A 68-year-old woman being treated with oral bisphosphonates for 8 years develops a stress fracture of the femoral shaft at the subtrochanteric region. Radiograph shows a 'beak' or 'flare' cortical thickening on the lateral cortex with a transverse incomplete fracture line. This is classified as:
- A Pathological fracture from metastatic disease
- B Atypical femoral fracture associated with long-term bisphosphonate use ✓
- C Paget's disease-related insufficiency fracture
- D Stress fracture from excessive exercise
Explanation
Atypical femoral fractures (AFFs) are a recognized complication of long-term bisphosphonate therapy (>3–5 years). The American Society for Bone and Mineral Research (ASBMR) defines AFFs by major features: location in the subtrochanteric or femoral shaft region, transverse or short oblique orientation, minimal or no trauma, non-comminuted pattern, and a periosteal 'beak' or medial cortical spike at the fracture site. They result from over-suppression of bone remodeling causing accumulation of microdamage. Treatment involves discontinuing bisphosphonates, supplementing with calcium/vitamin D, and prophylactic intramedullary nailing for complete or high-risk incomplete fractures.
Reference: Maheshwari Essential Orthopaedics, 6th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.