Aim

Community-acquired methicillin-resistant Staphylococcus aureus (CA-MRSA) is commonly associated with serious cases of community-onset skin and musculoskeletal infections (Co-SMSI). Molecular epidemiology analysis of CA-MRSA recovered from skin and soft tissues specimens is lacking in Latin America. This study aimed to identify phenotypic and genotypic features of MRSA isolates recovered from patients presenting Co-SMSI.

Aim

Currently, gram-negative bacteria (GNB), including multidrug-resistant (MDR-GNB) pathogens, are gaining importance in the aetiology of prosthetic joint infection (PJI). To characterize the antimicrobial resistance patterns of Gram-negative bacteria (GNB) causing hip prosthetic joint infections in elderly patients treated at a Brazilian tertiary academic hospital.

Aim

S. aureus and S. epidermidis remain the leading biofilm-forming agents causing orthopedic implant-associated infections (OIAI), but other coagulase-negative Staphylococcus (CoNS) with clinical importance is emerging. Besides, few studies have assessed specific genomic traits associated with patient outcome. This is a preliminary descriptive study of phenotypic and genomic features identified in clinical isolates of S. aureus and CoNS isolates recovered from OIAIs patients that progressed to treatment failure.

Aim

Infection is one of the worst complications following total joint arthroplasty, which is often associated with significant morbidity. Currently, due to the global burden of multidrug-resistant Gram-negative bacteria (MDR-GNB) infections, few multicentre studies have described a microbiological shift from Gram-positive cocci (GPC) towards MDR-GNB PJI (prosthetic joint infection). Additionally, the emergence of MDR-GNB impacts the therapeutic options and may increase the rate of PJI treatment failure. The purpose of the present study was to describe the predisposing factors associated to failure of treatment in an orthopaedic reference hospital in Brazil from 2014 through 2019.

Aim

Over the past three years, roughly 100,000 hip and knee replacements have been performed by the Brazilian Public Healthcare System. Prosthetic joint infection (PJI) is expected to range between 1% to 10% after primary and revisions joint arthroplasties, respectively. So far, there have been no published national PJI data which would be helpful at developing local preventive strategies and guide surgeons and clinicians. We aimed at describing the epidemiological, clinical and microbiological PJI results of a national and collaboration study among infectious diseases specialists and orthopaedic surgeons, including academic, public and private institutions.

Aim

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.

Aim

Infection is one of the worst complications following total joint arthroplasty, which is often associated with significant morbidity and increased medical costs. Although Gram–positive bacteria remains the most prevalent causative agents, an increase in prosthetic joint infections (PJI) due to gram-negative bacteria (GNB) has been reported. Additionally, the emergence of multidrug resistant resistance (MDR) in GNB impacts the therapeutic options and may increase the rate of treatment failure and drug toxicity adverse effects due the prescription of harmful and toxics antimicrobial schemes. The purpose of the present study was to describe the predisposing factors associated to PJI caused by MDR-GNB in a specialized orthopedic reference hospital in Brazil from 2014 through 2018.

Aim

Orthopedic implant related surgical site infection (SSI) is a severe complication which represents an important challenge concerning to its treatment. Therefore, gram-negative orthopedic infections have recently become a global concern.

Aim

We aimed to compare the in vitro antibacterial activity of Bioactive Glass (BAG) S53P4, which is a compound showing local antibacterial activity, to that of antibiotic-loaded polymethylmethacrylate (PMMA) against multidrug resistant bacteria from osteomyelitis (OM) and prosthetic joint infection (PJI) isolates.

Aim

Debridement, antibiotics and implant retention (DAIR) is the recommended treatment for all acute prosthetic joint infections (PJI). However, the efficacy of DAIR and identification of risk factors for failure in patients with late acute PJI, is not well described.

Aim

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.

Aim

The incidence of posttraumatic osteomyelitis (PTO) is increasing in spite of new surgical techniques and development of new antimicrobial therapies. It has been difficult to assess outcomes of PTO because of the numerous risk factors involving the patients, trauma characteristics, surgical conditions, diversity of etiologic agents and long period of follow-up required to determine the effects of any treatment. We aim to identify factors predisposing to develop recurrence of chronic PTO.

Shoulder arthroplasty has been performed by many years for the treatment of several conditions such as osteoarthritis, umeral head avascular necrosis and proximal umeral fractures following traumas. Surgical site infection (SSI) following shoulder arthroplasty remains a challenge, which increases morbidity including reoperations, implant removal, poor mobility, and raises extra medical costs. Identification of risk factors may help implementing adequate strategies to prevent infection. We aim to identify pre- and intra-operative risk factors associated with deep infections in shoulder arthroplasty.

An age and sex-matched case control study was conducted to describe the prevalence rate, clinical and microbiological findings and to evaluate patient and surgical risk factors for shoulder arthroplasty-associated infections (SAIs), among 158 patients who underwent shoulder replacement surgery due to any reason, from 1988 to 2011 at a tertiary public university institution. To evaluate risk factors from SAI we performed uni- and multivariate analysis by multiple logistic regression.

We analyzed 168 prosthetic shoulder replacement surgeries from 158 patients, with an overall infection rate of 9.5%, (16/168 cases). Gram-positive cocci and Gran-negative bacilli were equally isolated in 50% of cases, however the most common bacteria detected (18.8%) was Pseudomonas aeruginosa. Univariate analysis identified neither specific comorbidity nor pre-operative risk factors, but American Society of Anesthesiologists (ASA) score higher than 2 (odds ratio [OR] = 5.30, 95% confidence interval [CI] = 1.58 to 17.79; p=0,013) to be significant preoperative patient-related predisposing factor for SAI. On univariate analysis, the only surgery-related factor significantly associated with higher risk of SAIs was the presence of surgical haematoma (OR = 7.1, 95% CI = 1.1 to 46; p=0.04). On multivariate analysis ASA score higher than two (OR = 4.7, 95% CI = 1.3 to 16.9; p=0.01) was the only independent predictor for periprosthetic shoulder infection.

This study identified unusual pathogens and confirmed previously patient-related known factors such as higher ASA score that predispose to SAIs.

Intramedullary nailing (IMN) has been frequently indicated to treat long bone open and closed fractures, but infection following internal fixation may have devastating consequences, with higher costs. Treatment of intramedullary nail-associated infections (IMNI) is challenging and based upon surgery and adequate antibiotic administration, which requires the correct identification of causative microorganisms. However, there have been difficulties for the microbial diagnosis of IMNI, as the peri-prosthetic tissue cultures may show no microbial growth, particularly in patients with previous use of antibiotics. Sonication have shown higher sensitivity and specificity for microbial identification on a variety of orthopedic implant-associated infections. Aim: To compare clinical and microbiological results and sensitivity for the pathogen identification obtained by conventional peri-implant tissue culture samples with culture of samples obtained by sonication of explanted IMN implants, among patients presenting IMNI of long bones.

Methods: Longitudinal prospective cohort study performed at a tertiary public hospital, ongoing since August 2011. We analyzed all patients with indication for IMN implant removal, and orthopedic-implant associated infections was defined according to previous publications addressing osteosynthesis-associated infections (Yano 2014). Minimal of 2 samples from the peri-implant tissue were taken and sent under sterile conditions to the laboratory for culture. Statistical analysis was performed McNemar's test for related proportions.

Results: We included 26 patients presenting clinical signs of IMNI, of which tissue and sonication cultures were performed for 26 (100%) and 20 (77%) patients, respectively. Among them, 88% were male, with mean age was 35.9 years (range, 19–59 yo). Causes of trauma were mainly motorcycle crashes accounting 54% of accidents; tibia and fibula were affected in 65% and 27%, respectively. Gustilo open fracture classification was grade II (35%) and IIIA (35%). First stage management with external fixation for fracture stabilization was performed in 75% of trauma patients. Sensitivity of peri-prosthetic tissue culture and sonication was 80.7% (21/26), and 95% (19/20) (p< 0.05), respectively. Only one infected patient presented negative tissue and fluid cultures. Gram-positive cocci were isolated in 75% and 79% in tissue and sonication fluid cultures, respectively. Staphylococcus aureus, coagulase-negative staphylococci, Enterococcus sp., were isolated from tissue and sonication culture in 43.5% and 36.3%, 8.7% and 22.7%, 13% and 13.7%, respectively. Polymicrobial infection was diagnosed in 3.8% (1/26) and 15.8% (3/19), patients by tissue and sonication fluid cultures (p< 0,01), respectively.

Conclusion: Sonication of retrieved infected intramedullary nails has the potential for improving the microbiological diagnosis of IMNI.

Deep infection after acetabular fracture surgery is a serious complication, ranging between 1.2% and 2.5% and has been a challenge for patients and surgeons. It increases length of hospital stay by three to four times due to the need of extra surgeries for debridement, impairs future patient's mobility, and increases the overall costs of care. Aim: We aim to identify pre- and intra-operative risk factors associated with deep infections in surgically treated acetabular fractures.

Methods: In a single-center retrospective case-control study, 447 consecutive patients who underwent open reduction and internal fixation of acetabular fractures were included in the study. Diagnosis of surgical site infections required a combination of clinical signs and positive tissue culture or histological signs of tissue infection according to Lipsky et al (2010) and Fleischer et al (2009). To evaluate risk factors from SSI we performed uni- and multivariate analysis by multiple logistic regression.

Results: Among 447 patients studied, 23 (5.1%) presented diagnosis of postoperative infection. 349 (78.1%) were male with a mean age of 33.3 years old. Posterior wall fractures accounted for 119 cases (26.6%) followed by 102 (22.8%) double column fractures and 57 (12.8%) T fractures. Factors associated with a significantly risk of infection were patient-related: older age and alcoholism (OR = 5.15, 95% CI = 1.06 to 21.98; p=0.036); trauma-related: fractures of the lower limb (odds ratio [OR] = 2.7, 95% confidence interval [CI] = 1.8 to 6.78; p=0.017), comminution (OR = 3.6, 95% CI = 1.19 to 8.09; p=0.009), pelvic ring injuries (OR = 2.89, 95% CI = 1.07 to 7.63; p=0.037); and surgical-related: peri- operative complications (OR = 5.12, 95% CI = 1.85 to 13.8; p=0.001), and dislocation (OR = 0.21, 95% CI = 0.03 to 0.96; p=0.023). Duration of surgery longer than 300 min (p=0.002), and type of surgical approach (p<0.001) were also associated with infection.

Conclusion: Deep infections after acetabular fracture surgery were mainly associated with prolonged duration of surgery and the interrelation with the complexity of the fracture such as double column fractures, combined surgical approach, comminution and intra operative complications. Pelvic ring injuries, lower limb fractures, mean age, no dislocations at the time of accident and alcoholism is others associations.

There have been a worldwide change in the susceptibility patterns of antibiotics by many community-acquired microorganisms including those associated to wound infection after open fractures. However, the current antibiotic prophylaxis practice adopted by orthopedic surgeons to prevent infectious complications following open fractures has not changed, since Gustilo and Andersen classification was published several decades ago. Few studies have addressed the current pattern of infectious organisms identified in open fracture wounds and its susceptibility to antibiotics that have been empirically used. We aim to study the incidence of community-acquired resistant organisms isolated in lower extremities open fracture and analyze if antibiotic therapy based upon identified resistant pathogens, would decrease surgical site infection (SSI) rates.

In a prospective, single center cohort study, from August 2013 to March 2015 at a tertiary public university institution, 136 subjects presenting Gustilo type II or III lower extremities open fractures were randomly assigned in two arms. Both arms were submitted to surgical debridement, fracture stabilization, and empirical antibiotic therapy, but subjects on Group II had at least three samples of tissue cultures collected during debridement. Patients previously treated at an emergency department other them ours were excluded. When resistant bacteria was identified, antibiotic therapy was modified according to antibiogram tests. The primary outcome was to compare the infection rates between these two groups, after early 60-days follow up.

We included 136 patients with Gustilo-II (43.4%), –III, (34.5%) open fractures, of which 86% were male, with median age of 33.7 years, and 69.1% presented no comorbidities. Group II (collection of tissue cultures) accounted 36.7% of patients, and among them bacterial growth were detected in 36% (16/50). Microorganism resistant to empirical antibiotic therapy was identified in 18% (9/50), including Staphylococcus aureus, coagulase-negative Staphylococci, Enterococcus sp, Pseudomonas aeruginosa, Klebsiella sp, Serratia sp, Escherichia coli, and Enterobacter sp. Median duration of antibiotic treatment was eleven days. During 60-days of follow up, 71 patients (52.2%) were evaluated for signs of infection using the Centers for Disease Control and Prevention criteria, of which 63.4% (45/71) and 36.6% (26/71) were on Group I and II, respectively. No significant difference in the rates of SSI was observed between the study arms (19.2% vs 22.2%, respectively, P = 0.95).

We detected higher rates of bacterial resistance on Gustilo type II and III open fracture wounds, but adjusting antibiotic therapy towards these contaminants did not affected the rates of infection afterwards.