Carpal coalition: a rare coincidence with hand deficiencies.

Three cases in which congenital carpal fusion was associated with formation deficiencies of the hand are presented. In two patients with a lunate-triquetral and a capitate-hamate-trapezoid coalition, respectively, an ulnar deficient hand was also diagnosed. A subdivision of the first type of ulnar club hand deformities is proposed. Other skeletal anomalies included duplication of a phalanx and pseudoepiphysis of a metacarpal, respectively. In the latter case hypoplasia of the flexor tendons to the fingers, excluding the thumb, was also noted. In the third case, a proximal capitate-hamate coalition coexisted with aplasia of the flexor tendons to the middle finger.