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Knee osteoarthritis awaiting total knee arthroplasty — SCE Rheumatology MCQ

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ModerateIntra-articular Steroid TherapyKnee osteoarthritis awaiting total knee arthroplastySCE Rheumatology

A 69-year-old woman with end-stage medial-compartment knee osteoarthritis is listed for total knee arthroplasty in 9 weeks. Despite therapeutic exercise, weight management, a walking aid and topical NSAID treatment, she has developed a painful atraumatic effusion that is limiting sleep and mobility. An oral NSAID is unsuitable because her eGFR is 32 mL/min/1.73 m². Arthrocentesis yields non-purulent fluid with 900 leucocytes/mm³, no crystals and negative bacterial cultures. There is no fever or overlying infection, and her CRP is 4 mg/L. An intra-articular triamcinolone injection given 18 months previously provided substantial short-term relief. She requests another injection but wishes to retain the planned arthroplasty date. Which management plan is most appropriate?

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

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Correct answer: D — Defer intra-articular injection if retaining the arthroplasty date; if glucocorticoid is injected, delay surgery until at least 3 months afterwards

Explanation lettering: D = shown as A · C = shown as B · A = shown as C · E = shown as D · B = shown as E

The aspirate and systemic findings make septic or crystal arthritis unlikely, so an intra-articular glucocorticoid would otherwise be a reasonable short-term intervention for this osteoarthritis flare. The decisive feature is that ipsilateral joint replacement is planned in 9 weeks. EULAR recommends that intra-articular therapy be performed at least 3 months before joint replacement because observational evidence indicates a higher prosthetic joint infection rate when glucocorticoid injection occurs within the preceding 0–3 months. A is therefore inappropriate despite the previously favourable response. B is also incorrect: discussion with the surgeon does not remove the infection-risk interval or make a 9-week interval concordant with the recommendation. C still leaves less than 3 months between injection and surgery. D is not an appropriate workaround; NICE advises against intra-articular hyaluronan for osteoarthritis because clinically meaningful benefit has not been demonstrated, and changing the injectable does not establish a safe peri-arthroplasty strategy. If preserving the operative date is her priority, the injection should be deferred and non-injection symptom control optimised. If symptoms lead her to prioritise injection, this requires shared decision-making with the arthroplasty team and rescheduling surgery to at least 3 months afterwards.

Reference: EULAR recommendations for intra-articular therapies (25 May 2021) — https://ard.bmj.com/content/80/10/1299 NICE NG226: Osteoarthritis in over 16s—diagnosis and management (19 October 2022; updated October 2023) — https://www.nice.org.uk/guidance/ng226/chapter/Recommendations