527 - Chronic Destruction of the Knee Joint: A Rare Case of Recurrent Enterobacter Septic Arthritis following Arthroscopy

Thursday, February 22, 2024

5:00 PM – 6:30 PM EDT

Presenting Author(s)

CS

Cody Sheppard, BS

Osteopathic Medical Student
Burrell College of Osteopathhic Medicine
Albuquerque, New Mexico, United States
RK

Ryan B. Keller, BA

Osteopathic Medical Student
Burrell College of Osteopathic Medicine
Albuquerque, New Mexico, United States

Corresponding Author(s)

RK

Robin Knight, MD

Internal Medicine Hospitalist
Lovelace Medical Center
Albuquerque, New Mexico, United States

Case Diagnosis: Post-Arthroscopy Septic Arthritis diagnosed as an Enterobacter infection that led to joint effusion and marked osteoarthritis.

Case Description: A 58-year-old female with hypertension and reflux presented initially for left medial meniscus repair via arthroscopy after years of knee pain. Two days post-op, she began having drainage from the incision site and was started on empiric antibiotics. At a 2-week follow-up, the patient underwent left knee aspiration without cultures revealing purulent fluid. She was treated via irrigation and debridement (I&D) with drain placement and eventually discharged on a 6-week course of I/V ertapenem/daptomycin for left knee septic arthritis. The patient was ambulatory until 6-weeks post-op when she was admitted to the ED for recurrent left knee pain. I&D and major synovectomy with aspirate collection was performed. The culture grew Enterobacter cloacae while on antibiotic therapy. Post-discharge and completion of the antibiotic regimen, the limb pain and swelling worsened. This patient has ultimately become complicated with left knee effusion concerning for recurrent pyogenic arthritis possibly due to resistant Enterobacter infection.

Discussions: Prolonged cases of septic arthritis have shown the potential to cause significant destruction of joint architecture despite antimicrobial treatment, resulting in permanent osteoarthritic changes (1). In this case, the rare Enterobacter infection with joint effusion could have quickly been detected with a combined use of ultrasound, showing soft tissue changes, in addition to the mainstay knee arthrocentesis assays.

Conclusions: This case describes an arthroscopic complication of major joint osteoarthritis secondary to Enterobacter infection. While current research is centered on prosthetic implant infections, patients undergoing less-invasive arthroscopy should be monitored with serial imaging for infection to avoid joint degeneration and severe functional impairment. Prompt diagnosis and antibiotic therapy can allow for uncomplicated post-operative care and overall maintenance of joint integrity.