Surgical Outcome in Patients with Cervical Compression Myelopathy: A Study Using Magnetic Resonance Imaging

ABSTRACT

We have undertaken a clinical analysis of 33 patients who underwent decompressive surgery for cervical myelopathy and compared the preoperative and postoperative MRI images of these patients to clarify the relation between morphologic changes in the spinal cord and clinical improvement of myelopathy after decompressive surgery and to evaluate other factors which might affect the surgical outcome of these patients. The severity of myelopathy was evaluated using the scale proposed by the Japanese Orthopaedic Association(JOA score) and the postoperative outcome of the myelopathy was assessed using the postoperative JOA score, increase in points, and recovery rate. The patients were compared with respect to age, symptom duration, underlying cause and surgical method. There were no statistically significant differences in respect of symptom duration, underlying cause and surgical method, but, age, postoperative JOA score and recovery rate increased significantly in group with age under 50 years compared with that in group with age over 51 years. According to the morphologic changes of spinal cord on MRI after surgery, the patients were divided into the following four types Type I which showed complete disappearance of preoperative cord indentation was present in 23 cases, Type II which showed partial disappearance in 5 cases, Type III which showed no imprevement in 2 cases, and Type IV which showed cord enlargement in 3 cases. Excepting Type IV, increased restoration of spinal cord morphology after decompressive surgery was closely correlated with postoperative improvement in the myelopathy, suggesting that morphologic changes of the spinal cord closely reflect neurologic recovery. In Type IV, notwithstanding the peculiarpostoperative reaction, improvement was relatively good. These results suggest that the age factor may play a role in anticipating the surgical outcome of cervical compression myelopathy and the morphologic changes of the spinal cord on MRI may closely reflect the degree of neurologic recovery in the patients with the cervical cord compression.