Septic arthritis of the knee in Congo-Brazzaville. A review of 44 cases.

Septic arthritis is underdocumented in equatorial Africa, probably because of a paucity of microbiological resources. However, the causative agent was identified in 44 of 62 cases of septic arthritis of the knee seen at the rheumatology department of the Brazzaville Teaching Hospital between June 1989 and April 1996. There were 30 men and 14 women, with an age range of 7-75 years and a mean age of 42.12 years. Mean time between symptom onset and presentation was 89.8 days. A portal of entry was found in only two patients, and in both consisted of a skin lesion. Risk factors included AIDS.(n=6), sickle cell anemia (n=5), diabetes mellitus (n=4), and an intraarticular corticosteroid injection for osteoarthritis (n=2). All the patients but one had involvement of a single joint. Complications included fistulization in two cases, suppurative myositis in four, and osteomyelitis in two. The erythrocyte sedimentation rate was above 50 mm/h in 37 patients and above 100 mm/h in 28 patients. Peripheral leukocytosis was found in 29 cases. Plain radiographs disclosed joint:space narrowing with or without erosions in 38 cases. The following organisms were recovered: Staphylococcus (n=22), Streptococcus (n=6), Salmonella (n=3), Enterobacter (n=3), Proteus (n=1), Klebsiella (n=1), Escherichia coli (n=1), and the tubercle bacillus (n=1). Histologic evidence of tuberculosis was found in six other patients. Mean hospital stay duration was 34.1 days, and mean duration of antimicrobial therapy in nontuberculous cases was 54 days. Gentamycin combined with oxacillin was the most often used antimicrobial regimen. Arthrotomy was done in one case and surgical excision of suppurative muscle lesions in four cases. Mean follow-up was 84.3 days. Fifteen patients were lost to follow-up, and one died with septicemia. Of the 28 patients who were evaluated after the infectious episode, 19 had loss of motion in the knee. In equatorial Africa, septic arthritis of the knee is a common condition that is often diagnosed at the stage of advanced disease with secondary extension to bone and/or muscle. Risk factors include AIDS and sickle cell anemia. Clinical features. causative organisms, radiological findings, and outcomes match textbook descriptions.