Comparison of 2-year follow-up results of the hybrid surgery using Mobi-C combined with ROI-C and anterior cervical discectomy and fusion for the treatment of contiguous two-level cervical degenerative disc diseases.

Although the Mobi-C artificial disc and the ROI-C cervical cage have been widely used in the treatment of cervical degenerative disc diseases (CDDD), few reports addressed the features of combined application of both devices. This study is aimed at comparing the clinical and radiological outcomes of treating contiguous two-level CDDD using Mobi-C and ROI-C combined in a hybrid surgery (HS) with anterior cervical discectomy and fusion (ACDF) using ROI-C. We reviewed ninety-one patients who underwent HS (n = 48) or ACDF (n = 43) surgery for symptomatic contiguous two-level CDDD. >2 years' clinical and radiological outcomes were reviewed and evaluated retrospectively. At the last follow-up, significant improvement in the mean VAS, JOA, and NDI scores was found both in the HS and ACDF groups (p < 0.05), while the differences between groups were not significant (p > 0.05). The global range of motion (ROM) in the HS group was significantly larger than that in the ACDF group (p < 0.05). The local lordosis improved significantly after surgery in all patients (p < 0.05). Bone resorption and heterotopic ossification (HO) were found after surgery. The result showed that, for the selected patients, HS may provide an alternative approach for the treatment of contiguous two-level CDDD. HS also offers the benefit of both greater global ROM and greater ROM at the Mobi-C index level. Some degree of bone resorption may be an integral component in the early stage of bony fusion in the cage index level. Further studies and long-term follow-up are still needed.

Comparison of Multilevel Cervical Disc Replacement and Multilevel Anterior Discectomy and Fusion: A Systematic Review of Biomechanical and Clinical Evidence.

OBJECTIVE: The aim of this study was to comprehensively compare the clinical and biomechanical efficiency of anterior cervical discectomy and fusion (ACDF) with anterior cervical disc replacement (ACDR) for treatment of multilevel cervical disc disease using a meta-analysis and systematical review. METHODS: A literature search was performed using PubMed, MEDLINE, EMBASE, and the Cochrane Library for articles published between January 1960 and December 2017. Both clinical and biomechanical parameters were analyzed. Statistical tests were conducted by Revman 5.3. Nineteen studies including 10 clinical studies and 9 biomechanical studies were filtered out. RESULTS: The pooled results for clinical efficiency showed that no significant difference was observed in blood loss (P = 0.09; mean difference [MD], 7.38; confidence interval [CI], -1.16 to 15.91), hospital stay (P = 0.33; MD, -0.25; CI, -0.76 to 0.26), Japanese Orthopaedic Association scores (P = 0.63; MD, -0.11; CI, -0.57 to 0.34), visual analog scale (P = 0.08; MD, -0.50; CI, -1.06 to 0.05), and Neck Disability Index (P = 0.33; MD, -0.55; CI, -1.65 to 0.56) between the 2 groups. Compared with ACDF, ACDR did show increased surgical time (P = 0.03; MD, 31.42; CI, 2.71-60.14). On the other hand, ACDR showed increased index range of motion (ROM) (P < 0.00001; MD, 13.83; CI, 9.28-18.39), lower rates of adjacent segment disease (ASD) (P = 0.001; odds ratio [OR], 0.27; CI, 0.13-0.59), complications (P = 0.006; OR, 0.62; CI, 0.45-0.87), and rate of subsequent surgery (P < 0.00001; OR, 0.25; CI, 0.14-0.44). As for biomechanical performance, ACDR maintained index ROM and avoided compensation in adjacent ROM and tissue pressure. CONCLUSIONS: Multilevel ACDR may be an effective and safe alternative to ACDF in terms of clinical and biomechanical performance. However, further multicenter and prospective studies should be conducted to obtain a stronger and more reliable conclusion.

Defining the Ideal Lumbar Total Disc Replacement Patient and Standard of Care.

: Lumbar total disc replacement, now in use since 2004, was determined by the panel to be a standard of care for the treatment of symptomatic single-level lumbar degenerative disc disease in the active patient subpopulation as outlined by the investigational device exemption study criteria. The large body of evidence supporting this statement, including surgeons' experiences, was presented and discussed. Consensus statements focusing on decision-making criteria reflected that efficacy, long-term safety, clinical outcomes with validated measures, and cost-effectiveness should form the basis of decision-making by payers. Diagnostic challenges with lumbar degenerative disc disease patients were discussed among the panel, and it was concluded that although variably used among surgeons, reliable tools exist to appropriately diagnose discogenic back pain.

Challenges and Solutions for Lumbar Total Disc Replacement Implantation.

: Long-term data are now available to support the safety and efficacy of lumbar total disc replacement (TDR). Five-year randomized and controlled trials, meta-analyses, and observational studies support a similar or lower risk of complications with lumbar TDR compared with fusion. The panel concluded that published data on commercially available lumbar TDR devices demonstrate minimal concerns with late-onset complications, and that the risk of adjacent segment degeneration and reoperations can be reduced with lumbar TDR versus fusion. Survey results of surgeon practice experiences supported the evidence, revealing a low rate of complications with TDR. Panelists acknowledged the importance of adhering to selection criteria to help minimize patient complications.

Outcomes Following Multilevel Cervical Disc Arthroplasty in the Young Active Population.

BACKGROUND: Cervical radiculopathy is a common disorder that portends significant morbidity. The presence of radiculopathy can have a debilitating effect on patients as well as a significant economic impact. Active duty military patients with increased physical occupational demands can be significantly impacted by cervical disease. The resulting disability can have a strong negative impact on operational readiness. Several studies have demonstrated comparably good functional outcomes between cervical disc arthroplasty (CDA) and anterior cervical discectomy and fusion for single-level disease. To date, no study has specifically evaluated the functional and occupational outcomes following adjacent 2-level CDA in a young, active patient population as represented by the active duty military population. PURPOSE: To evaluate functional and occupational outcomes following adjacent 2-level CDA for cervical radiculopathy in the U.S. military population. We hypothesized that this population would have excellent symptomatic relief at the cost of a low return to duty rate. METHODS: We performed a case series with prospective follow-up of all patients who underwent adjacent two-level CDA at a single institution from 2011 to 2014. Each patient completed the Neck Disability Index questionnaire to assess functional outcome. Primary outcomes of interest were return to active military duty and complications. RESULTS: Follow-up was available for 18 of 21 (85.7%) patients. At an average follow-up of 21.4 ± 11.1 months, 12 patients (66.7%) reported complete symptomatic relief and were able to return to preoperative levels of function. Average self-reported pain score improved from 8.3 preoperatively to 1.1 postoperatively, and average postoperative Neck Disability Index score was 15.5 compared to 37.0 for those who medically retired. Radiographic analysis did not show any evidence of subsidence, migration of hardware, or heterotopic ossification. The average return to duty time was 9.6 weeks. DISCUSSION: We demonstrate that adjacent two-level CDA is capable of providing predictable symptomatic relief and maintenance of a high-demand preoperative level of function for cervical radiculopathy among a population of young and highly active individuals. Adjacent two-level CDA offers significant relief of symptoms with low risk of complication in a young, active, and high-demand cohort such as the U.S. military. Adjacent two-level CDA can be performed with the expectation of improving function, relieving symptoms, returning to preoperative levels of activity, and maintaining operational readiness.

Bryan Cervical Disc Arthroplasty Versus Anterior Cervical Discectomy and Fusion for Treatment of Cervical Disc Diseases: A Meta-analysis of Prospective, Randomized Controlled Trials.

STUDY DESIGN: A meta-analysis of randomized controlled trials (RCTs). OBJECTIVE: The purpose of this study is to evaluate the effectiveness and safety of Bryan cervical disc arthroplasty (BCDA) as compared with anterior cervical discectomy and fusion (ACDF) for treatment of cervical disc diseases (CDDs). SUMMARY OF BACKGROUND DATA: Previous meta-analyses focused on the comparison of effectiveness and safety between ACDF and CDA, which consisted of various types of disc prostheses. No meta-analysis has been conducted up to present to compare ACDF with a specialized type of artificial cervical disc. METHODS: We comprehensively searched PubMed, EMBASE, and Cochrane Central Register of Controlled Trails for prospective RCTs that compared BCDA with ACDF. The retrieved results were last updated on October 1, 2015, without language restrictions. We classified the trials into subgroups by short-term and midterm follow-up. RESULTS: Eight relevant RCTs involving 1816 individuals were included in the meta-analysis. In overall-term follow-up, the clinical outcomes indicated that BCDA was superior to ACDF considering lower NDI scores (P = 0.0009), greater range of motion at the index level (P = 0.02), and fewer adverse events (P = 0.004), but inferior to ACDF considering operation time (P < 0.00001). There was no significant difference between two groups regarding blood loss (P = 0.43), length of hospital stay (P = 0.12), and secondary surgical procedures (P = 0.20). CONCLUSION: BCDA presented better NDI improvement, greater range of motion at the index level, and fewer adverse events. However, the benefits of BCDA considering blood loss, length of hospital stay, and secondary surgical procedures are still incapable to be proved. More well design studies with longer term follow-up are needed to provide a better evaluation of the effectiveness and safety of the two procedures. LEVEL OF EVIDENCE: 1.

Cost-effectiveness analysis: comparing single-level cervical disc replacement and single-level anterior cervical discectomy and fusion: clinical 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/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.

Cervical total disc replacement with the Mobi-C cervical artificial disc compared with anterior discectomy and fusion for treatment of 2-level symptomatic degenerative disc disease: a prospective, randomized, controlled multicenter clinical trial: clinical article.

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).

An evaluation of information on the internet about a new device: the cervical artificial disc replacement.

STUDY DESIGN: Cross-sectional survey. OBJECTIVE: The objective of this study was to investigate the authorship, content, and quality of information available to the public on the Internet pertaining to the cervical artificial disc replacement device. SUMMARY OF BACKGROUND DATA: The Internet is widely used by patients as an educational tool for health care information. In addition, the Internet is used as a medium for direct-to-consumer marketing. Increasing interest in cervical artificial disc replacement has led to the emergence of numerous Web sites offering information about this procedure. It is thought that patients can be influenced by information found on the Internet. METHODS: A cross section of Web sites accessible to the general public was surveyed. Three commonly used search engines were used to locate 150 (50/search engine) Web sites providing information about the cervical artificial disc replacement. Each Web site was evaluated with regard to authorship and content. RESULTS: Fifty-three percent of the Web sites reviewed were authorized by a private physician group, 4% by an academic physician group, 13% by industry, 16% were news reports, and 14% were not otherwise categorized. Sixty-five percent of Web sites offered a mechanism for direct contact and 19% provided clear patient eligibility criteria. Benefits were expressed in 80% of Web sites, whereas associated risks were described in 35% or less. European experiences were noted in 17% of Web sites, whereas only 9% of Web sites detailed the current US experience. CONCLUSION.: The results of this study demonstrate that much of the content of the Internet-derived information pertaining to the cervical artificial disc replacement is for marketing purposes and may not represent unbiased information. Until we can confirm the content on a Web site to be accurate, patients should be cautioned when using the Internet as a source for health care information related to cervical disc replacement.

Lumbar total disc replacement impingement sensitivity to disc height distraction, spinal sagittal orientation, implant position, and implant lordosis.

STUDY DESIGN: A 3-dimensional finite element model of 2 lumbar motion segments (L4-L5 and L5-S1) was used to evaluate the sensitivity of lumbar total disc replacement (TDR) impingement to disc height distraction, spinal sagittal orientation, implant position, and implant lordosis. The models were implanted with a mobile-bearing TDR and exposed to simulated sagittally balanced erect posture. OBJECTIVE: The objective of this study was to determine the sensitivity of TDR impingement to disc height distraction, implant lordotic angle, implant anterior-posterior position, and spinal orientation relative to the horizon. SUMMARY OF BACKGROUND DATA: TDR has the potential to replace fusion as the "gold standard" for treatment of painful degenerative disc disease. However, complications after TDR have been associated with device impingement and accelerated polyethylene wear. METHODS: A previously developed finite element model of the lumbar spine was altered to include implantation of a mobile-bearing TDR. A series of sensitivity analyses was performed to determine impingement risk. Specifically, spinal orientation, disc height distraction, footplate lordotic angle, and anterior-posterior position were evaluated. RESULTS: Generally, TDR tended to result in an increase in extension rotation and facet contact force during simulated erect posture when compared with the intact models. Impingement risk was sensitive to all of the tested parameters. CONCLUSION: The data from this study indicate that lumbar mobile-bearing TDR impingement is sensitive to disc height distraction, anterior-posterior position, implant lordosis, and spinal sagittal orientation. TDR impingement risk can be minimized by choosing an implant with an appropriate amount of lordosis, not overdistracting the disc space, and taking care not to place the implant too far anterior or posterior.