Abstract
There are several differential diagnoses for knee monoarthritis. We report a patient with recurrent episodes of knee effusion, in which the non-specific clinical condition implied several diagnostic hypotheses, therapeutic inaccuracies, and a delay in implementing adequate treatment.
For more than 2 years, the patient underwent different Orthopedics and Rheumatology visits. She received multiple therapies, including a knee arthroscopy with partial meniscectomy with transient improvement of the complaints but not a definitive diagnosis. After collecting synovial fluid samples and successively negative microbiological tests, we established the diagnosis of overlap of septic arthritis by atypical microorganisms isolated from synovial tissue (Pantoea spp. and Staphylococcus saprophyticus) and Lyme arthritis. Washing and surgical debridement followed by targeted antibiotic therapy resulted in a transient response due to persistent infection (stage 3).
This case demonstrates the need for a multidisciplinary approach to knee monoarthritis.
Keywords
arthritis, septic - case report - gonalgia - Lyme disease - monoarthritis
