BACKGROUND: Research regarding femoral-neck fractures has mainly focused on bone mineral density and limited studies have been performed on relationship between the femoral-neck structure and its fracture. METHODS: Finite element models were established to estimate stress distributions across the femoral neck with various femoral-neck angle from 115 degrees to 140 degrees. The bone mineral density measurements across the femoral-neck region using dual-energy X-ray absorptiometry were taken from 89 healthy and 10 patients with a femoral-neck fracture. Femoral neck angles were determined on radiographs from a separate group of participants. FINDINGS: The results showed that the bone mineral density of the fracture patients was significantly smaller in all examined areas around femoral neck, especially in the ward's triangle. Under a same loading condition, the stress level may easily reach its intensity limit and therefore cause a fracture. The modeling results indicated that the posteromedial side of the femoral neck experienced the highest stress and was inversely related with the femoral-neck angle. As the angle decreased below 125 degrees, the stress around the femoral neck increased significantly and therefore increases risk of fracture at the site. INTERPRETATIONS: It is recommended that if the femoral-neck angle is below 125 degrees and is accompanied by low bone mineral density, the patient should be considered a high risk candidate for femoral-neck fracture. In addition, if the femoral-neck angle of one hip is significantly smaller than the other side and 125 degrees, the hip should be also considered as high risk.
BACKGROUND: Research regarding femoral-neck fractures has mainly focused on bone mineral density and limited studies have been performed on relationship between the femoral-neck structure and its fracture. METHODS: Finite element models were established to estimate stress distributions across the femoral neck with various femoral-neck angle from 115 degrees to 140 degrees. The bone mineral density measurements across the femoral-neck region using dual-energy X-ray absorptiometry were taken from 89 healthy and 10 patients with a femoral-neck fracture. Femoral neck angles were determined on radiographs from a separate group of participants. FINDINGS: The results showed that the bone mineral density of the fracturepatients was significantly smaller in all examined areas around femoral neck, especially in the ward's triangle. Under a same loading condition, the stress level may easily reach its intensity limit and therefore cause a fracture. The modeling results indicated that the posteromedial side of the femoral neck experienced the highest stress and was inversely related with the femoral-neck angle. As the angle decreased below 125 degrees, the stress around the femoral neck increased significantly and therefore increases risk of fracture at the site. INTERPRETATIONS: It is recommended that if the femoral-neck angle is below 125 degrees and is accompanied by low bone mineral density, the patient should be considered a high risk candidate for femoral-neck fracture. In addition, if the femoral-neck angle of one hip is significantly smaller than the other side and 125 degrees, the hip should be also considered as high risk.