Objective： To evaluate the effects and mechanism of radiation-sterilized allogeneic bone sheets in inducing vertebral plate regeneration after laminectomy in sheep. Methods ： Twelve adult male sheep （ aged 1.5 years and weighing 27 kg on average ） provided by China Institute for Radiation Protection underwent L3-4 and L4-5 laminectomy. Then they were randomly divided into two groups： Group A （n =6） and Group B （n =6）. The operated sites of L4-5 in Group A and L3-4 in Group B were covered by ＂ H-shaped＂ freeze-drying and radiationsterilized allogeneic bone sheets （ the experimental segments）, while the operated sites of L3-4 in Group A and L4-5 in Group B were uncovered as the self controls （ the control segments ）. The regeneration process of the vertebral plate and the adhesion degree of the dura were observed at 4,8,12,16,20 and 24 weeks after operation. X- ray and CT scan were performed in both segments of 1.34 and L4-5 at 4 and 24 weeks after operation. Results： In the experimental segments, the bone sheets were located in the anatomical site of vertebral plate, and no lumbar spinal stenosis or compression of the dura was observed. The bone sheets were absorbed gradually and fused well with the regenerated vertebral plate. While in the control segments, the regeneration of vertebral plate was not completed yet, the scar was inserted into the spinal canal, compressing the dura and the spinal cord, and the epidural area almost disappeared. Compared with the control segments, the dura adhesion degree in the experimental regenerated segments was much milder （ P 〈 0. 01 ）, the internal volume of the vertebral canal had no obvious change and the shape of the dura sack remained well without obvious compression. Conclusions： Freeze-drying and radiation-sterlilized allogeneic bone sheets are ideal materials for extradural laminoplasty due to their good biocompatibility, biomechanical characteristics and osteogenic ability. They can effectively reduce formation of post-laminec
[目的]研究同种异体骨支撑架结合自体骨和脱钙骨基质(decalcified bone matrix,DBM)植入治疗股骨头坏死生物力学变化。[方法]建立羊双侧股骨头坏死模型,4周后分为4组:单纯行髓芯减压组(A组)、髓芯减压后植入自体松质骨和OSTEOSET(2DBM组(B组)、髓芯减压后植入同种异体骨支撑架/自体松质骨OSTEOSE(2DBM组(C组)和正常对照组。术后分别于5、10、20周对股骨头行影像学、组织学观察和生物力学测定。[结果]影像学和组织学检查结果显示C组在髓芯减压区骨缺损修复及成骨方面较B组略高,B、C两组都较同时期的A组明显增强。生物力学测试结果表明,术后5、10、20周时C组力学强度较A、B两组明显增高,差异有统计学意义(P<0.05),在10、20周时C组股骨头生物力学强度和正常股骨头己无明显差异。[结论]应用同种异体骨支撑架结合自体骨和脱钙骨基质治疗股骨头坏死,能有效加强股骨头的力学结构,促进坏死骨的修复,防止股骨头关节面的塌陷。
