Clinical and epidemiological differences between septic arthritis of the knee and hip caused by oxacillin-sensitive and -resistant s. aureus

OBJECTIVE: To establish the risk factors for joint infection by oxacillin-resistant Staphylococcus aureus (MRSA) using clinical and epidemiological data. METHODS: All septic arthritis cases of the knee and hip diagnosed and treated in our institution from 2006 to 2012 were evaluated retrospectively. Only patients with cultures identified as microbial agents were included in the study. The clinical and epidemiological characteristics of the patients were analyzed, seeking the differences between populations affected by MRSA and oxacillin-sensitive Staphylococcus aureus (MSSA). RESULTS: S. aureus was isolated in thirty-five patients (46.0%) in our total sample, 25 in the knee and 10 in the hip. Of these 35 patients, 22 presented with MSSA and 13 presented with MRSA. Provenance from a health service-related environment, as described by the Centers for Disease Control and Prevention, was the only variable associated with oxacillin-resistant strains of this bacterium (p = 0.001). CONCLUSION: Provenance from a health service-related environment was associated with a higher incidence of MRSA-related septic arthritis, suggesting that this agent should be considered in the initial choice of antibiotic treatment. Previous surgeries of the knee or affected limb and the absence of leukocytes might also be related to infection with this agent. .

Clinical and epidemiological characteristics of septic arthritis of the hip, 2006 to 2012, a seven-year review

OBJECTIVE: To epidemiologically characterize the population treated at our orthopedic clinic with a diagnosis of septic arthritic of the hip between 2006 and 2012. METHODS: Fifteen patients diagnosed with septic arthritis of the hip between 2006 and 2012 were retrospectively evaluated. The patients' clinical and epidemiological characteristics were surveyed; a sensitivity profile relating to the microorganisms that caused the infections and the complications relating to the patients' treatment and evolution were identified. RESULTS: Septic arthritis was more common among males. Most diagnoses were made through positive synovial fluid cultures, after joint drainage was performed using the Smith-Petersen route. Among the comorbidities found, the most prevalent were systemic arterial hypertension, diabetes mellitus, and human immunodeficiency virus. The pathological joint conditions diagnosed prior to joint infection were osteoarthrosis and developmental dysplasia of the hip. The infectious agent most frequently isolated was Staphylococcus aureus. From the clinical and laboratory data investigated, 53.33% of the cases presented with fever, and all except one patient presented with increased measures in inflammation tests. Gram staining was positive in only 26.66% of the synovial fluid samples analyzed. Six patients presented with joint complications after treatment was administered. CONCLUSION: S. aureus is the most common pathogen in acute infections of the hip in our setting. Factors such as clinical comorbidities are associated with septic arthritis of the hip. Because of the relatively small number of patients, given that this is a condition of low prevalence, there was no statistically significant correlation in relation to worse prognosis for the disease. .