Bioresorbable highª²strength bone rod for internal fracture fixation

    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 find an ideal biomaterial for internal fixation. METHODS: Twenty rabbits with fracture of the femur diaphysis (superiorcondyle) were treated by intramedullary nailing of femur with composites rod of resorbable DLª²polylactic acid (PDLLA)ª²calcium metaphosphate (CMP). The animals were sacrificed at 2, 4, 8 and 12 weeks after surgery. The fracture healing, the material degradation and mechanical properties were studied with Xª²ray films, macroscopic, microscopic and electron microscopic observations. RESULTS: No marked inflammatory reaction was found and all the fractures healed with material resorbed. At 12 wk, the 95% CI of the bending strength, the elastic modulus and the tensile strength of the PDLLAª²CMP fibers composites was 78.88-92.32 MPa, 6.24-7.24 GPa, 93.91-111.57 Mpa, respectively. CONCLUSION: The PDLLAª²CMP has an excellent biocompatibility and mechanical properties, and it may be a promising implant material in orthopedics surgery. ......