Decreased complications but a distinctive fixation loosening mechanism of fully threaded headless cannulated screw fixation for femoral neck fractures in young adults

摘要

FTHCS fixation for FNF in a 40-year-old complicated by femoral neck shortening. The pelvic AP radiograph (a) and CT scan 3-D reconstruction images (b) showed the right hip with a comminuted femoral neck fracture. a The uninjured hip was outlined and the angle between the axis of the head and shaft (neck-shaft angle) was labeled. Immediate postoperative radiographs (c) showed near anatomical reduction with corrected neck-shaft angle. One-month (d) and 3-month (e) postoperative radiographs showed stability of the fixation. Unfortunately, 2-year radiographs (f) demonstrated fracture union with significant femoral neck shortening and varus displacement. The outline of the uninjured hip (solid line) overlapped on the fracture side (dotted line) is provided for comparison. From (c) to (f), two horizontal lines were drawn on each radiograph, one from the top of the femoral head and another from the tip of the greater trochanter. The difference in the measurement between these two horizontal lines revealed the amount of head collapse