Study of StimRouter for Chronic Knee OA Pain

Inclusion Criteria: 1. Subject is at least 21 years of age at the time of giving informed consent 2. Radiographic disease Stage ≥ 1 in the target knee according to the Kellgren-Lawrence grading of knee OA 3. Knee joint arthroplasty procedure is contraindicated 4. Full understanding of the requirements of the study and willingness to comply with all study visits and assessments 5. Subjects must have read and understood the informed consent form, and must have signed it prior to any study-related procedure being performed Exclusion Criteria: 1. Subject has undergone previous joint arthroplasty procedure (partial, total, patella-femoral) to the index knee 2. Unresolved effusion of the target knee clinically requiring aspiration within 12 weeks prior to Visit 1 (Baseline) 3. Treatment of the index knee with systemic or intra-articular corticosteroids (e.g., methylprednisolone) within 6 weeks prior to Visit 1 (Baseline) 4. Visco-supplementation (e.g., hyaluronic acid) in the index knee within 6 weeks prior to Visit 1 (Baseline) 5. Subject has an active systemic infection or an active local infection in or near the index knee joint, or has a previous history of joint infection. 6. Subject with bleeding disorders or active anticoagulation that cannot be stopped for a few days prior to the time of the surgical procedure. 7. Subject who has an active or existing skin disorder or irritation, which, in the opinion of the Investigator, precludes the use of skin gel electrodes. 8. Subjects has or plans to have a pacemaker, defibrillator, cochlear implant, and/or a sleep apnea implant. 9. Subject has or plans to have a Spinal Cord Stimulator (SCS), Peripheral Nerve field Stimulation system (PNfS), Dorsal Root Ganglion system (DRG), or implantable infusion pump. 10. Subject who currently requires or is likely to require Magnetic Resonance Imaging (MRI) within the MRI exclusion zone: the entire PNS lead must be at least 50 cm from the center of the MRI system's bore (the iso-center) and at least 16 cm outside of the MRI coil measured from the edge of the MRI coil. 11. Female subject who is pregnant or nursing or plans to become pregnant during the study. The effects of electrical stimulation on pregnancy are not known. Do not use electrical stimulation (including StimRouter) during pregnancy. 12. Any condition and findings in the medical history or in the pre-study assessments, that in the opinion of the Investigator, constitutes a risk or contraindication for participati…