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[Microscope-assisted minimally invasive decompression for degenerative lower lumbar spinal stenosis].

OBJECTIVE
To evaluate clinical results of microscope-assisted minimally invasive decompression for degenerative lower lumbar spinal stenosis.


METHODS
From May 2007 to November 2008, 26 patients with degenerative lower lumbar spinal stenosis were treated with microscope-assisted minimally invasive decompression. Including 9 males and 17 females, the mean age were 53.7 years (range in 47-75 years). The course of disease was from 2 to 8 years with an average of 3.6 years. Single segment symptom had 20 cases and double segments had 6 cases. The clinical effects were evaluated and improvement rate was calculated according to JOA scoring before and after operation.


RESULTS
The operative time in single segment was 60-90 minutes with an average of 75 minutes and in double segments was 80-180 minutes with an average of 95 minutes. The operative bleeding in single segment was 50-120 ml with an average of 85 ml and in double segments was 60-150 ml with an average of 100 ml. All the patients were followed up with an average of 8.6 months (range in 6-24 months). The clinical effects were evaluated according to JOA scoring,excellent in 18 cases,good in 7,poor in 1,the rate of excellent and good was 96% and improvement rate was 86%. The mean JOA scoring was respectively 3.92 +/- 0.83 and 12.67 +/- 1.92 before and after operation. There was significantly statistic difference between before and after operation (P < 0.01).


CONCLUSION
Microscope-assisted minimally invasive decompression for degenerative lower lumbar spinal stenosis can obtain satisfactory therapeutic effect,which had advantages of short operative time, less trauma, subtle operation, fast restoration, but it is inapplicable for the patients with obviously ossification or calcification of vertebral body, severe vertebral canal adherence.