Two-stage revisions for culture-negative infected total knee arthroplasties: A five-year outcome in comparison with one-stage and two-stage revisions for culture-positive cases.

BACKGROUND: Culture-negative periprosthetic joint infection (PJI) is very intractable when dealing with an infected total knee arthroplasty (TKA) patient. Two-stage revision has been proved to be a reliable solution for PJI patients. Whether it is still credible for culture-negative infected patients remains uncertain.
METHODS: Our group retrospectively reviewed all total knee revision patients from January 2003 to January 2014, 145 PJI patients were diagnosed as infection with the PJI diagnostic criteria and 129 patients were successfully followed. As different treating strategies were utilized, these patients were divided into culture-negative (18 cases, CN) group, culture-positive with one-stage revision group (CP1, 21 cases) and culture-positive with two-stage revision group (CP2, 87 cases) groups. The CN group and CP2 group underwent two-stage revision with antibiotic loaded cement spacers and intravenous antibiotics, CP1 group received one-stage revision. All the culture results and relevant medical records were thoroughly reviewed.
RESULTS: The mean follow-up time was 59.5 ± 32.3 months (range 12-158 months). The culture-negative rate was 14.2%. The overall infection control rate was 92.12%. Infection recurrence was observed in two cases in CP1 group (9.09%), six cases in CP2 group (6.90%) and two cases in CN group (11.1%). The reinfection rate of culture-negative patients and culture-positive patients was 7.34% and 11.1% with no significant difference (p = 0.94). No statistically difference was observed between CP2 group and CN group (p = 0.90). No Spacer fracture or dislocation was observed.
CONCLUSION: With combined or broad spectrum antibiotics, two-stage revision showed comparable outcome when treating culture-negative infected TKA patients at five-year follow-up.