Objectives: To compare the frequency and characteristics of septic arthritis in patients younger than 80 and aged 80 and older.
Setting: Single hospital center.
Participants: Patients admitted between 1979 and 2002 for septic arthritis.
Measurements: Age, sex, time to diagnosis, predisposing factors, joint, temperature, white blood cell count, microorganism, and short-term outcome.
Results: Of 335 patients, 206 (61.4%) were aged 60 and older, and 42 (12.5%) were 80 and older. The latter had an average age of 84 (range 80-97) and were mainly women (72%). Eighteen of the 42 had at least one risk factor. The mean time to diagnosis was 21 days (range 1 day to 3 months). Twenty patients (47%) had knee involvement, six (14%) shoulder involvement, ten (23.8%) a prosthetic infection, and five (12%) polyarticular infection. Ten (23%) were afebrile. In half of the cases, there was no increase in white blood cell count. The microorganisms isolated were Staphylococcus aureus (n=16, 38%), coagulase negative staphylococci (n=8, 19%), streptococci (n=12, 28%), and gram-negative bacilli (n=6, 14%). The mortality rate increased with age: 0.7% of patients younger than 60, 4.8% of those aged 60 to 79, and 9.5% of those aged 80 and older.
Conclusion: Advanced age is a risk factor for septic arthritis and poor outcome.