The innominate tubercle of the femur is a consistent surgical landmark and shows no variation between sex and side: An osteological study.

Abstract

During direct anterior approach hip arthroplasty, the innominate tubercle (IT) of the femur is used as a reference point for femoral neck osteotomy. A recent study found that IT dimensions are unaffected by femoral length, neck-shaft angle, and neck length. This study investigated the position of the tubercle relative to femoral side, sex and femoral neck dimensions. One hundred and ninety femora (95 pairs, complete with biographical data) from St. Bride's Church, London, were photographed with the apex of the tubercle marked. Using imaging software, axes were superimposed onto the image, allowing the X and Y co-ordinates of the tubercle apex to be derived. Statistical analysis was carried out. The position of the tubercle did not vary significantly and did not correlate with femoral side (p> .05). P values for variation of the X and Y coordinates were 0.351 and 0.996 in left and right femora, respectively. The tubercle position did not vary significantly with sex (p> .05). p Values for variation of the X and Y coordinates were 0.254 and 0.634 in males and females, respectively. There was little variation between tubercle position and femoral neck dimensions: correlation coefficient -0.20 (x coordinate) and -0.12 (y coordinate). The data showed that the position of the IT did not vary significantly with either sex or side and that, therefore, the tubercle can be considered a reliable surgical landmark during arthroplasty surgery.