143 patients with a displaced femoral neck fracture were randomized to treatment with either total hip arthroplasty (THA) or internal fixation; of these, 54 were mentally impaired and 89 were lucid elderly patients. Participants were followed-up over an extended time period to evaluate the long-term complication rates of each intervention. Results revealed that in the THA group, complication rates were lower compared to internal fixation, and occurred within the short-term. Additionally, the lowest failure rate was associated with THA patients whereas the highest was associated with internal fixation.