TREATMENT OF FLEXION INSTABILITY OF LUMBAR SPINE WITH GRAF BAND

Abstract

This study focused mainly on the long-lasting effectiveness of Graf band stabilization system on the stabilized lumbar motion segment together with the band fate and the final outcome. Graf soft stabilization operation was carried out to suppress the forward flexion and rotatory instability. Fifty-one patients were subjected to this study. Forty-five had pure forward flexion instability preoperatively. Among the 51 patients, 20 were irreducible mild spondylolisthesis and 8 reducible mild spondylolisthesis; 17 excessive flexion angular motion; one disc disease with mild stenotic symptoms; and 5 post-laminectomy instability. In this series, good or excellent results were obtained in 40 cases (78.7%); fair in 4; no improvement in 4; and poor in 3. JOA lumbar score increased from 16 at preoperative exam to 26.5 on average at the final examination. In 3 cases screws were malpositioned. In 2 cases, mild transient drop foot developed, and spontaneous fusion occurred in one disc surgery patient. There was no implant loosening or breakage, and no overstretch and tear of bands or disengagement. There was no recurrence of segmental instability at the immobilized segment. Also, there were no adjacent joint problems. In summary, the Graf procedure appears to be a good alternative to spinal fusion for the stabilization of the unstable segment with forward flexion instability.