Woolson S T, Hartford J M, Sawyer A
Stanford University Hospital, California, USA.
J Arthroplasty. 1999 Feb;14(2):159-64. doi: 10.1016/s0883-5403(99)90119-5.
The postoperative leg-length discrepancy was determined radiographically for a consecutive series of 351 patients (408 hips) who underwent bilateral or unilateral primary total hip replacement using a single method of leg-length equalization by preoperative planning with overlay templates. The method of equalization was performed by a measurement of the femoral head and neck segment to be resected from a reference point at the superior aspect of the dislocated femoral head. The amount of femoral bone resected was determined preoperatively by determining the dimensions of the acetabular component thickness and the femoral component head and neck height that would be replacing this resected bone and adjusting this distance for any preexisting leg-length discrepancy. Using this leg-length equalization method, the length of the modular femoral head neck was chosen preoperatively, rather than using soft tissue tension across the prosthetic hip joint to determine whether the leg lengths were equal. Postoperative leg lengths were determined radiologically from a measurement from the acetabular teardrop to the lesser trochanter. Ninety-seven percent of the patients had a postoperative leg-length discrepancy that was less than 1 cm, and 86% had a leg-length difference that was 6 mm (1/4 inch) or less. The average postoperative discrepancy for these 351 patients was 1 mm.
对连续351例患者（408髋）进行了术后双下肢长度差异的影像学测定，这些患者接受了双侧或单侧初次全髋关节置换术，采用术前使用重叠模板进行规划的单一双下肢长度均衡方法。均衡方法是通过从脱位股骨头上方的参考点测量要切除的股骨头和颈段来进行的。术前通过确定髋臼假体组件厚度以及将替代该切除骨的股骨假体组件头和颈高度的尺寸，并针对任何术前存在的双下肢长度差异调整该距离，来确定股骨切除量。使用这种双下肢长度均衡方法，术前选择模块化股骨头颈的长度，而不是利用假体髋关节周围的软组织张力来确定双下肢长度是否相等。术后双下肢长度通过从髋臼泪滴到小转子的测量进行影像学测定。97%的患者术后双下肢长度差异小于1厘米，86%的患者双下肢长度差异为6毫米（1/4英寸）或更小。这351例患者术后的平均差异为1毫米。
