Range of Motion in a Modular Femoral Stem System with a Variety of Neck Options

作者：Hariri Sanaz^*; Chun Sungwook; Cowan James B; Bragdon Charles; Malchau Henrik; Rubash Harry E

来源：Journal of Arthroplasty, 2013, 28(9): 1625-1633.

DOI：10.1016/j.arth.2012.10.011

• total hip arthroplasty
• biomechanics
• impingement
• dislocation
• modular femoral neck

Modular femoral stem systems decouple leg length, offset, and version. The hip ROM and type of impingement for 162 femoral head/neck combinations were measured at four extreme hip positions in a Sawbones pelvis and femur to identify constructs that lead to early impingement. Hip ROM increased in all positions with increasing head size and neck length. We identified a new type of impingement created by the build-up of the proximal femoral stem: femoral stem on acetabular liner impingement. Seventy percent of neutral neck options achieved our definition of acceptable ROM. In general, when utilizing a modular femoral stem, surgeons can minimize impingement by choosing the longest femoral neck that does not over-lengthen the limb, using the largest femoral head accommodated by the cup, and avoiding neck version unless the cup or stem is malaligned.

• 出版日期2013-10