Research, Evidence and Publications

This is the part of the blog where the studies get read closely. Orthobiologics is a field where a headline can say one thing and the data underneath says another, so these posts work through published papers, conference presentations and the studies run inside this practice, and state plainly what each one does and does not show. It is written for patients trying to decide whether a treatment is worth their time, and for physicians who want the reference rather than the summary.

Level of evidence is a label, not a guarantee

Orthopedic journals grade studies from level 1, the randomized trials, down to level 5, expert opinion, and that grade drives what clinicians believe. Our own review looked at 13 months of articles across 6 of the top 10 orthopedic surgery journals, 1425 papers in total. The average level of evidence was 3. Most of what gets published in orthopedics is not the randomized work that readers assume they are looking at.

The label itself can also be wrong. A 2021 paper on stem cell joint injections was listed as a level 2 prospective cohort study when it was actually a retrospective review of an insurance company database. Reading the methods section instead of the label is the whole skill.

Dose is the variable most studies leave out

Platelet rich plasma is not one treatment. Dose is volume multiplied by platelet concentration, so a study that reports only how many cc were injected has not reported a dose at all. That is exactly how a rotator cuff meta analysis published in Arthroscopy, which defined dose by volume alone, arrived at the conclusion that PRP does not help.

Where dose has been measured, the pattern is consistent. In tendon, ligament and muscle problems, 14 of 14 studies dosing below 3.5 billion platelets in a single injection did not help patients, while 9 of 11 studies dosing above that threshold did. For knee arthritis, a 2015 analysis of 24 studies and 2,315 patients found pain and function improved for about 6 months and were still better than preinjection at 12 months, and a well powered randomized trial of 90 patients using three monthly injections reported average pain scores falling from 8.0 to 5.7 at 6 months compared with 7.9 to 6.6 for saline. Level 1 work in Arthroscopy found PRP gave better function and pain relief than a steroid shot at 3 months for partial rotator cuff tears, and a 2023 level 1 study following 64 patients with lateral elbow tendinopathy for 2 years favored PRP over steroid. More of the dosing detail sits in the PRP hub.

Research run inside this practice

Some of what is posted here is our own data. An office based study enrolled 25 patients with partial thickness rotator cuff tears treated with a single bone marrow concentrate injection and followed them out past the first year. At 2 years, patients reported 80 percent less pain and rated themselves 84 percent better on the SANE score. That data set now runs past 7 years. A level 1 randomized study asking whether photoactivating a high dose PRP injection improves single injection results in knee arthritis has completed enrollment.

The bench work matters just as much. Nine commercially available PRP systems were run through a hematology analyzer to measure what they actually produce, and marrow aspiration needles were compared head to head in the same patient by colony forming units per ml. If you do not know what is in the syringe, you cannot interpret your own outcomes. The bone marrow hub goes further into that work.

Where the evidence is genuinely mixed

Not every question has a clean answer, and posts here say so. A randomized AJSM trial gave 19 patellar tendinopathy patients a single leukocyte rich PRP injection and followed them a year without finding strong evidence of benefit. A Canadian pilot of 12 patients using cultured bone marrow cells for knee arthritis showed better outcomes at higher doses, but the MRIs were unchanged at one year. A level 1 trial of allogeneic PRP against placebo followed about 40 knee patients per group for a year using a single spin system with low platelet recovery, which limits what can be concluded from it.

Telling research from marketing

Some products reach the market well ahead of the human data. More than 20 physicians, PhDs and researchers signed a consensus statement that umbilical cord blood, amniotic fluid and Wharton's jelly products contain no living stem cells. Mesenchymal stem cell exosomes are being studied for knee osteoarthritis, including a 2024 randomized trial of placental derived exosomes, but the FDA regulates them as a drug and none is approved. For the peptide BP-157 there is no peer reviewed, publicly posted human safety data, and the registered trial record is thin. Academic misconduct is a real risk too, as in the retraction of dozens of bone marrow stem cell papers by a Harvard cardiologist. The FDA and safety hub covers the regulatory side in detail.