John P. Collier

TL;DR: Elevated oxidation resulting from the use of gamma sterilization in air, the most common sterilization technique used by the orthopaedic implant industry, reduces static strength and elongation properties and significantly decreases the resistance of polyethylene bearings to fatigue, a frequent source of early damage of many of these devices.

TL;DR: There was a positive correlation between the intensity of wear and the level of contact stress, with noncongruent designs having greater wear than fully congruent geometries, and in the non-congruen designs, the thinner polyethylene components showed greater wear more than thickerpolyethylene inserts of the same design.

TL;DR: Evidence is presented that changes in the tapered interface between the head and the neck of 139 modular femoral components of hip prostheses which had been removed for a variety of reasons were due to galvanically-accelerated crevice corrosion, which was undetected in previous laboratory testing of this type of prosthesis.

TL;DR: In this paper, it was shown that gamma sterilization in air alters the chemical and mechanical properties of polyethylene over time, resulting in high subsurface oxidation, reduced ductility, and reduced strength.

TL;DR: The conclusion is drawn that local bone ingrowth cannot ensure a general freedom from pain, especially with partially coated prostheses, as indications of pain and looseness are evidence that fibrous tissue ingrowth alone is not always sufficient to ensure stability.