Why can two PRP preparations be different?

What to ask before the blood draw

List aspirin and any blood thinner when the clinic asks about medicines. Mention any blood or bleeding problem that a clinician has found. Don't change prescribed medicine by yourself. The nurse or doctor who manages it can tell you what to do.

Ask whether the prepared blood has many white blood cells or very few. Mixtures with more white cells tend to cause more soreness afterward. Those with fewer white cells have caused less soreness in joint studies. Neither kind can assure you of relief.

Does a higher platelet count always work better? Research hasn't shown such a simple rule. Asking for the count shows whether the clinic knows what it prepared. The number alone won't tell you how much better you'll feel.

What to expect during the visit

A QC Kinetix visit begins with a health review and an exam. The clinic calls its licensed staff medical providers; they examine sore areas and treat patients. They offer regenerative choices, their term for clinic-made care from your blood without surgery. They'll explain why a choice may suit the joint or tendon.

If you choose PRP, staff draw the blood and spin it. They then place the saved layer at the sore spot. Ultrasound sends harmless sound waves into the body and turns their echoes into a moving image. Staff can watch the ultrasound image while guiding treatment to the chosen spot.

Will you be able to drive afterward? Ask before the day of treatment. Also ask about work, stairs, walking, and exercise. Keep the written answers where you'll find them at home.

What to do during the first few days

Soreness and swelling can last for a few days after PRP. Blood mixtures with more white cells may cause more of both. Follow the clinic's written limits for movement. Call when your symptoms are stronger or last longer than staff described.

There isn't one recovery schedule for every person. Your work and the body part treated affect the advice. Ask when you can lift, stand, walk, and restart normal exercise. You'll be able to plan around a clear answer.

Fever, spreading redness, or swelling that grows quickly needs prompt care. New weakness, numbness, or severe trouble using the limb also needs attention. These aren't normal questions to save for follow-up. Get help based on how serious the symptoms feel.

Sources

1. A systematic review of 29 randomized trials of PRP for knee OA that reported a platelet count, concentration or dose found that the 28 treatment arms with statistically significant positive outcomes at 6 months had a mean platelet dose of 5,500 (+/-474) x 10^6, while the three arms without a positive difference averaged 2,302 (+/-437) x 10^6 (P<.01). The same separation held at 12 months: 5,464 versus 2,253 x 10^6 (P<.05).

   Berrigan WA, Bailowitz Z, Park A, et al. — A Greater Platelet Dose May Yield Better Clinical Outcomes for Platelet-Rich Plasma in the Treatment of Knee Osteoarthritis: A Systematic Review. Arthroscopy, 2025. DOI: 10.1016/j.arthro.2024.03.018.

2. A systematic review and meta-analysis of platelet dosage across musculoskeletal conditions identified a potential dose-response relationship in knee osteoarthritis, with an apparent threshold above 10 billion platelets for favourable clinical outcomes, and the effect more pronounced for function than for pain. For conditions other than knee OA the authors found the literature too unclear to identify an optimal dose.

   Berrigan W, Tao F, Kopcow J, et al. — The Effect of Platelet Dose on Outcomes after Platelet Rich Plasma Injections for Musculoskeletal Conditions: A Systematic Review and Meta-Analysis. Current Reviews in Musculoskeletal Medicine, 2024. DOI: 10.1007/s12178-024-09922-x.

3. A scoping review of PRP for knee and hip osteoarthritis reported that PRP for knee OA gives clinically comparable or superior outcomes to other injection treatments, that the evidence in HIP osteoarthritis is far less consistent, and that evidence is lacking to show the presence of leukocytes significantly influences clinical outcomes. It named leukocyte concentration, OA grade and formulation comparability as the open questions.

   Tanguilig G, Dhillon J, Kraeutler MJ, et al. — Platelet-Rich Plasma for Knee and Hip Osteoarthritis Pain: A Scoping Review. Current Reviews in Musculoskeletal Medicine, 2024. DOI: 10.1007/s12178-024-09916-9.

4. A systematic review of 105 clinical PRP studies in orthopaedics published 2006-2016 found that only 11 (10%) described the preparation protocol clearly enough for another investigator to repeat it, and only 17 (16%) reported any quantitative metric of the final PRP composition. The authors concluded that the current reporting of PRP preparation and composition does not allow the PRP products actually delivered to patients to be compared between studies.

   Chahla J, Cinque ME, Piuzzi NS, et al. — A Call for Standardization in Platelet-Rich Plasma Preparation Protocols and Composition Reporting: A Systematic Review of the Clinical Orthopaedic Literature. Journal of Bone and Joint Surgery (American), 2017. DOI: 10.2106/JBJS.16.01374.

5. A systematic review and meta-analysis of adverse events in randomized trials of intra-articular PRP for knee osteoarthritis found PRP associated with mild, transient adverse events - knee pain and swelling - that typically resolve without intervention, and more frequent with LEUKOCYTE-RICH formulations. Leukocyte-poor PRP had a safety profile similar to hyaluronic acid. Knee stiffness was more frequent with PRP than with normal saline (P=.031). No severe adverse events were reported in any group.

   Nakagawa HF, Kim J, Rabinowitz J, et al. — Assessment of adverse events and safety associated with intra-articular platelet-rich plasma injections compared to other injectates for knee osteoarthritis: A systematic review and meta-analysis. PM&R, 2026. DOI: 10.1002/pmrj.70141.

6. The devices used to spin PRP at the point of care are cleared by FDA as clinical centrifuges, product code JQC, a Class I device under 21 CFR 862.2050 - for example the Biomet GPS Platelet Separation Kit (K030555, cleared 2003) and the Harvest SmartPrep2 / SmartPrep Platelet Concentration System (K103340, cleared 2010). That clearance covers the equipment that separates blood. It is not an FDA approval of platelet-rich plasma as a treatment for osteoarthritis, tendinopathy or any other orthopedic condition, and copy must never blur the two.

   U.S. Food and Drug Administration (Center for Devices and Radiological Health) — 510(k) Premarket Notification database and Product Classification: JQC, Centrifuges (Micro, Ultra, Refrigerated) For Clinical Use, 21 CFR 862.2050. FDA accessdata (CDRH device databases), 2003.