Septic arthritis following arthroscopic reconstruction of cruciate ligaments of the knee: retrospective case review.

INTRODUCTION: Rupture of cruciate ligaments of the knee is a common injury that is repaired by arthroscopic reconstruction, which can give rise to septic arthritis. The objective of this article is to describe the clinical and microbiological aspects of this entity.

METHODS: Retrospective review of cases of septic arthritis following arthroscopic reconstruction of cruciate ligaments of the knee that occurred at a single institution from 2000-2015. According to time elapsed from surgery, infections were classified as acute (< 14 days), subacute (> 14 days and<30 days), and late (> 30 days). A descriptive and comparative analysis stratified by type of infection and causative microorganism was performed.

RESULTS: 3,219 patients underwent arthroscopic reconstruction of cruciate ligaments of the knee and 30 (0.9%) developed septic arthritis. Seventeen (57%) were acute infections and 12 (40%) subacute; there was one late infection. The causative microorganisms were coagulase-negative Staphylococci (n=13; 43%), Staphylococcus aureus (n=12; 40%), other grampositive cocci (n=3; 10%), and gramnegative bacilli (n=2; 7%). All patients underwent arthroscopic debridement; no grafts were removed. All patients received antibiotic therapy for a median of 23.5 days (range: 14 - 78 days); all infections were cured. No significant differences were found in any of the variables analysed among the infection type or the causative microorganism.

CONCLUSIONS: Septic arthritis after arthroscopic reconstruction of cruciate ligaments of the knee is uncommon. It generally presents within 4 weeks of surgery and is caused by Staphylococci. Its treatment consists of arthroscopic debridement (without necessarily removing the graft) and antibiotic therapy.