Introduction: Knee septic arthritis rapidly damages the knee joint. Gächter described a classification of joint infections based on arthroscopic findings: an arthroscopic staging of the common disease has prognostic and therapeutic consequences. The aim of this systematic review was to analyze the application of the Gächter classification system to knee septic arthritis, evaluating prognostic and therapeutic implications of this classification.
Materials and methods: A comprehensive electronic search of the literature was performed. The following search terms were used: (Arthroscopy* OR Arthrotom* OR Aspiration) AND Knee AND Septic AND Arthritis. The study reported the Gächter classification in septic knee arthritis and the eradication rate according to the type. The primary endpoint is the eradication rate of septic knee arthritis according to the Gächter sort. Secondary endpoints are surgical procedures according to Gächter classification and the rate of re-operations.
Results: Seven studies were included. The overall eradication rate of knee septic arthritis ranged from 90% to 100%: 95%-100% Gächter I; 97%-100% Gächter II; 67%-100% Gächter III; 50%-100% Gächter IV. Surgical treatments for knee septic arthritis included arthroscopic irrigation alone, articular irrigation, and debridement in knee arthroscopy or knee arthrotomy according to Gächter stage. However, 28% required re-operations for persistent infection: secondary procedures included further irrigation and debridement with the arthroscopic or arthrotomic approach.
Conclusion: Gächter classification showed a crucial prognostic role in predicting the outcome of surgical treatment of septic knee arthritis. Regardless of the procedure performed, a prompt operation and an accurate debridement of the synovial membrane are the most critical factors for eradicating infection and good clinical outcomes.
Level of evidence: Level II, prognostic study.
Keywords: Gächter classification; arthroscopic debridement; debridement; knee septic arthritis; open debridement..