title: Tribo-biological deposits on the articulating surfaces of metal-on-polyethylene total hip implants retrieved from patients.
abstract: Artificial total hip arthroplasty (THA) is one of the most effective orthopaedic surgeries that has been used for decades. However, wear of the articulating surfaces is one of the key failure causes limiting the lifetime of total hip implant. In this paper, Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) were employed to explore the composition and formation mechanism of the tribo-layer on the articulating surfaces of metal-on-polyethylene (MoPE) implants retrieved from patients. Results showed that, in contrast to conventional understanding, the attached tribo-layer contained not only denatured proteins but also a fraction of polymer particles. The formation of the tribo-layer was believed to relate to lubrication regime, which was supposed to be largely affected by the nature of the ultra-high-molecule-weight-polyethylene (UHMWPE). Wear and formation of tribo-layer could be minimized in elasto-hydrodynamic lubrication (EHL) regime when the UHMWPE was less stiff and have a morphology containing micro-pits; whereas the wear was more severe and tribo-layer formed in boundary lubrication. Our results and analyses suggest that enhancing interface lubrication may be more effective on reducing wear than increasing the hardness of material. This finding may shed light on the design strategy of artificial hip joints.
authors.affiliation: School of Engineering and Technology, China University of Geosciences (Beijing), Beijing 100083, China.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Cui
authors.affiliation: Department of Orthopaedic Surgery and Institute of Orthopaedics, The First Affiliated Hospital, Soochow University, Suzhou, Jiangsu 215006, China.
authors.forename: Yi-Xing
authors.initials: YX
authors.lastname: Tian
authors.affiliation: School of Engineering and Technology, China University of Geosciences (Beijing), Beijing 100083, China.
authors.forename: Wen
authors.initials: W
authors.lastname: Yue
authors.affiliation: Department of Orthopaedic Surgery and Institute of Orthopaedics, The First Affiliated Hospital, Soochow University, Suzhou, Jiangsu 215006, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
authors.affiliation: AML and CNMM, Department of Engineering Mechanics, Tsinghua University, Beijing 100084, China.|State Key Laboratory of Tribology, Tsinghua University, Beijing 100084,China.
authors.forename: Qunyang
authors.initials: Q
authors.lastname: Li
mesh_terms: D005260:Female; D006622:Hip Prosthesis; D006801:Humans; D008297:Male; D008422:Materials Testing; D018625:Microscopy, Atomic Force; D056951:Photoelectron Spectroscopy; D011095:Polyethylenes / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013499:Surface Properties
chemical_list: D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene