Prospective, multicenter study on the Total Knee Prosthesis available on the market "Persona Medial Congruent knee" Up to 10 Italian centers will provide a maximum of 200 patients undergoing total knee replacement with Persona prosthesis and Medial Congruent insert.

20 cases per center will be performed, 10 with posterior cruciate ligament sacrifice, 10 with posterior cruciate ligament preservation.

Patients will be recruited and enrolled in the study according to the inclusion and exclusion criteria specified below. In order to minimize the selection bias, patients will be enrolled consecutively; the first 10 patients will constitute a treatment group and the remaining 10 the complementary group.

Each patient will sign an informed consent for participation in the prospective study. The patients will be recruited at the Orthopedic and Traumatological Clinic 2nd of the Rizzoli Orthopedic Institute on an outpatient or hospitalization basis.

After the surgical treatment, the patient will continue his hospitalization at the Orthopedic and Traumatological Clinic 2nd of the Rizzoli Orthopedic Institute and, if deemed appropriate by the medical team, he will be discharged by planning the subsequent post-operative checks and diagnostic evaluations.

The data will be collected by investigators and provided to the Promoter center.

The Co-investigator who will evaluate the results will be blind to the assignment to the treatment group of the subjects in the study. The promoter of the study is the owner of the data and therefore responsible for data management. Study participants are identified with an identification code. All sensitive personal data will be stored in accordance with the current data privacy guidelines. All information will be treated with strict compliance with professional confidentiality standards. Participants will receive oral and written information relating to the processing of sensitive personal data.

The study is designed to have an alpha error of no more than 0.05. Based on an assumed 95% five-year survival, a sample size of n = 89 was calculated using SAS 9.4, Proc Power.

Assuming a 20% follow-up loss rate over five years, the study will enroll 100 patients in each patient group, then a total of 200 patients. The data collected from 200 patients (100 in each subgroup) will be archived in a descriptive way and will be the basis of all published study reports.

The categorical data (for example, gender) will be summarized using counts, percentages and the 95% confidence interval (CI), in the periods of interest. Continuous data, such as age, will be summarized using means, medians, standard deviation, minimum, maximum and 95% CI in the periods of interest. Implant survival and return to function will be summarized using the Kaplan-Meier method and presented as percentages and confidence intervals.

The expected duration of the study is 11 years, which corresponds to the time dedicated to the approval of the Ethics Committee, the enrollment of all patients, the completion of the 10-year follow-up, data analysis and preparation of the final report. The first 12 months will focus on patient enrollment. The study subjects will be involved from the moment of the intervention until the end of the 10-year follow-up (as per the current protocol 10 years FU 2 months).