Table 1.

Classification of radial longitudinal deficiency (adapted from [15], with permission)

Type	Thumb anomaly	Carpal anomaly	Distal part of radius	Proximal part of radius
N	Absence or hypoplasia	Normal	Normal	Normal
0	Absence or hypoplasia	Absence, hypoplasia, or coalition	Normal	Normal, radioulnar synostosis, or radial head dislocation
1	Absence or hypoplasia	Absence, hypoplasia, or coalition	>2 mm shorter than ulna	Normal, radioulnar synostosis, or radial head dislocation
2	Absence or hypoplasia	Absence, hypoplasia, or coalition	Hypoplasia	Hypoplasia
3	Absence or hypoplasia	Absence, hypoplasia, or coalition	Absence of physis	Variable hypoplasia
4	Absence or hypoplasia	Absence, hypoplasia, or coalition	Absence	Absence