Aim

Periprosthetic joint infection (PJI) is nowadays the most important problem leading to failure in primary and revision total knee (TKA) and total hip arthroplasty (THA), therefore accurate diagnosis of PJI is necessary. We evaluated a commercial multiplex PCR system1 for diagnosis of PJI in joint aspiration fluids prior to surgery.

Aim

Treatment of chronic prosthetic joint infection (PJI) combines exchange arthroplasty and effective antibiotic therapy. Staphylococci are the most frequent microorganism isolated in PJIs, with resistance to methicillin found in 15–50% of the cases. Data from randomized trials on treatment of methicillin-resistant staphylococci are lacking and the choice of antibiotic(s) and recommendations vary according to authors. To date, combination therapy including vancomycin is the treatment of choice.

Minocycline, a cyclin antibiotic, is naturally effective against methicillin-resistant staphylococci. We use this antibiotic since many years in combination with vancomycin for the treatment of multi-drug resistant staphylococcal bone and joint infections.

The aim of this study is to analyze the outcome of patients treated with combination antibiotic therapy including minocycline for the treatment of chronic methicillin-resistant staphylococcal PJI.

Purpose of the study: Arthrodesis is the treatment of choice for advanced-stage infection involving the tibiotarsal joint. In aseptic conditions, clinical and biomechanical experiments have shown that internal fixation can lead to a better rate of bone fusion. In septic conditions, external fixation, or a hybrid system, is preferred by many authors. The purpose of this retrospective study was to report the outcomes obtained with tibiotarsal arthrodesis with exclusive internal fixation in a septic environment.

Material and methods: From March 1992 to October 2005, twenty patients underwent tibiotarsal arthrodesis for the treatment of septic arthritis, 18 in a one-phase procedure and two in a two-phase procedure with bone graft. The series included four women and 16 men, mean age 50±15 years. The joint lesions were posttraumatic in 15 cases, related to primary osteonecrosis of the talus in one and to primary arthritis in four. Mean duration of the infection was 2.5 years. Resection of infected bone and soft tissue, to a zone considered healthy, was systematic. Arthrodesis used the Méary technique (n=9) or the Crawford-Adams technique (n=11). Fixation was achieved with screws, staples or both. Mean duration of antibiotics was 97.5±37.5.

Results: The clinical and functional outcome was assessed with the Kitaoka score. The x-rays included an ap and lateral view of the ankle and Méary views. All patients were reviewed at mean 64±36 months; none of the patients were lost to follow-up. The patients were considered cured if clinical and radiographic signs of infection were absent; deep samples confirmed relapse (same germ) or reinfection (different germ).

Discussion: The healing rate for infection was 90% (91% for Crawford-Adams). Radiographic bone fusion was achieved in 90% (100% for Crawford-Adams) with a mean delay of 4.8 months (range 3–11). The mean Kitaoka was improved 45±18.

Conclusion: Tibiotarsal arthrodesis in a septic context can be achieved by internal fixation alone. This method allows good position for the bone fusion and cure of the infection in 90% of cases.

Purpose of the study: Plurimicrobial infections account for 4 to37% of all infections of total hip arthroplasties (THA). According to data in the literature, they are the source of failure, contraindicating one-phase replacement procedures. The purpose of our study was to evaluate the results of our management practices in this group of patients and also to identify factors of risk associated with multimicrobial infection.

Material and methods: A prospective study included 116 patients with an infected THA from November 2002 to December 2006. Sixteen patients (13.8%), mean age 68±12.7 years had a plurimicrobial infection defined by having at last two interoperative bacteriological samples positive for two or more germs. Surgical treatment consisted in a single-phase replacement in seven cases, a two-phase replacement in seven, resection of the head and neck in one, and wash-out resection in one. Mean duration of the antibiotic therapy ws 91±6 days, including 46±14 days intravenously. Anaerobic germs were isolated more commonly in plurimicrobial infections than monomicrobial infections (50% versus 11%). Patients were assessed with prospectively collected data. Mean follow-up was 34±13 months, with none lost to follow-up. The main outcome was apparent cure rate of the initial infection at minimum two years follow-up, defined by the absence of clinical, biological and radiographic signs of infection, and absence of death attributable to infection or its treatment. If infection was suspected, a hip puncture or intraoperative samples confirmed the relapse (same germs) or reinfection (different germs).

Results: The cure rate was 100% for plurimicrobial infections and 97% for monomicrobial infections. There were however four reinfections in the monomicrobial group. In this series, the risk factor statistically associated with plurimicrobial infections was the presence of a fistula with an odds ratio of 5.4.

Discussion: A larger number of patients would probably enable identification of other risk factors associated with plurimicrobial infections.

Conclusion: The cure rate of plurimicrobial infections was higher than reported in the literature but for a small group of patients. The presence of a fistula was strongly associated with these plurimicrobial infections.

Introduction: The goal of the study was to evaluate our treatment protocols for peri-prosthetic infection after total hip replacement.

Méthode: A prospective study carried out between February 2003 and February 2005, included 100 patients treated for peri-prosthetic infection after total hip replacement. Debridement and prosthesis retention was performed in case of duration of symptoms of less than 14 days (11 cases), otherwise a one-stage (42 cases) or a two-stages (41 cases) prosthesis removal and re-implantation were carried out. A two-stage procedure was decided in case of important bone loss or undetermined germ. If general health state did not allow a re-implantation, an isolated prosthesis removal was performed (6 cases). Post-operatively, patients received intravenous antibiotics (6 weeks), then oral antibiotics (6 weeks). The mean follow-up was 2.2 years with no lost to follow-up. The main evaluation criteria was the rate of infection eradication with 2 years minimal follow -up. In case of a suspected new infection, a hip aspiration was performed to determine whether it was a non-eradication (same germ) or a new re-infection (other germ) which was not considered as a failure.

Results: Infection eradication rate was 95% and 100% for the one-stage surgical procedure. 5 failures were recorded (2 deaths and 3 non-eradications). However, 3 patients were re-infected with different germs. The rate of non-infected patiens at the last follow-up was 92%.

Conclusion: Our protocols were validated with a high success rate of 95%. Peri-prosthetic infection of the hip is severe even if well treated with a mortality rate of 2%.