Fixation and clinical outcome of uncemented peri-apatite-coated versus cemented total knee arthroplasty : five-year follow-up of a randomised controlled trial using radiostereometric analysis (RSA)

60 patients scheduled for total knee arthroplasty were randomized to either uncemented fixation with hydroxyapatite-coated components, or to cement fixation. Patients were assessed for component migration via maximum total point motion using radiostereometric analysis. Results demonstrated significantly greater total MTPM after 5 years in the uncemented group compared to the cemented group, but no significant difference between groups in the change in MTPM from 1 year 5 years. Therefore, the results suggested that the majority of the difference between groups in migration occurred within the first year of surgery.