Epidemiology of Congenital Upper-Limb Anomalies in Southern Taiwan Based on the Updated Oberg, Manske, and Tonkin Classification: A Series of 1,335 Anomalies in 1,188 Patients

J Hand Surg Am. 2023 Jul 28:S0363-5023(23)00291-5. doi: 10.1016/j.jhsa.2023.05.016. Online ahead of print.

Abstract

Purpose: This study aimed to investigate the relative frequency of congenital upper-limb anomalies (CULAs) in southern Taiwan using the 2020-updated the Oberg, Manske, and Tonkin (OMT) classification system and evaluate the practicality of the new classification system.

Methods: We retrospectively reviewed patients with CULAs from 1987 to 2021 at a referral center in southern Taiwan. All patients were analyzed based on medical records, photographs, and radiographs, and the anomalies were classified according to the 2020 OMT classification system.

Results: A total of 1,188 patients with 1,335 CULAs were retrospectively reviewed. The results demonstrated that the most common type of CULA was malformations (1,092 cases), followed by dysplasias (144 cases), syndromes (51 cases), and deformations (48 cases). Among the malformations, radial polydactyly was the most common anomaly (732 cases), followed by simple syndactyly (66 cases). Among the dysplasias, camptodactyly was the most common anomaly (52 cases), followed by thumb-in-palm deformity (45 cases) and vascular tumors (17 cases). In the deformations, constriction ring sequence accounted for all cases. Poland syndrome (21 cases) occurred most often in the category of syndromes.

Conclusions: The results of this study show that radial polydactyly (732 cases, 55%) is the most common CULA in southern Taiwan, followed by simple syndactyly (66 cases, 5%) and then camptodactyly (52 cases, 4%).

Clinical relevance: The OMT classification system is reasonably practical for precise classification of CULAs and enables easy comparison of studies over different time periods. However, continually updating the OMT classification system is required to better categorize the highly variable presentations of CULAs.

Keywords: Congenital anomalies; OMT classification; Oberg-Manske-Tonkin classification; congenital upper-limb anomalies; epidemiology.