Post-Market Study of the Ellipse PRECICE Intramedullary Limb Lengthening System

Inclusion Criteria: * Leg length discrepancy ≥ 1.5 cm and ≤ 6.5 cm due to short femur or tibia * Weight ≤ 114 kg if implanted with the 10.7 mm or 12.5 mm diameter nail, or ≤ 57 kg if implanted with the 8.5 mm diameter nail * Skeletally mature * Intramedullary canal without offset * Tibia or femur sufficient to contain the implant * Availability, willingness, and sufficient cognitive awareness to comply with protocol procedures and schedule * Must sign informed consent to permit the use of personal health data Exclusion Criteria: * Active infection or previous history of deep infection in the involved bone * Metal allergies or sensitivities to the components of the device * Distance from the nearest convenient external surface of the treated limb to the intramedullary canal \> 38 mm for the 8.5 mm PRECICE nail, \> 51 mm for the 10.7 mm PRECICE nail, or \> 76 mm for the 12.5 mm PRECICE nail * Significant range of motion deficit of the adjacent joints * Patients with a pacemaker, implanted cardiac defibrillator, or any other electronic or magnetic implant * Patients who require an MRI during implantation * Non-union * Impassable or obstructed intramedullary canal * Significant angular deformity that prevents device placement * Cannot bear weight on the contralateral limb * Procedural osteotomy cannot be made in an appropriate location * Deformities that require multilevel osteotomies or bi-lateral implantation at the time of study index surgery * Systemic bone disease * Pregnant or nursing women * Inadequate vascularity or evidence of vascular disease or peripheral neuropathy * Malignancies or tumors in the involved bone * Patient is a drug abuser * Open wounds or ulcers that could compromise treatment