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Grade I medial collateral ligament sprain — MSRA MCQ

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HardKnee InjuriesGrade I medial collateral ligament sprainMSRA

A 76-year-old woman attends general practice on the day after twisting her right knee while turning to get out of a car. She did not fall and was able to walk immediately afterwards. She has medial knee pain, but no locking, giving-way, paraesthesia or rapidly developing swelling. She can take four steps independently. There is mild focal tenderness along the medial collateral ligament, pain but no opening on valgus stress at 30 degrees, and no valgus laxity in full extension. She has full active extension and flexion to 115 degrees. There is no effusion, bony tenderness, deformity or neurovascular abnormality. This is assessed as a grade I medial collateral ligament sprain. Her regular medicines are ramipril, furosemide and amlodipine for heart failure with preserved ejection fraction and hypertension. Her most recent eGFR, checked 2 weeks ago, was 28 mL/min/1.73 m² and is stable. She weighs 72 kg, does not drink excess alcohol and has no liver disease. Alongside relative rest, ice and early gentle knee movement, which analgesic prescription is most appropriate today?

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

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Correct answer: C — Paracetamol 1 g orally up to four times daily as required, with a maximum of 4 g in 24 hours

This is a clinically stable grade I medial collateral ligament sprain: there is pain on valgus stress but no laxity, no effusion, preserved extension and weight-bearing ability, and no mechanical or neurovascular red flags. Analgesia and conservative care are therefore appropriate rather than acute imaging or orthopaedic referral. Paracetamol is the best initial analgesic here. The usual adult dose is 1 g up to four times daily, not exceeding 4 g in 24 hours. Although she has chronic kidney disease, she has no hepatic risk factors and this is intended as short-term treatment. Naproxen is contraindicated when creatinine clearance is below 30 mL/min. More broadly, NSAIDs can reduce renal perfusion and precipitate renal deterioration, particularly in older people with impaired renal function who also take an ACE inhibitor and a diuretic. Therefore ibuprofen and celecoxib are also poor choices; a short duration and co-prescribed omeprazole do not remove the renal risk. Omeprazole addresses upper gastrointestinal risk, not NSAID nephrotoxicity. Co-codamol would add opioid adverse effects, including sedation and falls risk, without being required for this uncomplicated injury; it would be a reasonable later option only if pain remained inadequately controlled despite safer first-line measures.

Reference: Naproxen Tablets BP 250 mg - Summary of Product Characteristics (Updated 2026) — https://www.medicines.org.uk/emc/product/530/smpc Paracetamol 500 mg Tablet - Summary of Product Characteristics (2025) — https://www.medicines.org.uk/emc/product/100828/smpc NHS: Knee pain (Last reviewed 21 December 2023) — https://www.nhs.uk/symptoms/knee-pain/