Prospective Randomized Study of Cementless vs Cemented UKA

Inclusion Criteria: * Patients with a pre-operative Knee Society Assessment Score of \<70 * Patients undergoing primary partial knee arthroplasty as unilateral arthroplasty or bilateral arthroplasty, simultaneously or otherwise * Patients diagnosed with osteoarthritis (Kellgren Lawrence Grade IV) or avascular necrosis limited to the medial compartment of the operative knee joint * Male or female patients who are at least 21 years of age at the time of surgery * Patients with full thickness cartilage loss, with or without bone loss in the medial compartment * Patients with functionally intact ACL and PCL * Patients who need to obtain relief of pain and/or improved function in their knee * Patients with fixed flexion deformity \< 15° * Patients who are able to follow post operative care instructions * Patients who are willing and able to return for scheduled follow-up evaluations * Patients in which natural alignment can be restored * Patients with BMI \< 40 * Patients who have completed a valid, IRB approved Informed Consent Form Exclusion Criteria: * Patients with a pre-operative Knee Society Assessment Score of ≥ 70 * Patients in which the device would be used to revise a failed prosthesis * Patients who are less than 21 years of age at the time of surgery * Disease or damage to the lateral part of the knee that in the investigator's opinion contraindicates a partial knee replacement * Patients diagnosed with rheumatoid arthritis or other forms of inflammatory joint disea…