三种手术方式固定不稳定性股骨转子间骨折的生物力学研究

摘要

Objective To study the biomechanics of simple locking proximal femoral plate (LPFP),LPFP combined with calcium phosphate cement (CPC) and proximal femoral nail antirotation (PFNA) in treatment of unstable intertrochanteric fractures.Methods Thirty-six femurs from 18 specimens with no pathological defects,fractures,malformations or neoplasms were enrolled in the study and were divided into three groups (Groups A,B and C),with 12 femurs per group.Intertrochanteric fractures were duplicated in accordance with Evans classification of type Ⅲ A.The fractures in Group A were treated by LPFP combined with CPC fixation,that in Group B treated with only LPFP fixation,while that in Group C fixed with PFNA.A comparative mechanical test of femoral specimens was performed in a special clamp.Results Axial compression test showed linear change of the load-displacement of three surgical fixations for intertrochanteric fractures under biological load.The measurement of torque-torsion angle of three fixations for intertrochateric fractures showed that the torque was enlarged with increase of torsion angle till the failure of internal fixation.Conclusion LPFP combined with CPC or PFNA can attain solid fixation of unstable intertrochanteric fractures.%目的 对单纯股骨近端锁定板(locking proximal femoral plate,LPFP)、LPFP联合磷酸钙骨水泥(calcium phosphate cement,CPC)、防旋股骨近端髓内钉(proximal femoral nail antirotation,PFNA)固定不稳定性股骨转子间骨折进行生物力学研究. 方法 18具标本共36根股骨纳入试验,标本证实无病理缺陷、骨折、畸形或肿瘤,分为A、B、C三组,每组各12根股骨,依据Evans分型中的ⅢA型股骨转子间骨折造模,A组采用LPFP联合CPC固定,B组采用单纯LPFP固定,C组采用PFNA固定.将股骨标本固定在特殊的夹具内进行力学对比测试. 结果 轴向压缩试验结果显示,在生理载荷作用下,三种内固定股骨上的载荷-位移关系基本上呈线性变化；股骨转子间骨折三种内固定扭矩-扭角测量结果表明,随着扭角的逐渐增大,扭矩也逐渐增大,直至内固定物失效. 结论 LPFP联合CPC或PFNA治疗不稳定性转子间骨折均能够达到坚强固定.