Single-center, laboratory blinded to include up to 400 subjects with knee osteoarthritis in unilateral or bilateral knees treated with Regenexx® SD in the osteoarthritic knee/s.Initial study procedures include baseline evaluation of medical history, knee history, knee examination, medication use, MRI, and subject-reported outcomes.~Subjects will be enrolled within the 120 days prior to Regenexx® SD injection. A preoperative visit will occur at the time of enrollment. Collection of synovial fluid from the OA knee/s will serve as the experimental condition, i.e. the osteoarthritic knee.Each osteoarthritic subject will undergo withdrawal of knee joint synovial fluid for each knee being treated (0.3-0.5 ml) which will be analyzed by the research laboratory via multiplexed enzyme linked immunosorbent assay (ELISA) and dimethylmethylene blue assay (DMMB) at pre-injection (2-8 days before Regenexx® SD treatment) and post-injection (2-8 days after Regenexx® SD). Documentation of osteoarthritic joint characteristics and injection procedure details will be recorded throughout the study.~The unaffected knee joint will undergo no treatment, but bilateral knees may be treated.~Components of the synovial fluid will be correlated to post-treatment clinical outcomes, which include patient-reported questionnaires as well as assessment of post-injection complications, adverse events, re-injections and surgical interventions. Patient-reported clinical outcomes are comprised of the IKDC Subjective Knee Evaluation, the Lower Extremity Function Scale, Numeric Pain Scale and a Patient Reported Percent Improvement form.
Single-center, lab blinded to include up to 400 subjects with knee osteoarthritis. Collection of synovial fluid from diseased knee before and after Regenexx®SD treatment will serve as the experimental condition, i.e. the osteoarthritic knee.