Veteran Affairs Osteoarthritis Knee Study

The primary objective of this study is to document the possible short- and long-term decrease in pain as scored by participants on a Numeric Rating Scale (NRS) after use of Avazzia PRO-Sport Ultra® device with pulsed microcurrent in patients with osteoarthritis of the knee. Patients with a clinical diagnosis of Osteoarthritis (OA) of the knee for a minimum of 6 months will be recruited for this study. Their OA has not responded/is not responding to treatment and continuing symptoms interfere with normal function. Additionally, patients will have a pain score of 3 or greater on the NRS even with pain medication. Secondary objectives include changes in: * Mobility via a Timed Up \& Go assessment (TUG). Participants are timed getting up from sitting in a standard armchair, walking approximately 3 meters, turning, walking back to the chair, and sitting down. * Patient-relevant outcomes via the Knee Injury and Osteoarthritis Outcome Score (KOOS). The KOOS is self-administered and assesses five outcomes: pain, symptoms, activities of daily living, sport and recreation function, and knee-related quality of life. * Brief Pain Inventory - Short Form * Use of pain medication.