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Suspected incomplete atypical femoral fracture associated with long-term bisphosphonate treatment — MSRA MCQ

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HardHip and GroinSuspected incomplete atypical femoral fracture associated with long-term bisphosphonate treatmentMSRA

A 74-year-old woman attends urgently with 6 weeks of progressive dull pain in her right lateral thigh, intermittently extending into the groin. It is worse on weight-bearing and she has begun using a stick outdoors. There has been no fall, change in exercise, fever or weight loss. She has taken alendronic acid 70 mg weekly for 7 years following a vertebral fragility fracture. She is adherent and also takes colecalciferol. An anteroposterior pelvis radiograph requested 10 days ago showed mild bilateral hip osteoarthritis and no fracture. Hip flexion and rotation are full and do not reproduce her pain. There is no focal greater-trochanteric tenderness, neurological deficit or lumbar spinal tenderness. She is systemically well. What is the most appropriate immediate management plan?

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

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Correct answer: B — Withhold alendronic acid and arrange same-day assessment for an incomplete atypical femoral fracture.

Explanation lettering: B = shown as A · E = shown as B · A = shown as E

This is a suspected incomplete atypical femoral fracture (AFF). The discriminating features are prolonged bisphosphonate exposure, insidious atraumatic lateral thigh/groin pain that is worsening with loading, and examination that does not support symptomatic intra-articular hip osteoarthritis or greater trochanteric pain syndrome. Prodromal thigh or groin pain can precede a complete atypical subtrochanteric or femoral-shaft fracture by weeks to months. The normal pelvis radiograph and incidental mild hip osteoarthritis should not cause diagnostic anchoring. The clinically important concern is an incomplete femoral fracture in a bisphosphonate-treated patient, requiring urgent assessment before displacement or completion occurs. Alendronic acid should be withheld while this is evaluated. A is inappropriate because the presentation is not explained by the mild radiographic osteoarthritis and continued treatment ignores a possible serious adverse effect. B delays assessment and continues the suspected causative medicine. C is reasonable as part of later osteoporosis reassessment, but DXA does not address the immediate fracture risk. D appropriately stops treatment but is insufficiently urgent given progressive weight-bearing pain and possible impending complete fracture.

Reference: Alendronic Acid 70 mg tablets — Summary of Product Characteristics (2026) — https://www.medicines.org.uk/emc/product/5206/smpc