兔腱内与界面诱导成骨促进腱-骨愈合

Intratendinous and interface induced ossification for improvement of tendon-bone healing in rabbit

[目的]探讨移植物成骨化诱导骨性连接促进肌腱-骨隧道(简称腱-骨)界面愈合的作用。[方法] 50只新西兰兔,其中30只一侧半腱肌肌腱内注入BMP愈合模型,一侧行肌腱移植物和腱-骨界面联合应用BMP(界面处理),对侧界面注射等量PBS为对照。采用X线片、大体解剖观察和组织形态学计量检测研究肌腱组织成骨化情况。[结果]术后12周时腱内处理侧肌腱组织H.E染色及Masson染色可见肌腱纤维内细胞增生明显,局部形成骨小梁样组织,部分区域还可见软骨样细胞存在。X线片检测结果显示肌腱组织钙化程度随术后时间延长而不断增加,肌腱组织钙化范围明显增大[4周:(5.51±0.45)mm^2;8周:(9.44±0.40) mm^2;12周:(20.26±0.98) mm^2,P<0.01]。此外,肌腱组织高密度区域IOD值也随时间增加而显著增高[4周:(1178.56±62.71);8周:(2135.26±90.92);12周:(4726.72±374.41),P<0.01]。术后12周时界面处理侧大体解剖观察可见肌腱移植物质地变硬,与周围骨组织紧密连接、局部融合。H.E染色和Masson染色结果显示肌腱移植物内部及腱-骨界面之间均可见新生骨组织形成,部分区域内新生骨组织与宿主骨组织形成骨性连接。处理侧与对照侧之间腱-骨界面愈合程度组织学评分差异有统计学意义[(6.60±0.77) vs(2.67±0.68),P <0.01]。[结论] BMP可诱导肌腱内骨化,并促进腱-骨界面形成骨性连接。

[Objective] To explore the effect of BMP-induced ossification intratendinously and at the interface on tendonbone healing. [Method] A total of 50 New Zealand rabbits were divided into two groups in this study. Of them, 30 rabbits received bone morphogenetic protein(BMP) injection intratendinously into the semitendinosus tendon randomly in one side,whereas PBS in equal volume on the contralateral side as a control, and 20 animals received BMP into the tendon graft and the tendon-bone gap of a tendon-bone healing model randomly on one side, while PBS in equal volume on the contralateral side as a control. The X-ray, gross observation and histomorphological assessment were conducted for evaluation of the ossification and healing. [Results] In the intratendinous study, the X-ray showed that the intratendinous calcification area significantly increased over time [(5.51±0.45) mm^2 at 4 weeks,(9.44±0.40) mm^2 at 8 weeks and(20.26±0.98) mm^2 at 12 weeks, P<0.01] associated with a significant increase of the integrated optical density ((1178.56±62.71) at 4 weeks,(2135.26±90.92) at 8 weeks and(4726.72±374.41) at 12 weeks, P<0.01)At 12 weeks after operation, the H.E. and Masson staining showed local formation of bone trabecular-like structure, accompanied with vigorous proliferation of fibroblast, and chondrocyte like cells. In the interface study, the tendon graft became hardened, tightly connected with bone tissue and partially fused in gross appearance. Additionally, The H.E and Masson staining revealed that the tendon bone interface was largely composed fibrocartilage and new bone tissue both inside and around grafts, with bony integration between the new bone and the host bone tissue. There was a significant difference between the experimental side and control side in histological score ((6.60±0.77) vs(2.67± 0.68), P<0.01)[Conclusion] BMP-induced ossification of tendon graft can enhance bony integration and healing of tendon-bone interface.