Cervical Disc Arthroplasty for the Treatment of Adjacent Segment Disease after Anterior Cervical Discectomy and Fusion

Study Design. A retrospective chart review was conducted at a single institution. Objective. The purpose of this study was to investigate clinical outcomes of cervical disc arthroplasty (CDA) used for the treatment of symptomatic adjacent segment disease (ASD) developed after anterior cervical discectomy and fusion (ACDF). Summary of Background Data. A major clinical concern following ACDF is the development of ASD. ASD after ACDF is often treated with an additional fusion, but risks include pseudoarthrosis and further ASD. CDA is a motion preserving alternative that addresses these concerns, and therefore, has been proposed as an alternative treatment for ASD after ACDF. Methods. CDA patients with prior adjacent-level ACDF (n=120) were identified from a consecutive series of CDA patients at one institution. Pre- to post- CDA patient-reported outcome measures were compared using the paired Wilcoxon signed-rank test. Results. A total of 142 devices were implanted – 98 patients underwent a one-level CDA, and 22 patients underwent two-level CDA. The mean follow-up duration after CDA was 32.11 months. Neck pain, arm pain, and Neck Disability Index (NDI) scores significantly improved from the preoperative to postoperative timepoint (respectively: 6.14 to 3.02, 4.42 to 1.61, 44.28 to 28.62, all P <0.001). In total, 7 patients underwent reoperation (5.83%). One of these patients underwent reoperation for pseudarthrosis at the level of ACDF following a hybrid procedure. The indications for index level reoperations (n=3) were foraminal stenosis, osteolysis, and postoperative hematoma. All patients with an adjacent level reoperation (n=3) received surgery at levels adjacent to the prior fusion, not the more recent CDA. Conclusion. The results of this study found CDA was effective for the treatment of ASD following ACDF. CDA appears to be a viable treatment option for ASD after ACDF in appropriately selected patients.