Lumbosacral arthrodesis with louis technique. Review of 186 cases.

A retrospective study was carried out of 186 patients surgically treated by lumbosacral arthrodesis using Louis plates from 1981 to 1989 with an average follow-up of 7.2 years (range 3-11). The average age of the patients was 42.2 years (range 11-71). The indication for surgery was a herniated disc and segmentary instability in 29% (54 patients), spondylolysis or spondylolisthesis in 26.3% (49 patients), arthrosis in 11.3% (21 patients), instability (narrowing of the disc space and zygapophyseal hypertrophy) and stenosis in 5.9% (11 patients), tumour in 5.4% (10 patients), fractures in 0.5% (1 patient) and combinations of the above in 21.5% (40 patients who mainly had a herniated disc and associated spinal stenosis). Iliac crest autograft was used in 33 cases (17.7%), bank allograft in 5 (2.6%), and in the other 148 patients the graft was obtained from the arthrodesis bed. After follow-up we observed loosening of the screws in 20 patients and screw rupture in 10. We only documented 2 cases of pseudarthrosis using dynamic X-radiography. We conclude that the Louis plate is a simple method that leads to lumbosacral arthrodesis with a low rate of pseudoarthrosis.