The spectrum of radial longitudinal deficiency: A modified classification

The Association of Radial Deficiency with Thumb Hypoplasia

“…Both of our previous studies suggested an association between the severity of radial deficiency and the severity of thumb hypoplasia 10,12 . The purpose of the current study was to determine if increased severity of radial deficiency is associated with increased severity of thumb deficiency.…”

“…Our institutional review board approved the retrospective chart and radiograph review. The findings on physical examination, radiographs, and operative findings for these 139 patients with 227 affected upper extremities were studied to determine if adequate clinical, radiographic, and operative information was available to classify the radius and thumb malformations according to the modified Bayne and Klug 6,12 and Blauth and SchneiderSickert 10,11 systems and to determine if there were associated malformations that called into question the diagnosis of radial longitudinal deficiency. Subjects were excluded from the Bones and joints All bones present, maybe hypoplastic All bones present and hypoplastic All bones present and hypoplastic *APB = abductor pollicis brevis, OP = opponens pollicis, FPB = flexor pollicis brevis, FPL = flexor pollicis longus, EPL = extensor pollicis longus, MP UCL = metacarpophalangeal ulnar collateral ligament, and RCL = radial collateral ligament.…”

“…In a subsequent study of this same population 12 , we determined that radial deficiency could be classified with a modification of the Bayne and Klug system 6 , which recognizes the spectrum of pathological entities involved in this condition, including radial deficiency, carpal anomalies, and hypoplasia of the thumb. Carpal anomalies are an integral component of radial deficiency and link thumb hypoplasia with radial deficiency.…”

Classification and Developmental Biology of Congenital Anomalies of the Hand and Upper Extremity

“…Classification of the condition was initially presented by Bayne and Klug 49 as types I through IV in 1987, based on the radiographic appearance of the radius. The classification was expanded by James et al 50 in 1999 to recognize radial-sided deficiencies limited to the carpus (type 0) and thumb (type N). More recently, the classification was extended by Goldfarb et al 40 to include type V. Type N. The radius and carpus are normal, with deficiencies limited to the thumb (see hypoplastic-thumb classification above).…”

“…Type I. Initially described by Bayne and Klug 49 as a ''short distal radius,'' the description was more specifically defined by James et al 50 as a distal portion of the radius that is >2 mm shorter than the distal portion of the ulna. The proximal portion of the radius is usually normal, but may be characterized by radioulnar synostosis or congenital dislocation of the radial head.…”