Abstract
Thirty two cases of lumbar canal stenosis with drop foot (twenty three males and nine females) were reviewed. The average age at the time of the operation was 59.2 years, ranging from 36 to 82. The follow-up period after operation averaged 31.9 months, ranging from 3 months to 120 months.
We have devised two types of classification, according to the neurological symptoms of lumbar canal stenosis. Twenty one cases were cauda equina type and eleven cases were nerve root type. For the cauda equina type, laminectomy was performed in eighteen cases, fenestration was performed in two cases, and Luque's S. S. I. was performed in one case whose radiographs showed instability. For the nerve root type, fenestration was performed in eight cases, and laminectomy was performed in three cases.
Operative results were assesed by JOA score and Hirabayashi's method. The average score before operation was 9.3 points, and after operation was 21.7 points. The average recovery rate was 61.9%. The main factors which decided the prognosis were morbidity period, bladder bowel disturbance, and the strength of the tibial anterior muscle. Nine cases of drop foot remained after the operation.
The operation was not so effective for the recovery of drop foot, but was enough for that of intermittent claudication and lower extremity pain. Because the symptoms of lumbar canal stenosis are progressive, the operation should be done as soon as possible even with elder patients.
