Hip prothesis: an in vitro wear protocol based on a comparison between gravimetric and profilometric analysis.
Ultra high molecular weight polyethylene acetabular cups were analysed by means of a shadowgraph method (using a profile projector) to measure linear wear. The results were compared with those of previous wear tests performed on a hip joint simulator. Twelve polyethylene acetabular cups were analysed. The specimens were evaluated visually for evidence of polyethylene wear. Examination of the polyethylene inner surface did not reveal evidence of surface failure such as delamination, fatigue cracks or scratches. Volumetric wear was calculated using a formula based on dimensional change due to the penetration of the femoral head in the acetabular cup. It was found to be of the same order of magnitude as the wear obtained in in vitro experimental tests.
Affatato
S
S
Medical Technology Laboratory, Rizzoli Orthopaedic Institute, Bologna, Italy. affatato@tecno.ior.it
Tagliati
M
M
Toni
A
A
D001696:Biomechanical Phenomena; D006622:Hip Prosthesis; D008962:Models, Theoretical; D011095:Polyethylenes; D011475:Prosthesis Failure
D011095:Polyethylenes