Total knee arthroplasty is a frequent surgery in France. It currently represents 70,000 interventions per year. The total knee prosthesis is also called tri-compartmental because it allows articulation between the femur and the tibia but also between the femur and the patella.

The patella belongs to the extensor system. It articulates with the femoral trochlea in which it slides. It has an important biomechanical role on the quadriceps strength in addition to allowing flexion-extension movements.

In the case of resurfacing, the joint face of the patella is cut off; A convex polyethylene implant is sealed with cement using studs on the same face.

In case of non-resurfacing, the surgeon leaves in place the cartilage of the patella which will be in direct contact with the femoral prosthetic trochlea.

Both methods have advantages and disadvantages. For some implants, it is recommended to resurface the patella because the implant is not very tolerant with the native patella. Other implants have been designed to be better adapted to the preservation of patellar cartilage.

There is currently no evidence that one method is superior to the other on new generation implants known as "patellar friendly".

It seems necessary to compare both methods in terms of long-term postsurgery results.

The analysis of the primary endpoint (International Knee Society score (IKS score)) will be based on the assumption that the postsurgery score will be identical in both groups. The t test for independent samples will be used to test this hypothesis.

Inclusion Criteria:

• Male or Female (age ≥ 18 years)
• Diagnosis of knee arthrosis (internal femoro-tibial arthrosis, external femorotibial osteoarthritis, femoro-patellar arthrosis)
• Indication of total first-line knee arthroplasty

Exclusion Criteria:

• Patient whose surgical complexity requires the placement of a strained prosthesis (ligament laxity, bone loss).
• Refusal to participate in the study
• Pregnant women, parturients or nursing mothers
• Persons deprived of their liberty by a judicial or administrative decision, persons subject to psychiatric care, persons admitted to a health or social institution for purposes other than research
• Minor Patients
• Major persons who are subject to a legal protection measure or are unable to express their consent
• Patient not affiliated to a social security scheme
• Patient participating in other interventional research excluding routine care studies not interfering with analysis of primary endpoint