Fixation for the millennium: the shoulder.

Abstract

Charles Neer designed his original prosthesis in 1951. It was made of cast cobalt chrome alloy and was only press-fit. There was not any significant loosening in his original series, but patients complained of easy fatigability. This finding was attributed to glenoid issues and a cemented glenoid replacement was introduced in 1973. High rates of lucencies were reported and raised issues regarding fixation. Cementless glenoid components have been found to have fewer lucencies but require metal backing. Higher failure rates have been reported for the cementless design versus the cemented glenoids. With humeral fixation, symptomatic loosening is not a problem with cement or coated press-fit fixation. Long-term outcome studies with cemented and uncemented stems have shown the incidence of humeral loosening to be low. Fixation of humeral components should be based on bone quality, patient age, prosthetic design, and surgeon preference.