Eighty patients scheduled for a bilateral total knee arthroplasty were randomized to receive medial pivot knee implant systems or posterior-stabilized knee implant systems. The outcomes of interest included knee flexion, physical performance test results (timed up and go test, stair climb test, self-paced walk test, chair to stand test, leg holding test), the new Knee Society Score results, EQ-5D quality of life results and Forgotten Joint Score (FJS) results. Outcomes were assessed at 2 years post-operation. The medial pivot implant group reported significantly worse knee flexion, including a worse performance from baseline when compared to the posterior-stabilized knee implant group. However, improvements in the timed up and go and self-paced walk test results were significantly in favour of the medial pivot implant group. Improvement from baseline in the objective new Knee Society Scores were significantly greater in the posterior-stabilized group. No significant differences were observed between the two groups in the remaining outcomes.