First clinical experience with a noninvasively extendable endoprosthesis: a limb-saving procedure in children suffering from a malignant bone tumor.

A modular endoprosthetic system that can be extended noninvasively has been applied for the first time in a growing child who underwent a tumor resection in his leg. The main goal of the study was to test the extendable mechanism that noninvasively corrects leg length differences caused by growth disturbances of the affected leg. The use of this endoprosthetic system resulted in good restoration of function. Six extensions were performed resulting in 19.5 mm of prosthetic growth. Unfortunately, an ingrown toenail caused infection of the endoprosthesis, and the infection necessitated extirpation of the prosthesis 15 months postoperatively. Two months later the patient died of acute leukemia. Analysis of the endoprosthesis revealed some manufacturing shortcomings, none of which impaired the function of the endoprosthesis.