Lumber spinal stenosis was defined as any type of narrowing of the vertebral canal, nerve root canals or intervertebral foramina. Complete decompression of the dural sac and nerve root is a primary objective of surgery, but stabilization of the
unstable
spine created by the decompression is as important as the decompression itself in the treatment of spinal stenosis. This study was performed to evaluated the effectiveness of transpedicular screw fixation in stabilization after decompression and
in
reduction of spondylolisthesis with concomittent posterolateral fusion. 36 patients with lumber spinal stenosis who were treated by decompression. transpedicular screw fixation and posterolateral fusion during the period from Sep. 1989 to Jun.
1991
were
analysed and following results were obtained. The patients were followed for a mean of 18.5 months(range, 12-35).
1. The etiologic factors of lumber spinal stenosis of 36 patients were spondylolisthesis in 21 patients(58.3%), degenerative in 13 patients(36.1%) and iatrogenic in 2 patients (5.5%).
2. In cases of spondylolisthesis, the average gain of reduction of slippage was 13.0% and the average loss of reduction was 2.0% in final followed up films.
3. 34 patients(94.4%) showed solid union of posterolateral bone graft at the mean of 3.5 months after operation(range, 3.0-4-5).
4. Symptomatic reliefs after operation were not significantly influenced by the level, site and etiology of the stenosis. So, complete decompression is essential in the treatment of the spinal stenosis.
5. The clinical results were excellent in 16 patients (44.4%), good in 15 patients(41.7%) and fair in 5 patients(13.9%)
6. Segmental spinal instrumentation with transpedicular screws is not only a reliable method of stabilization after wide decompression but also a good method of reduction and maintenance in the treatment of spondylolisthesis. Instrumentation
allows
better postoperative care and early ambulation.
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