[A new surgical treatment for lumbar spinal canal stenosis]

Using the method of Assessment of Treatment for Low Back Pain by the Japanese Orthopaedic Association, 159 cases of lumbar spinal canal stenosis treated between 1977 and 1988 were analyzed. Although walking ability was satisfactorily improved, low back pain, numbness, sensory disturbance, motor disturbance, and ability to lift heavy objects showed relatively poor improvement. Lumbar complaints remained in some of the cases radiographically evaluated as having worsened lumbar lordosis or an unbalanced range of motion. The improvement ratio was 82.6% on average, but it was 74.3% among cases that underwent wide laminectomy (non-fusion) due mainly to such nonspecific complaints as a feeling of heaviness in the lumbar region. The ratio increased to 88.5% after the introduction of wide fenestration with spinous process flap for conservation of the posterior component. Since this technique provides a wide operative field at a low risk for the occurrence of postoperative instability, it is strongly recommended for the treatment of degenerative multiple spinal canal stenosis.