Background Overall, bacteria are the most common cause of infectious arthritis. Its incidence appears to be increasing in developed countries with an annual incidence of 2-6 cases/100,000 inhabitants. It is more prevalent in extreme ages, and in patients with comorbidities. The 40% of patients with septic arthritis have a prior arthropathy. The most common causative microorganism is Staphylococcus aureus, followed by Streptococcus group, of which the Streptococcus pyogenes is the most involved. In 75% of cases the infection is acquired through the blood and in 80% of cases affects a single joint. The knee is the most affected joint. The diagnosis is confirmed by isolating the organism in synovial fluid and due to its high morbidity and mortality treatment with intravenous antibiotics should be started promptly.
Objectives To describe the demographic, clinical and laboratory features of patients with septic arthritis, with microorganism identified in synovial fluid and/or blood cultures between January 1985 and December 2014 at the University Hospital of Donostia (Guipuzcoa, Spain).
Methods Retrospective research of clinical data of patients diagnosed with septic arthritis between January 1985 and December 2014. Patients without microorganism identified in synovial fluid and/or blood cultures were excluded. Variables included were: age, sex, potential risk factors for infection, previous joint aspiration, history of arthropathy, clinical features, identified microorganism, affected joint, laboratory and imaging tests and the presence of osteomyelitis.
Results A total of 259 patients were enrolled with a diagnosis of septic arthritis and microorganism identified well in synovial fluid and/or blood. The 67.20% of the patients were male and the median age was 61 (IQR=31). Risk factors were identified in 72.7% of patients. The 39.92% of patients had previous arthropathy and 12.86% had history of previous arthrocentesis.
The most common causative agent was Staphylococcus Aureus in 62.89% of cases, followed in frequency by Streptococcus group (21.88%) and Escherichia coli (5.47%). In 76.11% of cases the diagnosis was made by isolation of germ in synovial fluid and in 19.03% of cases with isolation in synovial fluid and blood cultures. The knee joint was affected in 51.02% of cases.
Pain and swelling were present in most patients, 98.78% and 91.46% respectively. The 64.61% had fever. Osteomyelitis was present in 9.96% of patients. Conservative treatment was the most used (76.86%) and 23.14% required surgery at some point.
– The most common causative agent was S. aureus.
– Almost half of the patients had previous arthropathy
– A small percentage of patients had osteomyelitis.
Disclosure of Interest None declared