General Session: Arthroplasty - Hall F
Presented by: W. Lavelle
W. Lavelle(1), K.D. Riew(2), A. Levi(3), J. Florman(4)
(1) SUNY Upstate Medical University, Orthopedic Surgery, Syracuse, NY, United States
(2) Columbia University Medical Center, Orthopedic Surgery, New York, NY, United States
(3) University of Miami Miller School of Medicine, Neurosurgery, Miami, FL, United States
(4) Maine Medical Center, Neurological Surgery, Scarborough, ME, United States
Introduction: Cervical disc arthroplasty (CDA) is a potential substitute for anterior cervical decompression and fusion (ACDF) with the hope that maintenance of motion may decrease the likelihood of adjacent segment disease and avoid other morbidities associated with cervical fusion. The BRYAN® cervical disc has been studied with over 10 years of data currently being reported.
Objective: To report the assessed range of motion (ROM) at target levels and adjacent segments for BRYAN cervical disc arthroplasty over 10 years.
Methods: The study was a randomized multicenter IDE trial between, May 2002 and October 2004. This is an analysis of an FDA investigation comparing BRYAN CDA with ACDF for single level patients. Eligible patients were ≥ 21 years of age with symptomatic cervical disc disease who had failed conservative care for at least 6 weeks. Subjects were randomized by the sponsor. Patients were followed at regular intervals after the initial 2 year follow-up with the current data set entailing subjects who have been followed for greater than 10 years. All data was collected in a prospective manner. A total of 242 patients received CDA and 221 patients received ACDF.
Results: At the 10-year follow-up, 126 patients in the CDA group and 74 in the ACDF group were evaluated for ROM at the target level. The preoperative mean angulation at the target level was significantly higher in the ACDF group (mean=8.4º) versus the CDA group (mean = 6.5º), p< 0.001. In the CDA group, the mean angulation was significantly improved from 6 months postoperatively and preserved throughout the follow-up. At the 10-year follow-up, the angulation was 8.7º and significantly improved by 2.08º (p< 0.001) compared to preoperative. In ACDF, the angulation dropped significantly by 7.19º three months postoperatively and that consistency was maintained throughout the follow-up; at 10 years follow-up, the mean ROM was 0.60º and significantly decreased by 6.57º (p< 0.001) compared to preoperative. (Graph. 1) At 10 years follow-up, the cranial adjacent segment ROM improved by 1.99° (p< 0.001) in CDA group and 0.78° (p=0.073) in ACDF group; caudal adjacent segment ROM improved by 2.3° (p< 0.001) in CDA group and 1.65° (p=0.011) in ACDF group. Significant improvement in cranial adjacent segment ROM was observed in CDA group compared to ACDF group (p< 0.001).
Conclusion: The angular motion was preserved and improved with BRYAN cervical disc arthroplasty over the 10 years and not as a direct consequence of decreased adjacent segment motion. In the ACDF group, the angulation at target level was decreased at the 10 year follow up. The improvement of angulation in CDA could be due to the drop out of patients at the final follow-up.