Inclusion Criteria:  Patient meets the approved indications for use in accordance with product labeling for both the Persona Partial Knee System and the ROSA® Partial Knee System. Body mass index ≤40 kg/m2 Patient is of legal age and skeletally mature Patient is willing and able to provide informed consent. Patient is willing to be randomized into one of two study groups of UKA performed using ROSA® and UKA using Conventional Instrumentation Patient is willing and able to complete scheduled follow-up evaluations as defined in the study protocol. Patient qualifies for primary UKA based on investigator's clinical judgement and has an intact anterior cruciate ligament. Independent of study participation, patient is a candidate for the commercially available Persona Partial Knee System.  Exclusion Criteria:  Independent of study participation, patient meets any of the contraindications for use in accordance with product labeling of the Persona Partial Knee System and/or the ROSA® Partial Knee System. Orthopaedic procedure or pain management study of any joint within the last or next 6 months; furthermore, bilateral enrollment is excluded in this study. Prior ACL Repair Moderate to severe patello-femoral arthritis, that in the opinion of the investigator, would require patella-femoral arthroplasty. Patient is unwilling to sign the Informed Consent. Would, in the investigator's opinion, be unwilling or unable to comply with the postoperative care instructions or study follow-up schedule. Patient is considered a member of a protected/vulnerable population (Pregnant, prisoner, mentally incompetent, etc.). Patient is institutionalized or is a known drug abuser, a known alcoholic or cannot understand the requirements of study participation. Patient has a condition which would, in the judgement of the investigator, place the patient at undue risk or interfere with the conduct of the study.