Background: Congenital longitudinal deficiencies of the radius and
thumb are known to be associated with one another; however, the details of
their relationship are unknown. The purpose of this study was to determine
whether increased severity of radial deficiencies is associated with increased
severity of thumb deficiencies and to review the relationship between radial
deficiency and reconstructibility of a hypoplastic thumb.
Methods: Radiographs and charts of 227 affected upper extremities of
139 patients with radial longitudinal deficiency were reviewed. The associated
thumb deficiency was classified according to a modification of the Blauth and
Schneider-Sickert scheme and the radial deficiency was classified according to
a modification of the Bayne and Klug criteria for 191 extremities of 119
Results: The severity of the thumb deficiency was directly
proportional to the severity of the radial deficiency (p < 0.0001). Half of
the extremities had either a thumb deficiency or thumb and carpal deficiencies
without radial deficiency. Two-thirds (sixty-three) of the ninety-five limbs
with a normal radius had a thumb that could be surgically reconstructed.
Seventy-one (91%) of seventy-eight extremities with a thumb amenable to
surgical reconstruction had a radius that did not require surgical
reconstruction. All extremities with a radial and/or carpal deficiency had a
thumb deficiency. Forty-eight (94%) of fifty-one extremities with complete
absence of the radius had a thumb that was not reconstructible.
Conclusions: This study supports the growing body of evidence that
the components of radial longitudinal deficiency represent a progressive
spectrum of upper extremity abnormalities, and a distal progression of
severity, with distal structures likely to be more involved than proximal
Level of Evidence: Prognostic study, Level II-1
(retrospective study). See Instructions to Authors for a complete description
of levels of evidence.