The BLOST Protocol for In-Office Platelet-Rich Plasma Injections
Orthobiologics is a specialized subset of orthopedics focusing on using platelet-rich plasma (PRP), bone marrow aspirate concentrate (BMAC), or stem cells to increase the healing capabilities of soft tissue, tendons, ligaments, bone, and muscles.1-3 Over the past decade, PRP utilization has more than quadrupled and is expected to rise by 66% over the next 10 years.4 While newer technology has emerged, and we have more understanding of the biology behind PRP, there is no true standardization associated with PRP cell count/platelet count and post-procedural protocols.5-6 There is extensive research on PRP’s utility in larger joints in the human body, specifically the hip, the knee, and the shoulder with mixed results earlier on, but more favorable results in recent studies.7-12 Multiple studies also exist in the foot and ankle, and a recent concept review demonstrated its efficacy to treat a myriad of symptoms and pathology.13 We do know that there is a lack of Level 1 evidence for PRP in the foot and ankle, and that current studies are biased towards the system utilized, which often skews the results. Biological studies in fact have shown that increasing cell counts and platelet yields can optimize the outcomes associated with PRP.14-17
As we learn more about orthobiologics, we discover that augmenting the biology behind PRP can lead to better outcomes. In animal models, it has been found that PRP can modulate inflammatory pathways and stimulate metabolism.18,19 Laser therapy in conjunction with PRP can stimulate mitochondrial activity in our cells to enhance the effects of the PRP, and help speed up cellular repair.20-22
In this article, we present our protocol for PRP injections performed in the office with utilization of the Biology Laser Offloading Stretching Treatment (BLOST) protocol. Biology here is the actual PRP, the laser is a Multiwave Locked System (MLS), offloading is via durable medical equipment (DME), and stretching targets the pathology being treated. We will go into detail on each of the components in this protocol throughout this piece. We believe that to truly achieve maximal results with nonoperative regenerative medicine, there is more one must consider other than just introducing biology (PRP) into the area. Other factors must be controlled as well. To our knowledge, at present, this is the first article of its kind to the establishing such a protocol for in-office PRP injections. To date, the authors have utilized this protocol for a variety of foot and ankle pathologies such as Achilles tendinosis, plantar plate injuries, chronic ankle instability, and early stage arthritis; with good short term results.
Details of the BLOST Protocol
Patients undergoing this protocol receive an initial consultation in the office with a complete lower extremity-focused history and physical. We perform a musculoskeletal-focused physical examination and review all pertinent imaging. We provide the necessary orders for patients who require advanced imaging in the form of computed tomography (CT) or magnetic resonance imaging (MRI) and schedule a follow-up for review. We discuss treatment options with the patient once we obtain a complete picture and, in conjunction with the patient’s expectations, we implement a shared decision-making model to arrive at the appropriate treatment course. As part of this, we identify patients who are candidates for regenerative medicine. We often have a lengthy discussion with these patients about PRP and what to expect. In-office pamphlets support the discussion, and we encourage patients to do their own research as well. We often educate the patient on the system we utilize in our practice, so that they can see the data and research behind the system we use and fully understand the rationale behind it. They then schedule an appointment for the procedure once they are ready to proceed.
Patients present to the office the day of their procedure and we again conduct a lengthy informed consent discussion with them, reinforcing all risks and benefits of the procedure. We also reiterate that PRP by no means is a perfect treatment and they may not get any relief. After obtaining full informed consent, we then verify that the patient has stopped all nonsteroidal anti-inflammatory drugs (NSAIDs) 3 days prior to the procedure, and then educate them to continue to hold all NSAIDs and icing to the affected area for 4 weeks after the procedure, as we are trying to reduce an anti-inflammatory response that would counteract the inflammatory response produced by PRP.
We then triple prep the antecubital fossa of the arm with antiseptic solution, and draw 60 mL of venous blood with a 19-gauge butterfly needle into a syringe preloaded with roughly 7 mL of anticoagulant to prevent any coagulation of blood drawn from the medial cubital vein. We apply a pressure dressing and sterile bandage after removing the needle. The mixed venous blood and anticoagulant is weighted, and we then add the corresponding weight in water to a blank vial and place it into a centrifuge, setting it to 3500 rpm for 10 minutes. This allows for proper separation of the blood to its key components: red blood cells, the buffy coat, and platelet-poor plasma (Figure 1). We utilize a benchtop press with the system we use to push out the platelet-poor plasma into a free empty syringe, followed by the buffy coat into another free empty syringe (Figure 2). We now determine if we will proceed with leukocyte-rich or leukocyte-poor PRP. Utilizing a protein concentrator, we continuously cycle the platelet-poor plasma through the concentrator to help remove water and capture vital proteins found in the blood. This is then added to the buffy coat syringe to create our PRP for injection (Figure 3). We concentrate a specific volume of PRP depending on the joint injected: small joints (metatarsophalangeal joint, midtarsal joints, talonavicular joint, calcaneocuboid joints) being 3mL; larger joints (subtalar joint and ankle joint) being 4–5mL, and soft tissue (Achilles tendon, plantar fascia, posterior tibial tendon, peroneal tendons) being 5–7mL.
During the PRP preparation, the patient receives a proximal nerve block to anesthetize the area. We have found in our practice that patients do not tolerate PRP injections well due to the gauge of the needle and the pressure from the PRP being injected. We typically utilize approximately 5mL of 0.5% ropivacaine plain as a local anesthetic block. Ropivacaine is the anesthetic of choice as it is less cytotoxic to not only the surrounding soft tissue, but also the platelets in the PRP solution.24 Once the PRP is ready for injection, we prep the area using an ethyl alcohol solution. We perform all PRP injections under ultrasound guidance and visualization to ensure proper infiltration of the PRP into the intended area. Once the injection is complete, we cover the area with gauze and a light compression wrap, instructing patients to keep this on for 2 days.
Patients may wish to try to enhance their PRP treatment with a Multiwave Locked System (MLS), which is a class IV medical-grade cold laser. We often have patients complete their first laser session just prior to their PRP injection, during PRP preparation. All patients receive 12 sessions of MLS laser augmented with their PRP injections, and the setting of the laser and timing of treatment all depend on the specific underlying pathology (soft tissue versus joint). We typically recommend 2–3 MLS laser treatments each week until completion of the therapy, to not only continue producing a biologic response, but to compound the effects of the therapy.
Discussing More Protocol Details
We found that older PRP research often advocated for a period of immobilization and non-weight-bearing after PRP injection. We do not agree and believe that patients should bear weight on the affected extremity right away, but of course, with some support. Depending on the specific diagnosis, we either advocate for inserts in the sneaker (either over-the-counter or custom orthotics) or a lace-up ankle brace to help stabilize the ankle. This takes place in an effort to protect the area as the PRP is working and to prevent injury. We often have patients continue with these devices until we see them for their first post-procedure appointment. Our post-PRP appointments are every 2 months until 6 months of follow-up are complete.
As stated above, we believe that keeping these soft tissues and joints moving is paramount to the success of the treatment plan. We often educate our patients about specific stretches they could do to help with their outcome. A majority of our patients present with equinus contracture, and we find that stretching this, with either at-home stretching or a night splint, can help alleviate pathology more distally. Not only this, but as the human body heals itself, preventing scar tissue in contracted positions could also functional outcomes. Again, we often recommend pathology-specific at-home stretching or a night splint, as indicated. For some patients, we even employ formal physical therapy as a means to stretch, keep patients moving and possibly prevent future injury through muscular training.
Patients continue the aforementioned modalities until their first official follow-up with us, which is 2 months after the PRP injection. At this appointment, we check in with the patient to assess their response to the PRP and determine their perspective on percent of improvement since before PRP. We then follow up with them at 6 months after PRP as their final post-procedure check-in. The 6-month evaluation is our indicator as to how they responded to PRP. In our experience, not all patients respond the same way after PRP. Some patients experience a delayed response, and some get an immediate response after injection. We inform all patients prior to having PRP that they have to give it up to 6 months to see the true benefit of the procedure.
At the 2-month appointment, patients can wean out of their supportive devices to tolerance. We do recommend continued use of inserts/orthotics when biomechanically indicated. Although we often don’t restrict patients’ activity after PRP, we recommend they take it easy for the first 48–72 hours, as we have found this is the timeline during which patients may experience acute pain after PRP injection. Overall, however, we don’t restrict patients and recommend they continue with day-to-day activities with the proper support.
Final Thoughts
In our practice, we have had favorable outcomes with the BLOST protocol for in-office PRP. This is the first established protocol of its kind, to the authors’ knowledge, specifically for the foot and the ankle. Future studies are needed to test the efficacy of this protocol versus standard PRP injection alone in a controlled environment. We believe the research surrounding the ancillary procedures in conjunction with PRP support its routine usage and hope as future studies and information emerge, that the foot and ankle surgeon will adapt this protocol into their practice.
Dr. Cottom is a fellowship-trained foot and ankle surgeon with Modern Foot and Ankle/Florida Orthopedic Foot and Ankle Center, where he serves as Fellowship Director. He is a Fellow of the American College of Foot and Ankle Surgeons.
Dr. Verdoni is an Associate of the American College of Foot and Ankle Surgeons and a Surgical Fellow at Modern Foot and Ankle/Florida Orthopedic Foot and Ankle Center.
References
1. Rodeo SA, Bedi A. 2019-2020 NFL and NFL Physician Society Orthobiologics Consensus Statement. Sport Health. 2019;12(1):58-60.
2. Rodriguez-Merchan EC. Intra-articular injections of mesenchymal stem cells for knee osteoarthritis. Am J Orthop (Belle Mead NJ). 2014;43(12):E282-E291.
3. Liddle AD, Rodriguez-Merchan EC. Platelet-rich plasma in the treatment of patellar tendinopathy: a systematic review. Am J Sports Med. 2015;43(10):2583-2590.
4. Berlinberg EJ, Swindell H, Patel HH, et al. The epidemiology of platelet-rich plasma injections from 2010 to 2020 in a large US commercial insurance claims database: a recent update. J Am Acad Orthop Surg. 2023;31(3):e135-e147. doi:10.5435/JAAOS-D-22-00397
5. Kia C, Baldino J, Bell R, et al. Platelet-rich plasma: review of current literature on its use for tendon and ligament pathology. Curr Rev Musculoskelet Med. 2018;11(4):566-572.
6. Jildeh TR, Su CA, Vopat ML, Brown JR, Huard J. A review of commercially available point-of-care devices to concentrate platelet-rich plasma. Cureus. 2022;14(8):e28498.
7. Du D, Liang Y. A meta-analysis and systematic review of the clinical efficacy and safety of platelet-rich plasma combined with hyaluronic acid (PRP+HA) versus PRP monotherapy for knee osteoarthritis (KOA). J Orthop Surg Res. 2025;20:57.
8. Rosso C, Morrey ME, Schär MO, Grezda K; Swiss Orthopaedics Shoulder Elbow and Expert Group; Swiss Orthopaedics Shoulder and Elbow Expert Group. The role of platelet-rich plasma in shoulder pathologies: a critical review of the literature. EFORT Open Rev. 2023;8(4):213-222.
9. Rodríguez-Merchán EC. Intra-articular platelet-rich plasma injections in knee osteoarthritis: a review of their current molecular mechanisms of action and their degree of efficacy. Int J Mol Sci. 2022;23(3):1301.
10. Belk JW, Kraeutler MJ, Houck DA, Goodrich JA, Dragoo JL, McCarty EC. Platelet-rich plasma versus hyaluronic acid for knee osteoarthritis: a systematic review and meta-analysis of randomized controlled trials. Am J Sports Med. 2021;49(1):249-260.
11. Filardo G, Previtali D, Napoli F, Candrian C, Zaffagnini S, Grassi A. PRP injections for the treatment of knee osteoarthritis: a meta-analysis of randomized controlled trials. Cartilage. 2021;13(1_suppl):364S-375S.
12. Park YB, Kim JH, Ha CW, Lee DH. Clinical efficacy of platelet-rich plasma injection and its association with growth factors in the treatment of mild to moderate knee osteoarthritis: a randomized double-blind controlled clinical trial as compared with hyaluronic acid. Am J Sports Med. 2021;49(2):487-496.
13. Henning PR, Grear BJ. Platelet-rich plasma in the foot and ankle. Curr Rev Musculoskelet Med. 2018;11(4):616-623.
14. Boswell SG, Cole BJ, Sundman EA, Karas V, Fortier LA. Platelet-rich plasma: a milieu of bioactive factors. Arthroscopy. 2012;28(3):429-439.
15. Marx RE. Platelet-rich plasma: evidence to support its use. J Oral Maxillofac Surg. 2004;62(4):489-496.
16. Berrigan WA, Bailowitz Z, Park A, Reddy A, Liu R, Lansdown D. A greater platelet dose may yield better clinical outcomes for platelet-rich plasma in the treatment of knee osteoarthritis: a systematic review. Arthroscopy. 2024.
17. Pavlovic V, Ciric M, Jovanovic V, Stojanovic P. Platelet-rich plasma: a short overview of certain bioactive components. Open Med (Wars). 2016;11(1):242-247.
18. Allahverdi A, Sarifi D, Takhtfooladi MA, et al. Evaluation of low-level laser therapy, platelet-rich plasma, and their combination on the healing of Achilles tendon in rabbits. Lasers Med Sci. 2015;30(4):1305-1313.
19. Garcia TA, Camargo RCT, Koike TE, et al. Histological analysis of the association of low-level laser therapy and platelet-rich plasma in regeneration of muscle injury in rats. Braz J Phys Ther. 2017;21(6):425-433.
20. Jonasson TH, Zancan R, de Oliveira Azevedo L, et al. Effects of low-level laser therapy and platelet concentrate on bone repair: histological, histomorphometric, immunohistochemical, and radiographic study. J Craniomaxillofac Surg. 2017;45(11):1846-1853.
21. White C, Brahs A, Dorton D, Witfill K. Platelet-rich plasma: a comprehensive review of emerging applications in medical and aesthetic dermatology. J Clin Aesthet Dermatol. 2021;14(11):44-57.
22. Barbosa D, de Souza RA, de Carvalho WRG, et al. Low-level laser therapy combined with platelet-rich plasma on the healing calcaneal tendon: a histological study in a rat model. Lasers Med Sci. 2013;28(6):1489-1494.
23. Shin MK, Lee JH, Lee SJ, Kim NI. Platelet-rich plasma combined with fractional laser therapy for skin rejuvenation. Dermatol Surg. 2012;38(4):623-630.
24. Dregalla RC, Uribe Y, Bodor M. Effect of local anesthetics on platelet physiology and function. J Orthop Res. 2021;39(12):2744-2754.
