About This Page
This is a clinician-written, evidence-based summary aligned to the 2026 MLA Content Map. It is intended for medical students and junior doctors preparing for the UKMLA. Always cross-reference with NICE guidance, local protocols, and clinical judgement.
The Bottom Line
- Clinical diagnosis in patients ≥45 years with activity-related joint pain and no/minimal morning stiffness (<30 min) — no investigations routinely needed
- Affects knees, hips, hands (DIPs, PIPs, first CMC), and spine most commonly
- Core treatments: exercise and physical activity (most important), weight loss if overweight, patient education
- Pharmacological: topical NSAIDs first-line for knee/hand OA; oral NSAIDs short courses with PPI; paracetamol limited evidence
- Joint replacement (hip/knee arthroplasty) for severe OA refractory to conservative measures
Overview
Osteoarthritis (OA) is a degenerative joint disease characterised by progressive loss of articular cartilage, subchondral bone remodelling, osteophyte formation, and synovial inflammation. It is the most common form of arthritis and the leading cause of joint pain and disability in older adults. OA most commonly affects weight-bearing joints (knees, hips) and hands (DIP joints — Heberden nodes, PIP joints — Bouchard nodes, first CMC joint). Unlike RA, it is non-inflammatory (or low-grade inflammatory), mechanical in nature, and does not cause systemic features.
Epidemiology
OA affects approximately 8.75 million people in the UK. Prevalence increases markedly with age — radiographic knee OA is present in ~30% of those over 65. Risk factors include increasing age, female sex, obesity (strongest modifiable risk factor for knee OA), joint injury (ACL rupture, meniscal tear), repetitive occupational joint use, genetic predisposition, and muscle weakness. OA is the most common reason for hip and knee replacement surgery in the UK.
Clinical Features
Symptoms
Activity-related joint pain — worse with use, relieved by rest (mechanical pattern)
Morning stiffness <30 minutes (contrast: RA >30 min)
Joint stiffness after periods of inactivity (gelling)
Reduced range of movement
Functional impairment: difficulty walking, climbing stairs, gripping
Symptoms may fluctuate — "good days and bad days"
Hot swollen joint (excluding septic arthritis or gout) or rapid worsening
Signs
Bony enlargement: Heberden nodes (DIP joints) and Bouchard nodes (PIP joints)
Crepitus on joint movement
Restricted range of movement
Joint line tenderness
Bony deformity: varus/valgus (knee), squaring of thumb base (first CMC)
Muscle wasting around affected joint (quadriceps wasting in knee OA)
Small cool effusions may occur (contrast: large warm effusion = inflammatory or septic)
Investigations
First-line
Clinical diagnosisNICE NG226: diagnose OA clinically in people ≥45 years with activity-related joint pain and no morning stiffness (or <30 min). NO investigations routinely needed
Second-line
X-rayOnly if diagnostic uncertainty or atypical features. Classic findings (LOSS): Loss of joint space, Osteophytes, Subchondral sclerosis, Subchondral cysts
BloodsOnly if inflammatory arthritis or other diagnosis suspected — ESR, CRP, RF, anti-CCP should be NORMAL in OA
Specialist
MRINot routinely indicated for OA diagnosis — may be used pre-operatively or to assess for alternative pathology (meniscal tear, AVN)
1
Core treatments (ALL patients)
- Exercise and physical activity: strengthening and aerobic exercise — the most effective intervention. Offer structured exercise programme
- Weight loss if overweight/obese — particularly important for knee OA
- Patient education and self-management: understanding the condition, pacing activity
- Suitable footwear advice
2
Pharmacological
- Topical NSAIDs (ibuprofen gel, diclofenac gel): first-line for knee and hand OA
- Oral NSAIDs (ibuprofen, naproxen): short courses at lowest effective dose with PPI co-prescription
- Intra-articular corticosteroid injection: for flares — provides short-term relief (weeks-months)
- Paracetamol: NICE NG226 no longer recommends paracetamol routinely (limited evidence of benefit)
- Do NOT offer glucosamine, chondroitin, or rubefacients — no evidence of benefit (NICE)
- Do NOT offer opioids for OA unless short-term for acute flare (risks outweigh benefits for chronic use)
3
Surgical referral
- Consider referral for joint replacement (arthroplasty) if: significant impact on quality of life despite optimal conservative management
- Total hip replacement (THR) and total knee replacement (TKR) are highly effective for end-stage OA
- Do NOT offer arthroscopic lavage/debridement for knee OA (NICE) — no benefit
Complications
- Progressive disability: Reduced mobility, loss of independence — especially hip and knee OA
- Falls: From knee instability, muscle weakness, pain
- Depression: Chronic pain and disability — screen and treat
- NSAID complications: GI bleeding, renal impairment, cardiovascular risk — use lowest dose, shortest duration
- Secondary joint disease: AVN, crystal arthropathy may coexist
UKMLA Exam Tips
- 1OA = activity-related pain, <30 min morning stiffness, bony enlargement (Heberden/Bouchard nodes), DIP involvement
- 2RA = morning stiffness >30 min, symmetrical small joints, MCPs/PIPs (NOT DIPs), soft tissue swelling
- 3Clinical diagnosis in ≥45 years — NO routine bloods or X-rays needed (NICE NG226)
- 4X-ray LOSS: Loss of joint space, Osteophytes, Subchondral Sclerosis, Subchondral cysts
- 5Exercise is the most effective intervention — more effective than any drug
- 6NICE no longer recommends paracetamol routinely for OA. Topical NSAIDs first-line for knee/hand
- 7Do NOT offer arthroscopy for OA knee — no evidence of benefit
practicetest your knowledge on osteoarthritisApply what you've learnt with UKMLA-style questions from the iatroX Q-Bank — musculoskeletal and beyond.
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