The long-term results of total hip prostheses in 86 patients (87 hips) who had either primary cemented or cementless total hip arthroplasty after fusion take-down were analyzed. Thirty-eight patients (38 hips) had a surgical fusion and 48 patients (49 hips) had a spontaneous fusion. The mean age of patients was slightly older in the cemented group (49.8 years) than in the cementless group (43.8 years). Twenty-six of 42 patients (62%) in the cemented group and 32 of 44 patients (73%) in the cementless group were younger than 50 years. Clinical (Harris hip rating system) and radiographic evaluations were done preoperatively and at 6 weeks, at 3, 6, and 12 months, and yearly thereafter. The average followup was 10.2 years (range, 8-18 years) in the cemented group and 9.8 years (range, 8-17 years) in the cementless group. The revision rates were 16% in the patients who had surgical fusion and 18% in the patients who had spontaneous fusion. The revision rates were 17% in the cemented group and 18% in the cementless group. The average linear wear rate of polyethylene per year was 0.24 mm in the cemented group and 0.32 mm in the cementless group. The incidence of osteolysis was 52% in the cemented group and was 58% in the cementless group.