Periprosthetic Joint Infection after Primary Total Knee Arthroplasty With and Without Sinus Tract: Treatment Outcomes

Background. Sinus tract appears up to 20% of patients with periprosthetic joint infection (PH) after primary total joint arthroplasty (TJA). The adverse effect of different patient related risk factors is well known, but the role of the sinus tract in PJI recurrence wasn't properly investigated. The purpose of the study was to analyze the influence of a sinus tract on the effectiveness of two-stage reimplantation in PJI. Material and Methods. In order to reduce the influence of known risk factors on effectiveness of infection eradication several including criteria were introduced: patients with PJI after primary total knee arthroplasty (TKA), without surgeries before TKA and after infection manifestation and without attempts of antibiotic suppression. Finally, 119 of 475 patients with PJI after primary TKA, treated with two-stage protocol, were retrospectively analyzed: 33 patients with presence of the sinus tract, 86 - without sinus tract. Pathogen type, comorbidities, PH type, bone defects, duration of surgery, intraoperative blood loss and the effectiveness of two stage reimplantation were analyzed. Results. Pathogen structure in analyzed groups was comparable. Staphylococci were the leading cause of PJI in compared groups: 64.4% of patients without sinus tract and 59.1% of patients with sinus tract. Wherein S. aureus was more frequently isolated in case of active sinus tract while S. epidermidis played the leading role in compared group. Polymicrobial PJI was more likely to develop in patients with sinus tract (p = 0.09). Massive bone defects of femur and tibia (type 3 according AORI classification) were identified only in patients with sinus tract PJI, as well as significantly longer duration of the spacer implantation and higher intraoperative blood loss at this stage (p<0.05). Infection eradication after spacer implantation stage was achieved in 98.8% (n = 79) of patients without sinus tract while only 81% (n = 17) of patients with sinus tract PJI successfully passed this stage of surgical treatment (p<0.05), effectiveness of revision knee arthroplasty was 98.7% (ii = 78) and 76.5% (n = 13) respectively (p<0.05). Finally, complex effectiveness of two stage reimplantation in patients with sinus tract was significantly lower (61.9%) than in patients of compared group (97.5%), p<0.05. Conclusion. Presence of the sinus tract in patients with PJI after primary TKA adversely effects on the effectiveness of two-stage reimplantation, this fact could be explained by aggressive development of infection, caused by more virulent pathogens and higher frequency of polymicrobial cases among this cohort of patients. The established patterns require further research to develop tactics for managing this category of patients in order to increase the effectiveness of two-stage reimplantation.