Platelet Rich Plasma Injections In Young And Old Human Subjects

Inclusion Criteria 1. Grade 1-3 KL score will be recruited; 2. Symptoms of knee osteoarthritis for at least 3 months before presentation in one knee; 3. Have symptomatic complaints from osteoarthritis pain in no other joint affecting the hips, ankles or unaffected knee; 4. Will be able to attend and perform physical therapy. 5. English-speaking Exclusion Criteria 1\. Patients will be excluded if: 1. Received injection therapy for knee osteoarthritis in the past 6 months 2. Have signs of concomitant osteoarthritis of 1 or more other major joints of the lower extremities that impair their daily activity level 3. History of septic arthritis 4. Have underwent a previous knee surgery specifically for osteoarthritis or osteochondral defects less than 1 year before randomization (i.e. autograft or allograft surgery 5. High tibial osteotomy, partial knee replacement, patellar resurfacing), total knee replacement or existing surgical hardware in the knee 6. Patient with platelet disorders, bleeding disorder 7. Patient with rheumatologic disease, automimmune disorder, immunocompromised status, active history of cancer 8. Patient taking Chemotherapy, need for regular prednisone or antiinflammatory used 9. Pregnant, breastfeeding, or unwilling to practice birth control during participation in the study. 10. Uncontrolled illness, physical disability, or other contraindication to aerobic exercise training including, but not limited to: i. Acute myocardial Infarction (within 5 days of any planned study procedure); ii. Unstable angina; iii. Uncontrolled arrhythmia causing symptoms or hemodynamic compromise; iv. Recurrent syncope; v. Active endocarditis; vi. Acute myocarditis or pericarditis; vii. Symptomatic severe aortic stenosis; viii. Uncontrolled heart failure; ix. Acute (within 3 months) pulmonary embolus or pulmonary infarction; x. Thrombosis of lower extremities; xi. Suspected dissecting aneurysm; xii. Uncontrolled asthma; xiii. Pulmonary edema; xiv. Room air desaturation at rest ≤85%; xv. Respiratory failure; xvi. Acute non-cardiopulmonary disorders that may affect exercise performance or be aggravated by exercise (ie infection, renal failure, thyrotoxicosis); and xvii. Mental impairment leading to inability to cooperate.