skip to main content

Acute foot injury requiring Ottawa foot rule assessment — MSRA MCQ

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

ModerateAnkle and FootAcute foot injury requiring Ottawa foot rule assessmentMSRA

A 33-year-old woman attends a GP-led minor injuries unit 5 hours after inverting her right foot while running on uneven ground. She had immediate pain over the lateral border of the foot but was able to take four steps immediately after the injury and can take four steps in the unit. Examination shows mild swelling and focal bony tenderness at the base of the fifth metatarsal. There is no tenderness over the navicular, medial malleolus, lateral malleolus or posterior 6 cm of either malleolus. The ankle has a full active range of movement. There is no deformity, skin break or neurovascular abnormality. What is the most appropriate imaging management today?

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

Reveal the answer and explanation

Correct answer: A — Obtain plain radiographs of the foot

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

This is a positive Ottawa foot rule: she has pain in the midfoot/lateral foot region with focal bony tenderness at the base of the fifth metatarsal. Foot radiographs are therefore indicated, even though she could bear weight both immediately after injury and at assessment. Weight-bearing ability is an alternative Ottawa criterion; it does not negate the indication created by relevant bony tenderness. An ankle radiographic series is not indicated because she has no malleolar-zone tenderness, including at the posterior edge or tip of either malleolus, and can take four steps. Therefore, ankle radiographs alone (A) would image the wrong region, while imaging both ankle and foot (C) adds unnecessary imaging. Managing without radiography (B) may initially seem reasonable because she can walk, but would be appropriate only if she had neither inability to bear weight nor tenderness at the base of the fifth metatarsal or navicular. CT (E) is not first-line imaging for an uncomplicated acute injury meeting criteria for plain foot radiographs; it may be considered later if clinical concern persists despite non-diagnostic radiographs or for suspected occult/complex injury.

Reference: NICE NG38: Fractures (non-complex): assessment and management — Recommendations (2016) — https://www.nice.org.uk/guidance/ng38/chapter/recommendations Evaluation of the Ottawa clinical decision rules for the use of radiography in acute ankle and midfoot injuries in the emergency department (1994) — https://pubmed.ncbi.nlm.nih.gov/7912053/