Polymer and Materials Science
Wiley InterScience Backfile Collection 1832-2000
One-hundred-fifteen retrieved, porous-coated, uncemented patellar knee components of a wide variety of designs were examined for type and amount of tissue ingrowth and for wear and creep of the polyethylene-articulating surface. Examples of well-fixed patellar components of all designs presented regions of bone ingrowth independent of pore size, number of fixation pegs, and the presence or absence of coating on the pegs. Polyethylene breakdown, including delamination, pitting, subsurface cracking, and separation from the metal backing, was common. Comparative analysis indicates that solutions exist and include increasing congruency and polyethylene thickness and eliminating metal fixation buttons.
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