Abstract Background: Total knee arthroplasty (TKA) is the preferred treatment for those with end stage osteoarthritis (OA) and functional limitations. Aim of Study: The primary objective of this prospective RCT is to compare the functional outcomes of MB versus FB TKA. Patients and Methods: In the period between May 2014 and May 2016 in the Hospitals of Cairo University and the ministry of health, a prospective RCT was conducted on 40 patients with advanced tricompartemental OA of the knee joint. Results: Forty patients were followed-up for 12 months. Functional assessment using KSS (2011) was done to asses every patient pre-operatively, 2 weeks, 3 months and then every 3 months till 12 months post-operatively with nearly no difference between the two designs. Conclusion: There is nearly no statistically significant difference between MB and FB TKA on active knee flexion and on functional outcomes at 1 year follow-up.