Correlation between the incidence of hip fractures and the proximal femur by 3D geometric anatomy / 医用生物力学

ABSTRACT

Objective To measure the hip anatomic parameters and explore the differences between the hip fracture group and the normal group, analyze their effect on the incidence of hip fractures and fracture types by using computer aided design (CAD) and three-dimensional reconstruction technique. Methods Through CT scan images from the lower-extremity of hip fracture patient, the 3D anatomic model was established by Mimics10.01 software, and the 3D anatomic parameters of the normal proximal femur, namely femoral neck anteversion angle (FNAA), neck-shaft angle (NSA), femoral head diameter (FHD), length of femoral neck axis (LFNA) in the lower-extremity were measured. Results The averages of FNAA, NSA, FHD, LFNA in femoral neck fracture group were (7.9±4.6)°, (128.6±4.6)°, (46.0±4.6) mm, (47.1±5.1) mm, and those parameters in intertrochanteric fracture group were (15.5±6.8)°, (134.7±6.9)°, (45.3±3.6) mm, (46.7±3.4) mm. The FNAA and NSA in intertrochanteric fracture group were significantly larger than those in femoral neck fracture group regardless of gender (P<0.01). The FNAA and NSA in both fracture groups showed significant differences as compared with the normal group. ConclusionsThe risk of femoral intertrochanteric fracture will increase when the FNAA is larger than the normal range in Chinese, while the risk of femoral neck fracture will increase when the FNAA is smaller than the normal range in Chinese. The NSA of hip fracture patients was larger as compared with normal Chinese. The larger NSA will lead to a higher risk of femoral intertrochanteric fracture. There exist some differences in anatomic parameters of the proximal femur between the fracture group and the normal group, especially in the angle parameter. The femoral intertrochanteric fractures are more prone to occur in the older people, while the femoral neck fractures are more prone to occur in the younger people.