International Federation of Societies for Surgery of the Hand

OMT Classification Resources

The OMT Classification System: Guide for use

The IFSSH is pleased to share an instructional video on the use of the OMT Classification system, produced by Dr Charles Goldfarb and the 2022 IFSSH Committee for Congenital Conditions.

The Oberg, Manske and Tonkin (OMT) classification App

The IFSSH is pleased to endorse and share the OMT Classification App.

In 2014, the IFSSH Committee on Congenital Conditions recommends adoption of a revised classification system for Congenital Anomalies of the Hand and Upper Limb, originally proposed by Drs Oberg, Manske and Tonkin, popularly known as the ‘OMT’ classification.

The new system provides a comprehensive classification of every congenital hand differences, as well the most commonly associated syndromes. Balancing dysmorphology with etiology, the OMT classification remains flexible enough to allow changes, following discovery of new knowledge in the fields of developmental biology or genetics.

The purpose of the ‘OMT App” is to create a mobile platform where the classification can be easily accessed, for example, in the busy outpatient setting. The App is regularly updated to mirror any changes to the OMT classification, new knowledge of etiologies, as well as add to the growing collection of images. These updates will automatically be refreshed for all those who have downloaded the App.

Tips on using the App (Internet required):

Search for each condition by scrolling down the list. The App mirrors the actual classification.
Search for a condition by its nomenclature, e.g, radial longitudinal deficiency
Search for a condition by using key words, e.g., ‘fused digits’ or ‘short digits’ which has been designed for non-congenital hand specialists. This function is to allow use of the App by multi-specialties (geneticists, developmental biologists, pediatricians).
Search for a possible syndrome using keywords, e.g., ‘thumb’ or ‘syndactyly’ and all syndromes with thumb or syndactylies would appear.
For each syndrome, an Online Mendelian Inheritance of Man (OMIM) link is provided, that will take the user to the webpage for more information about the condition. For each condition or syndrome, there will be a display of the updated OMT classification, a short description and the current known etiology. For Syndromes, the hallmark features and upper limb deformities are described. Photographs and radiographs have been provided, where available.

Instructions for download

Contributors to App development:

Wee Lam initiated the concept and designed template layout and provided most of the description. Kerby Oberg provided information on known etiologies of the various conditions (Malformation, Deformation and Dysplasia). Wayne Lam verified accuracy of the genetic information for Syndromes. Various international surgeons contributed pictures and radiographs, in particular, Wiebke Husselmann, Charles Goldfarb, Marybeth Ezaki, Scott Oishi and others. App development and technical assistance were provided by Charayaphan Nakorn Boon Han and Huai Tan from the University of Edinburgh.