The purpose of this study is to understand how the components of osteoarthritic knee joint fluid (synovial fluid) change after lavage treatment with platelet poor plasma. Additionally, the study participants will complete outcome questionnaire surveys before and after the treatment in conjunction with when synovial fluid is removed from the knee (2, 4, and 6 weeks after lavage). This data will help determine if the treatment of an osteoarthritic knee joint with platelet poor plasma lavage is a suitable stand-alone therapy or to improve outcome by preparing a patient's knee for further regenerative therapies.

The objective of this study is to quantify the levels of catabolic markers in osteoarthritic (OA) knee synovial fluid microenvironment (ME) before lavage treatment with platelet poor plasma (PPP) and to determine whether the anti-catabolic capabilities of the PPP are sustainable or if the diseased synovial fluid returns to pre-lavage catabolic marker levels within the 6 week period of the study.

This data will be used to determine if treatment of a diseased (OA) knee with PPP lavage would be a suitable therapy for knee OA patients either as a stand-alone treatment or to improve outcome by preparing a patient's knee microenvironment for further treatment with cellular therapies. Incidence of post-operative complications, adverse events, re-injections, and surgical intervention; change in pain score will be considered while determining these direct and indirect associations upon completion of the PPP lavage treatment. Correlation of subject reported clinical outcomes for the PPP lavage treatment will be evaluated to determine whether the treatment provides beneficial clinical outcomes.

Inclusion Criteria:

• 1) Voluntary signature of the institutional review board approved Informed Consent
• 2) Male or female ages 35-85
• 3) Pain, swelling, and/or functional disability in the affected knee consistent with osteoarthritis in the knee joint
• 4) Physical examination consistent with osteoarthritis as observed on imaging
• 5) Unilateral or bilateral Kellgren-Lawrence grade 3 or greater knee osteoarthritis (moderate to severe OA) and/or diagnostic MRI imaging of the affected knee showing osteoarthritis (i.e. chondral loss, fissuring, defect, bone marrow lesion, meniscus tear, synovial thickening, etc…)
• 6) Mild effusion upon ultrasound evaluation.
• 7) Is independent, ambulatory, and can comply with all postoperative evaluations and visits

Exclusion Criteria:

• 1) Knee injections of any type within 3 months prior to the study.
• 2) Knee surgery within 6 months prior to the study.
• 3) Inflammatory or auto-immune based joint diseases or other lower extremity pathology (e.g., rheumatoid arthritis, systemic lupus erythematosus, psoriatic arthritis, polymyalgia, polymyositis, gout pseudogout)
• 4) Quinolone or Statin induced myopathy/tendinopathy
• 5) Severe neurogenic inflammation of the cutaneous nerves about the knee or thigh
• 6) Contraindications for MRI
• 7) Condition represents a worker's compensation case
• 8) Currently involved in a health-related litigation procedure
• 9) Is pregnant
• 10) Bleeding disorders
• 11) Currently taking anticoagulant or immunosuppressive medication
• 12)Allergy or intolerance to study medication
• 13)Use of chronic opioid
• 14)Documented history of drug abuse within six months of treatment
• 15)Any other condition, that in the opinion of the investigator, that would preclude the patient from enrollment