Group G streptococcal infection of joints and joint prostheses.

Eight cases of septic arthritis caused by beta-haemolytic streptococci of Lancefield group G are presented and compared with others previously reported. Involvement of prosthetic joints is notable (25%) as is accompanying cellulitis (75%) which is probably related to the portal of entry of the organism. Other associated conditions were rheumatoid arthritis (38%) and malignant neoplastic disease (25%). Carriage of the group G streptococcus was detected in two of the eight patients. Serological tests for streptococcal antibodies were found to be less useful in the diagnosis of septic arthritis due to group G streptococci than culture of aspirated fluid. In the absence of endocarditis, which was not present in any of our patients, the prognosis appears to be good after treatment with appropriate antibiotics and open drainage of the joint. Both affected joint prostheses, however, required removal.