Reactions 1260 - 11 Jul 2009

SCortisone

Infectious arthritis associated with a poplitealcyst: case report

A 54-year-old woman developed infectious arthritisassociated with a popliteal cyst, which coincided with aninjection of cortisone.

The woman had a history of rheumatoid arthritis, treatedwith etanercept. After complaining of right knee pain andswelling during outpatient hand surgery, she received aninjection of cortisone [dosage not stated] using an aseptictechnique. One week later, she reported a 1-day history ofright knee pain, swelling, tenderness, limited motion anddifficulty with weight bearing. No infectious agent was seenon culture or Gram stain. Twenty-four hours later, hersymptoms rapidly worsened and she presented to theemergency department. Her knee was swollen, warm anderythematous with limited motion. A large popliteal cystwas also identified. Inflammatory markers were elevated.Knee aspiration fluid was purulent, and a Gram stainshowed gram-positive cocci. She was diagnosed withinfectious arthritis.

The woman underwent arthroscopic irrigation anddebridement. Cultures of aspirated knee fluid grewStaphylococcus aureus. Postoperatively, she initiatedvancomycin and discontinued etanercept. A week afterpresenting to the emergency department, she returnedwith increasing pain, swelling and redness. After recurrentinfectious arthritis was identified, she underwent repeatirrigation and debridement. Cultures of purulent fluid againgrew S. aureus, this time penicillin-resistant. She washospitalised and administered vancomycin, with littleimprovement. The cyst grew and became more painful. Thenext day, it was excised, and further irrigation anddebridement was conducted. Subsequent gram stains andcultures were negative for organisms. After the excision,she improved rapidly, continuing on vancomycin for6 weeks. At last follow-up, the infection had not recurred.

Author comment: "Most cases of pyarthrosis associatedwith popliteal cyst arise in patients either spontaneously orafter cortisone injections. These patients typically also havesome level of immune compromise such as rheumatoidarthritis, endocarditis, renal impairment, or otherrheumatologic disorders."Eichinger JK, et al. Surgical management of septic arthritis of the knee with acoexistent popliteal cyst. Arthroscopy 25: 696-700, No. 6, Jun 2009 -USA 801146363

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Reactions 11 Jul 2009 No. 12600114-9954/10/1260-0001/$14.95 © 2010 Adis Data Information BV. All rights reserved