OBJECTIVETo investigate the risk factors for the failure in treating periprosthetic infection of coagulase-negative staphylococci by two-stage revision.

METHODSFrom January 2005 to June 2015, 57 patients with periprosthetic hip and knee joint infection of coagulase-negative staphylococcus by two-stage revision were retrospectively reviewed with an average age of (61.3±11.9) years old. According to the drug resistance of methicillin, the patients were divided into methicillin sensitive group(MSCoN) and methicillin resistance(MRCoN) group, 25 cases in MSCoN group(9 knees and 16 hips) included 12 males and 13 females, 32 cases in MRCoN group(11 knees and 21 hips) included 14 males and 18 females. Follow-up for at least 2 years, the inflammatory markers, incidence rate of sinus and the duration of the symptoms, reinfection or persistent infection rate after two-stage revision were compared between two groups.

RESULTSMSCoN group and MRCoN group were followed up(81.7±38.3) months and(65.9±33.8) months, respectively;23 cases and 27 cases were successfully treated;there was no significant difference between two groups(=0.643). The patients who had surgery history were 4.04 times higher of failure than the patients without a history of surgery[OR=4.04, 95%CI(0.62, 26.5)]. Patients who had sinus were 4.26 times higher of failure than the patients without sinus[OR=4.26, 95%CI(0.7, 25.9)].

CONCLUSIONSTwo-stage revision is an effective procedure in treating patients infected by MSCoN and MRCoN. There is no significant difference of treatment failure rate between MSCoN and MRCoN group by two-stage revision. Surgery history and sinus maybe the risk factors of treatment failure, while methicillin-resistance is not.