Symptomatic fibrous lunato-triquetral coalition.

In general, carpal coalitions are considered to be asymptomatic. Incomplete separated joints and associated changes similar to osteoarthritis and pseudoarthrosis are known as possible causes of wrist pain. We present the clinical history, plain-film, and MR imaging findings of two patients with symptomatic fibrous lunato-triquetral coalition. Conventional films disclosed a narrowed space between the lunate and triquetral bone with cysts and sclerosis similar to pseudoarthrosis. Magnetic resonance imaging showed bone marrow edema adjacent to the incomplete separated lunato-triquetral joint and Gd-DTPA enhancing fibrovascular tissue in the synovium and subarticular cysts, explaining the pain over the ulnar-sided wrist. Patients with congenital lunato-triquetral coalition may poorly tolerate stress loading or trauma, resulting in a symptomatic state similar to degenerative arthritis or pseudoarthrosis, which is demonstrated by enhanced MR imaging.