AN 18 YEAR CLINICAL REVIEW OF SEPTIC ARTHRITIS FROM TROPICAL AUSTRALIA

A retrospective study of 191 cases of septic arthritis was undertaken at Royal Darwin Hospital in the tropical north of Australia. Incidence was 9.2 per 100 000 overall and 29.1 per 100 000 in Aboriginal Austra lians (RR 6.6; 95% CI 5.0-8.9). Males were affected more than females (RR 1.6; 95% CI 1.2-2.1). There was no previous joint disease or medic al illness in 54%. The commonest joints involved were the knee (54%) a nd hip (13%). Significant age associations were infected hips in those under 15 years and infected knees in those over 45 years. Seventy-two percent of infections were haematogenous. Causative organisms include d Staphylococcus aureus (37%), Streptococcus pyogenes (16%) and Neisse ria gonorrhoeae (12%). Unusual infections included three melioidosis c ases. Polyarthritis occurred in 17%, with N. gonorrhoeae (11/23) more likely to present as polyarthritis than other organisms (22/168) (OR 6 .0; 95% CI 2.1-16.7). Univariate and multivariate analysis showed the hip to be at greater risk for S. aureus than other joints. Open arthro tomy was a more successful treatment procedure than arthroscopic washo ut or needle aspiration.