1. Department of OrthopedicsThe Second Hospital of Jilin University Changchun 130041 P. R. China
2. Department of Applied ChemistrySchool of ScienceXi'an Jiaotong University Xi'an 710049 P. R. China
3. Knee Surgery Department of the Institute of Sports MedicinePeking University Third Hospital Beijing 100191 P. R. China
4. Department of Orthopaedic SurgeryThe First Affiliated Hospital of Soochow University Suzhou 215006 P. R. China
5. Key Laboratory of Polymer EcomaterialsChangchun Institute of Applied ChemistryChinese Academy of Sciences Changchun 130022 P. R. China