Gram negative bacteria (GNB) are emerging pathogens in chronic post-traumatic osteomyelitis. However, data on multi-drug (MDR) and extensively drug resistant (XDR) GNB are sparse. A multi-centre epidemiological study was performed in 10 countries by members of the ESGIAI (ESCMID Study Group on Implant Associated Infections). Osteosynthesis-associated osteomyelitis (OAO) of the lower extremities and MDR/XDR GNB were defined according to international guidelines. Data from 2000 to 2015 on demographics, clinical features, microbiology, surgical treatment and antimicrobial therapy were retrospectively analyzed. Cure was assessed after the end of treatment as the absence of any sign relevant to OAO. Factors associated with cure were evaluated by regression analysis.Aim
Methods
Data on Prosthetic joint infection (PJI) caused by multi-drug resistant (MDR) or XDR (extensively drug resistant) Gram negative bacteria (GNB) are limited. Treatment options are also restricted. We conducted a multi-national, multi-center assessment of clinical data and factors of outcome for these infections. PJI were defined upon international guidelines. Data from 2000–2015 on demographics, clinical features, microbiology, surgical treatment and antimicrobial therapy was collected retrospectively. Factors associated with treatment success were evaluated by logistic regression analysis.Aim
Method
Acute postoperative periprosthetic joint infection (PJI) is a serious complication after any hemiarthroplasty (HHA) implanted due to a proximal hip fracture. The growing number of chronic institutionalized geriatric patients (CIGP) colonized with multi-drug resistant bacteria (e.g.: MRSA), not covered by usual antibiotic prophylaxis, has been identified as a risk factor for PJI after HHA. We therefore sought to compare the HHA infection characteristics between non-institutionalized patients (NIP) with proximal hip fractures and CIGP. We investigate (1) the rate of compliance with a new proposed protocol, (2) the acute infection rate, 3) the microbiologic characteristics of the infection, and 4) the success of the new protocol. We gathered clinical, operative and infection data on all patients who underwent HHA due to a proximal femoral fracture in our center, during a 3-year period. We focus in the cases of acute postoperative infection (Zimmerli´s criteria). The new proposed antibiotic prophylaxis is cefazolin except in CIGP in which co-trimoxazole is used. During the study period a total of 385 HHA in 385 patients were performed. In all cases the HHA was performed after a proximal femoral fracture. Overall, 109 patients (28,2%) were CIGP. We found an acute postoperative PJI in 21 out 385 HHA procedures, that is, a global acute infection rate of 5.43%. Ten out 109 (9.17%) CIGP patients resulted infected compared to 11 out 278 (3.9%) non-institutionalized patients (p: 0.049). One or more causative microorganisms were identified in 20/21 (95%) of PJI. Globally the Gram-Negative bacilli group accounted for the majority of the infections (60%). Staphylococus aureus was isolated in 3 cases (8.6%) with only a single MRSA infection. The percentage of polymicrobial infections was 47% (10 out of 21). Co-trimoxazole was used in the prophylaxis in 80.1% of the CIGP. In the infected cases a non-effective drug against the microorganism was used in the prophylaxis in 17 (81%) of the acute infected HHA. We confirm that institutionalized patients are more prone to acute infections after a HHA. Our current strategy of antibiotic prophylaxis has showed to be effective in preventing MRSA PJI in CIGP. However, we found an increased rate of infection due to gram-negative bacilli non-covered by the current antibiotic prophylaxis. According our data an extended antibiotic prophylaxis on gram-negative drug will be proposed to be implemented in CIGP scheduled to a HHA because a proximal femoral fracture.
