To retrospectively evaluate the effect of two-stage revision on periprosthetic knee infections with negative cultured result.

Twenty-seven cases of microorganism culture negative periprosthetic joint infections(PJI) after total knee arthroplasty from January 2010 to December 2017 were collected for this study. The treatment included using antibiotic-loaded bone cement spacer, post-operative parenteral antibiotic for three weeks, following by oral levofloxacin and rifampicin for three weeks. The successful rate of treatment for periprosthetic knee infections were evaluated. Logistic regression was used to analyze the correlation between sinus tract formation and duration of infection, antibiotic usage, etc.

A total of 27 cases of culture-negative PJI, of which 26 cases were cured, success rate of infection treatment was 96.3%, 24 cases(88.9%) preserved functional knees, two cases were cured by arthrodesis. Only one case failed to be eradicated infection, the failure rate was 3.7%. Gender, age, time of preoperative antibiotic infection control, C-reactive protein, erythrocyte sedimentation rate, white blood cell count, neutrophil percentage, D-dimer and other factors had no significant correlation with sinus tract formation(all P>0.05).

The culture-negative periprosthetic knee infections can be treated successfully by second-stage revision using antibiotic-loaded bone cement (vancomycin, tobramycin) implantation combined with intravenous cephalosporin infusions, the strategy may obtain a reasonable cure rate and preserve joint function. However, the effectiveness of this treatment strategy needs to be further demonstrated due to the lack of control group and short of cases.