PRP Injections for Joint, Tendon, and Ligament Injuries
Learn how platelet-rich plasma (PRP) injections may be used for joint pain, osteoarthritis, tendon and ligament injuries, including how PRP works, recovery and what to expect.
Platelet-Rich Plasma (PRP) Injections: What You Need to Know
Musculoskeletal injuries can be frustrating, especially when pain continues despite rest, physiotherapy, rehabilitation, or other conservative treatments. For certain joint, tendon, and ligament conditions, platelet-rich plasma (PRP) injections may be considered as part of a comprehensive treatment plan.
PRP therapy uses a concentrated portion of a patient's own blood containing platelets and other biologically active components involved in the body's natural healing response. It is increasingly used in sports medicine and musculoskeletal care for conditions such as osteoarthritis, chronic tendon injuries, ligament injuries, and other persistent musculoskeletal concerns.
PRP is not appropriate for every injury, and results can vary depending on the condition being treated, severity of the injury, PRP preparation, and individual patient factors. Understanding how PRP injections work and what to expect can help you decide whether they may be worth discussing with your healthcare provider.
What Are PRP Injections?
PRP stands for platelet-rich plasma. Platelets are components of the blood that are best known for helping with clotting, but they also contain growth factors and signaling proteins involved in tissue repair.
During a PRP treatment, blood is drawn from the patient and processed using a centrifuge. This separates the blood into different components and allows a platelet-concentrated portion of the plasma to be collected.
The PRP is then injected into the targeted joint, tendon, ligament, or other injured tissue.
According to the American Academy of Orthopaedic Surgeons (AAOS), PRP has been investigated for a variety of orthopedic conditions, particularly chronic tendon injuries and osteoarthritis.
How Do PRP Injections Work?
PRP is intended to deliver a concentrated number of platelets and their associated growth factors directly to an injured or degenerative area.
When tissue is injured, the body naturally initiates a complex healing response. Platelets participate in this process by releasing signaling molecules involved in cellular communication, collagen production, tissue remodeling, and regulation of inflammation.
PRP treatment attempts to concentrate these components at the area being treated.
This is different from an injection that is primarily intended to temporarily block pain or suppress inflammation. PRP is used with the goal of influencing the local healing environment over time.
For this reason, PRP should not necessarily be expected to provide immediate pain relief. When patients do respond to treatment, improvement may develop gradually over the following weeks/months.
What Musculoskeletal Conditions Can PRP Be Used For?
Some of the more commonly treated musculoskeletal concerns include:
• Osteoarthritis, particularly knee osteoarthritis
• Chronic tendinopathy or tendon injuries
• Rotator cuff and shoulder tendon problems
• Tennis elbow and golfer's elbow
• Patellar and Achilles tendinopathy
• Certain ligament injuries and sprains
• Some sports-related soft-tissue injuries
Research has been particularly focused on chronic tendinopathies and knee osteoarthritis. The AAOS notes that some of the stronger evidence for PRP has been seen in certain chronic tendon conditions, while research for many other applications continues to evolve. Read the AAOS overview of PRP here.
This is why an accurate diagnosis is important before deciding whether PRP is appropriate.
Who May Be a Good Candidate for PRP?
PRP may be considered when someone has a clearly identified musculoskeletal condition that has not adequately improved with appropriate conservative care.
However, pain alone does not determine whether someone is a good candidate for PRP.
The type of injury, degree of tissue damage, medical history, medications, overall health, previous treatments, and rehabilitation history should all be considered.
For example, chronic tendinopathy is very different from a complete tendon rupture, and mild to-moderate osteoarthritis requires a different treatment approach than advanced joint degeneration.
What Happens During a PRP Injection?
The exact procedure varies depending on the PRP system and area being treated, but the general process involves three steps.
1. Blood collection: The amount of blood drawn varies from case to case.
2. PRP preparation: The blood is placed in a centrifuge to separate and concentrate the platelet rich portion.
3. Injection: The prepared PRP is injected into the targeted joint, tendon, ligament, or other injured tissue.
The entire process uses blood collected from the patient rather than donated blood or synthetic growth factors.
Johns Hopkins' Musculoskeletal Center describes PRP as a minimally invasive, non-surgical treatment used for certain musculoskeletal injuries and chronic conditions.
What Is Recovery Like After a PRP Injection?
Soreness or temporary discomfort following a PRP injection is common. The amount of discomfort and recommended activity modification depend on the structure being treated.
Unlike treatments designed primarily to provide immediate pain relief, PRP may require time before improvement becomes noticeable.
After treatment, patients may temporarily modify activity before gradually returning to exercise and rehabilitation. This may include working with a team: physiotherapists, chiropractors, kinesiologists, etc.
For tendon and ligament injuries in particular, PRP is generally best viewed as one component of a broader rehabilitation plan, rather than a replacement for strengthening and progressive loading.
Post-PRP rehabilitation protocols vary considerably between studies and conditions. A 2024 review examining post-injection protocols for PRP in knee osteoarthritis found substantial variation in post-treatment recommendations, highlighting the importance of individualized aftercare.
How Many PRP Injections Are Needed?
There is no universal PRP protocol that applies to every injury.
Some conditions may be treated with a single PRP injection, while other patients may benefit from additional treatments.
The appropriate number of injections depends on the diagnosis, severity of the condition, treatment protocol, and response to the initial treatment.
Research also continues to investigate how differences in platelet concentration, PRP composition, and dosing may influence treatment outcomes. For example, a systematic review examining PRP dose in knee osteoarthritis found that platelet dose may be one factor influencing clinical outcomes.
Are PRP Injections Safe?
Because PRP is prepared from the patient's own blood, the injected PRP itself has a low risk of allergic reaction. However, every injection procedure carries potential risks.
These may include:
• Temporary pain or soreness
• Bruising or bleeding
• Temporary worsening of symptoms
• Infection
• Irritation of surrounding tissues
• Injury to nearby structures
Certain medical conditions, medications, blood disorders, or active infections may also influence whether PRP is appropriate.
A thorough medical history and physical assessment should therefore be completed before treatment.
What Does the Research Say About PRP?
PRP is an active area of musculoskeletal research, and evidence continues to evolve.
Current evidence suggests that PRP may improve pain and function for certain musculoskeletal conditions, with knee osteoarthritis and some chronic tendon disorders being among the better studied applications. However, PRP results cannot automatically be generalized to every type of injury.
One of the challenges with PRP research is that PRP is not a single standardized product. Studies can differ in platelet concentration, white blood cell concentration, preparation method, number of injections, injection technique, and rehabilitation protocol. Research examining PRP protocols has repeatedly highlighted this variability.
PRP should therefore not be viewed as a treatment that guarantees tissue regeneration or completely reverses joint degeneration.
Instead, the available research should be considered alongside the specific diagnosis, individual patient, severity of injury, and overall treatment plan.
Rather than asking whether PRP is a good treatment in general, a better question is:
Is PRP an appropriate treatment for this specific injury, for this particular patient, at this stage of recovery?
If you are experiencing persistent joint, tendon, or ligament pain and would like to determine whether PRP injections may be appropriate for your condition, consider booking a musculoskeletal assessment to discuss your diagnosis and treatment options.
References & Further Reading:
1. American Academy of Orthopaedic Surgeons (AAOS). Platelet-Rich Plasma (PRP). https://orthoinfo.aaos.org/en/treatment/platelet-rich-plasma-prp/
2. Johns Hopkins Medicine. Platelet-Rich Plasma (PRP) Injections.
https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/plateletrich plasma-prp-treatment
3. Johns Hopkins Musculoskeletal Center. Musculoskeletal Platelet-Rich Plasma Injections. https://www.hopkinsmedicine.org/musculoskeletal-center/platelet-rich-plasma injections
4. Mende E, et al. (2024). A Comprehensive Summary of the Meta-Analyses and Systematic Reviews Evaluating Platelet-Rich Plasma Treatment of Knee Osteoarthritis. https://pubmed.ncbi.nlm.nih.gov/38421752/
5. Levine OP, et al. (2024). Postinjection Protocols Following Platelet-Rich Plasma Administration for Knee Osteoarthritis: A Systematic Review.