Abstract
Purpose: Prospective randomized clinical and radiological study to compare the evolution of instrumented posterolateral lumbosacral fusion using either coralline hydroxyapatite(CHA), or iliac bone graft(IBG) in three comparable groups of patients.
Methods: 56 randomly selected adult patients with spinal stenosis were divided into three groups(A,B,C) included 17, 19 and 20 patients respectively and underwent decompression and fusion. The spines of Group A received IBG ; Group B IBG on the left side and CHA mixed with local bone and bone marrow on the right side; Group C CHA mixed with local bone and bone marrow bilaterally. The patients’s age was 61+11, 64+8 and 58+8 years for groups A, B and C respectively. SF-36, Oswestry Disability Index, and Roland-Morris surveys were used. Visual Analog pain Scale was used for pain. Roentgenograms (AP, lateral and oblique plus bending views) and CT-scans were used to evaluate the evolution of fusion. Two independent observers tested variability in evolution of the dorsolateral bony fusion 3 to 48 months postoperatively with the Christiansen’s and CHA resorption in Groups B and C.
Results: Intraobserver and interobserver agreement (r) for radiological fusion was 0.71 and 0.69 respectively, and 0.83 and 0.76 for evaluation of CHA resorption. There was no visible pseudarthrosis. Fusion was achieved one year postoperatively. CHA resorped 6 months postoperatively at the intertransverse spaces. Bone bridging started 3 months postoperatively in all levels posteriorly as well as between the transverse processes where IBG was applied. SF-36, Oswestry Disability Index, and Roland-Morris Score improved > 20 postoperatively in all groups. There was one pedicle screw breakage at the lowermost-instrumented level in group A and two in group C without pseudarthrosis. There was no deep infection. Operative time and blood loss were less in group C, while donor site complaints were observed in the patients of the groups A and B only.
Discussion & Conclusion: This study showed that autologous IBG remains the gold standard for posterior instrumented lumbar fusion to which each new graft should be compared. CHA was proven in this series not appropriate for intertransverse posterolateral fusion because the host bone in this area is little.
Theses abstracts were prepared by Professor Roger Lemaire. Correspondence should be addressed to EFORT Central Office, Freihofstrasse 22, CH-8700 Küsnacht, Switzerland.
