TWO-STAGE REIMPLANTATION FOR PEIPROSTHETIC HIP INFECTION CAUSED BY RESISTANT MICROORGANISMS

Abstract

Two-stage reimplantation is currently the most widely accepted method of treatment for a periprosthetic hip infection. However, it remains controversial whether the treatment protocol may be equally effective in the eradication of resistant microorganisms. We compared the results of two-stage reimplantation performed for periprosthetic hip infection caused by resistant microorganisms with those performed for periprosthetic hip infection caused by non-resistant microorganisms.

We reviewed a consecutive series of 32 patients (32 hips) who had a culture-proven deep infection at the site of hip arthroplasty and were treated by a two-stage reimplantation protocol. Based on the antibiotic sensitivities of the infecting microorganisms, the patients were divided into two groups. Resistant microorganism group consisted of 20 patients who had an infection with antibiotic-resistant bacterial strains (methicillin-resistant Staphylococcus aureus in 11 and methicillin-resistant Staphylococcus epidermidis in 9). Non-resistant microorganism group consisted of 12 patients who had an infection with antibiotic-sensitive bacterial strains. The treatment was considered a failure if the patient had a persistent infection after the first-stage procedure or a recurrence of infection after reimplantation. The mean duration of follow-up after the index procedure was 45 months (24 to 123).

Among the entire series of the 32 patients, the second-stage reimplantation was able to be performed in 29 patients (91%) and the remaining three went on to a permanent resection of the hip because of persistent infections. After the two-stage reimplantation, four patients had a recurrence of infection (relapse of infection with the same microorganism in three and reinfection with different resistant microorganism in one). Thus, overall treatment failure rate was 22% and all these failures occurred among patients with resistant microorganisms. Treatment failure rate of 35% in resistant microorganism group was significantly higher than that of 0% in the non-resistant microorganism group (p = 0.029). None of the variables evaluated in this study was found to be significantly associated with the treatment failure in the resistant microorganism group.

Current two-stage reimplantation protocol showed a high rate of treatment failure in our patients who had periprosthetic hip infection caused by methicillin-resistant bacterial strains. Further study is needed to develop optimal treatment strategy for this difficult-to-treat condition.