Clinical and Radiological Evaluation of Double Open Door Laminoplasty on Patients with OPLL

We performed clinical and radiological evaluation of double open door laminoplasty by longitudinal splitting of the spinous process on 20 patients (13 males, 7 females) with ossification of the posterior longitudinal ligament.1. Mean recovery rate by Hirabayasi's method was 67.6%.2. There was no significant difference of postoperative range of motion of the cervical spine between two groups; one group of the patients operated from C2 to C7 and the other from C3-C7.3. The distance between the posterior margin of the vertebral body and the posterior edge of the cord was measured at the level maximally occupied by ossification using postoperative CT-myelography. One case with tethering effect showed the longest distance.4. The case with tethering effect showed the root stretching and clarification sign which we stressed as an important radiological one in the postoperative myelography and CT-myelography.