skip to main content

Suspected spontaneously reduced tibiofemoral knee dislocation with multiligament injury — MSRA MCQ

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

ModerateKnee InjuriesSuspected spontaneously reduced tibiofemoral knee dislocation with multiligament injuryMSRA

A 35-year-old man presents to general practice 3 hours after a high-energy rugby tackle. His planted right knee was forced into hyperextension and valgus. Teammates saw the lower leg briefly displaced posteriorly relative to the thigh before it appeared to relocate when he was moved from the pitch. He reports severe pain, marked swelling and instability. He cannot continue playing but has used crutches to reach the surgery. Examination shows a large effusion and marked anterior-posterior and varus-valgus laxity. The foot is warm, with palpable dorsalis pedis and posterior tibial pulses, normal capillary refill and intact distal sensation. Knee radiographs obtained at the urgent treatment centre show no fracture or persistent dislocation. What is the most appropriate management today?

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

Reveal the answer and explanation

Correct answer: E — Arrange immediate transfer to the emergency department for ankle-brachial pressure index assessment, serial neurovascular examination and orthopaedic review

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

This presentation is highly suspicious of a tibiofemoral knee dislocation that has spontaneously reduced: there was witnessed posterior displacement of the tibia, a high-energy mechanism, major effusion and gross multiligament instability. Normal radiographs do not exclude a reduced dislocation, and palpable distal pulses do not alone exclude popliteal arterial injury. Immediate emergency assessment is required. In multiligament knee injury/suspected knee dislocation, ankle-brachial pressure index (ABPI) assessment and serial neurovascular examination are used to screen for occult vascular injury; an ABPI below 0.9 requires urgent vascular imaging/management. This should not be managed through routine outpatient pathways. B is attractive because CT angiography may be required, but vascular imaging should be selective following ABPI and clinical assessment rather than replacing serial assessment. C delays vascular exclusion despite a limb-threatening injury pattern. D may later define ligamentous injury but must not precede vascular assessment. E would be appropriate only for a stable knee injury without features suggesting dislocation or multiligament disruption.

Reference: Management of multiligament knee injuries (2020) — https://pubmed.ncbi.nlm.nih.gov/32296548/ Fracture Management ED Guideline, Glasgow Royal Infirmary (2026) — https://www.rightdecisions.scot.nhs.uk/media/1yfnbnvu/139-fracture-management-ed-gri-v8.pdf