碱性成纤维细胞生长因子和部分脱蛋白骨对兔股骨头缺损再血管化的影响

背景股骨头缺血坏死的治疗是骨科领域的一大难题.然而,近来的研究表明碱性成纤维细胞生长因子是一有效的血管生成因子,推测其在股骨头缺血坏死的治疗方面可能具有一定潜能.目的模拟临床上治疗股骨头坏死的开窗法的手术过程制备兔股骨头缺损,并植入碱性成纤维细胞生长因子和部分脱蛋白骨,以探讨碱性成纤维细胞生长因子对股骨头缺损的再血管化作用.设计随机对照实验.单位昆明医学院动物实验中心.材料实验于2002-07/2003-07在昆明医学院动物实验中心完成.成年雄性健康新西兰白兔27只,体质量2.2～2.8 kg.随机分为碱性成纤维细胞生长因子/部分脱蛋白骨复合骨组,单纯部分脱蛋白骨组,空白对照组,每组9只.方法①制备碱性成纤维细胞生长因子/部分脱蛋白骨复合骨含碱性成纤维细胞生长因子10 ng/mm3载体.②股骨头缺损模型的建立及修复取兔27只,在股骨头颈交界处开窗,建立骨缺损模型.复合骨组植入碱性成纤维细胞生长因子/部分脱蛋白骨;部分脱蛋白骨组植入单纯部分脱蛋白骨;空白对照组不植入任何植入物.实验动物分别于术后2,4,8周各时相点麻醉状态下进行墨汁灌注并处死,取材.主要观察指标①兔股骨头标本组织学检查及血管计数.②微血管面积图像分析.结果27只兔均进入结果分析.①兔股骨头标本组织学检查及血管计数术后8周,复合骨组移植材料被骨组织所取代,骨髓腔形成,其中有丰富的髓内血管存在;脱蛋白骨组移植材料亦被骨样组织包裹,且大部分部分吸收;空白对照组股骨头的缺损区被纤维组织填充,在缺损区周边的结缔组织中可见新生骨样组织和散在软骨细胞岛,血管数量较少.2周微血管计数复合骨组均显著高于部分脱蛋白骨组和空白对照组(31.833±7.914)比(22.917±2.079)和(11.250±4.220)(血管数量/视野),P＜0.01,P＜0.05];4周和8周微血管计数复合骨组和脱蛋白骨组均显著高于空白对照组.②微血管面积图像分析20μm厚的透明标本光镜下观察见术后2,4,8周,复合骨组修复区血管丰富并吻合成网,部分脱蛋白骨组血管丰富吻合成网,空白组血管散在.结论碱性成纤维细胞生长因子具有促进股骨头缺损的再血管化作用,其在治疗股骨头坏死方面具备一定的潜能和优势.

Revascularizing effect of basic fibroblast growth factor and partially deproteinised bone on femoral head defects in rabbits

BACKGROUND:The treatment of avascular necrosis of femoral head remains a clinical challenge. However, recent study shows that basic fibroblast growth factor (Bfgf) is an effective angiogenic growth factor. We suppose that Bfgf has the potential in treating avascular necrosis of femoral head through revascularizing effect and steogenesis.OBJECTIVE: To develop a rabbit model that simulates the clinical situation with trapdoor bone rafting and evaluate the revascularizing effect in the repair of femoral head defect with Bfgf/partially deproteinised bone (PDPB).DESIGN: A completely randomized controlled trial.SETTING: Animal Experimental Center of Kunming Medical College.MATERIALS: The experiment was conducted in the Animal Experimental Center of Kunming Medical College between July 2002 and July 2003.Totally 27 adult male healthy New Zealand rabbits, weighing 2.2 to 2.8 kg,were recruited and randomly divided into Bfgf/composite PDPB group,single PDPB group, and blank control group with 9 rabbits in each group.INTERVENTIONS: ① Preparation of Bfgf/PDPB: containing Bfgf 10 ng/mm3. ② Establishment and repair of femoral head defect model:Totally 27 rabbits were chosen. Bone defect model was stablished by opening a trapdoor between femoral head and femoral neck. Bfgf/PDPB was implanted in composite group; single PDPB was implanted in PDPB group; no implants were given in blank control group. The rabbits were killed after injection through blood vessels with prepared Chinese ink 2, 4and 8 weeks after operation, and then the femoral head of each rabbit was taken out as specimen.MAIN OUTCOME MEASURES: ① Histological examination and blood vessel counting. ② Image analysis of microvessel area.RESULTS: Twenty-seven rabbits all entered the result analysis. ① Histological examination and vessel count of femoral head specimens in rabbits:8 weeks after operation, composite bone group: implants were replaced with bone tissues and medullary cavity of bone formed. A lot of medullary vessels were present. DPB group: implants were enwrapped by bonelike tissues and most of them were absorbed. Blank control group: the area of femoral head defect was filled with fibrous tissues. New bonelike tissues and scattered chondrocyte island appeared in the adjacent connective tissues of defect area, with a small number of blood vessels. Microvessel count at week 2 in composite group was significantly higher than that in PDPB group and blank control group (31.833±7.914) vs (22.917±2.079)and (11.250±4.220) (number of blood vessel/field), P ＜ 0.01, P ＜ 0.05].The number of microvessels at weeks 4 and 8 in composite bone group and DPB group was significantly greater than that in blank control group. ②Image analysis of microvessel area: The transparent samples of 20 μm thick were observed under the optical microscope: 2, 4 and 8 weeks after operation, there were many vessels woven into nets. Many vessels woven into nets were also found in PDPB group; there were scattered vessels in blank control group.CONCLUSION: Bfgf has the revascularizing effect on the repair of femoral head defect, and has the potential and advantages in treating avascular necrosis of femoral head.