Johnston R C, Brand R A, Crowninshield R D
J Bone Joint Surg Am. 1979 Jul;61(5):639-52.
The normal mechanical function of the hip is substantially altered by a variety of disorders. The surgical treatment of such conditions, particularly total hip replacement, offers the opportunity not only to replace the articular surfaces of the joint, but also to improve long-term mechanical function by reducing the loads on the joint. A mathematical model of the hip was developed to evaluate the effects of such surgically achievable mechanical alterations as acetabular placement, femoral shaft-prosthetic neck angle, neck length of the femoral prosthesis, and transfer of the greater trochanter. The loads on the hip were lowered significantly by placing the center of the acetabulum as far medially, inferiorly, and anteriorly as was anatomically feasible. Minimum joint contact forces occurred when the femoral shaft-prosthetic neck angles were small, while the minimum moments about the prosthesis stem-neck junction were found when the angles were 130 to 140 degrees. A neck length of the femoral prosthesis of thirty-five millimeters resulted in moments that were lower than those for a neck length of forty-five millimeters. Lateral transfer of the greater trochanter reduced hip-joint forces and moments but distal transfer had little mechanical effect.
髋关节的正常机械功能会因多种疾病而发生显著改变。针对此类病症的手术治疗，尤其是全髋关节置换术，不仅提供了更换关节面的机会，还能通过减轻关节负荷来改善长期机械功能。我们建立了一个髋关节数学模型，以评估髋臼位置、股骨干 - 假体颈角度、股骨假体颈长度以及大转子移位等手术可实现的机械改变所产生的影响。通过将髋臼中心尽可能向内侧、下方和前方放置到解剖学上可行的位置，髋关节上的负荷显著降低。当股骨干 - 假体颈角度较小时，关节接触力最小；而当角度为130至140度时，假体柄 - 颈交界处的力矩最小。股骨假体颈长度为35毫米时产生的力矩低于颈长度为45毫米时的力矩。大转子向外侧移位可降低髋关节的力和力矩，但向远端移位几乎没有机械效应。
