Long-term follow-up studies of open-door expansive laminoplasty for cervical stenotic myelopathy.

Follow-up at an average time of 7.8 years postoperatively on open-door expansive laminoplasty (EL) was carried out to determine the long-term results of surgery. Thirty-three patients had ossification of the posterior longitudinal ligament and 18 had cervical spondylotic myelopathy. The average age at operation was 54.7 years. Japanese Orthopaedic Association scores and recovery rates increased during the 3 years after surgery and then plateaued. Radiographically, average spinal canal diameter remained enlarged past 5 years' follow-up. Factors leading to worsening of clinical symptoms included age greater than 60 years (4 patients), loss of sagittal canal diameter (2 patients), progression of ossification (4 patients), and minor trauma (1 patient). Postoperative motor paresis due to C5 and C6 root damage recovered to 4 (manual muscle testing) in all patients within 6 years. The conclusion is that open-door EL is safe and leads to good results that are maintained for over 5 years.