PURPOSE Residual feeling of leg length discrepancy (LLD) is a common cause of patient dissatisfaction following total hip arthroplasty (THA). The purpose of this study is to propose a method for determining an optimal leg length correction goal in THA. METHODS We conducted a retrospective study of 132 patients to examine the radiographic LLD (R-LLD), perceived LLD (P-LLD), and whether or not the patient has an uncomfortable feeling about the leg length after THA. RESULTS The residual discomfort rate in all patients was 9.1% (12/132 patients), and ten of these 12 patients felt uncomfortable due to a longer leg length. When R-LLD was within 7 mm, the rate was 6.8% (8/118 patients), which is nearly equal to the rate of 7.8% (5/64 patients) in cases in which R-LLD was within 2 mm. On the other hand, when R-LLD was 8 mm or more, the rate was 57.1% (4/7 patients). CONCLUSIONS The results of our study show that 7 mm may be a reasonable threshold for reducing the residual discomfort. However, even with little or no R-LLD, some patients will continue to experience discomfort. We think that this is because of pre-operative differences between R-LLD and P-LLD in such cases. If the patient has a pelvic declination on the affected hip side and a lumbar scoliosis angle that is convex toward the affected hip side before surgery, the ideal length may be a little shorter than the radiographic isometry, since such patients are likely to feel a longer leg length than that shown radiographically.

中文翻译：

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在全髋关节置换术中优化腿长校正。

目的残留的腿长差异（LLD）感觉是全髋关节置换术（THA）后患者不满意的常见原因。这项研究的目的是提出一种确定THA中最佳腿长校正目标的方法。方法我们对132例患者进行了回顾性研究，以检查X线摄影LLD（R-LLD），感知LLD（P-LLD），以及患者在THA后是否对腿长感到不适。结果所有患者的残余不适率均为9.1％（12/132例），这12例患者中有10例由于腿长较长而感到不适。当R-LLD在7毫米以内时，该比率为6.8％（8/118例），几乎等于R-LLD在2毫米以内的比率为7.8％（5/64例）。另一方面，当R-LLD为8mm以上时，该比率为57。1％（4/7例）。结论我们的研究结果表明7 mm可能是减少残余不适的合理阈值。但是，即使很少或没有R-LLD，一些患者也会继续感到不适。我们认为这是由于在这种情况下R-LLD和P-LLD的术前差异。如果患者在手术前患侧髋骨盆偏斜并且腰椎侧弯角向患侧髋侧凸，则理想长度可能比放射线照相等距短一些，因为这样的患者可能会感觉更长腿长比射线照相显示的长。一些患者会继续感到不适。我们认为这是由于在这种情况下R-LLD和P-LLD的术前差异。如果患者在手术前患侧髋骨盆偏斜并且腰椎侧弯角向患侧髋侧凸，则理想长度可能比放射线照相等距短一些，因为这样的患者可能会感觉更长腿长比射线照相显示的长。一些患者会继续感到不适。我们认为这是由于在这种情况下R-LLD和P-LLD的术前差异。如果患者在手术前患侧髋骨盆偏斜并且腰椎侧弯角向患侧髋侧凸，则理想长度可能比放射线照相等距短一些，因为这样的患者可能会感觉更长腿长比射线照相显示的长。