Knee osteoarthritis — KFP-style written assessment

KFP 1 (10 marks)

A 61-year-old postman presents with six months of right knee pain on his delivery round. Morning stiffness lasts 20 minutes and eases with movement. Examination shows bony swelling, crepitus, no effusion, stable ligaments, full extension. BMI 31. He requests an X-ray "to see how bad it is". ^[8]

1. State your diagnosis pathway with the specific clinical criteria, and what you tell him about imaging. (3) ^[8]
2. Outline the core treatments with quantified expected benefit. (4) ^[1][2][8]
3. He asks for painkillers. Give the first-line drug, its trial basis, and what you will not prescribe routinely. (3) ^[3][4]

Model answers

1. Diagnose OA clinically without imaging: he is over 45, has activity-related joint pain, and morning stiffness under 30 minutes. Explain that OA is diagnosed clinically, imaging is not needed to confirm it unless atypical features emerge, and management is guided by symptoms and physical function. ^[8]
2. Core treatments: therapeutic exercise (Cochrane high-quality evidence: pain reduced ~12 points on 100-point scale, SMD −0.49; function ~10 points; comparable with NSAIDs) and weight management — advise that any weight loss helps but 10% of body weight beats 5% (IDEA achieved 11.4% mean loss with diet+exercise, less pain, better function; dose-response shows 10–19.9% loss is substantially better). Add walking stick if helpful, education and self-management. ^[1][2][8]
3. Offer topical NSAID first (NNT 9.8 for diclofenac clinical success; similar efficacy to oral without systemic toxicity). Do not routinely offer paracetamol (Cochrane: no clinically important improvement, ~3 points vs MCID 9) or weak opioids. ^[3][4]