生物可吸收固定材料对实验性骨折愈合影响的超微结构观察

目的: 探讨自行研制的生物可吸收固定材料对骨折愈合的影响. 方法: 用生物可吸收固定材料(PDLLA/CMP)对20只兔(平均3.5 kg)股骨下端骨折进行髓内固定. 固定各2, 4, 8, 12和24 wk分别取骨折愈合区骨痂一组进行电镜下超微结构观察. 结果:①骨折第2周炎性反应期结束;②成纤维细胞出现在2～4 wk,成骨细胞出现在4 wk;③胶原纤维结构正常;④24 wk时骨细胞超微结构正常,无退变现象. 应用生物可吸收材料进行骨折内固定,骨折愈合细胞进程无明显变化;成骨过程活动正常;特别在较长时间固定后,骨细胞形态、结构无退变表现. 结论:用生物可吸收内固定物进行固定,其骨折愈合的超微结构表现与传统理论之间无明显差异,是一种有发展前途的可吸收内固定材料.

Ultrastructural observing the effect of bioabsorbable material internal fixation on experimental fracture healing

AIM: To investigate the effect of self designed bioabsorbable material internal fixation on experimental fracture healing. METHODS: Twenty rabbits with fracture of the femur were fixed intramedullary by use of absorbable material (PDLLA/CMP). The animals were sacrificed at 2, 4, 8, 12 and 24 weeks after surgery. Specimens were obtained from the callus of the united region and prepared for electron microscopic examination. RESULTS: It was found at ultrastructural level that inflammatory reaction ended to the 2nd week after fixation. Fibroblasts and osteoblasts appeared at 2 to 4 weeks with normal structure of collagenous fibers. The ultrastructure of bone cells was normal at 24 weeks without degenerative changes. Results suggest that internal fixation by absorbable material had no effect on the course of fracture healing, the osteogenesis appears to be normal. No degenerative changes in the structure of bone cells can be observed even after rather long term fixation. CONCLUSION: The appearance of the structure of union after fixation by absorbable material seemed to no significant different from the traditional concept. It can be a promising implant material in orthopaedics surgery.