Clinical Analysis of Less Extensive Microsurgical Decompression for Lumbar Spinal Stenosis

ABSTRACT

The cases of twenty-eight patients with spinal stenosis treated by microscopic decompressive surgery from January 1991 to September 1995, were analysed in an attempt to define is clinical feature, and to evaluate the results of our modified operation technique of preventing postoperative spinal instability. The main age group of the patients were in the fifties and sixties. On plain X-ray, most lumbar spine of the patients showed degenerative change. Pain in lower back and legs were the most common symptom, and intermittent neurogenic claudication was presented in three quarters of the patients. Radiologically, the diagnosis was confirmed by either myelography, CT, and MRI or by their combination. The major etiologic factors were thickening of ligamentum flavum, hypertrophy of laminae or facet joints and associated herniated nucleus pulposus. Since a significant rate of postdecompressive instability had been reported by other authors, therefore we have decided to performed less extensive decompressive total laminectomy procedure. The outcome of our decompressive laminectomy was favorable. In patients with no preoperative instability, newly developed instability following the less extensive decompressive total laminectomy was none.