DECODING PROXIMAL FEMORAL ARCHITECTURE: EXPLORING NECK SHAFT ANGLE VARIATIONS IN SOUTHEAST NIGERIAN ADULTS

Abstract

The proximal femur is a pivotal anatomical region susceptible to various pediatric and adult disorders, prompting continuous research on defining parameters such as the proximal femoral geometry (PFG) and the relationship between the femoral neck and shaft. This study delves into crucial parameters shaping this relationship, including the Neck-Shaft Angle (NSA), Femoral Head Diameter, and Neck Version. The NSA, also known by various terms like llodiaphyseal angle and angle of inclination, plays a vital role in walking mechanics, influencing femoral shaft clearance during the swing phase and gait control.

This angle holds significant clinical importance in assessing the hip and proximal femur, serving as a critical parameter in orthopedic procedures, particularly in surgeries like femoral neck fixation and the design of orthopedic implants and hip prostheses. Deviations from the normal NSA values (120° to 140°) signal pathology or femoral neck fractures, with values exceeding 140° associated with increased fracture risk, genu varum, and knee arthritis, while values below 120° are linked to conditions like trochanteric pain syndrome and Paget's disease.

Population-based variations in NSA are documented, attributed to factors such as human activity levels, genetics, sex, diet, and lifestyle. The NSA undergoes developmental changes, being higher in neonates, declining during childhood, assuming adult values by adolescence, and remaining relatively stable with minor declines in later life. The study also highlights the lack of established normal values among the Igbos in Southeast Nigeria, emphasizing the need for regional assessments.

This research aims to fill this gap by primarily establishing the normal value of the femoral neck shaft angle in Enugu, Southeast Nigeria. The findings hold potential implications for orthopedic surgeons, aiding in pre-operative implant selection, femoral neck fracture fixation, and gender determination from skeletal remains, particularly in medico-legal contexts. By addressing this research gap, the study contributes valuable insights into the regional nuances of proximal femoral anatomy, enhancing the precision of orthopedic interventions in the local population.