What does each name mean for the joint shot?

How does the clinic make a shot from your blood?

Platelet-rich plasma, called PRP, begins when the clinic draws some of your blood. A machine spins the blood and gathers platelets, which are the small blood pieces placed in the joint shot. Concentrated PRP contains more platelets than the clinic's standard PRP.

The platelet amount alone doesn't show whether your soreness will ease. Clinics can prepare PRP in different ways. Ask for the exact kind and whether the research covers your joint. The person doing the shot should also explain what you can expect afterward.

What do the other joint-shot names mean?

You may hear regenerative treatments, biologic therapies, or orthobiologics. These three clinic names can describe shots prepared using blood drawn from you, pelvic marrow, collected fat, or donor tissue. None identifies what fills the syringe or proves that your joint will rebuild itself.

Marrow concentrate starts when the clinic takes marrow from the pelvis. A machine spins the marrow and keeps a cell-rich liquid for the joint shot. Drawing the marrow and placing the prepared liquid into your joint are separate steps. A fat-based shot starts with collected body fat and follows a different process.

What will the clinic explain?

The doctor or nurse should name the exact shot being discussed with you. Ask whether it begins with your blood, pelvic marrow, body fat, or tissue from a donor. The answer needs to cover how the clinic collects and prepares that source. A broad treatment label isn't enough.

The visit should cover your joint exam, the procedure, and care afterward. Ask about total cost and the research for your joint. Other choices, including physical therapy or surgery, belong in the same talk. Clear answers make the choices easier for you to compare.

Sources

1. The International Society for Cell & Gene Therapy position statement holds that the acronym MSC should mean mesenchymal STROMAL cells and should only be called stem cells where rigorous in vitro and in vivo evidence of stemness exists for that specific preparation.

   Viswanathan S, et al. — Mesenchymal stem versus stromal cells: International Society for Cell & Gene Therapy (ISCT®) Mesenchymal Stromal Cell committee position statement on nomenclature. Cytotherapy, 2019. DOI: 10.1016/j.jcyt.2019.08.002.

2. The 2018 AAOS/NIH consensus work group recommended that minimally manipulated mixed cell preparations be called CELL THERAPY rather than stem cell therapy, and that their untested and uncharacterised nature be clearly communicated to patients and the public, because stem cells have properties these preparations do not meet.

   Chu CR, et al. — Optimizing Clinical Use of Biologics in Orthopaedic Surgery: Consensus Recommendations From the 2018 AAOS/NIH U-13 Conference. J Am Acad Orthop Surg, 2019. DOI: 10.5435/JAAOS-D-18-00305.

3. 21 CFR 1271.10(a) sets the four criteria a human cell or tissue product must meet to be regulated SOLELY under section 361 of the Public Health Service Act: it must be minimally manipulated; intended for homologous use only, as reflected by labeling and advertising; not combined with another article beyond water, crystalloids or a preserving agent; and either have no systemic effect and not depend on the metabolic activity of living cells, or else be for autologous use, use in a close blood relative, or reproductive use.

   US Code of Federal Regulations, Title 21 — 21 CFR 1271.10 - Are my HCT/P's regulated solely under section 361 of the PHS Act. , 2004.

4. FDA states in its consumer alert that the only FDA-approved stem cell products in the United States are blood-forming stem cells derived from umbilical cord blood, approved for disorders of the blood-forming system, and that NONE of these products - stem cells, stromal vascular fraction, umbilical cord blood, Wharton's jelly or amniotic fluid - has been approved for the treatment of any orthopedic condition, including osteoarthritis, tendonitis, disc disease, tennis elbow, back pain, hip pain, knee pain, neck pain or shoulder pain.

   US Food and Drug Administration, Center for Biologics Evaluation and Research — Consumer Alert on Regenerative Medicine Products Including Stem Cells and Exosomes. , 2020.

5. On 27 September 2024 the Ninth Circuit held in United States v. California Stem Cell Treatment Center that stromal vascular fraction produced by enzymatically digesting a patient's own fat IS a drug under the Federal Food, Drug, and Cosmetic Act, and that the same surgical procedure exception does not apply because the removed fat and the implanted SVF are not the same thing. The district court's ruling for the clinics was reversed.

   United States Court of Appeals for the Ninth Circuit — United States v. California Stem Cell Treatment Center, Inc., No. 22-56014 (9th Cir. Sept. 27, 2024). , 2024.

6. In a 480-patient, four-arm, multicenter randomized phase 2/3 trial, none of three orthobiologic cell injections - autologous bone marrow aspirate concentrate, autologous adipose stromal vascular fraction, or allogeneic umbilical cord tissue-derived mesenchymal stromal cells - was superior to any other, or to a corticosteroid injection control, on pain at 12 months.

   Mautner K, et al. — Cell-based versus corticosteroid injections for knee pain in osteoarthritis: a randomized phase 3 trial. Nat Med, 2023. DOI: 10.1038/s41591-023-02632-w.

7. A 2025 systematic review and meta-analysis of 8 randomized trials in 502 patients found intra-articular mesenchymal stem cells improved WOMAC scores versus control at 6 months (MD 7.44, 95% CI 1.45-13.42) and 12 months (MD 10.31, 95% CI 0.96-19.67), with wide confidence intervals and a small pooled sample.

   Cao M, et al. — Efficacy and safety of mesenchymal stem cells in knee osteoarthritis: a systematic review and meta-analysis of randomized controlled trials. Stem Cell Res Ther, 2025. DOI: 10.1186/s13287-025-04252-2.