Atypical femoral fracture — SCE Rheumatology MCQ

Instant feedback + full explanation. One question, done properly.

EasyMetabolic bone diseaseAtypical femoral fractureSCE Rheumatology

A 70-year-old woman who has received oral bisphosphonate treatment for osteoporosis for 7 years develops several weeks of dull lateral thigh pain without preceding trauma. A femoral radiograph shows focal thickening of the lateral subtrochanteric cortex with a transverse lucent line confined to the lateral cortex. What is the most likely diagnosis?

Educational content. Not a substitute for clinical judgement or local policy.

Reveal the answer and explanation

Correct answer: B — Atypical femoral fracture

The diagnosis is an incomplete atypical femoral fracture. The discriminating combination is prolonged bisphosphonate exposure, atraumatic prodromal thigh pain, focal lateral cortical thickening and a transverse lucent line beginning in the lateral cortex. These fractures typically occur in the subtrochanteric or femoral diaphyseal region and may progress to a complete transverse fracture. Trochanteric bursitis can cause lateral hip tenderness but does not produce a femoral cortical stress lesion. Hip osteoarthritis causes joint-space narrowing and osteophytes rather than lateral diaphyseal cortical thickening. Paget disease usually produces bone expansion, cortical and trabecular coarsening, and characteristic biochemical findings. A metastatic pathological fracture would usually be associated with a destructive or sclerotic focal lesion rather than this characteristic transverse lateral-cortex pattern.

Reference: Alendronic Acid 70 mg Film-coated Tablets, Summary of Product Characteristics, section 4.4: Atypical fractures of the femur, text revised 2026. https://www.medicines.org.uk/emc/product/101969/smpc