OA General Principles

History:

• •Activity-related joint pain - the cardinal symptom. Worsens with use, improves with rest. As OA progresses, pain may occur with shorter activity and eventually at rest or at night.
• •Morning stiffness lasting under 30 minutes - a key distinguishing feature from inflammatory arthritis (where stiffness typically exceeds 30 minutes). OA stiffness also occurs after inactivity (the 'gelling phenomenon') and resolves quickly with movement.
• •OA flares: temporary worsening of pain, swelling, and stiffness beyond baseline lasting 24 hours or more.
• •Progressive loss of function and reduced range of motion.
• •Joint swelling - intermittent and activity-related; may be bony (osteophytes - hard, non-tender) or soft tissue (effusion - fluctuant).
• •Crepitus on movement; instability reflecting muscle weakness, proprioceptive deficit, or structural change.
• •Ask about affected joint pattern, duration, impact on daily activities, occupation, sport, previous injury, family history, weight, and exercise level. Actively probe inflammatory features to redirect the differential.

Examination:

• •Bony enlargement: hard, non-tender osteophytes. Heberden's nodes (DIP), Bouchard's nodes (PIP), squaring at the thumb base (1st CMC).
• •Effusion: patellar tap or sweep test at the knee.
• •Crepitus during ROM; restricted ROM; fixed flexion deformity is a common late finding at knee and hip.
• •Malalignment: varus or valgus deformity; progressive deformity indicates structural change.
• •Muscle wasting (quadriceps in knee OA; gluteal in hip OA; thenar in 1st CMC OA).
• •Gait: antalgic, Trendelenburg (hip OA with gluteal weakness), varus or valgus thrust at the knee.
• •Assess adjacent joints and kinetic chain - hip OA may present as knee or groin pain (referred); lumbar spine pathology mimics hip symptoms.

NICE NG226 clinical diagnosis (no imaging required in a typical presentation): age 45 or over, activity-related joint pain, and either no morning stiffness or morning stiffness lasting 30 minutes or less.

Key differential diagnoses:

• •Inflammatory arthritis (RA, psoriatic, reactive, axial SpA): prolonged morning stiffness over 30 minutes, symmetrical polyarthritis, systemic features, raised inflammatory markers.
• •Crystal arthropathy (gout, CPPD): acute monoarticular flare with intense erythema; crystal analysis diagnostic. CPPD and OA frequently coexist.
• •Septic arthritis: hot swollen joint with systemic sepsis - emergency aspirate.
• •AVN: pain at rest and with activity, often disproportionate to radiographic change. MRI diagnostic.
• •Polymyalgia rheumatica: bilateral shoulder or hip-girdle pain and stiffness in patients over 50, stiffness over 45 minutes, raised ESR/CRP, dramatic response to low-dose prednisolone.
• •Referred pain: hip OA may refer to the knee or groin; lumbar spine pathology mimics hip symptoms.

Per NICE NG226, OA is diagnosed clinically in a typical presentation. Imaging is NOT routinely required and should NOT be used to assess disease severity for non-surgical management decisions. Symptoms and physical function, not imaging severity, drive management and referral.

Plain radiographs (when indicated for atypical presentation, age under 45, suspected alternative diagnosis, or surgical planning):

Classic radiographic hallmarks: joint space narrowing, osteophytes, subchondral sclerosis, and subchondral cysts. Additional features include loose bodies, malalignment, and chondrocalcinosis (CPPD).

Kellgren-Lawrence grading (0-4) is the standard radiographic system:

• •Grade 0: normal.
• •Grade 1: doubtful (possible osteophyte).
• •Grade 2: minimal (definite osteophyte, possible joint space narrowing).
• •Grade 3: moderate (definite joint space narrowing, some sclerosis, possible deformity).
• •Grade 4: severe (marked joint space narrowing, large osteophytes, severe sclerosis, definite deformity).

Radiographic severity does NOT reliably correlate with symptoms - patients with severe radiographic changes may have minimal symptoms and vice versa. Do not use imaging severity alone to guide management. Weight-bearing X-rays are generally preferred for knee OA because non-weight-bearing views can significantly underestimate joint space narrowing.

Blood tests are not routine. Consider if inflammatory arthritis is suspected (RF, anti-CCP, ESR, CRP), gout is suspected (serum urate), or haemochromatosis is suspected (ferritin and transferrin saturation - particularly for 2nd and 3rd MCP OA, the 'iron fist' pattern).

Joint aspiration if septic arthritis, gout, or CPPD is suspected - cell count, Gram stain, culture, and crystal analysis (MSU: negatively birefringent, needle-shaped; CPP: positively birefringent, rhomboid).

MRI is not routine. Consider for suspected AVN, internal derangement, early OA not visible on X-ray, or atypical presentations. Ultrasound can demonstrate effusion, synovitis, and osteophytes and can guide injection.

NICE NG226 (2022) is the definitive UK guideline. Management is multimodal - core treatments are the foundation with pharmacological, injection, and surgical options as adjuncts. Treatment decisions are based on symptoms and functional impact, NOT imaging severity.

Three CORE treatments (offer to ALL patients with OA):

• •Therapeutic EXERCISE: offer to ALL people with OA regardless of age, comorbidity, pain severity, or disability. Local muscle strengthening targeted to the affected joint (quadriceps for knee OA, hip abductors and external rotators for hip OA, grip and pinch for hand OA), general aerobic exercise (walking, cycling, swimming), and flexibility/ROM. Individualised, progressive, sustained long-term. Pain may increase when starting, but regular exercise remains beneficial. Supervised programmes outperform unsupervised home programmes alone.
• •Weight management (if overweight or obese): even modest loss (5-10% body weight) produces clinically meaningful improvements in pain and function. Offered alongside exercise, not standalone.
• •Information and SUPPORT: clear evidence-based information; address misconceptions ('OA is not simply wear and tear'; 'exercise does not damage the joint'; 'X-ray appearance does not determine treatment'); self-management strategies including pacing, goal-setting, and flare management.

Pharmacological management:

• •Topical NSAIDs: OFFER for knee OA; CONSIDER for OA at other joints. First-line pharmacological option.
• •Oral NSAIDs: consider if topical insufficient. Lowest effective dose, shortest duration. Offer gastroprotection (PPI) with oral NSAIDs. Assess cardiovascular, renal, and GI risk before prescribing.
• •Paracetamol: do NOT routinely offer (NICE NG226); a limited role only as infrequent short-term relief when alternatives are unsuitable.
• •Do NOT offer per NICE NG226: glucosamine, chondroitin, intra-articular hyaluronan, routine strong or weak opioids, acupuncture or dry needling, electrotherapy (TENS, ultrasound, interferential, laser, NMES), or rubefacients.

Non-pharmacological adjuncts:

• •Do NOT routinely offer insoles, braces, tape, splints, or supports unless there is joint instability or abnormal biomechanical loading AND exercise alone is insufficient AND the device is likely to improve function.
• •Manual therapy: only consider for hip or knee OA, and only alongside therapeutic exercise - never as standalone.
• •Walking aids: consider for lower limb OA.
• •Do NOT offer arthroscopic lavage or debridement.

Intra-articular corticosteroid injection: consider when other pharmacological treatments are ineffective or to support engagement with therapeutic exercise. Short-term relief only (approximately 2 to 10 weeks). Does not alter disease progression.

Surgical management: consider referral for joint replacement when symptoms significantly limit quality of life AND non-surgical management has been optimised. Referral should NOT be delayed based on radiographic appearance, age, or BMI. Do NOT use rigid scoring systems. Pre-operative optimisation: weight, fitness, comorbidities, expectations.

Referral: physiotherapy/MSK service for supervised exercise; rheumatology if inflammatory arthritis is suspected or OA is in atypical joints; orthopaedics when non-surgical management has been optimised and symptoms remain significantly limiting; weight management services where appropriate. Clinical reviews are tailored to patient need - patient-initiated follow-up is appropriate for most.

SEM relevance: exercise as first-line treatment for active patients; load management and training-load progression to protect joints; OA prevention through high-quality injury rehabilitation (post-ACL, post-meniscal injury) and neuromuscular training programmes.

Therapeutic exercise is a NICE NG226 core treatment - not an optional adjunct. It is individualised, progressive, and sustained long-term.

Phase 1 (initial engagement and pain management): education that addresses misconceptions and builds confidence; explain that pain may increase when starting exercise but regular exercise remains beneficial. Begin with gentle tolerable exercise, isometric strengthening if painful, progressing to isotonic and functional work. General aerobic exercise (walking, cycling, swimming). Aquatic exercise is useful for lower-limb OA. Topical NSAIDs support symptom management during exercise.

Phase 2 (progressive strengthening and functional improvement): progressive resistance training targeted to the affected joint - quadriceps as priority for knee OA; hip abductors and external rotators for hip OA; grip and pinch for hand OA. Balance and proprioception training. Functional exercises such as sit-to-stand, stair practice, and walking on varied terrain.

Phase 3 (long-term self-management): transition to independent exercise; ongoing strengthening and aerobic exercise as a lifelong habit; weight management maintenance; pacing, flare management, goal-setting; periodic review. Prehabilitation if surgery is being considered to optimise functional outcomes post-arthroplasty.

• •NICE NG226 (Osteoarthritis in over 16s, 2022) - the definitive UK guideline; supersedes the older CG177. Three core treatments (exercise, weight management, information/support); topical NSAIDs first-line pharmacological; symptoms and function drive management, not imaging severity.
• •Kellgren-Lawrence grading (1957) - the standard radiographic grading system (0-4) used in research and surgical planning; remember symptom-imaging discordance.
• •NICE quality standards on OA and arthroplasty referral - referral driven by symptoms and quality of life, not by age, BMI, or radiographic appearance.
• •OARSI (Osteoarthritis Research Society International) recommendations - the international consensus paralleling NICE on core conservative management.
• •Royal Osteoporosis Society and Versus Arthritis - UK patient-facing education and self-management resources to signpost.

• •OA is a whole-joint disease - not just wear and tear; cartilage, bone, synovium, capsule, and muscles all involved.
• •NICE NG226 clinical diagnosis: age 45+, activity-related pain, morning stiffness 30 minutes or less.
• •Three CORE treatments: exercise, weight management, information/support.
• •Topical NSAIDs first-line; offer PPI with oral NSAIDs; do NOT offer glucosamine, hyaluronan, or routine opioids.
• •Kellgren-Lawrence grading is 0-4; radiographic severity poorly correlates with symptoms.
• •OA in ankle, wrist, or elbow is atypical and prompts a search for a secondary cause.