The purpose of this study is to determine whether patient rehabilitation is equal for patients operated with two different knee implant designs.

The patients are randomized to treatment with either a simple hinge design implant (fixed bearing) or an implant with a mobile bearing polyethylene. This design difference might in principle enable the patients in the latter group to rehabilitate towards a more normal gait pattern.

Inclusion Criteria:

• Patients at Silkeborg Regional Hospital, Orthopedic Dept. referred to total knee arthroplasty.

Exclusion Criteria:

• Neurologic disease with impact on gait.
• Orthopaedic disease ipsilateral hip joint.
• Patients outside the age limits.
• No informed consent signed.
• Patients suffering from dementia.
• Patients primarily included, but who perioperatively has their posterior cruciate ligament injured or sacrificed.
• Patients who later develop deep venous thrombosis or infection in the operated knee.