Bilateral multilevel laminectomy with or without posterolateral fusion for cervical spondylotic myelopathy: relationship to type of onset and time until operation.

The authors retrospectively evaluated the relationship of several preoperative factors in 69 patients who had myelopathy due to multilevel cervical spondylosis without ossification of the posterior longitudinal ligament treated with Kirita's bilateral wide laminectomy. In 34 patients with focal instability or malalignments, posterolateral fusion was also combined. The clinical results at an average follow-up period of 3.5 years (range 1-10 years) after operation in the groups that had and had not undergone fusion were equally satisfactory, and preoperative focal instability was believed to be the sole useful indication for adding posterolateral fusion. The patients were classified in three groups according to the acuteness of the onset. The type of onset and time until operation were found to be the factors most strongly related to prognosis, and clinical outcome was correlated with the duration after onset when plotted as days in the acute, months in the subacute, and years in the insidious onset groups. Wide laminectomy with or without posterolateral fusion is a simple operation that is recommended, provided that it is performed early enough according to the type of onset.