Cervical Spondylotic Myelopathy: Surgical Results and Factors Affecting Outcome with Special Reference to Age Differences

OBJECTIVE: A variety of factors may affect the surgical outcome in patients with cervical spondylotic myelopathy. The aim of this study is to analyze the prognostic factors by comparing younger and elderly patient groups on the basis of preoperative radiological and clinical data. METHODS: To assess the prognostic factors after surgery had been performed, the clinical and radiological data of 64 patients who underwent expansive laminoplasty were reviewed. Patients were classified into two groups, a younger patient group (<65 yr of age; n = 29) and an deny patient group (≥65 yr of age: n = 35). The neurological status of the patients was assessed by use of the Japanese Orthopaedic Association scale. Radiological features were examined with compouted tomographic myelography and magnetic resonance imaging. The effects of the clinical and radiological findings on neurological outcome were investigated. RESULTS: The preoperative and postoperative mean Japanese Orthopaedic Association scores in elderly patients were significantly lower than those in younger patients. For elderly patients, the transverse area of the spinal cord at the level of maximum compression and symptom duration were the factors that predicted an excellent recovery. in contrast, the transverse area was the only predictor of excellent recovery in younger patients. Age, preoperative Japanese Orthopaedic Association score, canal diameter, and an intensity change on the spinal cord were not predictive in either age range. CONCLUSION: The transverse area of tile spinal cord may be a reliable predictor of excellent recovery in both younger and elderly patient groups. Shorter symptom duration was an important factor in the excellent recovery of elderly patients.