By Marc Darrow, MD, JD

A caller to my August 29, 2026, Living Pain-Free radio show asked a question I hear often: If you have a torn shoulder tendon and want to avoid surgery, should you choose platelet-rich plasma (PRP), a treatment using cells from your own bone marrow, or exosomes? Another caller wanted to know whether these injections repair tissue or simply relieve pain. These are the right questions to ask before paying for any procedure. Listen to or read the radio program.

The answer begins with a diagnosis. A partial rotator cuff tear, a tendon that has completely pulled away from the bone, shoulder arthritis, and pain referred from the neck may feel similar. They do not call for the same treatment. I consider the history, examine the painful structures and movement, review relevant imaging, and discuss what the patient hopes to regain. An image can help describe an injury, but it does not, by itself, tell us which finding is causing the pain.

What is PRP?

PRP is prepared from a sample of your own blood. A centrifuge separates a portion containing concentrated platelets, which are involved in the body’s response to injury. The preparation and injection method matter, and the label “PRP” does not describe one uniform product.

For a partial-thickness rotator cuff tear, PRP is one option to discuss alongside rehabilitation and other nonsurgical care. A 2024 review of 12 studies involving 762 patients reported some improvements in pain after PRP, but the studies differed substantially and durable functional benefits were less certain. It did not establish that an injection reliably closes a tear. (1)

The same distinction applies to other injuries: less pain and better function are meaningful outcomes, but they do not automatically demonstrate new tendon or cartilage on imaging. We should evaluate those questions separately.

What is bone marrow aspirate concentrate?

Bone marrow aspirate concentrate, often shortened to BMAC, is made by taking a sample of a patient’s own bone marrow and concentrating it. It contains a mixture of cells and signaling components. Calling every BMAC injection a “stem cell treatment” can oversimplify what is actually in the preparation; it is not a purified or cultured stem cell product.

Evidence depends on the condition being treated. A 2024 network meta-analysis of knee osteoarthritis injections found that PRP and BMAC produced better pain and function scores than corticosteroid injections at a minimum six-month follow-up. These group averages cannot predict one person’s response or establish that BMAC rebuilds a severely damaged joint. (2)

A 2024 prospective study followed patients with knee osteoarthritis after BMAC treatment for two years and reported improvement. Because that study did not randomly compare BMAC with a control treatment, it cannot show how much improvement was due to the injection itself. Knee studies also cannot be applied directly to a torn shoulder tendon or chronic low-back pain. (3)

In my practice, I discuss bone marrow procedures with selected patients after identifying the likely pain source, reviewing their previous care, and explaining the additional steps and uncertainty compared with PRP. A more involved preparation is not automatically a better choice.

Should exosomes be added to PRP or BMAC?

Exosomes are tiny particles released by cells and studied for how cells communicate. They are often advertised as a way to boost an injection. The clinical claim is ahead of the evidence: there is no established, FDA-approved exosome product for a rotator cuff tear, osteoarthritis, or back pain. The FDA states that there are currently no FDA-approved exosome products and that products in its regenerative medicine consumer alert have not been approved for orthopedic conditions. (4)

On the show, I described interest in combining exosomes with PRP or bone marrow preparations. My interest is a clinical perspective, not proof that the combination is safe, legally marketed for a proposed use, or superior to a simpler treatment. Patients should ask for the exact product name, its source, what human trial supports its use for their particular condition, and its regulatory status before considering an added product. A social media testimonial cannot answer those questions.

Does improvement mean the tissue regenerated?

Nikur, a caller with knee and back concerns, asked whether a treatment merely eases pain or repairs the underlying tissue. We aim to improve the patient’s pain and ability to move. Biological repair is a research question that requires appropriate evidence, such as reliable imaging or tissue evaluation, as well as meaningful clinical results. A patient who walks farther or returns to a gym has achieved something important; that experience alone cannot show that cartilage regrew or a tendon reattached.

Robert called to say he felt better and had returned to the gym after treatment in several areas. His experience is encouraging and worth hearing, but it cannot predict another patient’s result or identify which treated site or intervention made the difference. We discuss individual outcomes honestly, including the possibility of no benefit.

Who might benefit from an evaluation?

A patient with persistent, localized tendon or joint pain despite an appropriate exercise program may want to discuss an injection as one possible next step. Candidacy depends on the diagnosis, degree of tissue damage, overall health, goals, and available alternatives. Hashimoto’s thyroiditis, for example, is part of the medical history to review; it does not tell us whether a shoulder tear is suitable for PRP or BMAC.

Some findings require a different path. A new traumatic shoulder injury with major weakness or a complete, retracted tendon tear deserves prompt orthopedic assessment because the option to repair it may change with time. Progressive leg weakness, new bladder or bowel dysfunction, or numbness in the groin with back pain needs urgent medical evaluation. An injection should never delay assessment of those symptoms. Surgery can be appropriate when an injury or nerve problem calls for it, and a second opinion can help when the choice is uncertain.

For an individual evaluation, contact the Stem Cell Institute at 800-300-9300. This article is educational and does not replace a personal examination or urgent care when warning symptoms are present.

References

  1. Desouza C, Shetty V. Effectiveness of platelet-rich plasma in partial-thickness rotator cuff tears: a systematic review. J ISAKOS. 2024;9(4):699–708. doi:10.1016/j.jisako.2024.04.010.
  2. Jawanda H, Khan ZA, Warrier AA, et al. Platelet-Rich Plasma, Bone Marrow Aspirate Concentrate, and Hyaluronic Acid Injections Outperform Corticosteroids in Pain and Function Scores at a Minimum of 6 Months as Intra-Articular Injections for Knee Osteoarthritis: A Systematic Review and Network Meta-analysis. Arthroscopy. 2024;40:1623–1636.e1. doi:10.1016/j.arthro.2024.01.037.
  3. Jeyaraman M, Jeyaraman N, Ramasubramanian S, Ranjan R, Jha SK, Gupta A. Bone Marrow Aspirate Concentrate for Treatment of Primary Knee Osteoarthritis: A Prospective, Single-Center, Non-randomized Study with 2-Year Follow-Up. Indian J Orthop. 2024;58(7):894–904. doi:10.1007/s43465-024-01168-6.
  4. U.S. Food and Drug Administration. Consumer Alert on Regenerative Medicine Products Including Stem Cells and Exosomes. Updated July 22, 2020.