Comparison the Cortical Perforation of both the Recipient Beds and Grafts with the Cortical Perforation of Only the Recipient Beds

PURPOSE: The aim of this study is to compare volume and revascularization of autogenous block bone grafts in simultaneously cortical perforation of recipient beds and grafts, and only cortical perforation of recipient beds. MATERIALS AND METHODS: Two block bone in 8mm diameter was harvested in both skull using trephine bur on 20 New Zealand white rabbits. Harvested block bone was grafted on both inferior border of mandible. On the left side(experimental side), cortical bone of recipient beds and graftwere perforated, and on the right side(control side), the only recipient bed was perforated. The rabbits had been sacrificed and infused the India ink for the observation of revascularization at 20 day and 40 day after surgery. The specimens were processed for H-E staining and quantitative analysis(independent t-test, p<0.01) was made under an optical microscope. In additional, specimens were processed for the observation of revascularization. RESULTS: After 20 days, more bone volume was observed in experimental group, but no significant difference between two groups(p=0.106). There were significantly more bone volume in the experimental group at 40 days after surgery(p<0.01). After 20 days, more discrete vascular sprouts were observed in experimental side, but no difference at 40 days after surgery. CONCLUSION: We conclude that the cortical perforation of both the recipient beds and grafts improve revascularization at early stage and overall graft persistence.

Dynamic Stabilization with an Interspinous Process Device (the Wallis System) for Degenerative Disc Disease and Lumbar Spinal Stenosis

OBJECTIVE: We used an interspinous process device, the Wallis system, to treat patients with disc disease or lumbar spinal stenosis and retrospectively assessed the clinical and radiological outcomes. METHOD: The patients were divided into two groups, one with herniated disc disease(HDD) and the other with lumbar spinal stenosis(LSS). Nineteen patients and fourteen patients were enrolled in the HDD and the LSS group, respectively. Preoperative and postoperative pain and activities of daily living(ADL) were assessed in each group. The anterior, posterior disc height and height of the neural foramen were measured. The degree of flexion, extension and lateral flexion were measured. RESULTS: Both groups improved in pain and ADL after surgery. There were no significant changes in anterior, posterior disc height and height of the neural foramen after the operation in both groups. The change in coronal angle was statistically significant in the entire patient population. The kyphotic angle on the flexion lateral film was 6.1+/-4.1degrees preoperatively and 6.0+/-3.8degrees postoperatively in the entire patient population. Although it was not statistically significant, the kyphotic angle tended to decrease in the HDD group. The lordotic angle was 15.9+/-5.5degrees preoperatively and 13.5+/-6.3degrees postoperatively in overall patient population(from 15.5+/-3.9degrees to 14.0+/-2.7degrees in the HDD group and from 16.0+/-5.9degrees to 13.4+/-6.8degrees in the LSS group). The lordotic angle was significantly decreased in the LSS group. CONCLUSIONS: Interspinous process devices can induce favorable motion changes on lumbar motion such as decreasing tendency of flexion in the HDD group and decreasing tendency of extension in the LSS group. It suggests that interspinous devices may act as dynamic stabilizers in patients with degenerative disc disease and lumbar spinal stenosis.