Efficacy of Modified Expansive Open-Door Laminoplasty for Cervical Myelopathy

Abstract

Objectives: Expansive open-door laminoplasty is used widely for the treatment of cervical spondylosis and Ossification of the Posterior Longitudinal Ligament (OPLL). We have developed a unique modification of the surgical procedure to keep the lamina expanded, with the aim of preventing reclosure of the vertebral arch. To examine the effectiveness of and problems associated with the modified expansive open-door laminoplasty technique developed at our institution by evaluating the surgical outcomes. Methods and Materials: Fifty-six patients (46 men and 10 women) underwent the modified expansive open-door laminoplasty and were followed up for at least 1 year. Thirty-eight had Cervical Spondylotic Myelopathy (CSM) and 18 had OPLL. The patients were 34 to 89 years of age (mean: 60.9 years). The severity of myelopathy was evaluated according to the Japanese Orthopaedic Association’s scoring system. Surgical outcomes were evaluated using Hirabayashi’s system for determining recovery rate. In the radiographic analysis, the following angles were measured before and after surgery: lordosis angle and Range of Motion (ROM) at C2 - C7 on lateral radiographs, and opening angle on computerized tomography (CT). The presence and absence of axial pain and postoperative C5 palsy were also evaluated. Results: The rate of JOA score improvement was about 60%, the lordosis angle observed on lateral radiographs was maintained. ROM decreased after surgery in both the CSM and OPLL groups, and the extent of the decrease was similar to that in previous reports. The opening angle of the lamina was 62°- 65° on post-operative CT. Axial pain was reported by 34% of patients. Conclusions: Our modified procedure produced satisfactory postoperative outcomes based on the clinical data and imaging findings for both CSM and OPLL. The advantage of this procedure is that it avoids potential complications associated with bone grafts or implants.