The distance of the centre of femoral head relative to the midline of the pelvis: a prospective X-ray study of 500 adults

Yash B. Rabari, Amol Sanap, D. V. Prasad, Krunal H. Thadeshwar


Background: The mechanical axis of the femur is defined as the line joining the centre of the femoral head to the centre of the knee joint. One of the pre-requisites for a successful total knee replacement (TKR) is correct positioning of the implants, so that the mechanical axis of the limb is restored to neutral. During TKR surgery, the distal femoral anatomy can be visualized. However, to identify the mechanical axis of the femur, the location of the femoral head must be known.

Methods: We prospectively measured distance of centre of femoral head relative to the midline of the pelvis in 500 adults, using x ray of pelvic with both hip anteroposterior view done for medical causes during 2-May-2015 to 1-Jan-2017 with satisfied the following inclusion and exclusion criteria. Patient gender and age were known. Both hips were clearly shown on the radiograph and not affected by any developmental or acquired condition that might deform normal anatomy. Radiographs demonstrating unacceptable pelvic tilt or rotation were excluded. Also, we excluded any cases where degenerative changes in the native hip were more severe than grade 1, based on the Tönnis classification.

Results: There were total 500 patients in which 250 were male and 250 were female. The mean age of male was 52.14 year (SD ±80.80 mm, 95% CI 51.05 to 53.24 mm) and female was 52.11 years (SD ±8.82 mm, 95% CI 51.01 to 53.24 mm).The mean distance of femoral head centre from midline in male was 95.02mm (SD ±2.20 mm, 95% CI 94.75 to 95.30 mm) and in female was 91.54 mm (SD ±2.64 mm, 95% CI 91.22 to 91.87 mm).

Conclusions:This study provide a useful information to determine the femoral head center relative to the midline of pelvis which useful intraoperatively. 



Femoral head, Pelvis

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