The ISO/ISPO classification of congenital limb deficiency.

This classification originally produced by the ISPO "Kay" Committee in 1973, has now with minor modifications, become an International Standard (ISO 8548-1: 1989). It is limited to those deficiencies which are failures of formation and describes them on anatomical and radiological bases only. All are divided into transverse and longitudinal, and use simple terms and descriptors.