Treatment Of The Degenerative Low Lumbar Spinal Instability With Posterior Iliac Crest Or Granular Bone Graft For Lumbar Interbody Fusion: A Prospective Comparative Study

Objective:The spinal surgeons around the world have performed a lot of different surgeries on the patients with lumbar instability.The philosophy on how to chose certain kind of surgery was based on their own understanding of the pathology of lumbar instability. Posterior lumbar inetrbody fusion(PLIF),anterior lumbar interbody fusion(ALIF),Posterior lateral fusion(PLF),and transforaminal lumbar interbody fusion(TLIF) were widely applied by the surgeons.There still were some questions should be answered in those surgeries such as how to simplify the surgery,how to maintain the stability of the spine,how to increase the success rate of fusion,how to improve the quality of the patients life,and so on.The purpose of the present investigation was to compare the clinical outcome of two kinds of lumbar spinal fusion.The following surgeries were included in this study:(1)pedicle screw fixation and iliac bone graft;(2)pedicle screw fixation and granular bone graft.Methods:General document:There were 75 patients in the study,including 41 males and 34 females.Their age was from 27 years to 68 years and the average was 55.6 years.The medical history was from 6 months to 11 years and the average was 18 months.All 75 cases were followed up for 6 months～2years.Clinical manifestation:There were 72 cases with lower back pain and 47 cases with Intermittent Claudication.All of 75 cases with leg pain, and 37 cases with unilateral leg pain,23 cases with hibateral leg pain,15 cases with alternative leg pain.There were 57 cases restricted of elevation test of straight leg,66 cases with sensory disturbance,58 cases with movement disorders,and 45 cases abnormal of Achilles tendon reflex Achilles and knee jerk reflex,and 45 cases with coccygeal nerve injuries.There were 32 cases with degeneration of L_4～5,26 cases with degeneration of L₍5～S₁,6 cases with degeneration of L_3～4,and 11 cases with degeneration more than 2 segments. They were divided into two groups randomly:iliac bone group and granular bone group. Following markers were observed preoperatively and at the 3rd month,6th month and 12th postoperatively.The purpose of the present investigation was to compare the clinical outcome of two kinds of lumbar interbody fusion based on the Japanese Orthopaedic Association(JOA) score and the Oswestr Distability Index(ODI).At 6-24 months follow up,the stability of low lumbar was evaluated by reviewing the roentgenographic film,post-anterior,lateral,and bending views. Surgical technigue:All cases treated with posterior pedical screw fixation and lumbar interbody fusion.After fusion,there were two types of lumbar instrumented interbody fusions used in the investigation.â‘ Whole piece of iliac bone graft group:The dura sac and nerve roots were retracted gently towards the midline to expose the interbody space.The disc materials should be removed as much as possible bilaterally,but the end plate should keep intacted.The post iliac crest was chiseled as graft and inserted into the interbody space properly.The bone graft with three-planed cortex was prefered..The graft should be a little bit shorter than the body at sagital plane.The two body which would be fused should be compressed against the bone graft to make sure its position not be changed with the spinal movement.â‘¡Granular bone from lamina of vertebra and spinous processes graft group:Preparation before the bone graft was same to iliac bone graft group.The granular bone inserted into interbody space.Then to get a wedgy bone block from spinous processes and inserter it into interbody spacev astemly to avoid granular bone exodus.At last,we should to stop bleeding and to place drainage tube and sew up the incision.All the patients encountered the various lumbar fusion would be encouraged to carry a brace for walking 3～4 weeks postoperatively. Progressive rehabilitative therapy was then administered.Results:1.Significant difference of JOA score and ODI was founded in each group pre- and post- operative.But it was no significant difference between two groups.2.Significant difference of disc space height was observed in each group pre- and post- operative.It was also different between two groups that the disc space height lost more significant in granular bone-graft group.3.In each group,angle of interbody movement appeared significant changment comparision pre- and post- operative while comparing two groups,it wasn't significant different.4.In each group,there were no transparent region at the interface between the vertebral body and bone graft.No signs were found that bone graft dropped into the spinal canal in each group.Conclusion:The time of fusion,the fusion rate and catabatic grade of clinical results are no significant difference between two groups.Granular bone group was better than iliac crest group in costing time of surgery and bleeding,and no complication such as remained pain and so on.But granular bone group was significant loss of disc space height in patients utilizing iliac crest comparing to the patients.Pedical screw fixation+granular bone from lamina of vertebra and spinous processes graft for interbody fusion is the recommended surgical procedure for the treatment on degenerative low lumbar spinal instability.