Treatment of septic arthritis of the knee: a comparison between arthroscopy and arthrotomy

PURPOSE: The aim of this study was to compare the efficacy of arthroscopy and arthrotomy in patients with septic monarthritis of the knee. METHODS: Seventy consecutive patients who underwent surgery because of a bacterial monarthritis were evaluated. Patients were either treated with arthroscopy or with arthrotomy. Our primary outcome was the early recurrence of infection (>3 months after surgery), which made a second surgical procedure necessary. Furthermore, the influence of potential confounders on treatment outcome was analysed. RESULTS: Of the 70 patients, 41 were treated arthroscopically and 29 with arthrotomy. Eight patients (11.4 %) had to undergo a second surgical procedure because of early re-infection. The rate was significantly higher in patients treated with arthrotomy (n = 6; 20.7 %) compared with those treated by arthroscopy (n = 2) (p = 0.041). Range of motion was significantly better in patients who underwent arthroscopy (p < 0.001). Male sex had negative influence on the treatment success (p = 0.03). CONCLUSIONS: Patients with bacterial monarthritis of the knee who were treated with arthroscopy had a significantly lower re-infection rate and a better functional outcome than those treated with arthrotomy. As arthroscopy is the less invasive method, it should be considered the routine treatment, according to our data. LEVEL OF EVIDENCE: Therapeutic study, Level III.