Instability Of Lower Lumbar Treated With Posterior Lumbar Interbody Fusion Utilizing Iliac Crest Or Interbody Fusion Cage: A Pospective Comparative Study

Object: To prospectively compare the clinical and radiographic results of adult instability of lower lumbar treated with posterior lumbar instrumentation and interbody fusion utilizing iliac crest or interbody fusion cage.Methods: 32 instability of lower lumbar cases were collected from the inpatients in orthopaedics department from Feb, 2003 to Dec, 2005 .There were 22 males and 10 females.Their ages were from 35 to 78 and average age was 52.23.They were divided into two groups randomly. Bone-graft group: adopted posterior midline longitudinal incision, decompression for spinal stenosis were performed firstly, pedicle screws were conducted and separated to increase the interbody space, disc was removed while the anterior and lateral wall of fibrosus annulus were well preserved, the cartilage of endplate were gently curetted, enough cancellous bone harvested from iliac crest and laminectomy were inserted into the space. Finally, two tricortical bone grafts were conducted parallely with pedicle screw system compress and locking. Cage group:decompression for spinal stenosis and preparation of disc were just as the same as bone-graft group, enough laminectomy were inserted into the space. Finally, two quadrate PEEK cages filled with bone were conducted parallely with pedicle screw system compress and locking. Following markers were observed preoperatively and at the 1st month 3rd month 6th month and 12th month postoperatively: 1. The Japanese Orthopaedic Association(JOA) score. 2.Disc space height. 3.Angle of interbody movement. 4. Whether it had transparent region at the interface between the vertebral body and bone graft. All of statistic was treated with SPSS 12.0.Results: 1. Significant changement of JOA score was founded in each group pre- and post- operative. But it was no significant difference between two groups. 2. Significant changment 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 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.ConclusiomThe time of fusion,the fusion rate and catabatic grade of clinical results are no significant difference between two groups, iliac crest as well as interbody fusion cage can be used for interbody fusion for treatment of adult instability of lower lumbar and good clinical outcome can be achieved,no immunoreaction And iliac crest is low-cost. But there is significant loss of disc space height in patients utilizing iliac crest comparing to the patients...