BMP-2结合微骨折技术治疗犬关节全层软骨缺损的组织学和生物力学研究

目的研究重组人骨形态发生蛋白-2（recombinant human bone morphogenetic protein 2,rhBMP-2）结合微骨折技术治疗犬关节软骨全层缺损的可行性,为临床应用提供实验依据。方法在16只家犬的双侧股骨内外髁形成实验性关节软骨全层缺损,分别局部应用rhBMP-2结合微骨折技术（结合组）、rhBMP-2（BMP组）、单纯微骨折技术（微骨折组）、以及空白对照组4种方法。术后12周取材作大体、光学显微镜、透射电子显微镜观察。应用INSTRON万能材料实验机检测拉伸强度、蠕变率和松弛率。结果大体观察3个实验组之间没有明显差异（P〉0.05）,但与对照组存在差异（P〈0.05）。光学显微镜观察结合组与微骨折组、BMP组有显著差异（P〈0.05）,3组与对照组均有显著差异（P〈0.05）。电子显微镜观察12周结合组在细胞的同源性、形态、核浆比、细胞器功能状态、胶原分布等方面优于2个实验组和对照组。生物力学检测结合组在抗拉伸和粘弹性松弛率上优于其他2个实验组（P〈0.05）,但与正常软骨仍有差异（P〈0.05）。结论BMP-2结合微骨折技术是修复犬关节软骨全层缺损有效的方法,且在技术上是可行的。

Experimental study on the treatment of cane full-thickness articular cartilage defects by BMP-2 in combination with microfracture technique

Objective To study the feasibility of treatment of canine full-thickness articular cartilage defects by BMP-2 in combination with microfracture technique, and to provide evidence for its clinical application. Methods Experimental full-thickness articular cartilage defects were created in the medial and lateral condyles of the bilateral fumurs of 16 dogs. The 64 defects were randomly divided into 4 groups： the group in which defects were treated with BMP-2 only, with microfraeture technique alone, with BMP-2 in combination with subchondral bone drilling, and with no treatment （the control group）. Specimens were collected and examined 12 weeks after operation for macro-, optical- and electro-microscopic observations. Four more dogs were operated, specimens were collected in same manner and subjected to biomechanical experiments of one dimensional tensile, steer creep, and telaxation tests. Results Macroscopically there was no significant difference among the three treatment groups （ P 〉 0.05 ）, but each group was different to the control group （P 〈 0.05）. Defects were repaired in the control group with fibrous tissues, but with fresh cartilage in three treatment groups. Among them, defects in the group of rhBMP-2 in combination with microfracture technique showed best results in the respects of cell shape, ultrastructure and biomechanical tests. Conclusion Combination of BMP-2 treatment and microfracture technique can repair canine full-thickness articular cartilage defects, and is proven technically feasible.