Unexpected iatrogenic fracture of the femoral neck during subtrochanteric fracture fixation in a patient on bisphosphonate treatment for osteoporosis: Case report.

Osteoporotic patients being treated with bisphosphonates present an interesting dilemma when removing hardware such as dynamic hip screws "DHS". In this paper, we describe the case of a 66-year-old osteoporotic patient who was placed on long term bisphosphonate therapy after sustaining an intertrochanteric hip fracture which was stabilized with a DHS. She presented with a subtrochantric fracture on the ipsilateral side. She was planned for DHS removal and intramedullary nailing. Removal of the dynamic hip screw proved to be difficult, likely due to possible cold welding of the DHS to the barrel of the side plate and sclerotic bone formation around the hardware secondary to the extended bisphosphonate use. The patient had an intra-operative femoral neck fracture while attempting the DHS removal. We had to convert to an unanticipated total hip replacement. Careful considerations should be taken when removing hardware from patients on long term bisphosphonate treatment.