Performance of MOTO Medial® Unicompartmental Knee Arthroplasty

Inclusion Criteria: * Must be able to read, understand and provide written informed consent on the Institutional Review Board (IRB) approved Informed Consent Form (ICF). * Ability to understand and provide written authorization for use and disclosure of personal health information. * Subject who are able and willing to comply with the study protocol and follow-up visits. * Must be 18 years or older to participate. * Subjects must have medial knee disease in the affected knee compliant with the FDA-approved indications for use of MOTO Medial® UKA. * Must have had no prior arthroplasty to the medial compartment of the study knee. * Subjects must be able to return for the follow-up appointments, and have the mental capacity to cooperate and complete Patient Reported Outcome questionnaires, physical exam and radiographs. Exclusion Criteria: * Knee ligament instability (deficiency of cruciate or collateral ligaments) * Inflammatory Arthritis * History of prior knee infection * History of Alcoholism or Drug Abuse * Currently on chemotherapy or radiation therapy for neoplastic disease. Medacta MOTO Medial® Version 1 Confidential Page 9 of 36 June 5, 2017 * Currently on immunosuppressive medications including steroids * History of known sensitivity or allergy to materials used in orthopedic implants, specifically Titanium and Cobalt-Chrome alloys * Habitual use of narcotic pain medications prior to surgery (more than 3 doses or pills per week) * History of metabolic disorder affecting the skeletal system other than osteoarthritis or osteoporosis (e.g., Osteomalacia, Ricketts) * History of chronic pain issues for reasons other than knee pain. * Women who are pregnant. * Psychiatric illness * Any patient, in the opinion of the investigator, is unable to fully comply with the surgical, rehabilitation, or follow-up aspects of this procedure. * Prior joint arthroplasty on the target knee, including prior medial UKA (revision), lateral UKA, or Patellofemoral Joint * Prior high tibial osteotomy (HTO).