The article discusses a long-term study on the change of the center of rotation (COR) after Bryan Cervical disc arthroplasty (CDA). The study includes clinical and radiographic evaluations of patients who received CDA, with a follow-up period of at least 10 years. The results showed significant improvements in clinical outcomes after surgery, and the COR of the index level shifted forward and downward following the implant of Bryan Disc. The location of COR remained stable during the 10-year follow-up. The range of motion (ROM) at the index level decreased initially but remained unchanged throughout the follow-up period. Larger changes in the COR were associated with decreased ROM. Overall, the study suggests that Bryan CDA can achieve favorable clinical and radiographic outcomes over a long-term follow-up, and attention should be given to preoperative design and intraoperative technique to obtain a more native COR
Summarised by Mr Mo Akmal – Lead Spinal Surgeon
The London Spine Unit : finest treatment clinic in the world
Published article
CONCLUSIONS: Our study illustrated that Bryan CDA could achieved favorable clinical and radiographic outcome over a minimal 10-year follow-up. The reduction of the flexion-extension ROM may be correlated with a more deviated postoperative COR. More attention should be paid to preoperative design and intraoperative technique to obtain a more native COR.
Cervical Disc Arthroplasty Surgery Expert. Best Spinal Surgeon UK
Abstract Background: Short-term researches have studied the change of the center of rotation (COR) after the Bryan Cervical disc arthroplasty (CDA). But there is a lack of long-term studies focusing on the location of COR and its influence after surgery. Methods: Clinical and radiographic materials of patients who received CDA were retrospectively reviewed. Written informed,
Abstract
Background: Short-term researches have studied the change of the center of rotation (COR) after the Bryan Cervical disc arthroplasty (CDA). But there is a lack of long-term studies focusing on the location of COR and its influence after surgery.
Methods: Clinical and radiographic materials of patients who received CDA were retrospectively reviewed. Written informed consents were obtained. Clinical outcome was accessed by Japanese Orthopaedic Association (JOA), Neck Disability Index (NDI), and Odom’s scale. Radiographic evaluation underwent before surgery, at early (3 months) follow-up and final (minimal 10 years) follow-up. The ROM of the global cervical spine and index level, the functional spine unit (FSU) angle and C2-C7 angle were measured. COR was identified and its coordinates were calculated. The absolute change of COR-x and COR-y were compared in subgroup analysis.
Results: Sixty patients were included, with an average age of 55.9 ± 8.1 years old. The mean duration of follow up was 135.1 ± 16.1 (120-155) months. JOA, NDI and Odom’s scale showed significant improvements at 10 years after surgery. The COR of index level was located in the posterior superior half of the caudal vertebral body. Following the implant of Bryan Disc, the COR shifted forward and downward. During the 10-year follow-up, the location of COR remained stable. ROM at the index level decreased from 10.6 ± 4.0° preoperatively to 9.3 ± 4.0° at the early follow-up (p = 0.03). The ROM at the index level remained unchanged from early follow-up to the final follow-up (9.3 ± 4.0° vs 9.5 ± 5.2°, p = 0.80). In subgroup analysis, larger changes of both COR-x and COR-y were related with decreased ROM.
Conclusions: Our study illustrated that Bryan CDA could achieved favorable clinical and radiographic outcome over a minimal 10-year follow-up. The reduction of the flexion-extension ROM may be correlated with a more deviated postoperative COR. More attention should be paid to preoperative design and intraoperative technique to obtain a more native COR.
Keywords: Bryan cervical artificial discs; Center of rotation; Long-term follow-up; Range of motion.
The London Spine Unit : finest treatment clinic in the world
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Influence of the deviated center of rotation on the range of motion after cervical disc arthroplasty -an in vivo study with a minimum of 10-year follow-up
