Soft GRAF Fixation and Posterior Lumbar Interbody Fusion in Multiple Degenerative Lumbar Diseases

ABSTRACT

As a treatment of multiple degenerative lumbar disease, there is no doubt about wide decompressive laminectomy for neural decompression. But postlamenectomy instability caused by wide decompression can provoke neurologic deteriorations and further stabilization procedures may require to improve clinical symptom. Among stabilization procedures, posterior lumbar interbody fusion and posterior fixation with transpedicular screw can provide immediate stability postoperatively. But the posterior fixation with rigid rod or plate system can cause degenerative instability in adjacent segment and hardware failure due to hyperrigidity. Therefore, authors have tried posterior soft GRAF fixation and posterior lumbar interbody fusion with cages to avoid complications of rigid fixation systems and iliac bone graft in 124 patients with multiple degenerative lumbar diseases. The angular instability was improved from 14.9degrees+/-6.4degrees to 3.4degrees+/-3.5degreespostoperatively and translational instability was decreased from 6.4mm+/-1.1mm to 1.6mm+/-1.1mm (p<0.001). The height of intervertebral disc was increased from 9.8mm+/-2.1mm to 12.2mm+/-2.4mm significantly. The new instability on adjacent segment was not apparent during follow-up period. With this procedure, 88.7% of the patients were improved clinically. Results of this study show that soft GRAF fixation and posterior lumbar interbody fusion with cage(circumferential fusion or 360degreesfusion) can provide the three column stability immediately after operation without any hardware related complications. Also, it can give more physiologic property biomechanically than rigid fixation to degenerative spinal column.