A prospective 2-year study of 75 patients with adult-onset septic arthritis.

AIMS AND METHODS: To assess the clinical features of septic arthritis and characterize therapeutic strategies and outcome in a prospective study of 75 patients selected by positive synovial fluid culture.

RESULTS: Underlying joint disease was present in 46 patients, 25 of whom had rheumatoid arthritis and 15 osteoarthritis. Eleven patients were i.v. drug abusers. Fifty-six per cent of cases involved the knee, 15% involved two or more joints, and staphylococci and streptococci were cultured in >90%. Seventy-eight per cent of patients lived in areas of high social deprivation. Fever was present in 64% and the white cell count (WCC) was normal in 38%. The C-reactive protein was elevated in 98%. Leg ulcers were present in 11% of all patients but in 38% of patients who died (P<0.006). Median duration of antibiotic therapy was 15 days i.v. with subsequent oral treatment for 21 days. Thirty-seven per cent of cases required surgical intervention. Mortality was 11%. A raised WCC at presentation (P<0.02) and the development of abnormal renal function (P<0.015) were predictors of poor prognosis.