Radial Longitudinal Deficiency: Severity Differences Between U.S. and Japanese Cohorts

Schuyler J. Halverson, Shinichiro Takayama, Kensuki Ochi, Atsuhito Seki, Lindley B. Wall, Charles A. Goldfarb

Research output: Contribution to journalArticlepeer-review

1 Scopus citations


Purpose: Radial longitudinal deficiency (RLD) presents on a spectrum of severity and associated diagnoses. The literature is limited in describing patient presentation without comparative data between countries. In a study comparing 2 cohorts of patients, 1 in the United States and 1 in Japan, we hypothesized that there would be a similar presentation of forearm deficiency severity, thumb hypoplasia severity, and associated syndromes between the 2 cohorts. Methods: Patients with RLD were identified via a comprehensive chart review at 2 pediatric hospital cohorts, 1 in the United States and 1 in Japan, capturing patients presenting over 15 years. We assessed RLD and thumb hypoplasia severity via a modified Bayne and Klug and modified Blauth classifications. The relationship between these 2 diagnoses and the presence of common medical conditions were evaluated and correlated. Results: A total of 194 Japanese patients with 290 involved extremities were compared with 107 U.S. patients with 174 involved extremities. The U.S. cohort had a significantly more severe RLD, and a higher rate of bilaterality (63% vs 50%, respectively). A total of 131 Japanese patients (68%) and 41 U.S. patients (38%) had associated medical syndromes/associations, most frequently vertebral abnormalities, anal atresia, cardiac abnormalities, tracheoesophageal fistula and/or esophageal atresia, renal agenesis and dysplasia, and limb defects (VACTERL; 46 Japanese, 14 U.S.), Holt-Oram (44 Japanese, 5 U.S.), and thrombocytopenia absent radius syndrome (0 Japanese, 12 U.S.). Correlation analysis showed that increased RLD severity was associated with increased thumb hypoplasia severity in both groups, with 95% of modified Bayne and Klug III, IV, or V patients having severely affected thumbs (type IIIb, IV, or V). Conclusions: The U.S. patients had a more severe RLD and a higher rate of bilaterality. Japanese patients had a higher incidence of associated syndromes and radial polydactyly. Both cohorts showed that increased forearm severity was associated with more severe thumb hypoplasia. Type of study/level of evidence: Differential diagnosis/symptom prevalence study III.

Original languageEnglish
Pages (from-to)196-202.e2
JournalJournal of Hand Surgery
Issue number3
StatePublished - Mar 2020


  • Associations
  • hypoplastic thumb
  • radial deficiency
  • radial dysplasia
  • syndromes


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