Contrast-enhanced MRI compared to histological findings in the temporomandibular joint of antigen-induced arthritis in young rabbits.

OBJECTIVE To study the correlation between histological findings and Magnetic Resonance Imaging (MRI) findings in experimentally induced arthritis in the temporomandibular joint (TMJ) of growing rabbits and to study the effect of intraarticular corticosteroid injections. METHODS Arthritis was induced by ovalbumin in the left TMJ of 44 pre-sensibilized rabbits. Nine animals died during this procedure. Eight of the remaining animals with induced arthritis were treated with intraarticular corticosteroid injections one week after induction of arthritis. Twelve rabbits served as controls. MRI enhanced with Gadolinium-DTPA was performed on all animals 1 to 2 weeks after induction of arthritis and again before sacrifice and the degree of enhancement was calculated. Histology of the condyle was performed and degree of villous hyperplasia, synovial thickness, infiltration of inflammatory cells and pannus was graded. RESULTS TMJ arthritis was successfully induced in the rabbits and was verified by enhancement of the MRI and by histological changes one week after the induction. Joints treated with intraarticular corticosteroid injections revealed complete inhibition of the inflammation. CONCLUSION Enhancement of MRI in antigen-induced arthritis in the TMJ associated well with inflammatory changes shown histologically. An intraarticular corticosteroid injection prevents the initial inflammatory response in experimentally induced TMJ arthritis.