The aim of this prospective study is to compare the clinical and radiographic outcomes of standard and high-flexion posterior stabilized (PS) rotating-platform mobile-bearing (RP-MB) total knee arthroplasty. The investigators hypothesize that total knee arthroplasty performed with a high-flexion PS RP-MB design would improve range of motion, and that this would be reflected by a better clinical outcome and greater patient satisfaction.

A high-flexion, PS RP-MB prosthesis was designed to improve range of motion after total knee arthroplasty without compromising the theoretical advantages of the standard PS RP-MB system. To date, no study has prospectively compared the clinical and radiographic results of standard and high-flexion PS RP-MB designs.

Inclusion Criteria:

• A diagnosis of primary osteoarthritis of knee
• A candidate for total knee replacement arthroplasty

Exclusion Criteria:

• A diagnosis other than primary osteoarthritis
• A history of previous open knee surgery