Written and clinically reviewed by Jeremy Swisher, MD
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“Orthobiologic” is a category, not a promise.
The term is used for a range of biologically derived products intended to influence a joint, tendon, muscle, ligament, or bone environment. Definitions and terminology are not fully standardized, so the exact product and intended goal should always be stated.
Platelet-rich plasma
PRP is an autologous orthobiologic prepared from your own blood. It contains concentrated platelets in plasma, but it is not a stem-cell treatment.
Cell, tissue, and exosome products
Products described as bone marrow-derived, adipose-derived, amniotic, umbilical, or exosome-based differ substantially in composition, processing, evidence, and regulatory status.
Related injection options
Some resources include viscosupplementation within a broad orthobiologics category. This site discusses hyaluronic acid separately as a related, non-cell option with different evidence, labeling, cost, and coverage.
Biologic does not automatically mean regenerative.
A treatment may aim to change symptoms or the local biologic environment without regrowing cartilage, restoring a torn structure, or reversing the underlying disease.
Diagnosis-specific evidence
PRP can be reasonable for selected patients, but not for every condition.
Knee osteoarthritis
This is the most extensively studied PRP application. Pooled meta-analyses often report average benefit, while some rigorous saline-controlled trials have been negative. The 2026 AAPM&R guidance supports considering PRP for selected patients with mild-to-moderate knee osteoarthritis who remain symptomatic after core conservative care.
Read the evidence, candidacy, dose, medication, and aftercare guide
Persistent tendon conditions
For selected persistent tendon conditions, PRP may be discussed after the diagnosis is clear and an adequate progressive loading program has not provided enough improvement. Evidence remains mixed and tendon-specific, and high-quality placebo-controlled trials have not shown benefit for some conditions. PRP should not replace rehabilitation.
Other musculoskeletal uses
Evidence is limited, inconsistent, or negative for many joints, muscles, ligaments, and acute injuries. A result from one diagnosis should not be generalized to another body part or condition.
PRP should be discussed as an optional symptom-focused treatment, not as a guaranteed cure. The intended outcome should be concrete, such as improving pain, function, training tolerance, or participation.
PRP quality
The letters “PRP” do not describe one standardized product.
Preparation systems can produce meaningfully different platelet doses, volumes, and cell compositions. Product characterization makes the treatment easier to interpret and more reproducible.
How many platelets?
Final platelet concentration and injected volume can be used to calculate total deliverable platelets. Concentration alone is incomplete.
What else is present?
Leukocytes, neutrophils, and red blood cell contamination can distinguish biologically different preparations.
What is the full protocol?
Preparation method, injection number, image guidance, aftercare, and rehabilitation all affect how a treatment should be understood.
Knee osteoarthritis
Ten billion platelets is a consensus-based best-practice target, not a universal cutoff.
The 2026 AAPM&R guidance identifies at least 10 billion total deliverable platelets as a best-practice target for knee osteoarthritis. Current evidence does not prove that this number guarantees success, that a slightly lower dose cannot work, or that more is always better. The target should not be generalized to tendon injections or other joints.
Claims and safety
Be specific about what is being offered.
- PRP is not a stem-cell injection. It is a blood-derived product prepared from the patient receiving it.
- Device clearance is not the same as treatment approval. FDA clearance of a preparation device does not prove that the resulting injection treats a particular orthopedic diagnosis.
- Unapproved products deserve extra caution. The FDA warns that stem-cell, adipose-derived, umbilical, amniotic, and exosome products marketed for orthopedic conditions may be unapproved and can carry serious risks.
- Marketing terms are not product descriptions. Ask for the source, processing, composition, regulatory status, evidence for the exact diagnosis, cost, and alternatives.
Autologous does not mean risk-free.
Temporary soreness or swelling is common. Bleeding or bruising, infection, injury to nearby structures, and a fainting reaction are uncommon but possible. Seek prompt assessment for fever, rapidly worsening pain or swelling, spreading redness or warmth, or drainage.
Do not stop a medicine or supplement on your own.
Never stop prescribed aspirin, an antiplatelet medicine, or an anticoagulant without coordination with the prescribing and procedural clinicians. Review nonsteroidal anti-inflammatory drugs and supplements too. Exact stop windows are medicine-specific, and evidence that a particular window changes PRP outcomes remains limited.
The consultation
Begin with a diagnosis and a decision, not an injection order.
- 01
Confirm the pain generator
Review the history, examination, imaging when useful, and whether the proposed target plausibly explains the symptoms.
- 02
Review foundational care
Discuss activity planning, rehabilitation, health factors, medication options, and whether more time or a different diagnosis-specific plan is appropriate.
- 03
Compare options honestly
Clarify expected benefit, uncertainty, alternatives, risks, cost, insurance coverage, product availability, and what would count as a useful response.
- 04
Build the aftercare plan
Set activity limits, pain guidance, follow-up, and a progressive loading plan before returning to higher-demand movement or sport.
A consultation does not guarantee a same-day injection. Bring prior images and reports, a complete medication and supplement list, details of prior injections, rehabilitation notes, and the activities you most want to restore.
Common questions
Orthobiologics and PRP FAQs
What are orthobiologics?
Orthobiologics is an umbrella term for biologically derived products used with the goal of influencing a musculoskeletal environment. Definitions vary. This website focuses on platelet-rich plasma prepared from your own blood.
Is PRP a stem-cell treatment?
No. Platelet-rich plasma is prepared from your own blood and concentrates platelets in plasma. It is not a stem-cell injection.
Does PRP regrow cartilage?
PRP may improve pain and function for some patients with knee osteoarthritis, but it has not been shown to reliably regrow cartilage, reverse arthritis, or prevent future joint replacement.
Is hyaluronic acid an orthobiologic?
Definitions vary. Some orthopedic resources include viscosupplementation within a broad orthobiologics category. This site discusses hyaluronic acid separately as a related, non-cell viscosupplementation option because it is distinct from autologous PRP and has different product-specific evidence, labeling, cost, and coverage. Read the hyaluronic acid guide.
Are stem-cell or exosome injections offered as routine orthopedic treatments?
This website does not present stem-cell, adipose-derived, umbilical, amniotic, or exosome products as routine treatments. Ask any clinic to identify the exact product, source, processing, regulatory status, evidence for your diagnosis, and known risks.
Where can I see Dr. Swisher to discuss PRP?
Dr. Swisher evaluates patients at UCLA Health locations in Westwood and West Hills. Call 310-319-1234 for the most direct scheduling path. Candidacy, product availability, cost, and timing are reviewed first, so a procedure is not guaranteed at the initial visit.
Evidence
Sources and further reading
These sources include guidance, supportive evidence, negative evidence, and regulatory information.
- AAPM&R: Platelet-Rich Plasma for Knee Osteoarthritis Guidance, 2026
- Borg-Stein et al.: AAPM&R Guidance Statement on PRP for Knee Osteoarthritis, 2026
- Bensa et al.: PRP for Knee Osteoarthritis Meta-analysis of Placebo-Controlled Trials, 2025
- Bennell et al.: RESTORE Randomized Clinical Trial, 2021
- Nadeau-Vallée et al.: PRP as Second-Line Treatment After Failed Conservative Care for Chronic Tendinopathy, 2025
- Nelson et al.: An Update on Orthobiologics: Cautious Optimism, 2024
- FDA: PRP Device Clearance and Unsupported Treatment Claims, 2026
- FDA Consumer Warning About Regenerative Medicine Therapies, 2021
Evidence and recommendations can change. This page is educational and does not establish whether PRP or another procedure is appropriate for a particular patient.