Radial ray deficiency Type I radial ray deficiency 2025-08-10T07:59:02Z A type of radial ray deficiency characterized by short distal radius. The distal radial epiphysis is present but delayed in appearance. The growth of the distal radial epiphysis is decreased causing a normal appearing but short radius. There is little radial deviation of the hand due to adequate radial carpal support. The radius has normal proximal epiphyseal growth. Thumb hypoplasia is almost always present. Short distal radius