Influence of stem size on clinical outcome of primary total hip arthroplasty with cementless extensively porous-coated femoral components.

This study retrospectively evaluated the clinical outcome of primary total hip arthroplasty as a function of stem diameter in 1545 patients implanted with extensively porous-coated stems. Less than 2% of femoral components were loose or revised; femoral survivorship was 97.9% at 15 years. Of patients with stable components, 95 to 97% had increased function, decreased pain, and overall satisfaction. Although 17% of patients indicated activity-limiting pain, only 3% were dissatisfied with the results of their hip arthroplasty. Logistic regression demonstrated no statistical relationship between stem size and either revision, loosening, pain, or satisfaction. We conclude that patients with large-diameter, extensively porous-coated femoral components are no more likely to be revised, loose, or have thigh or activity-limiting pain than patients with smaller diameter stems.