Abstract
A man in his 40s with no prior orthopaedic history presented to an infectious disease clinic with persistent left knee pain and swelling following a traumatic meniscal tear and ensuing prodromal period of fever and chills. Aspiration of the left knee joint revealed a white cell count of 21.0 ×10(9)/L (83% neutrophils) with negative Gram stain and culture. However, Lyme PCR was positive and accompanied by serologies consistent with Lyme arthritis. He was treated with a standard course of antibiotic therapy with subsequent resolution of joint effusion and significant improvement in pain.This is to our knowledge the first report in the literature of Lyme arthritis seemingly provoked by traumatic knee injury. We propose disruption of normal joint anatomy and ensuing inflammation in response to acute injury incited and accelerated migration of previously latent Borrelia burgdorferi spirochetal infection into surrounding synovial tissue, leading to enhanced inflammatory activity and exacerbation of knee pain.