Although a tourniquet may reduce bleeding during total knee replacement (TKA), and thereby improve fixation, it might also cause complications. Migration as measured by RadioStereometric Analysis (RSA) can predict future loosening. We will investigate if the use of a tourniquet influences fixation measured with RSA.

The use of a tourniquet during total knee replacement (TKA) is a generally accepted routine at many departments. It is thought to facilitate dissection and reduce peroperative bleeding, but the main argument for its use is that bleeding bone surfaces might impair the fixation of cemented prostheses, because of less cement penetration.

We investigate in a RCT 50 patient with radiostereometric analysis, where 25 is randomized to a tourniquet during the hole operation and 25 are not.

Primary outcome is MTPM, a meassure of migration(loosening) of the kneeprosthesis.

Secondary outcomes are total bleeeding, pain, range of motion and outcome of a patient self assesed knee score (KOOS) Total follow up time 2 years

Inclusion Criteria:

• primary or secondary osteoarthritis without other severe disease (ASA 1-2).

Exclusion Criteria:

• were inability to give informed consent,
• rheumatic arthritis,
• malignancy,
• coagulation disorder or medical treatment influencing the coagulation,
• liver disease,
• severe heart disease or bilateral operation.