Useful Method for Minimizing Leg Length Discrepancies in Hip Arthroplasty: Use of an Intraoperative X-ray

Purpose: There are numerous opinions about the methods and usefulness of minimizing leg length discrepancies after hip arthroplasty. In this study, we tried to evaluate the usefulness of an intraoperative x-ray in addition to preoperative templating for minimizing leg length discrepancy. Materials and Methods: We reviewed pre- and post-operative pelvis AP x-rays of 46 patients who underwent hip arthroplasty due to a traumatic femoral neck fracture or intertrochanteric fracture between May 2008 and February 2009. A leg length discrepancy is the difference in vertical distance between a horizontal line drawn along the bottom of the ischial tuberosities and the most inferior points of the lesser trochanter. It was measured in a pelvis AP x-ray. In each case, pre-operative templating was performed and an intraoperative pelvis AP x-ray was taken again to assess the accuracy of preoperative planning. Implant positions were readjusted when necessary. Results: The mean post-operative leg-length discrepancy was 0.3 mm (SD, 3.1 mm). The range was from -5.8 mm to +5.9 mm. Conclusion: Combining preoperative templating and intraoperative x-rays is a useful method of minimizing leg length discrepancy during hip arthroplasty.