[Clinical study of lumbar spinal canal stenosis on 70 operated cases --clinical symptoms, pathogenesis, operative method, postoperative results].

In surgical treatment of lumbar spinal canal stenosis, the stenotic area related to the clinical symptoms was determined and the stenotic form and stenotic factors in this stenotic area were estimated before operation. The most appropriate decompression of the stenotic area was performed taking the stenotic form into consideration and retaining the spinous process and interspinous ligament. In cases of stenosis of the spinal canal, posterolateral decompression of the dural sheath was performed by means of resection of the medial edge of the bilateral inferior articular processes and the yellow ligaments. In cases of stenosis of the spinal canal associated with stenosis of the lateral recess, the root was decompressed by unroofing the lateral recess in addition to posterolateral decompression of the dural sheath. And in cases with stenosis of the lateral recess, the root in an affected area was decompressed. Neither operation on the intervertebral disc nor incision of the dural sheath was performed. After operation as described above, symptoms, operative findings and postoperative results were investigated in 70 cases which could be directly examined. In this paper we discuss the relationship between the symptoms and the stenotic area, stenotic forms and stenotic factors. When our postoperative results were compared with those of cases with extensive laminectomy, it was seen that none of the patients we treated had low back pain nor recurrence of intermittent claudication and that lessening of paralysis was sufficient.