Patients treated with surgical irrigation and debridement for infection after ACL reconstruction have a high rate of subsequent knee surgery

Objectives The purpose of this cross-sectional study was to describe the rates of additional surgery and patient-reported outcomes in patients who underwent surgical irrigation and debridement (I&D) for infection following anterior cruciate ligament reconstruction (ACLR) and test the hypothesis that additional surgery is associated with worse patient-reported outcomes. Methods Patients diagnosed with a postoperative infection following ACLR (defined as one requiring surgical treatment with either a deep or superficial I&D) were identified from a prospective cohort. Both primary and revision ACLRs were included, as well as any graft type (autografts and allografts). Patient-reported outcomes (International Knee Documentation Committee [IKDC], Knee Injury and Osteoarthritis Outcome Score [KOOS] and Marx activity level) and subsequent surgeries were collected at 2-year and 6 year follow-up from the initial ACLR surgery. Baseline demographics and 2-year and 6-year outcomes (from initial ACLR) were compared between patients who did or did not undergo additional surgery subsequent to I&D using Wilcoxon rank-sum tests for continuous variables and Fisher's exact tests for categorical variables. Results Twenty-one of 3210 ACLR patients (0.7%) had a postoperative infection requiring surgical I&D. This group consisted of 12 men and 9 women, mean (SD) age of 25.8 (11.3) years, 18 primary and 3 revision ACLRs and 16 autografts and 5 allografts. The mean time from ACLR to the surgical I&D was 39 days. In these patients, IKDC scores improved from 44±17 prior to initial ACLR to 83±16 at 6-year follow-up (p<0.001). While all KOOS scores improved from baseline to final follow-up, activity level decreased from 11±6 to 7±5 points (p<0.001). Follow-up related to subsequent surgery was obtained on 20 of 21 patients (95%). Forty per cent of the infection group (n=8 of 20) underwent additional surgery following their I&D, with three patients (15%) undergoing revision ACLR and one patient (5%) undergoing total knee arthroplasty. Patients who underwent additional surgery had lower Marx activity at 2 years compared with patients who had no subsequent surgeries (4±3vs 9±5 points, p=0.018). Conclusion Patients who undergo I&D for an infection following ACLR have a high rate of additional surgery but still attain reasonable clinical outcomes 6 years after ACLR.