IS IT NECESSARY TO DECORTICATE SEGMENTALLY INSTRUMENTED SPINES TO ACHIEVE FUSION

Study Design. The effects of spinal instrumentation and decortication on spinal arthrodesis rates-when performed independently and when used together-were studied in an experimental animal model. Materials and Methods. Fifty-two immature New Zealand white rabbits underwent six different spinal procedures. The animals were killed six weeks postoperatively and their spines were evaluated by gross examination, radiography, manual stress testing, and histologic means. Results. The addition of rigid instrumentation to autologous iliac grafting significantly improved fusion rates in animals that were not decorticated. However, when decortication was done, a statistically significant improvement could not be documented. The addition of decortication to autologous iliac grafting significantly improved fusion rates in noninstrumented spines, but in instrumented spines, a statistically significant improvement could not be demonstrated.