Twenty-Year Radiographic Outcomes Following Single-Level Cervical Disc Arthroplasty: Results From a Prospective Randomized Controlled Trial.

STUDY DESIGN: Prospective randomized controlled trial. OBJECTIVE: Compare range of motion (ROM) and adjacent segment degeneration (ASD) following cervical disc arthroplasty (CDA) versus anterior cervical discectomy and fusion (ACDF) at 20-year follow-up. SUMMARY OF BACKGROUND DATA: Anterior cervical discectomy and fusion is the standard of treatment for single-level cervical disc degeneration causing radiculopathy. CDA is claimed to reduce shear strain, and adjacent-level ROM changes are hypothesized to hasten ASD with ACDF. MATERIALS AND METHODS: This study collected data on 47 patients randomized to ACDF or CDA. Lateral cervical spine radiographs were evaluated preoperatively, postoperatively, and at 20 years for alignment, ROM, ASD, and heterotopic ossification. RESULTS: Eighty-two percent (18/22) of CDA patients and 84% (21/25) of ACDF patients followed up at 20 years. At 20 years, total cervical (C2-C7) ROM was statistically different between the CDA and fusion groups (47.8° vs . 33.4°, P =0.005). Total cervical ROM was not significantly different between preoperative and 20-year periods following CDA (45.6° vs . 47.4°, P =0.772) or ACDF (40.6° vs . 33.0°, P =0.192). Differences in postoperative and 20-year index-level ROM following CDA were not significant (10.1° vs . 10.2°, P =0.952). Final ASD grading was statistically lower following CDA versus ACDF at both adjacent levels ( P <0.005). Twenty-year adjacent-level ossification development was increased following ACDF versus CDA ( P <0.001). Polyethylene mean thickness decreased from 9.4 mm immediately postoperatively to 9.1 mm at 20-year follow up ( P =0.013). Differences in adjacent-level ROM from preoperative to 20-year follow-up in both the ACDF and CDA groups did not meet statistical significance ( P >0.05). CONCLUSIONS: Cervical disc arthroplasty maintains index-level and total cervical ROM with very long-term follow-up. Total cervical ROM was higher at 20 years in CDA relative to ACDF. CDA results in lower rates of ASD and adjacent-level ossification development than ACDF.

20-year Clinical Outcomes of Cervical Disk Arthroplasty: A Prospective, Randomized, Controlled Trial.

STUDY DESIGN: Prospective, randomized, controlled trial. OBJECTIVE: To compare clinical outcomes of anterior cervical discectomy and fusion (ACDF) and cervical disk arthroplasty (CDA) at 20 years. SUMMARY OF BACKGROUND DATA: Concern for adjacent-level disease after ACDF prompted the development of CDA. MATERIALS AND METHODS: Forty-seven patients with single-level cervical radiculopathy were randomized to either BRYAN CDA or ACDF for a Food and Drug Administration Investigational Device Exemption trial. At 20 years, patient-reported outcomes, including visual analog scales (VAS) for neck and arm pain, neck disability index (NDI), and reoperation rates, were analyzed. RESULTS: Follow-up rate was 91.3%. Both groups showed significantly better NDI, VAS arm pain, and VAS neck pain scores at 20 years versus preoperative scores. Comparing CDA versus ACDF, there was no difference at 20 years in mean scores for NDI [11.1 (SD 14.1) vs. 19.9 (SD 17.2), P =0.087], mean VAS arm pain [0.9 (SD 2.4) vs. 2.3 (SD 2.8), P =0.095], or mean VAS neck pain [1.2 (SD 2.5) vs. 2.9 (3.3), P =0.073]. There was a significant difference between CDA versus ACDF groups in the change in VAS neck pain score between 10 and 20 years [respectively, -0.4 (SD 2.5) vs. 1.5 (SD 2.5), P =0.030]. Reoperations were reported in 41.7% of ACDF patients and 10.0% of CDA patients ( P =0.039). CONCLUSIONS: Both CDA and ACDF are effective in treating cervical radiculopathy with sustained improvement in NDI, VAS neck and VAS arm pain at 20 years. CDA demonstrates lower reoperation rates than ACDF. There were no failures of the arthroplasty device requiring reoperation at the index level. The symptomatic nonunion rate of ACDF was 4.2% at 20 years. Despite a higher reoperation rate in the CDA group versus ACDF group, there was no difference in the 20-year NDI, VAS Neck, and VAS arm pain scores.

Technique Pearls for Successful Cervical Disc Arthroplasty From More Than 20 Years of Surgical Experience.

STUDY DESIGN: Surgical technique paper. OBJECTIVE: To describe tips and pearls for cervical disc arthroplasty (CDA). BACKGROUND: CDA has proven to be an effective means of treatment for degenerative cervical disc disease and cervical radiculopathy in properly selected patients who have previously failed non-operative treatment. METHODS: Surgical tips and pearls garnered from more than 20 years of experience with CDA surgery are described. RESULTS: This discussion focuses on pearls for successful procedures, including patient selection, patient positioning, surgical technique, and postoperative protocols. CONCLUSIONS: In correctly selected patients, CDA can be effective in treating cervical degenerative disc disease and radiculopathy. The techniques described here can increase the chance of success and decrease complications.

Evaluation of DIAM™ Spinal Stabilization System for lower lumbar disc degenerative disease: A randomized, prospective, single-site study.

OBJECTIVE: To determine the efficacy of DIAM Spinal Stabilization System compared with nonoperative treatment for patients with low back pain and lower lumbar disc degenerative disease. METHODS: A single center collected prospective outcomes data on 38 patients randomized to an interspinous device or non-operative treatment for symptomatic lumbar degenerative disc disease with treatment crossover allowed at 6 months. RESULTS: At all postoperative timepoints out to 2-years, statistically significant improvements in ODI and back pain scores were observed with the interspinous device. Clinically significant improvements (ODI >15-point improvement) were seen in 87.5% of DIAM patients at 2-years postoperatively. A high cross-over rate was noted from the non-operative cohort to the operative group (12 of 15) due to continued pain with nonoperative care. Additionally, 80% of patients receiving the DIAM implant reported a >15-point ODI reduction from pre-surgical scores at 2-year follow-up. CONCLUSION: The DIAM device demonstrates improvement in ODI and Back Pain scores maintained out to a 2-year follow-up timepoint and performed superior to conventional nonoperative treatment regimens commonly used in low back pain.

Functional Outcomes Associated With Adjacent-level Ossification Disease 10 Years After Cervical Disc Arthroplasty or ACDF.

STUDY DESIGN: A retrospective review of a prospective, randomized control Food and Drug Administration (FDA) investigational device exemption trial comparing anterior cervical discectomy and fusion (ACDF) with Bryan cervical disc arthroplasty. OBJECTIVE: Determine the clinical significance of adjacent-level ossification disease (ALOD) on long-term functional outcomes after ACDF or arthroplasty. SUMMARY OF BACKGROUND DATA: ALOD occurs when the anterior longitudinal ligament and annulus adjacent to the index surgical level calcifies. As previously reported, ALOD happens more commonly after an arthrodesis than an arthroplasty. No investigation has previously examined 10-year clinical outcomes associated with ALOD. MATERIALS AND METHODS: Forty patients were included in the 10-year follow-up. The index level was radiographically blinded and the cephalad-adjacent level was evaluated for ALOD. These scores underwent statistical analysis to compare the 2 surgical groups (ACDF and arthroplasty) for differences in the development of ALOD at a decade follow-up. Two investigational groups, on the basis of a high or low ALOD score, then proceeded through statistical analysis to compare the functional outcomes of patients in each group. RESULTS: Statistical evaluation of ALOD findings in patients from each surgical group found a significantly higher rate of high-grade ALOD in patients who underwent cervical arthrodesis with plate fixation compared with cervical arthroplasty (68.2% vs. 11.1%, P=0.0003). Functional outcomes of patients were also assessed at the 10-year mark and outcomes in patients with either high-grade or low-grade ALOD were compared. When stratified by high versus low-grade ALOD, no significant difference was found for Neck Disability Index (NDI) (P=0.6431), VAS-arm (P=0.4497), or VAS-neck (P=0.8700) scores between groups. CONCLUSIONS: The present study suggests that there are no significant long-term functional outcome differences between patients with and without significant ALOD. Our findings suggest ALOD may be a radiographic finding that does not alter patient-reported outcomes. LEVEL OF EVIDENCE: Level III-therapeutic.

Long-term Clinical Outcomes of Cervical Disc Arthroplasty: A Prospective, Randomized, Controlled Trial.

STUDY DESIGN: Prospective, randomized, single-center, clinical trial. OBJECTIVE: To prospectively examine the 7- and 10-year outcomes of cervical arthroplasty to anterior cervical discectomy and fusion (ACDF). SUMMARY OF BACKGROUND DATA: Degeneration of the cervical discs causing radiculopathy is a frequent source of surgical intervention, commonly treated with ACDF. Positive clinical outcomes are associated with arthrodesis techniques, yet there remains a long-term concern for adjacent segment change. Cervical disc arthroplasty has been designed to mitigate some of the challenges associated with arthrodesis whereas providing for a similar positive neurological outcome. As data has been collected from numerous prospective US FDA IDE trials, longer term outcomes regarding adjacent segment change may be examined. METHODS: As part of an FDA IDE trial, a single center collected prospective outcomes data on 47 patients randomized in a 1:1 ratio to ACDF or arthroplasty. RESULTS: Success of both surgical interventions remained high at the 10-year interval. Both arthrodesis and arthroplasty demonstrated statistically significant improvements in neck disability index, visual analog scale neck and arm pain scores at all intervals including 7- and 10-year periods. Arthroplasty demonstrated an advantage in comparison to arthrodesis as measured by final 10-year NDI score (8 vs. 16, P = 0.0485). Patients requiring reoperation were higher in number in the arthrodesis cohort (32%) in comparison with arthroplasty (9%) (P = 0.055). CONCLUSION: At 7 and 10 years, cervical arthroplasty compares favorably with ACDF as defined by standard outcomes scores in a highly selected population with radiculopathy. LEVEL OF EVIDENCE: 1.