A simple method to minimize leg length discrepancy in hip hemiarthroplasty

Purpose: We developed a simple method to minimize leg length discrepancy (LLD) during hip arthroplasty. The purpose of this study is to evaluate the accuracy of the method. Patients and methods: A total of 47 patients who suffered from unilateral femoral neck fracture and underwent hip hemiarthroplasty between 2015 and 2018 were enrolled in this study. We measured the diameter of the contralateral femoral head (D) and the distance (L) between the center of the femoral head and the top of lesser trochanter in the antero-posterior pelvic X-ray view before the operation, the ratio (R) of D to L was calculated. During the operation, the diameter of the femoral head (d) was measured using a Vernier caliper. Then, the distance should be obtained from the center of the femoral head prosthesis to the lesser trochanter was calculated according to the contralateral ratio R. Results: The mean LLD was 4.4±3.2 mm (-4.0 to 11.1 mm), 80.9% of the patients had LLD <6 mm, 93.6% of the patients with LLD <10 mm, only 6.4% ≥10 mm LLD. Conclusion: This method is a simple, cost-effective, fast and accurate way to reduce the postoperative leg length discrepancy.