skip to main content

Joint Aspiration — SCE Rheumatology MCQ

Instant feedback + full explanation. One question, done properly.

ModerateJoint AspirationSCE Rheumatology

A 71-year-old man presents with a 12-hour history of an atraumatic, acutely painful swollen right knee. He started apixaban 5 mg twice daily 4 weeks ago for a proximal deep-vein thrombosis. Examination shows a warm, moderately tense knee effusion without overlying cellulitis. His temperature is 37.2°C and he is haemodynamically stable. C-reactive protein is 48 mg/L, platelet count is 232 × 10⁹/L, eGFR is 74 mL/min/1.73 m² and liver biochemistry is normal. He takes no antiplatelet drug and has no personal history of abnormal bleeding. Diagnostic aspiration is required to distinguish crystal arthritis, infection and anticoagulant-associated haemarthrosis. Which is the most appropriate periprocedural plan?

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

Reveal the answer and explanation

Correct answer: A — Perform aspiration now without interrupting apixaban, with local compression after the procedure

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

Joint aspiration and intra-articular procedures have a low periprocedural bleeding risk. EULAR advises that antithrombotic treatment is not itself a contraindication unless the individual has a high bleeding risk; observational evidence estimates bleeding rates of 0–2%, including no bleeding events in a large series of procedures performed during continued direct oral anticoagulation. This patient has normal platelets, preserved renal and hepatic function, no concurrent antiplatelet therapy and no bleeding history. Conversely, he requires prompt diagnostic aspiration and is only 4 weeks into treatment for a proximal DVT, making unnecessary interruption undesirable. Aspiration should therefore proceed while apixaban is continued, using meticulous technique and post-procedure compression. A and B are tempting because brief DOAC interruption is used for procedures with greater bleeding risk, but it is not routinely required for arthrocentesis and would delay diagnosis. D substitutes one therapeutic anticoagulant for another without reducing procedural risk and introduces avoidable complexity; bridging may be considered for selected high-risk patients interrupting longer-acting anticoagulants for higher-risk procedures. E is inappropriate because reversal is reserved for major bleeding or genuinely urgent procedures carrying substantial bleeding risk, not uncomplicated knee aspiration.

Reference: EULAR recommendations for intra-articular therapies (25 May 2021) — https://ard.bmj.com/content/80/10/1299 The Risk of Bleeding Complications in Intra-Articular Injections and Arthrocentesis in Patients on Novel Oral Anticoagulants: A Systematic Review (2021) — https://pubmed.ncbi.nlm.nih.gov/34659968/ Arthrocentesis and Joint Injection in Patients Receiving Direct Oral Anticoagulants (2017) — https://pubmed.ncbi.nlm.nih.gov/28778256/