Clinical Outcomes of Joint Arthroplasty

Inclusion Criteria: * All patients over 21 years of age who require a primary robotic-arm assisted unicompartmental knee arthroplasty or bicompartmental knee arthroplasty. These patients will have failed non-operative management of their joint disease and are candidates for partial joint replacement because of pain and stiffness that interferes with their performances or normal daily activities. Exclusion Criteria: * Patient had an active infection * Onlay implants were implanted without bone cement * Patient does not have enough bone stock to allow for insertion and fixation of the components * Patient does not have sufficient soft tissue integrity to allow for stability * Patient has a neurological or muscular deformity that did not allow for control of the knee * Patient will be excluded from participation in the study if they are cognitively unable to answer study questions * Pregnant women are excluded.