Rapid bone destruction caused by multidrug-resistant Pseudomonas aeruginosa septic arthritis: A case report.

RATIONALE: Infections due to multidrug-resistant (MDR) Pseudomonas aeruginosa are strongly associated with poor outcomes, including prolonged hospitalization and an increased risk of mortality. Antimicrobial options for the treatment of severe infections due to MDR P aeruginosa are quite limited, and treatment remains challenging.

PATIENT CONCERNS: A 65-year-old woman presented to our orthopedic clinic with a 3-month history of progressive pain and stiffness in her left knee. Her primary care provider administered a hyaluronic acid injection, which unfortunately resulted in worsening symptoms. Subsequent treatment included a 1-month course of intravenous gentamicin and ceftriaxone, which failed to alleviate her symptoms.

DIAGNOSIS: MDR P aeruginosa septic arthritis of the knee. The culture isolate was tested for susceptibility to multiple antibiotics. Magnetic resonance imaging evaluations were conducted, showing notable erosive and osteolytic changes around the joint surfaces that had progressed significantly.

INTERVENTIONS: The patient underwent arthroscopic irrigation and synovectomy. The treatment regimen included a combination of intravenous colistin and piperacillin/tazobactam administered over a 6-week period. Total knee arthroplasty was performed 6 months later without additional antibiotic treatment.

OUTCOMES: Patient's knee condition remained continuously stable without abnormal findings of inflammation. The patient's knee range of motion increased 0 to 125 degrees, her pain almost disappeared, and she was able to maintain activities of daily life.

LESSONS: This case underscores the challenges of managing infections with MDR organisms in complex clinical scenarios, emphasizing the need for timely intervention and appropriate antibiotic therapy.