Radial Longitudinal Deficiencies With Hypoplastic/Absent Thumbs and Cutaneous Syndactyly of the Most Radial Digits

PurposeTo describe radial longitudinal deficiency with hypoplastic or absent thumb and cutaneous syndactyly between the most radial digits. In addition, to discuss the clinical relevance and unique treatment decisions involved in optimizing functional outcomes in these patients.MethodsA total of 163 extremities of 122 patients with radial longitudinal deficiencies were reviewed. We reviewed radiographs and clinical images that were available, with most radial hypoplastic digit and cutaneous syndactyly to the adjacent finger.ResultsThere were 7 hands with this type of deformity. Four cases had a hypoplastic thumb associated with cutaneous syndactyly between the thumb and index finger. Three cases had a deformity in which the thumb was absent and the hypoplastic index finger was syndactylized to the long finger. Proximal and distal radioulnar synostoses were associated with these deformities in 3 patients.ConclusionsBecause the most radial digit is severely hypoplastic in this type of deformity, pollicization is usually indicated. However, the pollicization procedure must be modified due to associated syndactyly with different degrees of hypoplasia or absence of the intrinsic muscles. This type of deformity should be distinguished from hypoplastic thumb without syndactyly.Type of study/level of evidenceTherapeutic IV.