Proximal femoral bone morphological measurements: Relevance in orthopaedic and forensic medicine

Abstract

Background: Numerous surgical procedures are performed on and around the proximal femur to restore the anatomy and maintain the function of the limb. Hip joint prostheses and surgical implants that are usually used for these procedures were manufactured using dimensions from other populations.
Objective: This study documented the anatomic dimensions of proximal femur of Nigerians, devised various equations through regression analysis for pre-operative estimation of certain parts of the proximal femur and for use in forensic medicine. This study also correlated the dimensions of the proximal femur with different surgical implants available.
Methods: A total of 56 adult dry femoral bones were studied. Parameters measured were Maximum Femoral Length (MFL), length of the femur between the tip of the greater trochanter and the lateral condyle (termed Trochanteric Length (TL) of the femur), Femoral Neck Length (FNL), Femoral Neck Diameter (FND), Femoral Neck Axial Length (FNAL), Femoral Neck Shaft Angle (FNSA) and Proximal Femoral Shaft Diameter (PFSD). The monographs of surgical implants were obtained. Analyses were done with Microsoft excel 2010 (Microsoft Corporation, Redmond, Washington, United States) and STATA version 13 (StataCorp, Texas. USA). Statistical significance was set at p ≤ 0.05.
Results: The average measured values of the parameters were: MFL was 47.9cm, TL was 45.8cm, FNL was 22.9mm, FNAL was 96.9mm, FND was 30.3mm, PFSD was 28.4mm and FNSA was 130.8°. Regression analysis revealed significant statistical relationship between the lengths of femur and other parameters measured; with equations that can be used in clinical settings to estimate certain parameters: MFL = 2.5 + TL; range ± 1cm. FND = 6 + 0.05*TL(mm); range ± 5mm; FNAL = 5 + 0.206*TL(mm); range ± 15mm. TL was used in the equations because it can be measured easily in clinical settings. In forensic medicine, MFL can be estimated from the FND and FNAL, using the equations: MFL = 30.5 + 0.18*FNAL and MFL = 42.14 + 0.19*FND.
Conclusion: This study has provided data of the dimensions of proximal femur in Nigerians. Various equations generated from this study will be useful in pre-operative planning, clinical settings and forensic medicines.