Introduction: We studied from July 1997 infected hip and knee arthroplasties treated with only antimicrobial therapy without removal of the implants. The patients enrolled were not eligible for surgical operation or refused it. We tried to understand the role of this kind of therapy for the infections at stage I, II and III.

Material and Methods: We evaluated patients with hip or knee infected arthroplasties at stage I, II and III, respectively: an early infection (2–4 weeks after the prosthesis implantation), a chronic infection that appears more than one month after the operation and an hematogenous infection. The prosthetic hip infections were treated with an oral therapy for 6 months, while the prosthetic knee infections were treated for 9 months. Follow up examinations were conducted regularly for two years

Results: We observed 35 patients from July 1997: 15 with an infection at stage I, 17 at stage II: and 3 at stage III. In 23 patients the prosthesis affected was the hip, while in 12 patients it was the knee. The infections were due in most cases to Staphylococci (85.7%), while in 4 patients (3 cases of hematogenous infection) the pathogens isolated were Gram negative bacteria and 1 infection was due to Clostridium perfrigens. Only in 9 (25.6%) patients was performed a debridement before the beginning of the medical therapy. The overall success rate at one year of follow up was 72.7% (24/33), the success for the patients in stage I was 86.6%(13/15), in stage II 60% (9/15) and for stage III was 66.6% (2/3).

Conclusions: In patients with arthroplasty infection at stage I and III a long-term antimicrobial treatment, without the implant removal, could be a good chance, especially when the pathogen isolated is a S. aureus or a S. coagulase negative. As we expected the success rate for infection at stage II was the lower that we observed between all the prosthetic joint infection, treated with the only antimicrobial therapy. The gold standard for the treatment of stage II should be prosthesis revision (1 or 2 stages); but in our study we enrolled patients not eligible for surgical operation, because of severe clinical conditions, or patients that refused it. With these results we cannot recommend the medical therapy alone, but we can use it as a salvage therapy. As for the infections at stage I and III, no relapse had been observed after one year of follow up; we think that, especially for infections at stage II, a one-year follow up could be sufficient for the identification of the relapses.

Introduction: The purpose of this study is the evaluation of the role of combination chemotherapy with rifampin in the treatment of Staphylococcus-infected arthroplasties, without removal of the implants. The study started on July 1997 and is still open today. The enrolled patients refused surgical operation or were not eligible for it.

Material and Methods: we examined patients with hip or knee infected arthroplasties. The hip prostheses infections were treated with an oral therapy for 6 months, while the knee prostheses infections were treated for 9 months. Follow up was extended to two years. Cure should be defined as the absence of clinical, radiological and biological evidence of infection after two years, but we also considered the clinical success at one year as the study is still open, so that not all the patients finished the two-years follow-up, and more, no relapses had been observed after one year of follow-up.

Results: 42 patients with an arthroplatsy infection (16 knee prostheses and 26 hip prostheses due to Staphilococcus spp (23 S aureus and 19 SCN) were enrolled in our study; the middle age was 69.4. 27 of 42 patients treated with rifampin were examined at one year follow up; no relapses had been observed after one year of follow-up. Rifampin was used in combination with: ciprofloxacin (n° 16), TMP/SMX (n° 10) or fusidic acid (n° l).

The success rate after 1 year was of 81.5% (22 of 27 patients): 90% success rate for methicillin-resistant Staphilococci (9/10) and 76.5% for methicillin-susceptible Staphilococci (13/17). The patients with infection due to S. aureus had a success rate of 83.3% (10/12). whereas for infections due to SCN was 80% (12/15). The success rate for hip prostheses infection was of 83.3% (15/18) and 77.8% (7/9) for knee prostheses infection. The overall success rate after two years of follow up today is 77% (17/22), two patients dead because of cancer.

Conclusions: the long-term treatment with rifampin combination appears to be a satisfactory choice for patients that can’t be eligible for surgical revision or that refuse it.