Correlating the OA Knee Microenvironment to Outcomes After Regenexx-SD Treatment: A Multi-Site Study

Study Purpose

Multi-center study to include up to 600 subjects with knee osteoarthritis in unilateral or bilateral knees treated with Regenexx® SD in the osteoarthritic knee/s. Synovial fluid drawn from patients' knee/s prior to receiving Regenexx-SD treatment will be correlated with their clinical outcomes after treatment.

Recruitment Criteria

Accepts Healthy Volunteers

Healthy volunteers are participants who do not have a disease or condition, or related conditions or symptoms

Study Type

An interventional clinical study is where participants are assigned to receive one or more interventions (or no intervention) so that researchers can evaluate the effects of the interventions on biomedical or health-related outcomes.

An observational clinical study is where participants identified as belonging to study groups are assessed for biomedical or health outcomes.

Searching Both is inclusive of interventional and observational studies.

Eligible Ages 35 Years - 85 Years
Gender All
More Inclusion & Exclusion Criteria

Inclusion Criteria:

  • - 1) Voluntary signature of the IRB approved Informed Consent 2) Unilateral or bilateral osteoarthritic 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 in one knee joint 5) Kellgren-Lawrence grade 2 or greater knee osteoarthritis 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) Is independent, ambulatory, and can comply with all post-operative evaluations and visits.

Exclusion Criteria:

  • - 7) Knee injections of any type within 3 months prior to the study.
8) Knee surgery within 6 months prior to the study. 9) Patient undergoing lavage with treatment. 10) 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) 11) Quinolone or statin-induced myopathy/tendinopathy 12) Severe neurogenic inflammation of the cutaneous nerves about the knee or thigh 13) Contraindications for MRI 14) Condition represents a worker's compensation case 15) Currently involved in a health-related litigation procedure 16) Is pregnant 17) Bleeding disorders 18) Currently taking anticoagulant or immunosuppressive medication 19) Allergy or intolerance to study medication 20) Use of chronic opioid 21) Documented history of drug abuse within six months of treatment 22) Any other condition, that in the opinion of the investigator, that would preclude the patient from enrollment

Trial Details

Trial ID:

This trial id was obtained from, a service of the U.S. National Institutes of Health, providing information on publicly and privately supported clinical studies of human participants with locations in all 50 States and in 196 countries.


Phase 1: Studies that emphasize safety and how the drug is metabolized and excreted in humans.

Phase 2: Studies that gather preliminary data on effectiveness (whether the drug works in people who have a certain disease or condition) and additional safety data.

Phase 3: Studies that gather more information about safety and effectiveness by studying different populations and different dosages and by using the drug in combination with other drugs.

Phase 4: Studies occurring after FDA has approved a drug for marketing, efficacy, or optimal use.

Lead Sponsor

The sponsor is the organization or person who oversees the clinical study and is responsible for analyzing the study data.

Regenexx, LLC
Principal Investigator

The person who is responsible for the scientific and technical direction of the entire clinical study.

Christopher Centeno, MD
Principal Investigator Affiliation Regenexx, LLC
Agency Class

Category of organization(s) involved as sponsor (and collaborator) supporting the trial.

Overall Status Enrolling by invitation
Countries United States

The disease, disorder, syndrome, illness, or injury that is being studied.

Knee Osteoarthritis
Additional Details

Initial study procedures include baseline evaluation of medical history, knee history, knee examination, medication use, MRI, and subject-reported outcomes. 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). 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. The objective of this study is to correlate the pre- Regenexx-SD treatment levels of pro-inflammatory cytokines, anti-inflammatory cytokines, matrix metalloproteinases, and catabolic articular cartilage breakdown products in the osteoarthritic knee synovial fluid microenvironment with 6 month post-treatment clinical outcomes. This data will be used to establish a predictive a priori testing "model" to determine if a patient is a good candidate for the Regenexx-SD treatment based on their initial osteoarthritic knee synovial fluid microenvironment phenotype. It may also be used to determine if the micro-environment can be altered to improve outcome before receiving Regenexx-SD. Incidence of post-operative complications, adverse events, re-injections, and surgical intervention and change in pain score will be considered while determining these direct and indirect associations upon completion of the Regenexx-SD treatment. Components of the synovial fluid will be correlated to post-treatment clinical outcomes, which include several self-reported questionnaires as well as assessment of post-injection complications, adverse events, re-injections and surgical interventions. Patient reported questionnaires include IKDC Subjective Knee Evaluation, Lower Extremity Function Scale, Pain Scales and a Modified Single Assessment Numeric Evaluation (SANE).

Arms & Interventions


Experimental: Knee Synovial Fluid collection before Regenexx-SD

Measure components of knee synovial fluid 2-4 days before the Regenexx-SD treatment.


Procedure: - Bone Marrow Concentrate treatment

Correlate patient outcomes 6 months after receiving the Regenexx SD treatment with measurements of synovial fluid collected before treatment

Contact a Trial Team

If you are interested in learning more about this trial, find the trial site nearest to your location and contact the site coordinator via email or phone. We also strongly recommend that you consult with your healthcare provider about the trials that may interest you and refer to our terms of service below.

Interventional Orthopedics of Atlanta, Atlanta, Georgia



Interventional Orthopedics of Atlanta

Atlanta, Georgia, 30305

Regenexx Des Moines, Des Moines, Iowa



Regenexx Des Moines

Des Moines, Iowa, 50321

Regenexx Las Vegas, Las Vegas, Nevada



Regenexx Las Vegas

Las Vegas, Nevada, 89074