School of Mechanical, Aerospace and Civil Engineering, The University of Manchester, Manchester M13 9PL, UK.
J Orthop Res. 2012 Dec;30(12):1999-2006. doi: 10.1002/jor.22164. Epub 2012 Jun 15.
The surgical treatment of femoroacetabular impingement (FAI) often involves femoral osteochondroplasty. One risk of this procedure is fracture of the femoral neck. We developed a finite element (FE) model to investigate the relationship between depth of resection and femoral neck stress. CT data were used to obtain the geometry of a typical cam-type hip, and a 3D FE model was constructed to predict stress in the head-neck after resection surgery. The model accounted for the forces acting on the head and abductor muscular forces. Bone resection was performed virtually to incremental resection depths. The stresses were calculated for five resection depths and for five different activities (i) standing on one leg (static case); (ii) two-to-one-to-two leg standing; (iii) normal walking; (iv) walking down stairs; and (v) a knee bend. In general, both the average Von Mises stresses and the area of bone that yielded significantly increased at a resection depth of ≥10 mm. The knee bend and walking down stairs demonstrated the highest stresses. The FE model predicts that fracture is likely to occur in the resection area first following removal of a third (10 mm) or more of the diameter of the femoral neck. We suggest that when surgeons perform osteochondroplasty for hip impingement, the depth of resection should be limited to 10 mm.
髋关节撞击综合征（FAI）的手术治疗常涉及股骨骨软骨切除术。该手术的一个风险是股骨颈骨折。我们开发了一种有限元（FE）模型来研究切除深度与股骨颈应力之间的关系。使用 CT 数据获取典型凸轮型髋关节的几何形状，并构建了一个 3D FE 模型来预测切除手术后头部-颈部的应力。该模型考虑了头部的力和外展肌的力。对骨进行虚拟切除以达到递增的切除深度。针对五种切除深度和五种不同的活动（i）单腿站立（静态情况）；（ii）二到一到二腿站立；（iii）正常行走；（iv）下楼梯行走；以及（v）膝盖弯曲，计算了应力。一般来说，当切除深度≥10mm 时，平均 Von Mises 应力和屈服的骨面积都会显著增加。膝盖弯曲和下楼梯活动显示出最高的应力。FE 模型预测，在切除股骨颈直径的三分之一（10mm）或更多后，首先容易在切除区域发生骨折。因此，我们建议在进行髋关节撞击的骨软骨切除时，应将切除深度限制在 10mm 以内。
