1998 Volume 12 Issue 2 Pages 187-194
The authors reviewed 103 cases of degenerative lumbar spinal canal stenosis (LSCS) for which interlaminar laminotomies with medial facetectomy (ILMF) were undertaken except for 7 cases of foraminal stenoses. A unilateral total facetectomy was performed for the latter. The surgical indication was for radiculopathy and/or intermittent claudication refractory to the conservative therapy. The patients' ages ranged from 21 to 78 years, with an average of 62. There were 61 males and 42 females. Degenerative LSCS accounted for 72%, while developmental ones accounted for only 7%. The operated intervertebral level was single in 70%, double in 25% and triple in 5%. The most common operated level was L4/5 (64%), followed by L5/S (19%), L3/4 (15%) and L2/3 (3%). Discectomy was carried out in 22 patients with extruded discs and in 2 patients with marked disc bulging. Degenerative spondylolisthesis (one degree) was encountered in 25 patients. Spinal fixation using a pedicle screw was made in 3 patients with unstable spondylolisthesis and only in the initial two patients who underwent total facetectomy. A long-term evaluation which was made by phone interview (ranging from 1 to 9 years, averaging 3.5 years) showed that low back pain and leg pain were absent or negligible in 53%, slight in 26%, moderate in 18% and severe in 3%. As to the performance status, "normal walking" was noted in 63%, "mild difficulty in walking long distances" in 26%, "unable to walk more than 100 meters" in 9% and "unable to walk" in 2%. As a whole, approximately 90% of the patients followed up had enjoyed a useful life. Of the causes that incapacitated about 10% of the patients, half were unrelated to lumbar spinal diseases. None of the 22 patients with stable spondylolisthesis developed significant spinal instability, nor did the patients without prior listhesis. There were no patients who developed spinal restenosis due to the regrowth of bone. Eight patients required reoperation because of lumbar disc hernias in 3, foraminal stenosis in one and scar tissue in another and technical errors in 2. In conclusion, ILMF is a very useful procedure for degenerative central canal stenosis as well as lateral recess stenosis. This procedure carries significantly fewer later complications, such as listhesis and disc hernia. Concurrent instrumental fixation should be limited to the patients with significantly unstable spondylolisthesis.
