Primary prosthetic surgery for the treatment of gonarthrosis is currently one of the most prevalent surgical treatments in Traumatology. The Arthroplasty Register in Catalonia, which started in 2005, counted more than 60.000 knee prothesis until 2015. Regarding the peridiocity for taking control radiographs in patients undergoing knee replacement surgery, there is no consensus. This means, that in similar studies that evaluate the results of prosthetic surgery, there is a great variability in radiological follow-up protocols, especifically during the firts post-operative years. Given the high prevalence and the long survival period demonstrated by these implants, it seems reasonable to be able to establish the real value of the radiographs performed during the first year of follow-up after surgery. From this perspective, the aim of our study is to evaluate if conducting just two radiographs instead of five during the first postoperative year after the surgery, has any influence on the clinical and functional results of our patients.

Inclusion Criteria:

• Patients who voluntarily agree to be part of the study and sign the informed consent
• Patients awaiting prosthetic knee surgery with a diagnosis of gonarthrosis without age limit (>18 years)
• All cases of prothesis cemented to the tibia and femur will be included, regardless of whether or not the patellar component is prosthetic
• Patients with knee prothesis and cruciate ligament retention, with ultracongruent polyethylene or posterostabilized as a maximum degree of prosthetic constriction
• The implants will be the usual ones used in our Center for primary prosthetic knee surgery, Journey (smith-Nephew) and Persona or NexGen (Zimmer)

Exclusion Criteria:

• Patients who do not voluntariily agree to participate
• Patients undergoing primary prosthetic surgery in relation to tibial plate fractures
• Patients awaiting a unicompartimental or patellofemoral prothesis
• Patients who, for any reason, want to leave the study during the follow-up period