Post-Market Study of the EPIK Knee System

Inclusion Criteria: * Meet the indications for use of the EPIK Uni-compartmental knee system * Must be a primary surgery * Have a primary diagnosis of OA in the medial knee compartment * Have active and passive flexion \> 90º * Have a fixed flexion contracture \< 10º * Have an intact ACL and PCL * Be a primary, unilateral surgery * Have BMI ≤ 35.00 * Must not have infection (or history of infection within last 3 months), chronic or acute, local or systemic * Must not be pregnant * Be willing and able to sign the informed consent * Be willing to follow study procedures, including all follow up visits * Be over 18 years of age (≥ 18) and 60 years or younger (≤ 60) at time of consent Exclusion Criteria: * Prior total or uni-knee arthroplasty (must be a primary surgery) * Patello-femoral joint symptoms * Bilateral surgical procedures * BMI \> 35.00 * Muscular, neurological or vascular deficiencies which compromise the affected extremity * Insufficient bone quality which may affect the stability of the implant * Infection (or history of infection within last 3 months), chronic or acute, local or systemic * Is younger than 18 years of age (\<18) or over 60 (\>60) years of age * Mental conditions that may interfere with the subject's ability to give an informed consent or willingness to fulfill the study requirements * High levels of physical activity (ex. Competitive sports, heavy physical labor) * Documented (active) alcohol or drug addictions * Loss of ligamentous structures * Prisoner * Metals sensitivity * Subject is pregnant