TOE DACTYLITIS IN PATIENTS WITH SPONDYLOARTHROPATHY - ASSESSMENT BY MAGNETIC-RESONANCE-IMAGING

Objective. To investigate using magnetic resonance imaging (MRI) the p art played by flexor and extensor tenosynovitis and synovitis of the m etatarsophalangeal (MTP), proximal interphalangeal (PIP) and distal in terphalangeal (DIP) joints in producing the ''sausage-like'' aspect of spondyloarthropathy (SpA) toe dactylitis. Methods. Twelve sausage-lik e toes and corresponding contralateral toes of 7 consecutive patients meeting Amor criteria for SpA were studied by MRI. Results. All dactyl itic toes showed fluid collections in the flexor synovial sheaths on M RI. Due to tile sheath distension the plantar bone to skill distance w as significantly increased (p < 0.05) in the dactylitic toes compared to normal contralateral toes, Peritendinous soft tissues were not invo lved since these were significantly thicker (p < 0.05) in normal toes. Extensor synovial sheaths were involved in only 4 dactylitic toes, Of the 36 joints of the 12 dactylitic toes only 2 MTP joints showed caps ule distension, Considering MRL as the ''gold standard,'' examination showed 100% sensitivity and specificity for flexor sheath involvement but lacked sensitivity for extensor synovial sheaths and showed a low specificity for joint capsule distension, Conclusion. Like finger dact ylitis, toe dactylitis may also be due to flexor tenosynovitis and syn ovitis of MTP, PLP, and DIP joints may not be a required condition for sausage-shaped appearance, Extensor tenosynovitis may be present: in addition to flexor tenosynovitis. Physical examination is a sufficient method for diagnosing toe dactylitis.