This study was performed to investigate and define the factors affecting the results of surgery for a cervical myelopathy.

Seventy-eight cervical myelopathy cases, who underwent surgery from Jan. 1991 to Sep. 2001, were retrospectively reviewed. The patients were composed of developmental stenosis in 9, spondylosis in 21, OPLL in 12, HIVD in 34 and trauma in 2 cases. The causes of the disease, age, onset, pre-op JOA score, pre-op and post-op spinal canal diameter, Pavlov ratio and cord diameter and signal changes of cord on MRI were examined. The mean follow-up period was two years. The clinical results were evaluated according to the JOA score. Statistical analysis was made using the Pearson correlation coefficient and the Kruskal-Wallis method.

The mean pre-op and post-op JOA score were 11.2 and 14.8 respectively. The mean recovery rate was 68.0%. The preoperative JOA score showed a positive correlation with recovery rate, and age, sagittal diameter and transverse area of the cord on MRI correlated negatively with the recovery rate. The result was poorer the higher the level involved. Patients with signal changes in the cord on MRI had a poor outcome after surgery.

The prognostic factors affecting the results of the surgery for cervical myelopathy were age, pre-op JOA score, disease level, and sagittal diameter, transverse area and the signal changes in the cord on MRI.