[Influence of calcar femoral on stress distribution of the upper femur and its clinical application].

Relation between the integrity of the internal structure of upper femur and femoral neck fracture was investigated by means of photo-electric technique. It was found that the stress increased significantly in the upper femur when its calcar femoral was defective, and that the nearer the defective area to the femoral head the greater was the stress. This increased stress was especially significant at the heel strike period of stance phase during walking. As a result of osteoporosis and deficit of the calcar femoral in the elderly, upper femur fracture, mostly subcapital or transcervical type is commonly seen in the aged. The feasibility and principle of internal fixation with thread-screw pins for subcapital and transcervical fracture have been discussed in conjunction with the distribution of tensile and compressive stresses.