top of page

Regenerative Research Roundup - March 2022

Welcome to the Regenerative Research Roundup, where we look through recently published research and bring you the best of the best in a quick-to-read digest.

This month, we have new research on the effect of platelet concentration on Knee OA; PRP in treating hair loss; and PRP augmentation during rotator cuff repair.

Let's explore!


Leukocyte-Rich versus Leukocyte-Poor Platelet-Rich Plasma for the Treatment of Knee Osteoarthritis: A Double-Blind Randomized Trial

The American Journal of Sports Medicine // Level of Evidence: l

For years, clinicians have debated the impact of Leukocytes in the PRP preparations. It's widely understood that PRP with leukocytes (LR-PRP) is preferred for soft tissue applications while PRP without leukocytes (LP-PRP) is preferred for joint injections. However, a new paper from AJSM seems to suggest both are adequate.

  • 192 patients with symptomatic knee OA (Kellgren-Lawrence grade 1-3)

  • 3 weekly injections of LR-PRP or LP-PRP - mean platelet concentration >4x above baseline. (5mL injectate).

  • Patients were evaluated at baseline and thereafter at 2, 6, and 12 months for IKDC, KOOS, VAS, and Tegner.

Authors concluded that both interventions produced strong clinical improvement out to 12 months with no difference in clinical outcomes at any timepoint. However, they did report GREATER post-injection pain and swelling in 12% of patients receiving LR-PRP vs. 5% in LP-PRP.

The takeaway? Platelet concentration matters more than leukocyte concentration in driving Knee OA outcomes - LP-PRP can help reduce post-injection pain.


Intra-articular injections of platelet-rich plasma decrease pain and improve functional outcomes than sham saline in patients with knee osteoarthritis

Knee Surgery, Sports Traumatology, Arthroscopy // Level of Evidence: l

As an immediate follow up to the prior article, here we have another prospective, parallel-group, double-blind, multi-center, sham-controlled randomized investigating the use of LP-PRP in Knee OA.

  • 610 patients with symptomatic knee OA (Kellgren-Lawrence grade 1-3)

  • 3 weekly injections of LP-PRP - mean platelet concentration in PRP is 4.3­ fold (5mL injectate)

  • Patients were evaluated at baseline and thereafter at 3, 6, 12, 24, 60 months for WOMAC, IKDC, VAS, biochemical marker concentrations, cartilage volume, and adverse events.

Authors concluded that LP-PRP was superior to sham saline in treating KOA. P-PRP was effective for achieving at least 24 months of symptom relief and slowing the progress of KOA, with both P-PRP and saline being comparable in safety profiles.

What does this study have in common with the RCT above? Both used a PRP system that was able to deliver over 5 billion platelets per dose.


Effectiveness of Platelet-Rich Plasma Therapy in Androgenic Alopecia—A Meta-Analysis

Journal of Personalized Medicine // Level of Evidence: l

The evidence for using PRP to treat Androgenic Alopecia is continuing to grow! This time, another group of authors conducted a meta-analysis that aimed to properly characterize the treatments and correlate them with efficacy as determined by percentage change in hair density.

  • 15 clinical trials included (86.7% were randomized, 46.7% were double-blind, and 26.7% were single-blind)

  • Criteria included percentage change in hair density, mean hair diameter, PRP preparation method, amount used per treatment, terminal hairs and pull test.

Authors concluded that PRP was an effective treatment option in treating AGA in both sexes. However, the total number of PRP treatments and the amount of PRP injected per treatment do not appear to influence the outcome, but an increased frequency of application (number of treatments per month) results in larger increases in hair density. For best results it is advisable to apply a complex combined therapy protocol as early as possible.


Platelet-Rich Plasma Augmentation of Arthroscopic Rotator Cuff Repair Lowers Retear Rates and Improves Short-Term Postoperative Functional Outcome Scores: A Systematic Review of Meta-Analyses

Arthroscopy, Sports Medicine, and Rehabilitation // Level of Evidence: ll

The purpose of this study is to conduct a systematic review of meta-analyses of rotator cuff repair using platelet-rich plasma (PRP) to identify whether PRP improves clinical function and rate of tendon retears.

  • 13 meta-analysis included

  • Total of 1,800 patients with an average follow up of 12 to 36 months

Authors concluded that the use of PRP for arthroscopic rotator cuff tear, when compared with controls, leads to a lower number of re-tears, improved short-term postoperative scores, and functional outcome


If you have any questions or comments regarding the above research, or are wondering how you can apply it to your regenerative practice, please leave a comment below or shoot me an email at




This blog post provides general information to help the reader better understand regenerative medicine, musculoskeletal health, and any related subjects. The views and opinions expressed in this post are those of the author and may not reflect the views and opinions of MDBiologix. All content provided in this blog, website, or any linked materials, including text, graphics, images, patient profiles, outcomes, and information, are not intended and should not be considered or used as a substitute for medical advice, diagnosis, or treatment. Please always consult with a professional and certified healthcare provider to discuss if any treatment is right for you.


bottom of page