Brucellar arthritis of the knee: a case report with delayed diagnosis.

Brucellar septic arthritis has become extremely rare in Western developed countries since bovine brucellosis has been successfully eradicated. Nevertheless, we should remain vigilant for this disease, as brucellosis is still endemic in many parts of the world. The authors present the rare manifestation of a brucellar septic arthritis of the knee joint, associated with a lytic lesion of the proximal tibia. The diagnosis of brucellosis was delayed by 11 months because of the microbiological and histological negativity of repeated joint fluid aspirations, bone biopsies and synovial specimens. Eventually Brucella melitensis could only be isolated from one extended culture of synovial fluid. The treatment with a combination antimicrobial therapy of rifampicin and tetracycline was successful, but the lytic lesion needed reconstruction with bone grafts. A high index of suspicion for brucellosis is needed in any patient coming from an endemic region with a non-specific and chronic arthritis to allow for early diagnosis and treatment.