21 patients who underwent spinal fusion using pedicle screws for lumbar canal stenosis were reviewed. There were 11 males and 10 females. The mean age at surgery was 61 years and the mean follow-up period was 28 months. Degenerative spondylolisthesis was found in 18 patients and degenerative lumbar canal stenosis with antero-posterior instability in 3 patients.
The improvement rate of JOA score was 73% and bony union rate was 95%. Low back pain was improved in 12 (63%) out of 19 patients, and intermittent claudication in 17 (81%) out of 21 patients. Leg symptom, however, remained in 14 (70%) out of 20 patients. Numbness mainly deteriorated the leg symptoms.
Instrumentation and bone graft were added in the segments adjacent to fusion for 2 patients: a 64-year-old female showing pedicle screws pull-out and graft bone collapse due to osteoporosis, and a 69-year-old male developing new scoliosis on the adjacent segment which had been decompressed without fusion. Attention should be paid to using pedicle screws for osteoporotic patients and to decompression without fusion for segments adjacent to fusion.