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Platelet Rich Plasma (PRP)

PRP injection are gaining popularity especially in sports medicine.  PRP is a form of regenerative therapy also known as Orthobiologics. 

This page has been written to help you understand the science and evidence behind PRP treatment to help you make an informed choice.

Generally PRP therapy is not covered by major insurers at present.

What is PRP?

PRP Stands for Platelet Rich Plasma. Blood is composed of a liquid component known as plasma and cells called  Platelets, White cells & Red cells.

Platelets are important for blood clotting and healing. White cells are important in inflammation and immunity. Red cells are important for carrying oxygen around your body.

PRP contains concentrated platelets (upto 500%) and  growth factors that play a vital role in initiating tissue repair and regeneration. Different growth factors accelerate new blood, connective tissue repair and inflammation/ tissue healing.

How is PRP performed?

15 ml of bloods is taken from one your veins in your arm using a needle and syringe. The blood is then spun in a centrifuge to separate the plasma, platelets and other cells. 

The PRP layer is siphons from the top using a syringe ready for injecting into the site under ultrasound guidance. 

It is important to be aware that different systems produce differing PRP concentrations of platelets and white cells.

How does PRP work? What is the Science behind it?

Platelets have a key role in clotting to stop bleeding 'Haemostasis'. Clotting can be thought of the first step of tissue healing. 

Bioactive signalling proteins, granules and growth factors are released by platelets when activated to promote tissue healing.

The interaction between these growth factors and surface receptors on target cells activates signalling pathways that induce production of proteins needed for the regenerative processes such as cellular proliferation(increase in cell number), matrix formation (Scaffold that forms tendons) and collagen synthesis (micro strands of tissue that forms tendons).


Laboratory studies have demonstrated under the microscope increase in cell numbers (Fibroblasts), Collagen production and  increased gene expression of matrix molecules (proteoglycans and glycoproteins) in damaged tendons with PRP.

However, while it may seem logical that plasma with the highest possible platelet concentration will get better results than plasma with a lower platelet concentration, studies have shown that this is not necessarily the case. If plasma concentration is too high it may inhibit cell growth.

​Furthermore, the exact role of White blood cells is unclear and the proportion of White blood Cells (Leucocytes) varies on the type of PRP system used.  Recent meta-analyses (Analysis of multiple studies) of PRP use identified that leukocyte-rich PRP had a strongly positive outcome in the treatment of tendinopathies (worn tendons). [Fitzpatrick J, Bulsara M, Zheng MH. The effectiveness of platelet-rich plasma in the treatment of tendinopathy: a meta-analysis of randomized controlled clinical trials [published online June 6, 2016]. Am J Sports Med. doi:10.1177/0363546516643716]

However, there may also be negative effects from these white blood cells in causing further inflammation, leading to fibrosis. A healthy immune system depends on white blood cells, but the cells’ role in PRP therapy is unclear.

What conditions is PRP used to treat?

In relation to musculoskeletal conditions PRP has been used in the treatment of conditions relating to pain caused by tendons and joints.

Tendon damage is commonly referred to as tendinitis, tendinosis, or tendinopathy. Tendinitis is an inflammatory condition, but research has shown that most tendon injuries do not exhibit inflammation. Rather, the primary problem appears to be a breakdown (degeneration) of the structural composition (collagen), strength, and stability. In some cases this degeneration results in tendon tears. Medical professionals describe this tendon degeneration as tendinosis or tendinopathy.

In relation to joints, cartilage damage that causes pain and stiffness in joints is called osteoarthritis. Pain is caused by the inflammation in the joint and the stiffness by the worn out cartilage.

The theoretical aim of PRP is to help regenerate the damaged tendons or cartilage. 

Are PRP injections effective & what is the evidence?

The evidence relating to clinical use of PRP is difficult to conclusively interpret as outcome varies depending on the preparation method and composition of the PRP, underlying medical condition, location on the body and tissue type.

Never the less, although there is growing evidence for the efficacy of PRP, there is no conclusive high quality evidence at present and studies show conflicting results.

What is certain is that PRP does not work on everyone and not in all conditions currently used for. 

There is no conclusive evidence to support one type of PRP method over another and no conclusive evidence to support PRP use over standard treatment with Cortisone.

However, PRP is very safe and offers an alternative to steroid injections in certain conditions without the small risks associated with steroids. 

Patient with orthopedist doctor in his office. Elbow sonography..jpg

Tennis Elbow:

The body of evidence for the efficacy of PRP in the treatment of recalcitrant Tennis elbow is growing. Studies have shown conflicting results when compared with placebo and steroids. In terms of grading scientific quality there are very few good quality studies  out there making any certain conclusion about PRP efficacy difficult. 

Meta-analysis which synthesise data from multiple studies have drawn different conclusions. One Meta-analysis paper concluded no difference in outcome when compared to steroid, another no conclusions could be drawn either to support or refute PRP use, one other did not support use of PRP or even physiotherapy and one supported PRP treatment for Tennis elbow. 


A recent well designed study from the UK found 70% of patients treated with platelet-rich plasma avoided surgical intervention. PRP and surgery produce equivalent functional outcome but surgery may result in lower pain scores at 12 months.

[Watts, A. C., Morgan, B. W., Birch, A., Nuttall, D., & Trail, I. A. (2020). Comparing leukocyte-rich platelet-rich plasma injection with surgical intervention for the management of refractory tennis elbow. A prospective randomised trial. Shoulder & elbow, 12(1), 46–53.]

This is keeping with my own experience and outcome data (unpublished) using PRP for the treatment of Tennis elbow.

Reference links:

Golfers elbow:

Golfers elbow is much less common than Tennis elbow and this is reflected by the lack of studies looking specifically at the use of PRP in Golfers elbow. One study assessed PRP against cortisone injections for the treatment of both Golfers and Tennis elbow (epicondylitis). The authors reported at Six months after treatment with PRP, patient's with elbow epicondylitis had a sustained improvement in pain and function in contrast to steroid, which worn off after 2-3 months.



Biceps tendinitis/ tendinopathy:

There are very few studies assessing the use of PRP for biceps related pain. Of the few studies that are available they have demonstrated improvement in pain after PRP for biceps tendinopathy. However, the evidence is not completely clear to make firm conclusions about PRP being better then Cortisone injections. One advantage of PRP is negating the risk, albeit low, of tendon rupture which is associated with cortisone injection into the biceps.

Reference links:

Rotator cuff tendinopathy:

Several studies have reported improvement in patient outcomes for rotator cuff tendonitis after 3 weeks of PRP injection versus a placebo injection. The overall impact of PRP in relation of what is considered important by clinicians was small but much better in the longer term compared to other injection treatments. 


Rha DW, Park GY, Kim YK, Kim MT, Lee SC. Comparison of the therapeutic effects of ultrasound-guided platelet-rich plasma injection and dry needling in rotator cuff disease: a randomized controlled trial. Clinical rehabilitation. 2013 Feb;27(2):113-22.

Sari A, Eroglu A. Comparison of ultrasound-guided platelet-rich plasma, prolotherapy, and corticosteroid injections in rotator cuff lesions. Journal of back and musculoskeletal rehabilitation. 2020 Jan 1;33(3):387-96.

Kesikburun S, Tan AK, Yilmaz B, Yasar E, Yazicioglu K. Platelet-rich plasma injections in the treatment of chronic rotator cuff tendinopathy: a randomized controlled trial with 1-year follow-up. The American journal of sports medicine. 2013 Nov;41(11):2609-16.


There is no current evidence to show any benefit of PRP in mild to moderate osteoarthritis. The is no evidence demonstrating cartilage regeneration of joint surfaces with PRP. 

Reference links:


Common questions:

Is PRP painful?

PRP is relatively more painful than a Cortisone injection and not suitable if you are needle phobic.

Will you use Local Anaesthetic?

Yes to numb the skin around the injection site.

How long does the procedure take?

20 mins

Do I need more than one injection?

There is no conclusive evidence to demonstrate multiple PRP injections have more therapeutic benefit than a single.

Is physiotherapy important after procedure?

Yes. Rehabilitation helps the damaged tendon fibres to remodel and strengthen.

When can I return to sports?

Generally I advice patient to avoid sports for at least 2 weeks and then return to play gradually between 3-6 weeks. It is important to focus on sports specific drills and technique during this phase of your recovery. Return to competitive play is very much based on individual symptoms and competition pressures. 

When can I return to manual work?

Generally 6 weeks is advisable to avoid repetitive manual work or heavy lifting. 

How long will the PRP last?

This is different for each person and specific conditions. Patients generally fall into three groups; No improvement, Some temporary improvement (3 months or less) or lasting improvement (6- 12 months or more).

Keeping you moving

Contact us for information on self pay packages for ultrasound guided PRP injections

0118 33 88 277

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