Postoperative lumbar canal stenosis due to anterior spinal fusion.

Three cases of postoperative lumbar spinal canal stenosis due to anterior spinal fusion were reported. In these cases stenosis occurred at the adjacent intervertebral disc level of the fused segment a considerable time after anterior spinal fusion performed for spondvlolisthesis. At the stenotic level of the lumbar spinal canal, hypertrophy of the lamina, body spur formation in the articular process, hypertrophy and calci fication of the yellow ligament and narrowing of the lateral recess were noted. These changes are believed to have been caused by excessive stress on the adjacent intervertebral disc, as is the case with stenosis occurring after posterior spinal fusion. [