Purpose

Arthroscopic knee surgery uses irrigation fluid, which accumulates in a sterile reservoir during surgery. It has not yet been examined whether the irrigation fluid or suture material used during arthroscopic surgery show bacterial contamination. In the present study, we aimed to determine the time-dependent contamination rate and to clarify its relevance for postoperative infections.

Material And Methods

We included 155 patients in the study, who underwent reconstruction of the anterior cruciate ligament (ACL) in 58 cases, meniscal surgery in 63 cases and combined ACL reconstruction and meniscus repair in 34 cases. During arthroscopic surgery, samples of the pooled irrigation fluid were obtained from the sterile reservoir every 15 minutes and additionally suture material of ACL graft and meniscus repair was examined for bacterial colonization. All samples were sent for microbiologic analysis with an incubation time of 14 days. Postoperative follow-up examinations for clinical signs of infections were conducted after 6 weeks, 12 weeks and 12 months in our orthopaedic outpatient department.

Results

The number of positive microbiological findings in the fluid samples increased over time and showed a strong statistical correlation with the duration of surgery (R2 = 0.81, p = 0.015). The contamination rate of suture and fixation material was 28.4% (n = 29). One infection (caused by Staphylococcus lugdunensis) was observed during follow-up examinations.

Conclusion

Contact with the fluid reservoirs should be avoided as the bacterial contamination rate of the pooled irrigation fluid increases over time. Additionally, we recommend repeated skin disinfection before the introduction of suture material or ACL grafts to the surgical site.