Ultrasonographic evaluation of knee joints in patients with Lyme disease

The aim of this study was to evaluate the ultrasonographic images of patients with chronic knee pain and serologic features of Lyme disease.

Seventy-six patients hospitalized in The Department of Infectious Diseases and Neuroinfections of the Medical University in Białystok, Poland were included in the study. Patients were divided into two groups: (1) the Lyme disease group included patients with pain in one or both knees and anti-Borrelia burgdorferi antibodies with symptoms lasting for over 6 months; (2) the control group included patients suffering from pain in one or both knees for over 6 months, but for whom B. burgdorferi infection was excluded.

The most frequent ultrasonographic finding in the Lyme disease group was effusion, and its frequency was significantly higher than in the control group. No patient in the control group presented with synovitis or cartilage damage, while these were quite frequent findings in the Lyme disease group. Baker's cysts were more frequent in the Lyme disease group, but this was statistically non-significant.

Ultrasonography may be useful in following the sequelae of Lyme disease. The abnormalities found in Lyme disease patients are non-specific and ultrasonography is not useful in the differential diagnosis.