牛骨形态发生蛋白复合纤维蛋白促进骨质疏松性椎体骨折愈合的实验研究

目的探讨以纤维蛋白为牛骨形态发生蛋白(bBMP)载体促进大鼠骨质疏松性椎体骨折愈合的机制。方法选择雌性SPF级8月龄SD大鼠81只,随机选取54只经去除卵巢建立骨质疏松模型,27只行伪手术。3月后以腰5椎体手术开窗刮除术区内松质骨的方法建立骨折模型,去除卵巢建立的骨质疏松模型随机分为两组:A组为骨质疏松椎体骨折bBMP治疗组,B组为骨质疏松椎体骨折空白组。每组各27只,C组为伪手术组。于术后1,2,4,6,8,12周观察影像学、组织学与力学性能。结果(1)影像学观察:术后两组X线片示腰5椎体有一骨折缺损透光区。A,C组在术后6周时透光区与周围骨质无明显差别,而B组仍清晰可见,于8周时无明显差别。(2)组织学观察:三组软骨细胞在骨质愈合1周时出现,形成软骨岛,但B组软骨细胞每高倍镜下数量明显少于A,C组,另外,软骨细胞改建成成熟骨细胞,骨小梁形成数量,胶原纤维排列较A,C组有明显差异。(3)力学性能测定:在骨质愈合6~12周,腰5椎体的最大载荷、弹性模量、最大应力明显高于同期B组,差异显著(P<0.05),而A,C组之间无统计学意义(P>0.05)。结论bBMP复合纤维蛋白明显促进骨质疏松性椎体骨折愈合,证明在骨质疏松性松质骨骨折修复过程中bBMP以纤维蛋白为载体作用显著,骨折愈合质量明显增高。

Studies on Vertebral Fracture Healing in Osteoporosis with Bovine Bone Morphogenetic Protein and Human Fibrin

Objective To repair osteoporotic vertebral fractures with bovine bone morphogenetic protein (bBMP) and human fibrin in rat and quantify the outcome of bone healing in an animal model of osteoporosis in terms of alteration in roentgenography, bone structure and bone mechanics. Methods Eighty-one 8-month-old female Sprague-Dawley (SD) rats were randomized into three groups (n=27/group), i.e. Group A (osteoporotic vertebral fracture models treated with bovine bBMP and human fibrin), Group B (osteoporotic vertebral fracture models without any treament) and Group C (common vertebral fracture rats with pseudo-operation). The callus of each rat was examined by roentgenography, bone histology and biomechanical testing in 1, 2, 4, 6, 8 and 12 weeks postoperatively. Results Roentgenography showed that the area of the vertebral fracture of Group B was different from that of Group A or C in 6 weeks but was the same in 8weeks postoperatively. Bone histology showed that chondrocytes were seen in one week, but it was Group B that possessed fewer chondrocytes, smaller trabecular number and more rarefied collagen. The outcome in compression testing of vertebral column was significant different between Group A or Group C and Group B (P<0.05), but was not different between Group A and Group C (P>0.05). Conclusion The composites of bBMP and fibrin can be used effectively to repair vertebral fracture.