Type 0 ulnar longitudinal deficiency

To describe the characteristics of type 0 ulnar longitudinal deficiency (ULD) in which deficiencies are present in the hand and carpus without involvement of the forearm or elbow.

A retrospective chart, radiograph, and clinical photograph review (1960-2005) of patients previously diagnosed with ectrodactyly, hand hypoplasia, or ULD was performed to evaluate for a diagnosis of ULD isolated to the hand.

Thirteen extremities were identified. Three extremities had complete absence of the small-finger ray (phalanges and metacarpal) and 6 extremities had complete absence of the ring- and small-finger rays. Four hands showed hypoplasia of the small finger, 3 in conjunction with a ring- and small-metacarpal synostosis and 1 in isolation. Three extremities also had radial-sided hypoplasia or aplasia of the rays. Additional common findings included simple syndactyly, delta phalanx, and carpal fusions, most commonly of the capitohamate joint.

Patients with isolated ulnar-sided hand deficiency such as ectrodactyly of the ring and/or small fingers or synostosis of the small metacarpal of the ring finger in the presence of a normal forearm may be diagnosed as having type 0 ULD. We propose that type 0 be added to the current classification systems for ULD representing those extremities with deficiencies isolated to the hand.