Article in Japanese

Diarthrodial joint arthritis undetected by MRI in its early stage

Madoka YASUKOHCHI¹⁾, Eiki OGAWA²⁾, Kensuke SHOJI²⁾, Isao MIYAIRI²⁾

Bacterial arthritis involving the small diarthrodial joints is rare. This study reported a case of Lisfranc (tarsal-metatarsal) arthritis, without abnormal findings from magnetic resonance imaging (MRI) at the early phase of infection, which was diagnosed ultimately by repeated MRI. A previously healthy male, aged 7 years old, visited this emergency department with fever, and pain on the dorsum of the right foot. However, contrast-enhanced MRI of the foot showed no abnormality on day 2 of the illness, and the patient was admitted for cellulitis. Although he received antibiotics, clinical improvement was slow. MRI performed 13 days after onset showed synovial inflammation and hyperplasia in the tarsal-metatarsal and tarsal joints, and bone marrow edema in the tarsal, and metatarsal bones, and calcaneus, leading to the diagnosis of septic arthritis and osteomyelitis. A follow-up MRI performed 47 days after the symptoms appeared showed residual bone marrow edema. The patient received antibiotic therapy for six months to treat presumed chronic osteomyelitis. Repeated MRI testing should be considered when bacterial arthritis of the diarthrodial joints is clinically suspected.

---

1) Department of Postgraduate Education and Training, National Center for Child Health and Development
2) Division of Infectious Diseases, National Center for Child Health and Development

Key words	Bacterial arthritis, Small diarthrodial joints arthritis, Lisfranc joint, Contrastenhanced MRI
Received	December 11, 2018
Accepted	March 12, 2019

31 (2)：169─174,2019