Objective To evaluate the effectiveness of one-stage total knee arthroplasty (TKA) for femoral supracondylar fracture combined with knee osteoarthritis. Methods Between January 2012 and March 2015, a total of 19 patients (19 knees) with femoral supracondylar fracture and knee osteoarthritis were treated with one-stage TKA. Of 19 cases, 8 were male and 11 were female with an average age of 69.6 years (range, 60-85 years). The mean body mass index was 22.6 kg/m2 (range, 22.0-27.5 kg/m2). The left knee was involved in 13 cases, and the right knee in 6 cases. The causes of femoral supracondylar fracture were falls in 10 cases, traffic accidents in 8 cases, and other injury in 1 case. All fractures were classified as type A according to AO/Association for the Study of Internal Fixation (AO/ASIF) classification. The interval of injury and operation was 4-13 days (mean, 8.6 days). The disease duration of osteoarthritis ranged from 30 to 90 months (mean, 52.6 months). During follow-up, the knee society score (KSS) and the range of motion (ROM) were used to evaluate the knee function; anteroposterior and lateral X-ray films of the knee were used to observe the position of the prosthesis. Results All the incisions healed at the first stage, and there was no early complication such as pulmonary infection, pressure ulcer, and urinary tract infection. All patients were followed up 2-4 years with an average of 2.6 years. The ROM and KSS functional scores and clinical scores were significantly improved at 15 days and 2 years after operation, showing significant differences when compared with those before operation (P<0.05). There were significant differences in the ROM and KSS functional scores and clinical scores between two time points after operation (P<0.05). X-ray films showed the fracture bone healing, good alignment, no loosening of prosthesis at 2 years after operarion. Conclusion One-stage TKA for femoral supracondylar fracture combined with knee osteoarthritis can achieve good effectiveness. It can not only reconstruct joint function, but also cure osteoarthritis and fracture at the same time, shorten the healing time, reduce the incidence of related complications.