Title : Gram-negative bacillary arthritis following arthroscopy
Abstract:
Background: The rate of septic arthritis after arthroscopy ranges from 0.15% to 1%. Staphylococci are the leading causative organisms after knee arthroscopy whereas Cutibacterium acnes is often the causative organism after shoulder arthroscopy. Gram-negative bacillary infections are uncommon. Our aim was to describe the clinical, biological, therapeutic characteristics and outcome of gram-negative bacillary arthritis following arthroscopy.
Cases description: We report 9 cases of gram-negative bacillary arthritis following 8 arthroscopic knee ligament surgery and one arthroscopic shoulder rotator cuff repair. Over this period (18 months), 93 arthroscopies were performed. The sex-ratio was 8 with a mean age of 24 [18-43] years. Risk factors for infection were smoking (n=7), diabetes (n=2), obesity (n=2) and complex surgical procedures (n=2). The mean time to onset of clinical signs was 20 [3-33] days. In all cases, symptoms were not specific including persistent pain (9/9), persistent effusion (5/9) and a low-grade fever (4/9). Laboratory evidence of systematic inflammation was noted in all cases (high C-reactive protein value with a mean value of 49mg/L). Pseudomonas aeruginosa was identified for all patients in joint aspiration collected fluid and deep specimens collected during arthroscopic lavage. All patients underwent emergent abundant arthroscopic lavage with synovectomy in 4 cases. Combination of 2 effective antibiotics, piperacillin- tazobactam or imipenem with ciprofloxacin, was administered intravenously for an average duration of 15.3 [14-21] days. Oral treatment was ciprofloxacin monotherapy. Mean total antibiotic duration was 66 [42-90] days. Eradication of infection was achieved for all patients and functional outcomes were satisfying according to surgeons.
Conclusions: Gram-negative bacillary arthritis following arthroscopy is a healthcare associated infection and a therapeutic emergency. Pseudomonas aeruginosa is an extremely rare causative organism identified in less than 0.2% of cases. Infection is often particularly challenging to diagnose as the clinical symptoms may resemble those often produced by the procedure itself. Consequently, emergent joint aspiration is essential. Outcome depends on an early. diagnosis. The treatment must combine emergent abundant arthroscopic lavage with synovectomy as indicated by the stage of infection and administration of effective antibiotics for at least 6 weeks. Early diagnosis and treatment lead to eradication of infection and satisfying functional outcome. Prevention based on asepsis and risk factors control is essential.
