212 patients scheduled for bilateral simultaneous total hip arthroplasty had their hips randomized to two different femoral stems; one hip was treated using an ultrashort femoral stem, while the other hip was treated with a conventional femoral stem. Patients were followed-up for a mean of 11.8 years. Significant differences that were observed between groups included lower stress-shielding and greater bone mineral density in Gruen Zones 1 and 7 in the ultrashort stem compared to the conventional stem. Otherwise, the were no significant differences in the other radiographic outcomes, clinical outcomes, or survivorship between groups.