Keyak J H, Skinner H B, Fleming J A
Department of Orthopaedic Surgery, University of California, Irvine Medical Center, Orange 92868-5382, USA.
J Orthop Res. 2001 Jul;19(4):539-44. doi: 10.1016/S0736-0266(00)00046-2.
Identifying the loading conditions under which the femur is most likely to fracture may aid the prevention of hip fracture. This study quantified the effect of force direction on fracture load, a factor inherently associated with fracture risk. Finite element (FE) models of four femora were used to determine the force directions associated with the lowest fracture loads. Force directions were varied three-dimensionally for two types of loading, one representing impact from a fall and one similar to joint loading during daily activities (atraumatic loading). For the fall configuration, the force direction with lowest fracture load corresponded to an impact onto the posterolateral aspect of the greater trochanter. For atraumatic loading, the lowest fracture loads for the force directions analyzed occurred when posterior force components were relatively large or when posterior and lateral components were both small, similar to conditions while standing on one leg or climbing stairs. When both fall and atraumatic configurations are considered, the type of loading associated with greatest fracture risk, i.e., with the greatest applied force and lowest fracture load, is impact from a fall onto the posterolateral aspect of the greater trochanter. Therefore, evaluation of hip fracture risk and development of fracture prevention technologies should focus on this high-risk loading condition.
确定股骨最易发生骨折的负荷条件可能有助于预防髋部骨折。本研究量化了力的方向对骨折负荷的影响，骨折负荷是一个与骨折风险内在相关的因素。使用四个股骨的有限元（FE）模型来确定与最低骨折负荷相关的力的方向。对于两种类型的负荷，力的方向在三维空间中变化，一种代表跌倒时的撞击，另一种类似于日常活动中的关节负荷（无创伤性负荷）。对于跌倒情况，骨折负荷最低的力的方向对应于大转子后外侧的撞击。对于无创伤性负荷，在所分析的力的方向中，当向后的力分量相对较大时，或者当向后和向外的分量都较小时，骨折负荷最低，这类似于单腿站立或爬楼梯时的情况。当同时考虑跌倒和无创伤性情况时，与最大骨折风险相关的负荷类型，即施加力最大且骨折负荷最低的情况，是从高处跌落到大转子后外侧的撞击。因此，髋部骨折风险评估和骨折预防技术的开发应关注这种高风险的负荷条件。
