Early Migration in a High Congruent Rotating Platform Total Knee Prosthesis Design

Inclusion Criteria: * Patient is diagnosed with osteoarthritis and requiring primary arthroplasty * Patient is capable of giving informed consent and expressing a willingness to comply with this study * Patient has no major deformities * The ability to perform a lunge and step-up motion without the help of bars or a cane. * No or slight pain during activity according to the Knee Society Pain Score (Ewald, 1989; Insall et al., 1989) Exclusion Criteria: * The patient is unable or unwilling to sign the Informed Consent specific to this study * The individual has a functional impairment of any other lower extremity joint besides the operated knee * Patient has a flexion contracture of more than 15° * Patient has a varus/valgus contracture of more than 15° * Patients requiring revision arthroplasty * The patient does not understand the Dutch or English language good enough to participate. * The use of walking aids * The inability to walk more than 500 meters