A fully implantable motorized intramedullary nail for limb lengthening and bone transport.

This article describes an intramedullary nail that contains a fully implantable motorized programmable sliding mechanism for limb lengthening and bone transport that reduces the risk of infection, discomfort, and scarring usually associated with the external fixators used for the same purpose. Twelve patients were treated surgically with the new system. Eleven patients had unilateral femur shortening between 3 and 7.5 cm, and one patient had a 12-cm defect after tumor resection. In all patients with femur shortening the leg length discrepancy was corrected completely. In the case of bone defect the segment transport worked well without any problems. There was no infection and no axial deformity. Immediately after chemotherapy, delayed bone formation was seen. In two early cases of limb lengthening a technical problem led to replacement of the motor.