the objective of the present study is to compare the post-operative laxity using stress radiographs and clinical scores in two groups of patients undergoing primary PS TKA with identical prosthetic model performed in two specialized centers, of which one group implanted with standard technique and one group through the intraoperative use of the tensioner

Inclusion Criteria:

• Male and female subjects candidates for primary cemented total knee prosthesis model Attune PS mobile plate DePuy.
• Patients who possess all the psychophysical capabilities to be able to undergo the operation and all the check-ups with radiological tests included (e.g. all patients who are not willing to go to the institute for all the scheduled follow-up visits will be excluded) .
• Patients who have signed the "informed consent" approved by the Ethics Committee.
• Patients who are aged between 50-85.

Exclusion Criteria:

• Social conditions that prevent participation in the study in all its phases (homeless patients, with restrictions on personal freedom, etc.)
• Patients suffering from deep venous insufficiency of the lower extremities or with a personal or family history of deep venous thrombosis or pulmonary embolism
• Patients with a history of erysipelas in the lower extremities
• Patients suffering from neurological or psycho-cognitive disorders
• Patients suffering from post-traumatic arthrosis
• Patients who have already undergone prosthetic surgery and/or arthrodesis at the level of a lower limb joint
• Patients with axial knee deformities >15°
• Pregnant female patients
• Patients with rheumatic diseases