RESUMO
With current developments in surgical instrumentation, the surgical management of symptomatic isthmic lumbar spondylolisthesis is diversifying. Many authors agree, the basic elements for this condition, are decompression of compressed neural structure, bone fusion, and internal fixation with or without reduction. In eleven isthmic lumbar spondylolisthesis patients treated between Jannuary and December 1994, we applied band fixation instead of the usual metalic rigid fixation after decompression and posterior interbody fusion using carbon fusion cages. Serial lumbar X-rays were taken, and we studied the changes in displacement, disc height and bone fusion, as well as evaluating surgical outcome and complications. Preoperative percent-slip was 18.5+/-5.5, and this fell to 12.7+/-6.3 and 12.4+/-6.1 at postoperative 6 and 18 months respectively. Percent-disc height was higher than its preoperative value, and the increase was maintained(21.2+/-6.2 preoperatively; 30.0+/-6.0 and 29.7+/-5.1 at postoperative 6 and 18 months respectively). In all patients, fusion was good, and there were no surgical complications. Over 18 months, the outcome in nine patients was good or excellent, but in 2 patients, it was not good. The poor results may be because the tension band was too tight and possible neural damage or incomplete decompression. On the basis of these observations, we concluded that posterior lumbar interbody fusion with Graf band fixation is good for fusion and for the maintenance of displacement and disc height, and that if performed with care, this is a possible surgical option in cases of isthmic lumbar spondylolisthesis.