摘要
目的 :对临床常用的股骨颈骨折三枚加压松质骨螺钉内固定技术 ,进行体外力学稳定性测试。方法 :采用一具青年男性正常新鲜股骨作为试验标本 ,与股骨颈长轴垂直锯断 ,作成股骨颈头下型骨折 ,然后用三枚AO松质骨空心螺钉进行固定。骨折前后均在生物力学测试装置上测定其股骨头垂直位移和转角位移 ,以及股骨上端的应变变化 ,并进行归一化系数分析。结果 :股骨头垂直位移随着负荷增大而增加 ,骨折态股骨头垂直位移约为正常态的 2倍。骨折态的应变分布也发生了变化 ,股骨张力侧所受应变下降 ,而压力侧增加 ,说明股骨颈骨折三枚AO松质骨螺钉内固定后应力传导移向股骨上端内侧。无论正常态和骨折态 ,股骨头的扭转角均很小 ,但骨折态的最大扭转角为正常态的 11.9倍。结论 :股骨颈头下型骨折经三枚加压松质骨螺钉内固定后 ,其力学稳定性仍比正常态差 ,而且力学分布移向整个股骨的受压区域。因此在骨折愈合前 。
Objective: To evaluate biomechanical stability of three cancellous screws internal fixation technicqe used for treatment of femoral neck fracture. Methods:One fresh, male human femur was selected. After initial mechanical characterization of the intact femur, subcapital femoral neck fracture was created, reduced, and instrumented with 3 cannulated cancellous screws. then it was tested again and the data was normalized with the same intact femur. Results: The vertical head displacement increases with axial loads, which the fractured is about 2 times of the intact. The strain distribution is changed after fracture, with decreased tension and increased compression. It is demonstrated that axial loading is shifted from lateral side to inner side of the femur after fracture and instrumentation. whether the fractured or the intact, its torsional angle is minimal. But that of the fractured is 11.9 times of the intact. Conclusion:After subcapital femoral neck fracture is instrumented with 3 cannulated cancellous screws, the mechanical stability is not as strong as that of the intact and load distribution is shifted to the inner side of the femur. So the fractured hip should be protected before fracture healing.
出处
《中国临床医学》
2003年第6期859-861,共3页
Chinese Journal of Clinical Medicine
关键词
股骨颈骨折
加
松质骨空心螺钉
内固定
生物力学
Femoral neck fracture Internal fixation Cannulated cancellous screws Biomechanics
