Proximal femoral anatomy in the normal human population.

UNLABELLED: In this study, we developed a complete description of the morphology of the proximal femur. Then, using this framework, we (1) determined normal population means, standard deviations, and ranges; (2) established differences among subpopulations; and (3) showed correlations among the various measurements. To accomplish these objectives, we analyzed 375 adult femurs. Specimens were digitally photographed in standardized positions, measurements being obtained using ImageJ software. Three parameters of the head-neck relationship were assessed. Translation was examined through four raw offset measurements (anterior, posterior, superior, inferior) used to calculate anterior-posterior and superior-inferior ratios. Rotation was investigated through anteroposterior (AP) and lateral physeal angles. Concavity was examined using alpha, beta, gamma, and delta angles. Two parameters of the neck-shaft relationship were assessed, neck version and angle of inclination. Average anterior-posterior and superior-inferior ratios were 1.14 and 0.90. Average AP and lateral physeal angles were 74.33 degrees and 81.83 degrees , respectively. Averages for alpha, beta, gamma, and delta angles were 45.61 degrees , 41.85 degrees , 53.46 degrees , and 42.95 degrees , respectively. Average neck version and angle of inclination were 9.73 degrees and 129.23 degrees , respectively. Differences existed between males and females and between those younger and older than 50 years. Correlations were observed between translation and concavity, and translation and the neck-shaft relationships. LEVEL OF EVIDENCE: Level II, prognostic study. See the Guidelines for Authors for a complete description of levels of evidence.