title: Preliminary study of interfacial shear strength between PMMA precoated UHMWPE acetabular cup and PMMA bone cement.
abstract: Followed by successful demonstration of high interfacial tensile strength in a new design of cemented all-polyethylene acetabular cup, interfacial shear strength was investigated in this study, with the use of canine-size prototypes of polymethylmethacrylate (PMMA) precoated UHMWPE acetabular cups. In addition to the PMMA precoated prototypes, three different types of controls were also prepared and tested: grooved UHMWPE cups, PMMA (bone cement) cups, and noncoated, plain UHMWPE cups. The interfacial shear strength of the precoated prototypes was 10.1 +/- 0.69 MPa (n = 6), whereas it was 24.3 +/- 0.78 MPa (n = 2) for the PMMA cup, 6.95 +/- 0.21 MPa (n = 2) for the grooved UHMWPE cup, and 0.34 +/- 0.47 MPa (n = 2) for the UHMWPE cup. These results indicate benefits of the PMMA precoating to stabilize the polyethylene acetabular cup securely when applied with bone cement in simulated clinical applications. Analysis of the failed PMMA precoated UHMWPE prototype cups suggested that the chemically induced bonds between precoated PMMA layer and bone cement played a key role in developing high shear strength. After the interfacial shear test of the PMMA precoated prototypes, major disruptions at the interface between treated UHMWPE and precoated PMMA layer were observed by scanning electron microscopy (SEM), which was a unique failure pattern, not found with other prototypes.
authors.affiliation: Department of Biomedical Engineering, 330 Engineering Technology Building, The University of Memphis, Memphis, Tennessee 38152, USA. kpark@memphis.edu
authors.forename: K D
authors.initials: KD
authors.lastname: Park
authors.forename: J
authors.initials: J
authors.lastname: Kim
authors.forename: S J
authors.initials: SJ
authors.lastname: Yang
authors.forename: A
authors.initials: A
authors.lastname: Yao
authors.forename: J B
authors.initials: JB
authors.lastname: Park
mesh_terms: D000818:Animals; D001843:Bone Cements / Q000737:chemistry*; D002484:Cementation / Q000295:instrumentation / Q000379:methods*; D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D019544:Equipment Failure Analysis; D006622:Hip Prosthesis; D010865:Pilot Projects; D011095:Polyethylenes / Q000737:chemistry*; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D011475:Prosthesis Failure; D033081:Shear Strength; D013499:Surface Properties
chemical_list: D001843:Bone Cements; D020099:Coated Materials, Biocompatible; D011095:Polyethylenes; C111601:ultra-high molecular weight polyethylene; D019904:Polymethyl Methacrylate