Computed tomography reference values estimation for femoral neck shaft angle in Egyptian healthy adults of both sexes

Abstract

Background Accurate measurement of the femoral neck shaft angle (NSA) is critical for the diagnosis and treatment of hip pathology, but its current reference values remain limited in the Egyptian adult population. This study was designed to provide reference that is reliable for femoral NSA measured by computed tomography (CT) in Egyptian healthy adults of both sexes. This was a cross-sectional descriptive study and analysis of the femoral NSA of healthy Egyptian adults of both sexes measured by CT. Six hundred hips in 300 adults (aged 18 and 60 years; 300 females) were evaluated in the simulated anterior pelvic plane (APP) and the rotation-corrected coronal reconstruction femoral neck plane (FNP) on both sides. We compared the measurements with age and sex, and a two-tailed nonparametric Wilcoxon test was used to discover differences between both measurements. Results The mean NSA was 129.46° ± 5.06°, with a mean value of 129.65° ± 4.13° for males and 129.28° ± 3.71° for females. Simulated APP had a higher mean NSA 129.6° (range 115.7°–146.7°; SD 5.06°) than rotation-corrected coronal reconstruction in the FNP 127.73° (range 115.3°–144.6°; SD 4.9°). It was observed that there was a significant variation in the measurements of NSA between the two methods. The side influenced the NSA significantly on both views (p < 0.001); no significant differences were found between age and gender. Conclusions The current study attempts to develop population-specific data for femoral NSA reference values in Egyptian communities. No considerable difference was measured in NSA among males and females. It was observed that there was a side difference, with the NSA value being higher on the left than the right. We noted also that proper measurement of NSA is made possible by using NSA values obtained from rotation-corrected coronal reconstruction in the FNP. We anticipate that the findings will contribute to a better understanding of proximal femur morphology and may aid the majority of our population in selecting an implant that is compatible with hip anatomy.