The purpose of this study is to investigate whether subjects receiving a high-flexion knee prosthesis show a better knee function than patients receiving a standard knee prosthesis. Thigh-calf contact force measurements are used to quantify knee function. The investigators' hypothesis is that high-flexion knees show a better knee function.

Study title:

Functional evaluation of a standard and a high-flexion knee prosthesis using thigh-calf contact force measurements.

Objective:

The objective of this study is to investigate whether subjects receiving a high flexion knee prosthesis (Sigma RP-F, J&J, UK) show a better knee function than patients receiving a standard knee prosthesis (Sigma FB, J&J, UK).

Study Design:

Prospective double blind randomized study.

Study population:

Subjects who will receive total knee arthroplasty (TKA) because of invalidating gonarthritis based on primary osteoarthritis or rheumatic disorders or trauma.

Intervention:

• 28 subjects will receive the standard Sigma FB knee prosthesis.
• 28 subjects will receive the high flexion Sigma RP-F knee prosthesis.

Inclusion Criteria:

Patients receiving a total knee replacement due to disabling gonarthrosis (cartilage damage):

• Primary due to osteo-arthritis
• Secondary due to rheumatoid arthritis or trauma

Exclusion Criteria:

• Patients suffering from juvenile rheuma
• Patients suffering from hemophilia
• Patients that are incapable to give informed consent
• Patients who receive a total knee replacement due to an oncological resection
• Patients who have received a total knee replacement on the contralateral leg
• Patients who have disabling gonarthrosis on both legs
• Patients having a BMI < 25 kg/m^2
• Patients who have to receive a different prosthesis than used in this study for biomechanical reasons (e.g. revision prosthesis)