Osteoarthritis

Vignette: A 66-year-old lady has been referred to SDEC for few months history of knee pain, worse on right. She states that she has had knee pain on the right for a few years, but it has progressively gotten worse and in the last 6 months or so she has noticed similar pain on the left.

Past medical history: Type 2 DM, Hypertension, Hypercholerestolemia, Chronic kidney disease, mild COPD (smokes 2 cigarettes a day.) BMI 30.

Medications: Metformin 500mg bd, Amlodipine 5mg od, Simvastatin 40mg On, Symbicort inhaler, Ventolin inhaler prn, Paracetamol regular

Observations: HR 82 bpm, BP 152/70, Sats 95% on air, RR 20, Temp 37.1

Please discuss your approach in this patient.

Model answer:

As the patient appears haemodynamically stable, candidate should choose to focus on detailed history taking. Full history taking should include each system to exclude potential illnesses. Should try and ask specific questions about MSK disorders – any recent injuries? Morning stiffness? Mono/polyarthritis? Any rash? Any fevers/swelling?

Physical examination: May take a systemic approach, respiratory system (clear), CVS (normal), GI system (normal), skin (normal), MSK –demonstrates scattered non-painful Heberden’s nodes, tenderness to palpation of the medial joint lines of both knees, worse on the right. No swelling, full ROM of both knees but some stiffness.

Investigations: Bloods tests including FBC, U&Es, CRP/VBG. Imaging is not indicated when clinically suspecting OA!

Differential diagnosis: Inflammatory arthropathy (RA, AS, Gout), Septic joint, Trauma, Bursitis, Greater trochanteric pain syndrome

Further History:

Her right knee is stiff for 5-10 minutes most mornings and often feels stiff after prolonged sitting. Her pain is typically worse at the end of the day, or when she is more active, particularly with gardening, and improves somewhat with rest.

How would you manage this patient further?

Candidate should be able to suggest from this that this is most likely to be osteoarthritis.

Management: should include non-pharmacological treatment including weight loss, exercise as well as pharmacological treatment including topical NSAID for knee OA, oral NSAID if ineffective + no contraindications. Consider intra-articular corticosteroid injections when other pharmacological treatments are ineffective or unsuitable, or to support therapeutic exercise. Explain to the person that these only provide short-term relief (2 to 10 weeks).

Follow up: Consider patient-initiated follow-up for most people with osteoarthritis (via GP mostly)

High scoring candidates may be asked about referral for joint replacement: