Long-term clinical and magnetic resonance imaging follow-up assessment of patients with lumbar spinal stenosis after laminectomy

Study Design. A cross-sectional retrospective study to observe the correlat ion between postoperation findings shown on magnetic resonance imaging and clinical observations of 56 patients 10 years after laminectomy for lumbar spinal stenosis. Objective. To evaluate the relation between: postoperation findings on magn etic resonance imaging and surgical outcome in patients surgically treated for lumbar spinal stenosis. Summary of Background Data. Surgical management of lumbar spinal stenosis i s based on the compression seen in radiologic imaging of neurovascular stru ctures in the vertebral canal, but the success of surgical decompression an d its correlation with clinical observations very seldom have been monitore d by postoperation radiologic imaging. Methods. In this study, 56 patients surgically treated for lumbar spinal st enosis were re-examined clinically by use of the Oswestry disability questi onnaire. Their walking capacity was evaluated by the treadmill test :Severi ty of pain before and after the treadmill test was investigated Using a vis ual analog scale. Patients' perception of improvement measured as the chang e in their condition during the;preceding 5 years was elicited by a questio nnaire. On the basis of the stenotic findings on magnetic resonance imaging , the patients were classified into no stenosis (NoSten, n = 15) and stenos is (Sten, n = 41) groups, and a summative degenerative scale also was const ructed with the findings categorized as follows: disc degeneration, disc he rniation, facet joint arthrosis, and degenerative spondylolisthesis. Results. Whereas the patients' perception bf:improvement correlated very st rongly with the Oswestry score and walking capacity, there was no statistic al difference between the NoSten and Sten groups in the:Oswestry score, wal king capacity, perception of improvement, or severity of pain. The effect o f the summative degenerative scale on the patients' walking capacity was 13 times greater than the effect of the minimum area-of the dural sac. Conclusions. Patients' perception of improvement had a much stronger correl ation with long-term surgical outcome than structural findings seen on post operation magnetic resonance imaging, Moreover, degenerative findings had a greater effect on patients' walking capacity than stenotic findings.