[1] ASTAR, Inst Mat Res & Engn IMRE, 2 Fusionopolis Way,Innovis 08-03, Singapore 138634, Singapore
[2] Nanyang Technol Univ, Sch Mat Sci & Engn, 50 Nanyang Ave,Block N4 1 01-30, Singapore City 639798, Singapore
[3] Chinese Univ Hong Kong, Dept Orthopaed & Traumatol, Sha Tin, Hong Kong 999077, Peoples R China