骨缺损修复机制探讨

The mechanism of the healing of long bone defect

目的通过引导性骨再生和组织工程软骨移植研究长骨骨缺损的修复机制。方法实验组在几丁质纤维载体上增殖21d的新生兔关节-干骺端复合物的软骨细胞(含载体)被装入硅胶管内,移植到成年兔桡骨干1cm的缺损上,对照组骨缺损处仅套接空套管。结果实验组术后4周时3例移植的软骨细胞在骨缺损内均形成软骨样组织,术后16周时9例中仅2例缺损愈合。对照组术后16周时9例(空套管)均骨性愈合。新生兔四肢关节-干骺端软骨细胞移植到同种成年兔桡骨缺损区后未修复骨缺损,未再现软骨内化骨过程。同时移植物可能因为占据空间、防止骨髓的成骨成分进入等原因中断了骨缺损修复过程。结论骨缺损的修复可能是先由骨膜增生形成成骨空间,然后由骨髓成分成骨,也就是一个在骨膜保护下的骨髓作用为主的天然的引导性骨再生过程。

Objective Study the mechanism of the healing of bone defect after transplantation of the tissue-engineered cartilage into the bone defects and with guided bone regeneration tubes.Method The chondrocyte harvested from the articular-epiphysis complex of a newborn rabbit was cultured in vitro with fibrous chitin mash for 21days. Then the mash with chongrocyte were transplanted into the defects of the radius of 12 adult rabbits in silicon tubes (study group), while the defects in control group were bridged with empty silicon tubes. Result 4 weeks late, 3 of the defects in the study group were filled with cartilage-like tissue that was disappeared in 16 weeks. 2 of the other defects healed with bone in 16 weeks. Control group: all of the 9 defects healed 16 weeks.The osteogenic process did not happen in the tissue-engineered cartilage in the bone defects. The transplanted cartilage did not change into bone itself, and it may block the ostrogenic factors of bone marrow from entering the defects. Conclusion The healing of bone defect might be an osteogenic process of bone marrow under the protection of proliferated periosteoum. The mechanism of guided bone regeneration might be the strengthening of the nature “guiding tube”-the generation of the periostium.