X C Liu1, R Rizza2, V Anewenter3, J Thometz1, C Crouch4. 1. Department of Orthopaedic Surgery, Children's Wisconsin, Medical College of Wisconsin; Milwaukee, WI, USA. 2. Dept. of Mechanical Engineering, Milwaukee School of Engineering, Milwaukee, WI, USA. 3. Rapid Prototyping Center, Milwaukee School of Engineering, Milwaukee, WI, USA. 4. Hanger Clinic; Milwaukee, WI, USA.