Remote-controlled internal lengthening plate for distraction osteogenesis in pediatric patients

Abstract

Objectives: Limb lengthening by distraction osteogenesis is a technique widely used to treat limb length discrepancy resulting from trauma, congenital limb defects and long bone non-union. For decades, patients have resorted to the Ilizarov apparatus, prone to pin tract infections and scarring. Although implantable lengthening nails have reduced the incidence of complications, they are not applicable in pediatric patients with open growth plates. The aim of this project is to design a remote-controlled internal lengthening device suitable for implantation in children.

Methods: The proposed device has the form of an internal remote-controlled telescopic lengthening plate, screwed to the lateral side of the bone with locking screws. This is appropriate for use with pediatric patients. It has been tested on an experimental bench which has the form of a vertically sliding platform, on which were stacked weights simulating soft-tissue resistance forces.

Results: This internal lengthening plate generated distraction forces of up to 735 N on wooden and synthetic bones (Sawbones^TM). Furthermore, it maintained a constant distraction speed over the course of the procedure for a given weight.

Conclusions: This device represents a major advancement in the field of pediatric limb-lengthening, addressing a demographic gap left open by current implantable devices.

Keywords: Limb lengthening; callotasis; distraction osteogenesis; fixator; lengthening plate; novel device; pediatric.