Fifteen operative cases of degenerative spondylolisthesis were examined in our department. There were 4 male and 11 female patients whose ages ranged from 33 to 75 years (average, 51 years). The involved levels of the lumbar spine were as follows; L3:1, L4:12, L5:1, and both L4 and L5:1.
In each case, clinical symptoms, X-ray findings, operative findings, etc. were reviewed. Clinical symptoms were evaluated by JOA score system. Subjective symptoms were scored 3.8 points per 9 on the average, always with a score of 1 point for lower limb pain or numbness. Objective findings were scored with an average of 4.1 points per 6. On the X-ray, slipping ratio ranged from 5 to 40% (average, 13.4%). The canal diameter of L4 was measured by the plain X-P with a value from 15 to 21mm (average, 17.5mm).
Instability could be detected in 13 cases by functional X-ray analysis on the lateral view. Concerning operative findings, such a hypertrophy of the facet joint and yellow ligament as that of the degenerative type of lumbar canal stenosis usually compressed the dural tube and nerve roots from posterolateral side.
Both clinical symptoms and X-ray findings were compared with those of conservative cases. Though there were no significant differences in X-ray findings, clinical symptoms of the operative cases were severely damaged, especially the subjective symptoms. Thus, the decision for surgery has been indicated mainly due to extent of impairment of patients.
