Abstract
Introduction
“Bioexpandable” prostheses after resection of malignant bone tumors in children to lengthen the bone using the method of callus distraction may offer new perspectives and better long-term results.
Materials and Methods
The bioexpandable prosthesis is equipped with an encapsulated electromotor which enables the device to perform distraction in an osteotomy gap with about 1mm/day. The new bone is improving the ratio from bone to prosthesis and therewith the potential stability of the final stem. The device is indicated, when limb length discrepancy is getting more than 3 cm or at maturity and can be used in a minimal invasive way for femur lengthening.
Results
11 patients were treated with the bioexpandable prosthesis. The mean age of the patients was 13,5 years and the mean amount of lengthening was 74mm. In 2 cases lengthening was performed in 2 steps and in 1 case in 3 steps. All lengthening procedures could be finished without complications. There was no infection and no technical problem. The bone regenerate in one tibia case was poor so that bone grafting from the iliac crest was necessary.
Conclusions
The “bioexpandable” prosthesis is a new concept for limb lengthening after tumor resection in children. The latest patented version of the prosthesis under development allows all lengthening manoeuvres and the placement of the final stem via small incisions not only for the femur but also for the tibia.
