A total knee design has been developed to support high flexion requirements of post-total knee replacement lifestyles. The extent of flexion, following total knee replacement, is influenced by relative femoral tibial kinematics, posterior knee soft tissue impingement, patella and patellar tendon tracking, preoperative knee flexion, and postoperative physical therapy. A new implant design incorporates features to prevent posterior tibial displacement in high flexion, improved conformity of the femoral/tibial articular surface contact to 155 degrees of flexion, greater femoral/tibial articular surface contact area in high flexion, and a shortened patellar tendon pathway. The requirement for tibial internal-external rotation during some knee flexion activity is accommodated by a rotating tibial poly-ethylene option within the implant system. Laboratory tests indicate the achievement of greater articular surface contact in high flexion conditions through extending the posterior femoral condyle curvature and accommodating the tibial polyethylene articular surface. Joint simulator testing indicates improved wear performance of the high flexion design. A prospective controlled multicenter clinical trial has been initiated to evaluate this high flexion implant design along with surgical techniques and post-surgery physical therapy developed to support patient achievement of high knee flexion following total knee arthroplasty.