An experimental study of damage accumulation in cemented hip prostheses

An experimental study of damage accumulation in cemented hip prostheses Pages 214-219 BAO McCormack, PJ Prendergast, DG Gallagher Close Preview Purchase PDF (1224 K) | Related Articles AbstractAbstract | ReferencesReferences Abstract Objective. To develop a methodology to characterize the pattern of crack initiation and damage accumulation in intramedullary fixated cemented prostheses. Design. An experimental physical model of intramedullary fixation was developed which both represents the implant structure and permits monitoring of fatigue crack growth. Background. Many joint replacement prostheses are fixed into the medullary cavity of bones using a poly(methylmethacrylate) ‘bone cement’, which forms a mantle around the prosthesis and locks it to the bone. The endurance of the replacement is, to a great extent, determined by the mechanical durability of the cement and the implant interfaces under cyclic stresses generated by dynamic loading. The cement mantle is subjected to complex multiaxial stresses which vary in particular distribution depending on the prosthesis design. Methods. Damage accumulation is reported in terms of the number of cracks, the location of cracks, and the rate of crack growth. Results. The results clearly show the nature of damage accumulation in the cement mantle, and that many of the cracks which propagate within the cement mantle are related to cement porosity. Conclusion. This study gives experimental evidence to support the hypothesis of a damage accumulation failure scenario in cemented hip reconstructions. Article Outline • References