Radiographic Assessment of the Proximal Femoral Anatomy in An Indigenous African Adult Population

Abstract

Background: Hip surgeries such as fracture fixation, corrective osteotomy, hemiarthroplasty, or total hip arthroplasty require accurate preoperative templating for a successful outcome. Such templating is done using the proximal femur and the acetabulum radiographs, depending on the planned surgery. Understanding the normal radiographic anatomy of the proximal femur is crucial to differentiate a normal from pathological anatomy. Proximal femoral anatomic indices include the femoral head diameter, femoral neck diameter, femoral neck length, femoral offset, femoral neck axis length and the femoral neck-shaft angle. Aim: This study assesses and establishes the average values of the proximal femoral anatomy in an indigenous African adult population. Method: This cross-sectional study examined 190 normal anteroposterior (AP) radiographs of the pelvis. The mean age, weight and height of the subjects were obtained. The following proximal femoral anatomic parameters were measured: femoral neck length (FNL), femoral neck diameter (FND), femoral head diameter (FHD), femoral neck-shaft angle (FNSA), femoral offset (FO) and femoral neck axis length (FNAL). The authors compared the mean difference of the parameters between the genders and the age categories and assessed the parameter correlations with the patients’ weight and height. Results: Males constituted 63 (33.2%) of the study population. The mean age of the subjects was 51.46 years (SD = 16.37). The mean weight was 76.13 kg, while the mean height was 1.62 m. The mean values of the proximal femoral parameters were as follows: FNL 4.52cm, FND 3.42cm, FHD 4.76cm, FNSA 132.960, FO 4.09cm, and FNAL 10.34cm. Males have a significantly higher mean value in all the parameters except the FO. None of the parameters showed any significant difference among the age categories except the FNL. A post-hoc analysis showed that the difference in the FNL lies between the young and the elderly age groups. The subjects’ height correlated with all the parameters except FNSA, while the weight correlated with the FND, FNSA and FNAL. Conclusion: The proximal femoral anatomy in Africans differed from those published in foreign literature. This knowledge is crucial for implant manufacturing companies and preoperative templating for hip surgeries. KEY WORDS: Proximal femur, Anatomy, Black population.