Platelet-rich Plasma vs. Hyaluronic Acid for Glenohumeral Osteoarthritis

Inclusion Criteria: * English speaking/literate * Age 18-100 years * Visual analog score pain \>= 5 * Greater than or equal to 3 months of pain after onset of symptoms that has failed conservative treatments * Confirmation of glenohumeral OA via routine imaging (MRI and x-ray; must be recent and within the past year) * Transient relief of symptoms after diagnostic intra-articular injection into the glenohumeral joint Exclusion Criteria: * Non-English speaking/illiterate * Painful active, concurrent cervical spine conditions * Current non-steroidal anti-inflammatory drug (NSAID) use * History of taking coumadin or similar anticoagulant, have a known coagulopathy, bleeding dyscrasia, or platelet count \< 150,000/cubic mm * Allergic reaction to poultry or previous viscosupplementation * Involved in workers' compensation or active litigation involving affected shoulder * Inability to refrain from NSAID use for 5 days prior to and 6 weeks after injection * History of corticosteroid injection to affected shoulder within the last 3 months * History of viscosupplementation or platelet-rich plasma to affected shoulder within the last 6 months * Presence of acute fracture * History of shoulder tumor * Known uncontrolled systemic illness (uncontrolled diabetes, human immunodeficiency virus, vasculitis, autoimmune/inflammatory disease) * Psychiatric and somatoform disorders