1. BioMfG Laboratory, Center for Computer-Aided Design, The University of Iowa, Iowa City, IA, 52242; Department of Biomedical Engineering, The University of Iowa, Iowa City, IA, 52242; Department of Orthopaedics and Rehabilitation, The University of Iowa, Iowa City, IA, 52242
2. BioMfG Laboratory, Center for Computer-Aided Design, The University of Iowa, Iowa City, IA, 52242; Department of Mechanical and Industrial Engineering, The University of Iowa, Iowa City, IA, 52242
3. Department of Orthopaedics and Rehabilitation, The University of Iowa, Iowa City, IA, 52242
4. BioMfG Laboratory, Center for Computer-Aided Design, The University of Iowa, Iowa City, IA, 52242; Department of Mechanical and Industrial Engineering, The University of Iowa, Iowa City, IA, 52242 e-mail: