The purpose of the current study is to assess the ability of alpha-2-macroglobulin treatment to reduce the level of pro-inflammatory synovial fluid biomarkers in patients with osteoarthritis of the knee.

This is a double-blinded rationalized control trial with prospective data collection. The study will collect and analyze the synovial fluid, serum, and urine of patients presenting with knee osteoarthritis in Kellegren-Lawrence grade 2 or 3. It will compare synovial fluid biomarker levels between patients receiving an intra-articular alpha-macroglobulin, intra-articular PR injection and intra-articular corticosteroid serving as a control. Pre-injection pain and function will be assessed. Post-injection pain, function and outcomes will be assessed after six weeks and three months.

Inclusion Criteria:

• Patients osteoarthritis classified as Kellegren-Lawrence grade 2 or 3

Exclusion Criteria:

• Mentally impaired (e.g, Alzheimer's subjects, dementia, etc.)
• Younger than 18 years of age
• Greater than 90 years of age
• Patients with underlying inflammatory arthropathies