Platelet-Rich Plasma (PRP) Therapy

Overview

Platelet-rich plasma (PRP) therapy typically involves drawing a small amount of a patient’s blood, concentrating platelets with a centrifuge, and injecting the platelet-rich portion into a targeted tissue area. It may be used in some musculoskeletal conditions such as certain tendon disorders, mild-to-moderate osteoarthritis symptoms, or sports-related soft-tissue injuries, and it can also be used in some dermatologic and wound-related settings. The goal often involves supporting the body’s natural healing response through platelet-derived growth factors and signaling proteins. Outcomes can vary, and the overall evidence base generally remains mixed across conditions, preparation methods, and injection protocols.

Indications

This procedure may be considered when:

• •Chronic tendinopathy that may include lateral epicondylitis (tennis elbow) or patellar tendinopathy, particularly when conservative care has had limited benefit
• •Plantar fasciitis symptoms that can persist despite initial non-procedural management
• •Mild-to-moderate knee osteoarthritis symptoms where injection therapy may be considered as part of a broader management plan
• •Rotator cuff tendinopathy or partial-thickness tendon injury in selected cases, often as an adjunct to rehabilitation
• •Muscle strain injuries in some sports medicine settings, although evidence can vary by injury type and timing
• •Adjunct use in certain surgical contexts (for example, some orthopedic procedures) where biologic augmentation may be considered, recognizing variable evidence
• •Selected dermatologic applications (for example, some hair loss protocols) in specialized settings, with variable evidence and protocol differences

How It Works

The procedure typically involves several coordinated steps:

• •Venous blood is collected into a sterile container or tube system, often with an anticoagulant to reduce premature clotting during processing.
• •Centrifugation separates components by density, typically producing a red blood cell layer, a buffy coat (leukocytes/platelets), and plasma fractions.
• •The platelet-rich fraction is isolated; the final platelet concentration can vary widely by device, spin parameters, and whether buffy coat is included.
• •PRP can be characterized as leukocyte-rich or leukocyte-poor, and this composition may influence inflammatory signaling and post-injection soreness.
• •Some protocols can include activation (for example, with calcium chloride or thrombin) to promote platelet degranulation; other protocols rely on in vivo activation after injection.
• •After injection, platelets can release growth factors and cytokines (for example, PDGF, TGF-β, VEGF) that may influence chemotaxis, angiogenesis, and extracellular matrix remodeling.
• •Local signaling may modulate inflammation and pain pathways, although the direction and magnitude of effect can differ by tissue type and PRP formulation.
• •In tendon applications, needling/fenestration can create microtrauma that may stimulate a repair response; PRP is often used as a biologic adjunct to this process.
• •In intra-articular use (for example, knee osteoarthritis), PRP may influence synovial environment and cartilage homeostasis signaling, with variable clinical correlation.
• •Clinical response often depends on underlying pathology, chronicity, rehabilitation participation, injection accuracy, and PRP preparation variability.
• •Because PRP is autologous, immunologic incompatibility is generally less likely than with donor-derived products, although local reactions can still occur.

Risks

As with any surgical procedure, potential risks include:

• •Injection-site pain or flare reaction that can occur in the first several days, particularly with some tendon protocols or leukocyte-rich preparations
• •Bleeding or bruising at the blood draw site or injection site, especially in patients with bleeding risk factors
• •Infection at the injection site, which is uncommon but can be clinically significant if it occurs
• •Nerve irritation or injury related to needle placement, which may cause transient numbness, tingling, or pain
• •Vascular injury or hematoma formation, particularly in anatomically complex regions
• •Allergic or sensitivity reactions to antiseptics, local anesthetics, or additives used in some preparation/activation protocols (rather than to PRP itself)
• •Worsening of symptoms or lack of improvement, reflecting variable response and mixed evidence across conditions
• •Tendon injury progression or rupture risk in vulnerable tendons, which may relate to underlying disease severity and activity factors rather than PRP alone
• •Post-procedure stiffness or swelling, particularly after intra-articular injection
• •Rare systemic symptoms such as lightheadedness or vasovagal response during blood draw or injection

Recovery Expectations

Recovery follows a gradual progression:

• •Day 0: Observation typically spans minutes to a short period after the injection to monitor for immediate reactions such as dizziness or significant pain.
• •Days 1–3: Local soreness, swelling, or a flare reaction can occur and may gradually lessen; activity modification is often discussed for the treated region.
• •Week 1: Many patients can resume light daily activities, depending on the injection site and clinician protocol; wound care generally involves keeping the injection site clean and dry for a short span.
• •Weeks 2–4: Symptom changes can begin to appear in some conditions; structured rehabilitation or physical therapy may be introduced or progressed depending on indication.
• •Weeks 4–8: Functional improvement may become more noticeable in some tendon and joint indications, although response can vary widely.
• •Weeks 8–12: Some protocols assess response and consider whether additional injections may be appropriate; imaging is not typically required unless symptoms change or complications are suspected.
• •Months 3–6: Longer-term outcomes are often evaluated in chronic tendinopathy and osteoarthritis studies, with variable durability and magnitude of benefit.

Alternatives

Depending on individual circumstances, alternatives may include:

• •Activity modification and structured physical therapy/rehabilitation programs tailored to the affected tissue
• •Oral or topical pain-relief medications that can be used in some patients, depending on overall health context and clinician guidance
• •Corticosteroid injection for selected inflammatory conditions, recognizing that benefits and risks can vary by tissue and timing
• •Hyaluronic acid injection for knee osteoarthritis symptoms in selected patients, with variable guideline support and outcomes
• •Dry needling or percutaneous needle tenotomy techniques for certain tendinopathies
• •Extracorporeal shock wave therapy for selected tendon and plantar fascia conditions
• •Surgical options (for example, tendon debridement/repair or arthroscopic procedures) when non-surgical measures have had limited benefit and pathology is appropriate

Sources

• American Academy of Orthopaedic Surgeons (AAOS) OrthoInfo - Platelet-Rich Plasma (PRP)
• Cleveland Clinic - Platelet-Rich Plasma (PRP) Injections
• Mayo Clinic - Platelet-rich plasma (PRP) therapy (overview of use and evidence considerations)