Open-door laminoplasty for cervical myelopathy resulting from adjacent-segment disease in patients with previous anterior cervical decompression and fusion

Study Design. This is a retrospective study of patients with cervical myelopathy resulting from adjacent-segment disease who were treated by open-door expansive laminoplasty. Objectives. The purpose of this study was to evaluate the effectiveness of laminoplasty for cervical myelopathy resulting from adjacent-segment disease. Summary of Background Data. Adjacent-segment disease is one of the problems associated with anterior cervical decompression and fusion. However, the optimal surgical management strategy is still controversial. Methods. Thirty-one patients who underwent opendoor expansive laminoplasty for cervical myelopathy resulting from adjacent-segment disease and age-and sex-matched 31 patients with myelopathy who underwent laminoplasty as the initial surgery were enrolled in the study. The pre-and postoperative Japanese Orthopedic Association scores ( JOA scores) and the recovery rate were compared between the two groups. Results. The average JOA scores in the patients with adjacent-segment disease and the controls were 9.2 +/- 2.6 and 9.4 +/- 2.3 before the expansive laminoplasty and 11.9 +/- 2.8 and 13.3 +/- 1.7 at the follow-up examination, respectively; the average recovery rates in the two groups were 37.1 +/- 22.4% and 50.0 +/- 21.3%, respectively (P = 0.04). The mean number of segments covered by the high-intensity lesions on the T2-weighted magnetic resonance images was 1.87 and 0.9, respectively (P = 0.001). Conclusions. Moderate neurologic recovery was obtained after open-door laminoplasty in patients with cervical myelopathy resulting from adjacent-segment disc disease, although the results were not as satisfactory as those in the control group. This may be attributed to the irreversible damage of the spinal cord caused by persistent compression at the adjacent segments.