Factors affecting the anatomical localization of proximal femoral fractures in geriatric patients.

PURPOSE: This study aims to investigate the relationship between proximal femoral geometry and the anatomical localization of proximal femoral fractures in geriatric patients. The analysis was based on morphometric measurements obtained from the contralateral, uninjured hip. METHODS: Between January 2017 and December 2024, 864 patients (549 females, 315 males; mean age: 80.09 ± 7.65 years) with proximal femoral fractures were retrospectively analyzed. Fractures were classified as subcapital, transcervical, basicervical, intertrochanteric, or subtrochanteric according to standardized radiographic criteria. Morphometric parameters measured on anteroposterior pelvic radiographs of the contralateral hip included hip axis length (HAL), femoral neck axial length (FNAL), femoral neck and head diameters, femoral shaft diameter, caput-collum-diaphyseal (CCD) angle, medial femoral offset, and center-edge (CE) angle. Absolute and proportional values (relative to HAL and FNAL) were compared among fracture types. RESULTS: Extracapsular fractures were more frequent (58.4%) than intracapsular ones (41.6%), with intertrochanteric fractures being the most common subtype (48.6%). Femoral shaft diameter, femoral shaft diameter/HAL ratio, and CE angle were all significantly greater in extracapsular fractures (p = 0.04, p = 0.003, p = 0.002). Among fracture subtypes, femoral neck diameter was higher in transcervical fractures than basicervical fractures (p = 0.046). Subcapital fractures had higher femoral neck diameter/HAL ratios than basicervical fractures (p = 0.04). Notably intertrochanteric fractures also showed higher femoral shaft diameter/HAL ratios and CE angles, but lower CCD angles than other types. CONCLUSION: Geometric variations of the proximal femur are closely linked to the anatomical localization of fractures in geriatric patients. Incorporating morphometric evaluation into routine assessment may improve the prediction of fracture risk and support individualized management in orthopaedic trauma care.