Abstract
RATIONALE: Pseudomonas aeruginosa-induced septic arthritis is a relatively uncommon phenomenon. It has been documented in children with traumatic wounds, young adults with a history of intravenous drug use, and elderly patients with recent urinary tract infections or surgical procedures. PATIENT CONCERNS: Fifty-nine year-old female had no reported risk factors. The patient sought medical attention due to a 6-month history of persistent pain and swelling in her right ankle. DIAGNOSES: Magnetic resonance imaging and a 3-phase bone scan revealed findings suggestive of infectious arthritis with concurrent osteomyelitis. Histopathological examination of the synovium suggested chronic synovitis, and synovial tissue culture confirmed the presence of P aeruginosa. INTERVENTION: Arthroscopic synovectomy and debridement, followed by 6 weeks of targeted antibiotic therapy for P aeruginosa. OUTCOMES: Following treatment, the patient experienced successful recovery with no symptom recurrence, although she retained a mild limitation in the range of motion of her ankle. LESSONS: To our knowledge, this is the first reported case of chronic arthritis and osteomyelitis caused by P aeruginosa in a patient without conventional risk factors. This serves as a crucial reminder for clinicians to consider rare causative organisms in patients with chronic arthritis. Targeted therapy is imperative for preventing further irreversible bone damage and long-term morbidity.