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Suspected displaced bucket-handle meniscal tear causing a true locked knee — MSRA MCQ

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ModerateSoft Tissue InjurySuspected displaced bucket-handle meniscal tear causing a true locked kneeMSRA

A 28-year-old man attends a GP-led urgent treatment centre 3 days after twisting his right knee while pivoting during football. He developed an effusion later that evening and has since had medial joint-line pain. He reports that the knee became stuck while getting out of a car this morning and he has been unable to straighten it since. Radiographs obtained on the day of injury showed no fracture or osteoarthritis. He walks with crutches. The knee has a moderate effusion and medial joint-line tenderness. Passive extension remains limited by a firm, springy block at 20 degrees of flexion despite analgesia and relaxation; passive flexion reaches 80 degrees. There is no erythema or increased warmth. Distal neurovascular examination is normal. What is the most appropriate management today?

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

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Correct answer: C — Arrange same-day urgent orthopaedic assessment without waiting for MRI

Explanation lettering: D = shown as B · B = shown as D

This is a true locked knee: after an acute twisting injury, passive extension remains restricted by a fixed, springy mechanical block rather than pain alone. The associated effusion and medial joint-line tenderness make a displaced meniscal tear, particularly a bucket-handle tear, likely. A locked knee requires urgent orthopaedic assessment because a displaced, potentially repairable meniscal tear may need timely arthroscopic management. MRI should not delay this referral. A is appropriate for a stable acute knee injury without locking or significant mechanical restriction. B is tempting because MRI can identify a meniscal tear, but local NHS referral guidance specifically advises urgent orthopaedic referral for a locked knee and notes that MRI may delay treatment. D is inappropriate because routine pathways are for persistent symptoms without an urgent mechanical block. E may be appropriate for some acute injuries managed through a fracture clinic pathway, but a true locked knee requires urgent orthopaedic assessment today rather than delayed review.

Reference: MRI Criteria (Accessed 15 August 2026) — https://www.rightdecisions.scot.nhs.uk/nhs-tayside-refguide/surgery-and-orthopaedics/orthopaedic-and-trauma-surgery/knee/mri-criteria/?topic=nursing-midwifery Meniscal Problems (Accessed 15 August 2026) — https://www.rightdecisions.scot.nhs.uk/nhs-tayside-refguide/surgery-and-orthopaedics/orthopaedic-and-trauma-surgery/knee/meniscal-problems/?UNLID=877857945202621916518&useNavigation=true