50 patients with primary osteoarthritis undergoing total hip arthroplasty were randomized to receive either the Furlong Active femoral stem or the traditional Furlong HAC femoral stem. The purpose of this study was to evaluate the 3-D migratory patterns of the two stems using radiostereometry. Results after 3 months demonstrated significantly greater subsidence of the Furlong Active stem compared to the Furlong HAC stem, though subsidence of each stem plateaued after 3 months and displayed minor changes through to 5 years. Both groups displayed initial retroversion of the implant at 3 months, though minimal differences through to 5 years thereafter. Clinical outcome significantly improved in both groups over 5 years, with no significant differences detected between groups at 1, 2, or 5 year follow-up.