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

    YANG Tuanª²Min, LIU Miao, YANG Aiª²Ling, SHI Zongª²Li

    1Department of Orthopaedics, First Hospital, Xi¡¯an Jiaotong University, Xi¡¯an 710061, China, 2People¡¯s Hospital of Xunyi County, Xunyi 711300, China, 3Institute of Material and Engineering, Lanzhou Jiaotong University, Lanzhou 730070, China

    ¡¾Abstract¡¿ AIM: To investigate the effect of selfª²designed 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. ......