Prospective long-term longitudinal radiographic follow-up after treatment of cervical disc disease with the Bryan Cervical Disc Prosthesis

Introduction The purpose of this study is to assess the change in motion at the index level and the change in motion and disc degeneration at the adjacent levels after surgery for cervical disc disease with a Bryan Cervical Disc Prosthesis. Material and Methods Intervertebral disc degeneration was assessed using an objective scoring system ranging from 0 (no degeneration) to 9 (severe degeneration). Based on lateral radiographs, range of motion (ROM) was calculated using a custom developed tool with a measurement error of 0.3°. Results In total, 63 patients were included in the study. In April 2008, 61 patients had 4 years, 42 had 6 years, and 9 had 8 years follow-up. On average, preoperative ROM was 8.8+/-5.7° at index level, and 11.1+/-5.0° and 9.4+/-5.5° at the cranial and caudal adjacent levels. At index level, ROM stabilized around the preoperative value at 4 year, 6 year and 8 year follow-up. At the adjacent levels, a similar trend was observed. The mean preoperative degeneration score was 2.4+/-2.0 at the index level, 1.1+/-1.5 at the cranial and 0.8+/-1.4 at the caudal adjacent level. The degeneration score at the adjacent levels increased not abnormally at 4 year, 6 year and 8 year follow-up. There was a significant correlation between preoperative and postoperative degeneration for both adjacent levels (r>0.76). Conclusion ROM at the index level is maintained up to 8 years after surgery. Moreover, the insertion of the prosthesis did not lead to an abnormal increase in ROM of the adjacent levels. The prosthesis seems to protect against acceleration of adjacent level degeneration as seen after interbody fusion.Walraevens J., Vander Sloten J., Demaerel P., Suetens P., van Loon J., Van Calenbergh F., Goffin J., ''Prospective long-term longitudinal radiographic follow-up after treatment of cervical disc disease with the Bryan Cervical Disc Prosthesis'', Annual scientific meeting of the Belgian Society of Neurosurgery, March 21, 2009, Liège, Belgium.status: publishe