The purpose of this study is to compare the percentage of early micromibilisation in unicompartmental knee arthroplasties in robot-assisted technique vs standard technique.

The purpose of the study is to compare the percentage of early micromobilisation by static radiostereometric analysis (RSA) - primary outcome, gait analysis by inertial sensors to assess gait kinematics, and clinical perdormance measured by american knee society score (AKSS), oxford knee score (OKS), patient satisfaction score (PSS) and EQ5-D - secondary outcomes, among 2 groups of patients, of 25 individuals each, whi undergo medial unicompartmental knee arthroplasty.

The first group will be operated with a robot-assisted technique (with CORI Surgical System, Smith and Nephew, USA), the other with standard technique and the same implant (Journey UNI II, Smith and Nephew, USA).

The study will be a randomized and controlled blind superiority trial. Patients will not be informed about performing the surgery with one technique or the other in order to avoid potential biases in the data analysis.

Patients will be recruited at the orthoaedic and traumatologic 2nd clinica (head prof S. Zaffagnini) at IRCSS Istituto Ortopedico Rizzoli in Bologna, Italy.

Inclusion Criteria:

• Unicompartmental Knee Arthrosis
• Femoral condyles or medial tibial plate osteonecrosis
• Healthy anterior cruciate ligament, posterior cruciate ligament and collateral ligaments of the affected knee
• Post traumatic loss of joint configuration
• Moderate varism deformity
• Patients between 50 and 80 years old
• Patients able to undergo a 2-year follow up after surgery

Exclusion Criteria:

• Bi or Tricompartmental arthrosis
• Unhealty anterior or posterior cruciate ligaments or collateral ligaments
• Patients with neuromuscolar, degenerative and joint-related conditions
• Patients younger than 50
• Patients older than 80
• Patients unable to undergo a 2-year follow up after surgery

No sharing planned

At the research office of health professions at IRCCS Istituto Ortopedico Rizzoli in Bologna, Italy (coordinating centre), a block of 5 randomisation list using the site "www.randomisation.com" will be generated. A sequence of opaque envelopes will be set up with a sequential number on the outside. A label will be placed iside the envelope that will contain the words "CORI" or "STANDARD", according to the sequence indicated by the generated list. Envelopes will be always sealed at the Research Centre and the list kept under lock. The envelopes will be placed in a dedicated box and delivered to the studio manager.