Do Anterior Cervical Osteophytes Prevent Dynamization of Cervical Dynamic Plates?

Study Design: A retrospective study. Objective: To evaluate radiographic changes of patients with osteophytes at the anterior border of the caudal vertebral body who were treated with anterior cervical discectomy and fusion using dynamic rotational plates. Summary of Background Data: Dynamic cervical plates are widely used in surgeries of the anterior cervical spine. One concern in using dynamic plates is that the subjacent anterior osteophytes might act as a bony block and prevent dynamization of the plate. To our knowledge, there are no studies that have investigated the validity of this concern. Materials and Methods: Twenty-eight patients were selected for the study out of patients who had undergone 1-level anterior cervical discectomy and fusion using a dynamic rotational plate. They were divided into 2 groups on the basis of the presence of osteophytes located at the anterior border of the subjacent vertebrae. Thirteen patients had osteophytes and 15 control patients did not. The mean follow-up period was 10.8±8.4 months (range, 6-36 mo). Lateral radiographs were taken preoperatively, immediately postoperatively, and at the final follow-ups to assess changes in the following radiographic parameters: Cobb angle of the adjacent segments and fused segment, horizontal distance between C2 and C7 plumb lines, height of the bone graft, vertebral heights of the operated segment, and migration distance of the plate. Results: No statistical significance was found in the Cobb angles of the adjacent segments and fused segment, distance between the C2-C7 plumb lines, height of the graft, height of vertebral bodies of the operated segment, and migration distance of the plate through the preoperative, postoperative, and final follow-ups between the 2 groups. Conclusion: Osteophytes did not appear to affect the dynamization of plates in any of the measured radiographic parameters.