[Thumb Lengthening Following Amputation at the Proximal Phalanx using a Semicircular Distraction Ring Fixator: Results of 5 Cases].

Traumatic amputation of the thumb at the proximal phalanx or the metacarpophalangeal joint can be treated by distraction lengthening depending on the location of the amputation, the patient's age, occupation and functional demands. We report the results of proximal phalanx lengthening in 5 patients using a semicircular ring-type external fixator device. This prototype was developed at our clinic in collaboration with a specialised small company (Rotomed AG, Allmenstrasse 4, CH-4512 Bellach, www.rotomed.ch) based on the principles of Ilizarov's external fixator. In all patients, subjective and objective results were satisfactory (26.2 mm distraction length and an average Michigan Hand Outcome Score of 82.2%) without any rotational/axial deformities or complications requiring revision surgery.