup analysis stratified by different types of disc prostheses was also performed. Conclusions: CDA is associated with higher clinical indexes and fewer complications than ACDF, indicating that it is a safe and effective treatment for CDDDs. However, the operative time of CDA is longer than ACDF. Because of some limitations, these findings should be interpreted with caution. Additional studies are needed. Large, definitive RCTs are needed.
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Object: Cervical total disc replacement (TDR) is intended to treat neurological symptoms and neck pain associated with degeneration of intervertebral discs in the cervical spine. Anterior cervical discectomy and fusion (ACDF) has been the standard treatment for these indications since the procedure was first developed in the 1950s. While TDR has been shown to be a safe and effective alternative to ACDF for treatment of patients with degenerative disc disease (DDD) at a single level of the cervical spine, few studies have focused on the safety and efficacy of TDR for treatment of 2 levels of the cervical spine. The primary objective of this study was to rigorously compare the Mobi-C cervical artificial disc to ACDF for treatment of cervical DDD at 2 contiguous levels of the cervical spine. Methods: This study was a prospective, randomized, US FDA investigational device exemption pivotal trial of the Mobi-C cervical artificial disc conducted at 24 centers in the US. The primary clinical outcome was a composite measure of study success at 24 months. The comparative control treatment was ACDF using allograft bone and an anterior plate. A total of 330 patients were enrolled, randomized, and received study surgery. All patients were diagnosed with intractable symptomatic cervical DDD at 2 contiguous levels of the cervical spine between C-3 and C-7. Patients were randomized in a 2:1 ratio (TDR patients to ACDF patients). Results: A total of 225 patients received the Mobi-C TDR device and 105 patients received ACDF. At 24 months only 3.0% of patients were lost to follow-up. On average, patients in both groups showed significant improvements in Neck Disability Index (NDI) score, visual analog scale (VAS) neck pain score, and VAS arm pain score from preoperative baseline to each time point. However, the TDR patients experienced significantly greater improvement than ACDF patients in NDI score at all time points and significantly greater improvement in VAS neck pain score at 6 weeks, and at 3, 6, and 12 months postoperatively. On average, patients in the TDR group also maintained preoperative segmental range of motion at both treated segments immediately postoperatively and throughout the study period of 24 months. The reoperation rate was significantly higher in the ACDF group at 11.4% compared with 3.1% for the TDR group. Furthermore, at 24 months TDR demonstrated statistical superiority over ACDF based on overall study success rates. Conclusions: The results of this study represent the first available Level I clinical evidence in support of cervical arthroplasty at 2 contiguous levels of the cervical spine using the Mobi-C cervical artificial disc. These results continue to support the use of cervical arthroplasty in general, but specifically demonstrate the advantages of 2-level arthroplasty over 2-level ACDF. Clinical trial registration no.: NCT00389597 (ClinicalTrials.gov).
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Background Cervical total disk replacement (TDR) is intended to address pain and preserve motion between vertebral bodies in patients with symptomatic cervical disk disease. Two-year follow-up for the ProDisc-C (Synthes USA Products, LLC, West Chester, Pennsylvania) TDR clinical trial showed non-inferiority versus anterior cervical discectomy and fusion (ACDF), showing superiority in many clinical outcomes. We present the 4-year interim follow-up results.
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Study Design A systematic review with meta-analysis of randomized controlled trials and comparative retrospective cohort studies. Objective The purpose of this study is to compare 10-year outcomes of cervical disc arthroplasty with that of anterior cervical discectomy and fusion for the treatment of cervical degenerative disc disease (CDDD). Summary of Background Data ACDF is a gold standard for the treatment of CDDD. However, the loss of motion at the operated level may accelerate adjacent segment disease. The preservation of motion with CDA attempts to prevent this complication of cervical fusion. Short and midterm data reveal comparable results for CDA versus ACDF, however, long-term results are unknown. Methods A systematic review with meta-analysis was performed to determine if CDA had improved outcomes compared to ACDF at 10-year follow-up. PubMed and Web of Science database searches through 2023 were performed to identify randomized controlled trials and comparative retrospective cohort studies involving treatment of one or two-level CDDD. Results Six studies were eligible for analysis. CDA had significantly improved NDI scores, VAS scores for pain, and JOA scores ( P < 0.05), however, none of these met minimal clinically important differences (MCID). CDA had significantly fewer secondary surgeries and adverse events ( P < 0.05), however, these did not meet MCID. There were no significant differences in neurological success. Conclusions We found that significantly fewer secondary surgeries and adverse events were seen after CDA than after ACDF at 10-year follow-up. CDA had statistically, but not clinically, improved NDI, VAS, and JOA scores in comparison to ACDF. CDA was not statistically different from ACDF in terms of successful neurologic outcome.
Article
Study design: Descriptive epidemiologic study. Objective: To compare trends in utilization and predictive factors for single-level cervical disc arthroplasty (CDA) relative to anterior cervical discectomy and fusion (ACDF) over the years. Background: CDA is an alternative to ACDF for the treatment of cervical spine pathologies. With both procedures performed for similar indications, controversy on best practice exists. Methods: Patients who underwent single-level CDA or ACDF were identified in the 2010 through 2021 PearlDiver M151Ortho dataset. The yearly number of CDAs performed and proportionality were assessed. Predictive patient factors for undergoing CDA as opposed to ACDF were determined. Kaplan Meyer survival analysis with an endpoint of cervical spine reoperation compared 5-year outcomes between CDA and ACDF. Results: From 2010-2021, 19,301 single-level CDAs and 181,476 single-level ACDFs were identified. The proportional utilization of CDA relative to ACDF increased from 4.00% in 2010 to 14.15% in 2018 (P<0.0001), after which there was a plateau between 2018 and 2021 where proportional utilization was 14.47% (P=0.4654). Multivariate analysis identified several predictors of undergoing CDA rather than ACDF, including: younger age (odds ratio [OR] per decade decrease 1.72), having surgery performed in the Midwest, Northeast, or West (relative to South, OR 1.16, 1.13, 2.26, respectively), having Commercial insurance (relative to Medicare, OR 1.75), and having surgery performed by an orthopedic surgeon (relative to neurological surgeon, OR 1.54) (P<0.0001 for each). There was no statistically significant difference in 5-year survival to further cervical spine surgery between CDA and ACDF at five years (97.6% vs. 97.7%, P=0.4249). Conclusion: While the use of CDA relative to ACDF rose from 2010 to 2018, its use has subsequently plateaued between 2018 and 2021 and remained a relatively low percent of the single level anterior cervical surgeries performed (14.47% in 2021). Causes for such changes in trend are unclear.
Article
Objectives Despite lack of nationwide Medicare Coverage by the Centers for Medicare and Medicaid Services, the utilization of cervical disc arthroplasty (CDA) has risen in popularity. The purpose was to compare primary and revision cervical disc arthroplasty (CDA) from 2010 to 2020 with respect to: 1) utilization trends, 2) patient demographics; and 3) healthcare reimbursements. Methods Using the PearlDiver database, we studied patients undergoing primary and revision CDA for degenerative cervical disc pathology from 2010 to 2020. Endpoints of the study were to compare patient demographics (including Elixhauser Comorbidity Index (ECI)), annual utilization trends, lengths of stay (LOS), and reimbursements. Chi-square analyses compared patient demographics. T-tests compared LOS and reimbursements. A linear regression was used to evaluate for trends in procedural volume over time. P values <0.05 were statistically significant. Results In total, 15,306 patients underwent primary (n= 14,711) or revision CDA (n= 595). Patients undergoing revisions had a greater comorbidity burden (mean ECI= 4.16 vs 2.91; p<0.0001). From 2010 to 2020, primary CDA utilization increased by 413% (447 vs 2297 procedures; p<0.001); comparatively revision CDA utilization increased by 141% (32 vs 77 procedures; p<0.001). Mean LOS were greater for revision cases (1.37 vs 3.30 days, p<0.001). Reimbursements for revisions were higher on the day of surgery (5,585vs5,585 vs 13,692) and within 90 days of surgery (7,031vs7,031 vs 19,340), all p<0.0001. Conclusions There is a high rate of annual growth in CDA utilization and revision CDA in the United States. Reimbursements for revision CDA were more than double primary cases.
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Biomechanical studies have demonstrated that cervical fusion results in increased motion and intradiscal pressures at adjacent levels. Cervical disc arthroplasty (CDA) is an alternative treatment for cervical radiculopathy and myelopathy resulting from degenerative disc disease. By maintaining segmental motion, surgeons hope to avoid some of the primary drawbacks of anterior cervical discectomy and fusion (ACDF), such as pseudoarthrosis and adjacent segment disease. First introduced in the 1960s, CDA has evolved over the years with changes to implant geometry and materials. Early devices produced suboptimal outcomes, but more recent generations of implants have shown long-term outcomes rivaling or even surpassing those of ACDF. In this article, the rationale for CDA as well as the history of such devices is reviewed.
Article
Anterior cervical diskectomy and fusion has been and remains the benchmark surgical management of cervical degenerative disk disease. However, an increased use of cervical disk arthroplasty (CDA) has been found in the past few years. The purported benefits of CDA included preserved motion, less adjacent-level degeneration, and less morbidity. Short-term results from randomized control trials clearly showed noninferiority of CDA compared with fusion. With long-term comparison data becoming available, results are equivalent and superior in many metrics compared, favoring CDA. Concerns remain regarding the best way to manage CDA failures. Nonetheless, appropriate patient selection and adherence to strict surgical technique make CDA a viable treatment.
Article
Study design: Markov model analysis. Objective: The aim of this study was to determine the 7-year cost-effectiveness of single-level anterior cervical discectomy and fusion (ACDF) versus cervical disc replacement (CDR) for the treatment of cervical disc degeneration. Summary of background data: Both ACDF and CDR are acceptable surgical options for the treatment of symptomatic cervical disc degeneration. Past studies have demonstrated at least equal effectiveness of CDR when compared with ACDF in large randomized Investigational Device Exemption (IDE) studies. Short-term cost-effectiveness analyses at 5 years have suggested that CDR may be the preferred treatment option. However, adjacent segment disease and other postoperative complications may occur after 5 years following surgery. Methods: A Markov model analysis was used to evaluate data from the LDR Mobi-C IDE study, incorporating five Markov transition states and seven cycles with each cycle set to a length of 1 year. Transition state probabilities were determined from complication rates, as well as index and adjacent segment reoperation rates from the IDE study. Raw SF-12 data were converted to health state utility values using the SF-6D algorithm for 174 CDR patients and 79 ACDF patients. Results: Assuming an ideal operative candidate who is 40-years-old and failed appropriate conservative care, the 7-year cost was 103,924forACDFand103,924 for ACDF and 105,637 for CDR. CDR resulted in the generation of 5.33 quality-adjusted life-years (QALYs), while ACDF generated 5.16 QALYs. Both ACDF and CDR were cost-effective, but the incremental cost-effectiveness ratio (ICER) was 10,076/QALYinfavorofCDR,whichwaslessthanthewillingnesstopay(WTP)thresholdof10,076/QALY in favor of CDR, which was less than the willingness-to-pay (WTP) threshold of 50,000/QALY. Conclusion: ACDF and CDR are both cost-effective strategies for the treatment of cervical disc degeneration. However, CDR is the more cost-effective procedure at 7 years following surgery. Further long-term studies are needed to validate the findings of this model. Level of evidence: 1.
Article
Background: Spinal fusion surgery is performed about half a million times per year in the United States and millions more worldwide. It is an effective method for reducing pain, increasing stability, and correcting deformity in patients with various spinal conditions. In addition to being a well-established risk factor for a variety of medical conditions, smoking has deleterious effects on the bone healing of spinal fusions. This review aims to specifically analyze the ways in which smoking affects the outcomes of spinal fusion and to explore ways in which these negative consequences can be avoided. Purpose: This article provides a complete understanding of the ways smoking affects spinal fusion from a biochemical and clinical perspective. Recommendations are also provided for ways in which surgeons can limit patient exposure to the most serious negative outcomes associated with cigarette smoking. Study design/setting: This study was a retrospective literature review done using the NCBI database. The research was compiled at NYU Hospital for Joint Diseases and the NYU Center for Musculoskeletal Care. Methods: A comprehensive literature review was done spanning research on a variety of subjects related to smoking and spinal fusion surgery. The biochemistry of smoking and fusion healing were examined in great detail. In addition, both in vivo animal studies and human clinical studies were evaluated to explore fusion success related to the effects of smoking and its biochemical factors on spinal fusion surgery. Results: Smoking significantly increases the risk of pseudoarthrosis for patients undergoing both lumbar and cervical fusions. In addition to nonunion, smoking also increases the risk of other perioperative complications such as infection, adjacent-segment pathology, and dysphagia. Treatment options are available that can be explored to reduce the risk of smoking-related morbidity, such as nicotine replacement therapy and use of bone morphogenetic proteins (BMPs). Conclusions: It has been clearly demonstrated from both a biochemical and clinical perspective that smoking increases the rate of perioperative complications for patients undergoing spinal fusion surgery, particularly pseudoarthosis. It has also been shown that there are certain approaches that can reduce the risk of morbidity. The most important recommendation is smoking cessation for four weeks after surgery. In addition, patients may be treated with certain surgical techniques, including the use of BMPs, to reduce the risk of pseudoarthrosis. Lastly, nicotine replacement therapy is an area of continued interest in relation to spinal fusion outcomes and more research needs to be done to determine its efficacy moving forward.
Article
Background: Anterior cervical discectomy and fusion (ACDF) is a commonly performed procedure for patients with symptomatic degenerative conditions of the cervical spine. The objective is to assess the impact of preoperative depression and other baseline characteristics on patient reported clinical outcomes following ACDF surgery based on the experience at our institution. Methods: This was a retrospective cohort study of some patients undergoing ACDF at a single institution from 2012 to 2014. Ninety-three patients that underwent an ACDF procedure were included. The primary outcome measure was post-operative Nurick score. Results: Sixteen (17.2%) patients had a formal diagnosis of depression compared to 77 (82.8%) patients without depression. On univariate analysis, patients with depression had statistically significantly higher Nurick scores compared to patients without depression after surgery (coefficient =0.55, 95% CI: 0.21-0.90, P=0.002). On multivariate analysis, there was a trend toward higher postoperative Nurick scores in patients that had depression (coefficient =0.31, 95% CI: -0.01-0.63, P=0.057). Conclusions: This small retrospective study reveals an inverse relationship between preoperative depression and functional outcome. Further research should be performed to investigate this relationship and to investigate if treating depression can improve postoperative outcomes.
Article
Study design: Meta-analysis of randomized controlled trials. Objective: To evaluate the reported rate of adjacent segment disease (ASD) of cervical disc arthroplasty (CDA) compared with anterior cervical discectomy and fusion (ACDF). Summary of background data: Motion-maintaining technologies such as CDA have developed rapidly because of the concern of ASD. To date, however, it still has been under debate whether CDA is superior to ACDF regarding the incidence of ASD. Methods: We comprehensively searched PubMed, EMBASE and Cochrane Central Register of Controlled Trails for prospective randomized controlled trials (RCTs) that reported the incidence of ASD between CDA with ACDF. The retrieved results were last updated on November 20, 2015 without language restrictions. Two independent authors selected qualified studies, assessed methodological quality and extracted requisite data. Results: Fourteen relevant RCTs involving 3235 individuals with a follow-up period of two to seven years were included in the meta-analysis (1696 in CDA group and 1539 in ACDF group). The outcomes indicated that CDA was superior to ACDF considering the lower rate of ASD [risk ratio (RR), 0.57; 95% confidence interval (CI), 0.37 to 0.87; P = 0.009]. And compared with ACDF, there were significantly fewer adjacent segment reoperations in the CDA group (RR, 0.47; CI, 0.32 to 0.70; P = 0.0002). Subgroup analysis stratified by different types of disc prostheses was also performed. Conclusions: CDA was superior to ACDF regarding fewer ASDs and relative reoperations on the basis of available evidence from a meta-analysis of 14 RCTs. CDA may be a better surgical procedure to reduce the incidence of ASD for patients with cervical disc disease compared with ACDF. Further well-designed studies should continue to pay attention to excellent patients with longer term follow-up to evaluate the incidence of ASD of these two procedures. Level of evidence: 1.
Article
Background Anterior cervical discectomy and fusion is a standard surgical treatment for cervical radiculopathy and myelopathy, but reoperations sometimes are performed to treat complications of fusion such as pseudarthrosis and adjacent-segment degeneration. A cervical disc arthroplasty is designed to preserve motion and avoid the shortcomings of fusion. Available evidence suggests that a cervical disc arthroplasty can provide pain relief and functional improvements similar or superior to an anterior cervical discectomy and fusion. However, there is controversy regarding whether a cervical disc arthroplasty can reduce the frequency of reoperations. Questions/purposesWe performed a meta-analysis of randomized controlled trials (RCTs) to compare cervical disc arthroplasty with anterior cervical discectomy and fusion regarding (1) the overall frequency of reoperation at the index and adjacent levels; (2) the frequency of reoperation at the index level; and (3) the frequency of reoperation at the adjacent levels. Methods PubMed, EMBASE, and the Cochrane Register of Controlled Trials databases were searched to identify RCTs comparing cervical disc arthroplasty with anterior cervical discectomy and fusion and reporting the frequency of reoperation. We also manually searched the reference lists of articles and reviews for possible relevant studies. Twelve RCTs with a total of 3234 randomized patients were included. Eight types of disc prostheses were used in the included studies. In the anterior cervical discectomy and fusion group, autograft was used in one study and allograft in 11 studies. Nine of 12 studies were industry sponsored. Pooled risk ratio (RR) and associated 95% CI were calculated for the frequency of reoperation using random-effects or fixed-effects models depending on the heterogeneity of the included studies. A funnel plot suggested the possible presence of publication bias in the available pool of studies; that is, the shape of the plot suggests that smaller negative or no-difference studies may have been performed but have not been published, and so were not identified and included in this meta-analysis. ResultsThe overall frequency of reoperation at the index and adjacent levels was lower in the cervical disc arthroplasty group (6%; 108/1762) than in the anterior cervical discectomy and fusion group (12%; 171/1472) (RR, 0.54; 95% CI, 0.36–0.80; p = 0.002). Subgroup analyses were performed according to secondary surgical level. Compared with anterior cervical discectomy and fusion, cervical disc arthroplasty was associated with fewer reoperations at the index level (RR, 0.50; 95% CI, 0.37–0.68; p < 0.001) and adjacent levels (RR, 0.52; 95% CI, 0.37–0.74; p < 0.001). Conclusions Cervical disc arthroplasty is associated with fewer reoperations than anterior cervical discectomy and fusion, indicating that it is a safe and effective alternative to fusion for cervical radiculopathy and myelopathy. However, because of some limitations, these findings should be interpreted with caution. Additional studies are needed. Level of EvidenceLevel I, therapeutic study.
Article
Study design: A Markov state-transition model was developed to evaluate the cost-effectiveness of anterior cervical discectomy and fusion (ACDF) and cervical disc replacement (CDR) at 5 years. Objective: To determine the cost-effectiveness of ACDF and CDR at 5 years. Summary of background data: ACDF and CDR are surgical options for the treatment of an acute cervical disc herniation with associated myelopathy/radiculopathy. Cost-effectiveness analysis provides valuable information regarding which intervention will lead to a more efficient utilization of health care resources. Methods: Outcome and complication probabilities were obtained from existing literature. Physician costs were based on a fixed percentage of 140% of 2010 Medicare reimbursement. Hospital costs were determined from the Nationwide Inpatient Sample. Utilities were derived from responses to health state surveys (Short Form 36) at baseline and at 5 years from the treatment arms of the ProDisc-C trial. Incremental cost-effectiveness ratios were used to compare treatments. One-way sensitivity analyses were performed on all parameters within the model. Results: CDR generated a total 5-year cost of 102,274,whereasACDFresultedina5yearcostof102,274, whereas ACDF resulted in a 5-year cost of 119,814. CDR resulted in a generation of 2.84 quality-adjusted life years, whereas ACDF resulted in 2.81. The incremental cost-effectiveness ratio was -557,849perqualityadjustedlifeyeargained.CDRremainedthedominantstrategybelowacostof557,849 per quality-adjusted life year gained. CDR remained the dominant strategy below a cost of 20,486. ACDF was found to be a cost-effective strategy below a cost of $18,607. CDR was the dominant strategy when the utility value was above 0.713. CDR remained the dominant strategy assuming an annual complication rate less than 4.37%. Conclusion: ACDF and CDR were both shown to be cost-effective strategies at 5 years. CDR was found to be the dominant treatment strategy in our model. Further long-term studies evaluating the clinical and quality-of-life outcomes of these 2 treatments are needed to further validate the model. Level of evidence: 5.
Article
Object: The authors assess the long-term safety and efficacy of cervical disc replacement with the Prestige Cervical Disc in a prospective, randomized, multicenter trial at 7 years of follow-up. Methods: At 31 investigational sites, 541 patients with single-level cervical disc disease with radiculopathy were randomized to 1 of 2 treatment groups: 276 investigational group patients underwent anterior cervical discectomy and arthroplasty with the Prestige disc, and 265 control group patients underwent anterior cervical discectomy and fusion. Clinical outcomes included Neck Disability Index, the 36-Item Short-Form Health Survey, and neck and arm pain scores. Radiographs were assessed for angle of motion and fusion. Clinical and radiographic outcomes were evaluated preoperatively, intraoperatively, and at 1.5, 3, 6, 12, 24, 36, 60, and 84 months. Results: Of the 541 patients treated, 395 patients (73%; 212 investigational and 183 control patients) completed 7 years of clinical follow-up. Significant improvements achieved by 1.5 months in both groups were sustained at 7 years. In the investigational group, mean Neck Disability Index improvements from preoperative scores were 38.2 and 37.5 at 60 and 84 months, respectively. In the control group, the corresponding means were 33.8 and 31.9. The differences between the investigational and control groups at the 60-month and 84-month periods were significant (p = 0.014 and 0.002, respectively). The overall rates of maintenance or improvement in neurological status in the investigational group were significantly higher: 92.2% and 88.2% at 60 months and 84 months, respectively, compared with 85.7% and 79.7% in the control group (p = 0.017 and 0.011, respectively). At 84 months, the percentage of working patients in the investigational group was 73.9%, and in the control group, 73.1%. Postoperatively, the implant effectively maintained average angular motion of 6.67° at 60 months and 6.75° at 84 months. Cumulative rates for surgery at the index level were lower (p < 0.001) in the investigational group (11 [4.8%] of 276) when compared with the control group (29 [13.7%] of 265) (based on life-table method), and there were statistical differences between the investigational and control groups with specific regard to the rate of subsequent revision and supplemental fixation surgical procedures. Rates for additional surgical procedures that involved adjacent levels were lower in the investigational group than in the control group (11 [4.6%] of 276 vs. 24 [11.9%] of 265, respectively). Conclusions: Cervical disc arthroplasty has the potential for preserving motion at the operated level while providing biomechanical stability and global neck mobility and may result in a reduction in adjacent-segment degeneration. The Prestige Cervical Disc maintains improved clinical outcomes and segmental motion after implantation at 7-year follow-up. Clinical trial registration no. NCT00642876 ( ClinicalTrials.gov ).
Article
Object: In recent years, there has been increased interest in the use of cervical disc replacement (CDR) as an alternative to anterior cervical discectomy and fusion (ACDF). While ACDF is a proven intervention for patients with myelopathy or radiculopathy, it does have inherent limitations. Cervical disc replacement was designed to preserve motion, avoid the limitations of fusion, and theoretically allow for a quicker return to activity. A number of recently published systematic reviews and randomized controlled trials have demonstrated positive clinical results for CDR, but no studies have revealed which of the 2 treatment strategies is more cost-effective. The purpose of this study was to evaluate the cost-effectiveness of CDR and ACDF by using the power of decision analysis. Additionally, the authors aimed to identify the most critical factors affecting procedural cost and effectiveness and to define thresholds for durability and function to focus and guide future research. Methods: The authors created a surgical decision model for the treatment of single-level cervical disc disease with associated radiculopathy. The literature was reviewed to identify possible outcomes and their likelihood following CDR and ACDF. Health state utility factors were determined from the literature and assigned to each possible outcome, and procedural effectiveness was expressed in units of quality-adjusted life years (QALYs). Using ICD-9 procedure codes and data from the Nationwide Inpatient Sample, the authors calculated the median cost of hospitalization by multiplying hospital charges by the hospital-specific cost-to-charge ratio. Gross physician costs were determined from the mean Medicare reimbursement for each current procedural terminology (CPT) code. Uncertainty as regards both cost and effectiveness numbers was assessed using sensitivity analysis. Results: In the reference case, the model assumed a 20-year duration for the CDR prosthesis. Cervical disc replacement led to higher average QALYs gained at a lower cost to society if both strategies survived for 20 years (3042/QALYforCDRvs3042/QALY for CDR vs 8760/QALY for ACDF). Sensitivity analysis revealed that CDR needed to survive at least 9.75 years to be considered a more cost-effective strategy than ACDF. Cervical disc replacement becomes an acceptable societal strategy as the prosthesis survival time approaches 11 years and the $50,000/QALY gained willingness-to-pay threshold is crossed. Sensitivity analysis also indicated that CDR must provide a utility state of at least 0.796 to be cost-effective. Conclusions: Both CDR and ACDF were shown to be cost-effective procedures in the reference case. Results of the sensitivity analysis indicated that CDR must remain functional for at least 14 years to establish greater cost-effectiveness than ACDF. Since the current literature has yet to demonstrate with certainty the actual durability and long-term functionality of CDR, future long-term studies are required to validate the present analysis.
Article
Study design: Prospective randomized clinical trial. Objective: Determine the reasons for, and rates of, secondary surgical intervention up to 5 years at both the index and adjacent levels in patients treated with cervical total disc replacement (TDR) or anterior cervical discectomy and fusion (ACDF). Patients undergoing TDR received ProDisc-C. Summary of background data: Several outcome-based prospective, randomized clinical trials have shown cervical TDR to be equivalent, if not superior, to fusion. The ability of TDR to allow decompression while maintaining motion has led many to suggest that adjacent-level degeneration and reoperation rates may be decreased when compared with fusion. Methods: A total of 209 patients were treated and randomized (TDR, n = 103; ACDF, n = 106) at 13 sites. A secondary surgical intervention at any level was considered a reoperation. Results: At 5 years, patients who received ProDisc-C had statistically significant higher probability of no secondary surgery at the index and adjacent levels than patients who underwent ACDF (97.1% vs. 85.5%, P = 0.0079). No reoperations in patients who received ProDisc-C were performed for implant breakages or device failures. For patients who underwent ACDF, the most common reason for reoperation at the index level was pseudarthrosis, and for patients who underwent both ACDF and TDR, the most common reason for adjacent-level surgery was recurrent neck and/or arm pain. Conclusion: Five-year follow-up of a prospective randomized clinical trial revealed 5-fold difference in reoperation rates when comparing patients who underwent ACDF (14.5%) with patients who underwent TDR (2.9%). These findings suggest the durability of TDR and its potential to slow the rate of adjacent-level disease.
Article
Cervical total disc replacement (CTDR) represents a relatively novel procedure intended to address some of the shortcomings associated with anterior cervical discectomy and fusion (ACDF) by preserving motion at the treated level. This prospective, randomized, multicenter study evaluates the safety and efficacy of a new metal-on-metal CTDR implant (Kineflex|C) by comparing it with ACDF in the treatment of single-level spondylosis with radiculopathy. The study was a prospective, randomized US FDA Investigational Device Exemption (IDE) pivotal trial conducted at 21 centers across the US. The primary clinical outcome measures included the Neck Disability Index (NDI), visual analog scale (VAS) scores, and a composite measure of clinical success. Patients were randomized to CTDR using the Kineflex|C (SpinalMotion, Inc.) cervical artificial disc or ACDF using structural allograft and an anterior plate. A total of 269 patients were enrolled and randomly assigned to either CTDR (136 patients) or to ACDF (133 patients). There were no significant differences between the CTDR and ACDF groups when comparing operative time, blood loss, length of hospital stay, or the reoperation rate at the index level. The overall success rate was significantly greater in the CTDR group (85%) compared with the ACDF group (71%) (p = 0.05). In both groups, the mean NDI scores improved significantly by 6 weeks after surgery and remained significantly improved throughout the 24-month follow-up (p < 0.0001). Similarly, the VAS pain scores improved significantly by 6 weeks and remained significantly improved through the 24-month follow-up (p < 0.0001). The range of motion (ROM) in the CTDR group decreased at 3 months but was significantly greater than the preoperative mean at 12- and 24-month follow-up. The ROM in the ACDF group was significantly reduced by 3 months and remained so throughout the follow-up. Adjacent-level degeneration was also evaluated in both groups from preoperatively to 2-year follow-up and was classified as none, mild, moderate, or severe. Preoperatively, there were no significant differences between groups when evaluating the different levels of adjacent-level degeneration. At the 2-year follow-up, there were significantly more patients in the ACDF group with severe adjacent-level radiographic changes (p < 0.0001). However, there were no significant differences between groups in adjacent-level reoperation rate (7.6% for the Kineflex|C group and 6.1% for the ACDF group). Cervical total disc replacement allows for neural decompression and clinical results comparable to ACDF. Kineflex|C was associated with a significantly greater overall success rate than fusion while maintaining motion at the index level. Furthermore, there were significantly fewer Kineflex|C patients showing severe adjacent-level radiographic changes at the 2-year follow-up. These results from a prospective, randomized study support that Kineflex|C CTDR is a viable alternative to ACDF in select patients with cervical radiculopathy.
Article
Background context: Advancements in the philosophy of "motion preservation" have led to the use of total disc arthroplasty (TDA) as an alternative to fusion for degenerative disc disease (DDD) in the cervical spine. A commonly proposed theory is that TDA could reduce the incidence of adjacent segment disease. All the published clinical studies for TDA discuss the "equal efficacy" results of different investigational device exemption (IDE) trials between TDA and anterior cervical discectomy and fusion (ACDF) but have not addressed the issue of adjacent segment disease. Purpose: To present the comparison of outcome data with respect to clinical success rates, symptom-free period, and incidence of adjacent segment disease in 93 patients with one- and two-level cervical DDD treated with TDA or ACDF in three different Food and Drug Administration (FDA) investigational trials. Study design: Prospective, randomized, FDA IDE trials. Patient sample: Ninety-three patients with established symptomatic one-or two-level cervical disc disease who failed to respond to conservative treatment were randomized to receive TDA (59) or ACDF (34) as part of clinical trials involving three different artificial discs at our institution. Subjects were blind to the assigned group until after the surgery. Outcome measures: Visual analog pain score (VAS), Neck Disability Index, and cervical spine radiographs were collected at 6 weeks and at 3, 6, 12, 24, 36, and 48 months after surgery. Method: Success of the index surgery was assessed based on outcome measures at the seven data points. Success was defined as reduction by more than 30 points in both VAS and Neck Disability Index, absence of neurological deficits, and no further intervention at the index level. Adjacent segment disease was established by radiology, neurophysiology, and subsequent interventions administered to the patients. Results: At median follow-up of 37 months (range, 24-49 months), 64 (25 ACDF and 39 TDA) patients satisfied the criteria for clinical success. Neck Disability Index was a better predictor of outcome than pain score (p<.05). Sixteen percent of TDA patients and 18% ACDF patients developed adjacent segment degeneration and were treated actively (p=.3). Concurrent lumbar DDD significantly increased the risk of adjacent segment degeneration (p=.01). Age, gender, smoking habits, and number of levels at index surgery had no predictive value. Conclusion: Total disc arthroplasty is equivalent to ACDF for providing relief from symptoms in the treatment of one- and two-level DDD of cervical spine. The risk of developing adjacent segment degeneration is equivalent after both procedures but is significantly higher in patients with concurrent DDD in lumbar spine.
Article
The purpose of this study was to determine long-term clinical outcomes in patients undergoing anterior cervical surgery in which a cervical disc prosthesis was used to treat single-level degenerative cervical disc disease. In this prospective, nonblinded study, 541 patients at 32 investigational sites were randomly assigned to 1 of 2 treatment groups. The results of the investigational group, in which patients received the Prestige disc prosthesis, were compared with those of the control group, in which patients underwent an instrumented interbody fusion. Data were collected preoperatively, intraoperatively, and at 1.5, 3, 6, 12, 24, 36, and 60 months postoperatively. To date, 271 patients have completed 5 years of clinical follow-up (144 investigational and 127 control patients). Significant improvements in Neck Disability Index (NDI) scores, Physical Component Summary scores of the 36-Item Short-Form Health Survey, and neck and arm pain scores were achieved by 1.5 months in both groups and sustained at 5 years. The mean NDI improvements from preoperative scores were 35.4, 36.3, and 38.4 at 24, 36, and 60 months, respectively, in the investigational group. The corresponding mean NDI improvements were 33.9, 31.3, and 34.1 in the control group. The intergroup differences at both 36 and 60 months were significant (p = 0.008 and 0.022, respectively). The overall rates of maintenance or improvement in neurological status in the investigational group were 91.6%, 92.8%, and 95.0%, respectively, at 24, 36, and 60 months compared with 83.6%, 83.2%, and 88.9% in the control group (p = 0.006, 0.004, and 0.051, respectively). The implant effectively maintained angular motion, averaging more than 7.3 degrees at 36 months and 6.5 degrees at 60 months after surgery. No implant migration was observed up to 60 months. There were statistically significant differences between the investigational and control groups with regard to the rate of revision and supplemental fixation surgical procedures performed subsequent to the index procedure. Additional surgical procedures for adjacent-segment disease were observed in both treatment groups. Rates for surgery at adjacent levels trended lower in the investigational group (8 patients [11 surgeries]) compared with those in the control group (13 patients [16 surgeries]), but the differences were not statistically significant (p = 0.376). Some of the second surgeries involved both index and adjacent levels. The Prestige disc maintains improved clinical outcomes and segmental motion after implantation at 5-year follow-up.
Article
Enthusiasm for cervical disc arthroplasty is based on the premise that motion-preserving devices attenuate the progression of adjacent-segment disease (ASD) in the cervical spine. Arthrodesis, on the other hand, results in abnormal load transfer on adjacent segments, leading to the acceleration of ASD. It has taken several decades of pioneering work to produce clinically relevant devices that mimic the kinematics of the intervertebral disc. The goal of this work is to trace the origins of cervical arthroplasty technology and highlight the attributes of devices currently available in the market.
Article
This study attempts to develop a comprehensive set of comorbidity measures for use with large administrative inpatient datasets. The study involved clinical and empirical review of comorbidity measures, development of a framework that attempts to segregate comorbidities from other aspects of the patient's condition, development of a comorbidity algorithm, and testing on heterogeneous and homogeneous patient groups. Data were drawn from all adult, nonmaternal inpatients from 438 acute care hospitals in California in 1992 (n = 1,779,167). Outcome measures were those commonly available in administrative data: length of stay, hospital charges, and in-hospital death. A comprehensive set of 30 comorbidity measures was developed. The comorbidities were associated with substantial increases in length of stay, hospital charges, and mortality both for heterogeneous and homogeneous disease groups. Several comorbidities are described that are important predictors of outcomes, yet commonly are not measured. These include mental disorders, drug and alcohol abuse, obesity, coagulopathy, weight loss, and fluid and electrolyte disorders. The comorbidities had independent effects on outcomes and probably should not be simplified as an index because they affect outcomes differently among different patient groups. The present method addresses some of the limitations of previous measures. It is based on a comprehensive approach to identifying comorbidities and separates them from the primary reason for hospitalization, resulting in an expanded set of comorbidities that easily is applied without further refinement to administrative data for a wide range of diseases.
Article
Although the prevalence of indications and contraindications to lumbar total disc replacement (TDR) has been evaluated, no study to date has quantified the potential candidacy for cervical disc replacement in practice. To report the potential candidacy rate for cervical TDR from both an academic and private practice spine surgery setting. Retrospective case series. Patient record review of 167 consecutive patients who underwent cervical spine surgery by 1 of 2 orthopedic spine surgeons between January 1, 2003 and January 1, 2005. Evaluation of potential candidacy for cervical TDR, with emphasis on both contraindications and indications. In this study, we used the published contraindications and indications listed in trials of four different cervical disc arthroplasty devices: ProDisc-C (Synthes Spine, West Chester, PA), PRESTIGE LP (Medtronik Sofamor Danek, Memphis, TN), Bryan Cervical Disc prosthesis (Medtronik Sofamor Danek, Memphis, TN), and Porous Coated Motion (PCM; Cervitech, Rockaway, NJ). The proportion of patients who met both inclusion and exclusion criteria was calculated. We also examined the proportion of patients who would be candidates for cervical TDR if the indications were expanded to include the treatment for adjacent segment disease (ASD). Of the 167 patients (mean age 50.8 years, range 20-89 years) reviewed, 91.6% (153/167) had fusion surgery and 8.4% (14/167) had nonfusion surgery. Fifty-seven percent (95/167) had absolute contraindications to cervical TDR, and within this group the average number of contraindications was 2.1 (SD=1.2, range 0-5). Forty-three percent (72/167) met the strict inclusion criteria, and had no exclusion criteria. If the indications were expanded to include treatment for ASD, an additional 4.2% (7/167) of the patients would have qualified as candidates for cervical TDR. Compared with lumbar TDR, total disc replacement may have a larger potential role in the treatment of cervical degenerative conditions, as 43% of patients would have met the strict criteria for TDR candidacy, or 47% if the indications were expanded to include treatment for ASD.