Patients with bilateral procedures can be included in total hip arthroplasty research without biasing results

We explored the influence of bilaterality on the results of a trial of cemented vs uncemented acetabular components. Harris hip scores after 6 months, 2 years, 5 years, and 10 years were analyzed in 240 arthroplasties in 215 patients. Thus, 190 cases in 190 patients were compared to 50 cases in 25 patients. The group of 190 patients were further split into a group of 90 patients who had contralateral hip impairment, knee or spine problems, or significant comorbidities and into a group of 100 patients who had unilateral hip arthropathy. There was no significant difference between the cemented and uncemented groups or between any of these groups and the total group on Harris hip score, indicating that the inclusion of bilateral cases did not alter the outcome.