Subcapital femoral neck fracture after closed reduction and internal fixation of an intertrochanteric hip fracture: a case report and review of the literature.

A subcapital femoral neck fracture in a healed intertrochanteric fracture treated by an open reduction and internal fixation is a rare, but catastrophic, event. We present the case of an 86-year-old woman, a community ambulator, who sustained a displaced right intertrochanteric hip fracture during a fall. She was treated with closed reduction and internal fixation with a dynamic compression hip screw and side plate. Four months later, she was noted to have a displaced subcapital femoral neck fracture and underwent hip screw and side plate hardware removal and cemented bipolar hemiarthroplasty. Both postoperative recoveries were uncomplicated, and she was discharged to a rehabilitation facility able to ambulate with minimal assistance. This devastating complication in patients with osteoporosis may be prevented by deeper placement of the dynamic hip compression lag screw to within 5 mm to 8 mm of the subchondral bone, which may decrease the stress forces in the subcapital femoral neck.