Measurement of the relative position of the femoral head center, greater trochanter, and lesser trochanter

Understanding the relationship between the greater trochanter, the lesser trochanter, and the femoral head center is helpful to achieve satisfactory lower limb length in hip arthroplasty, and it may be more important when the contralateral side of the surgical hip cannot be referenced. This work aims to measure the relative position of the femoral head center, the greater trochanter, and the lesser trochanter, and analyze the relationship between these anatomical landmarks.The femoral head diameter (D), the linear distance (G) from the femoral head center (C) to the greater trochanter, and the linear distance (L) from the femoral head center to the lesser trochanter were measured by pelvic X-ray. The basic information of the data was analyzed, the ratios of G to D and L to D were calculated, the functional relationship between the data was analyzed after the factors of gender and age were included, and the 95% reference intervals of the basic data and ratio data were calculated.A total of 97 patients with 194 hips were enrolled in this study. The diameter D was 5.08±0.43 cm, the distance G was 4.68±0.45 cm, and the distance L was 4.28±0.49 cm. The G/D ratio was 0.92±0.07, and the 95% reference range was 0.78-1.06. The L/D ratio was 0.84±0.08, and the 95% reference range was 0.68-1.00. Gender (g) was included in the regression analysis, and the regression equations G =1.890+0.536*D and L =1.129+0.620*D were obtained. Age was not related to the distances G and L.The basic data of G, D, and L was measured, and the relationship between these anatomical landmarks was analyzed.