Comparison of clinical outcomes between cervical disc arthroplasty and anterior cervical discectomy and fusion for the treatment of single-level cervical spondylosis: a 10-year follow-up study

BACKGROUND CONTEXT: The theoretical advantage of cervical disc arthroplasty includes preserved motion at the cervical level, which may reduce degeneration of the adjacent segments. The long-term follow-up results are still controversial. PURPOSE: The present study aimed to retrospectively study the long-term efficacy and complica-tions of cervical disc arthroplasty using a single commercially-available device in a single center. STUDY DESIGN: This was a propensity-score matched cohort study. PATIENT SAMPLE: This study enrolled 148 single-level cervical degenerative disease patients from January 2009 to March 2012. After 1:1 propensity score matching, 39 patients remained in the ACDF or ACDR groups. OUTCOME MEASURES: The outcome measures were neurological functions (Neck Disability Index (NDI) and Japan Orthopedic Association (JOA) scores), radiographic evaluations (cervical curvature, operative segment range of motion, degenerative condition of adjacent segments, hetero-topic ossification (HO) of the surgical segment), and complications. METHODS: NDI and JOA scores were used to evaluate patient neurological functions. Cervical curvature (C2-C7 Cobb angle) and operative segment range of motion (ROM) were compared between the two groups. Grading criteria for osteophyte formation were used to evaluate the degen-erative condition of adjacent segments. HO after ACDR was graded according to the McAfee grad-ing method. RESULTS: The average follow-up time was 119.3 +/- 17.2 months. Satisfactory improvements in neurological function were obtained for both the ACDR and ACDF groups. There were no signifi-cant differences in VAS or NDI scores between the two groups. In the ACDR group, the ROM of the operative segment increased from 6.7 +/- 4.3 degrees before the operation to 8.9 +/- 3.5 degrees on the second day after the operation (p<.001). The ROM of the operative segment was 8.1 +/- 4.0 degrees at the 1-year follow-up, 7.2 +/- 3.6 degrees at the 2-year follow-up, 5.7 +/- 4.5 degrees at the 5-year follow-up and 4.3 +/- 3.9 degrees at the last follow-up. ASD was more likely to develop in the caudal adjacent segments and progressed with the follow-up time. At the last follow-up, HO was present in 27 patients (69.23%), while high-grade HO (McAfee scores III and IV) was detected in 6 patients (15.38%). CONCLUSIONS: Through nearly 10 years of follow-up, ACDR was as effective as ACDF for treating single-level degenerative cervical disc disease. However, HO and the role of ACDR in the protection of ASD remains to be further observed and followed up. (c) 2022 Published by Elsevier Inc.