Abstract:

Objective： To retrospectively analyze the clinical data of the patients with reoperation for cervical myelopathy due to progressing ossification of the posterior longitudinal ligaments, with previous open-door expansive laminoplasty, and to evaluate the outcomes. Methods: From May 2006 to July 2012, a retrospective study was performed on a consecutive series of 17 patients with previous open-door expansive laminoplasty, who had received the reoperation for cervical myelopathy due to progressing ossification of the posterior longitudinal ligaments. The reoperation was performed based on the clinical manifestations and segments of responsibility. The anterior approaches were performed in 12 cases, and the posterior approaches in 5 cases. The correlation between the clinical factors and Japanese Orthopedic Association (JOA) scores or the JOA recovery rate was evaluated by Pearson or Spearman correlation test. The pre-and post-operative JOA scores were analyzed by repeated measures ANOVA and the JOA recovery rates were compared with paired t test. Results: The mean follow-up was 137.5 months (range 60-348 months). There were no serious complications after surgical procedures. There was one case that had C5 palsy in the first operation and had recovery after one week. Another case had C5 palsy in the reoperation with posterior approach, which had recovery at the end of 6 months post-operation. Three cases had the cerebrospinal fluid leakage of the reoperation, with two cases in the anterior approaches and one case in the posterior approach. There was no significant correlation between the clinical variables and JOA scores or JOA recovery rates. The JOA scores of the patients in the first operation were improved from 9.4±4.1 to 12.8±2.8 (P<0.01), and the JOA recovery rate was 45.6%. The JOA scores of the reoperation were improved from 10.2±2.8 to 12.7±2.4 (P<0.05) at the end of  6 months and 14.3±1.9 (P<0.01) by the last follow-up. There were significant differences between the JOA recovery rates by the last follow-up (63.2%) and at the end of 6 months (39.3%) of the reoperation or 45.6% of the first operation (P<0.01). Conclusion: The reoperation for cervical myelopathy duo to progressing ossification of the posterior longitudinal ligaments can significantly promote the recovery of the spinal cord, based on the clinical manifestations combined with segments of responsibility of the imaging.

Key words: Ossification, heterotopic, Longitudinal ligaments, Reoperation, Cervical vertebrae, Laminoplasty