title: Is It a Simple Stress Fracture or Bisphosphonate-related Atypical Fracture?
abstract: A number of reports regarding atypical fractures of the femur have raised questions concerning the possible correlation between long-term bisphosphonate treatment and the occurrence of insufficiency fractures in the proximal femur. However, clinically, it is often confused whether is it a fatigue fracture because of implant induced stress concentration or a bisphosphonate-related atypical fracture, especially in a patient with a subtrochanteric fracture who receive bisphosphonate therapy after open reduction and internal fixation, such as dynamic hip screw (DHS) fixation for previous ipsilateral femoral neck or intertrochanteric fracture. The authors experienced a case of a progressive femoral insufficiency fracture in a woman who had been on Fosamax (Alendronic acid with Vitamin D; Merck & Co. Inc, NJ, USA) therapy for four years after ipsilateral femoral neck fracture treated with a two hole DHS system. Despite a high suspicion of an insufficiency femoral subtrochanteric fracture by bone scan, the occult fracture progressed to a displaced femoral subtrochanteric fracture one year after. The fracture site was fixed with a 6 hole DHS plate, and six months after reoperation the patient had no symptoms and the fracture site had united without any complication.
authors: Department of Orthopaedic Surgery, Chung-Ang University College of Medicine, Seoul, Korea.
authors: Soo Yong
authors: SY
authors: Kang
authors: Department of Orthopaedic Surgery, Seoul National University Bundang Hospital, Seongnam, Korea.
authors: Ji-Hoon
authors: JH
authors: Baek
authors: Department of Orthopaedic Surgery, SM Christianity Hospital, Pohang, Korea.
authors: Bun Jung
authors: BJ
authors: Kang
authors: Department of Orthopaedic Surgery, Chung-Ang University College of Medicine, Seoul, Korea.
authors: Min Kyu
authors: MK
authors: Kim
authors: Department of Orthopaedic Surgery, Chung-Ang University College of Medicine, Seoul, Korea.
authors: Han-Jun
authors: HJ
authors: Lee
keywords: Bisphosphonate; Early diagnosis; Femoral fractures; Fractures stress; Osteoporosis