1 Departments of Orthopaedic Surgery (M.M., T.L., C.-C.P., S.M., Y.P.Y., and S.B.G.), Material Science and Engineering (Y.P.Y.), and Bioengineering (Y.P.Y. and S.B.G.), Stanford University School of Medicine, Stanford, California.
2 Department of Mechanical Engineering, Stanford University School of Engineering, Stanford, California.
3 Department of Orthopaedic Surgery, Yamagata University Faculty of Medicine, Yamagata, Japan.