What is a PRP injection?

What is a PRP injection?


What is PRP?

Platelet rich plasma (PRP) is a kind of injectable treatment know as a biologic. PRP is an injection of a concentration of the patient’s own plasma, which is especially rich in platelets.

The primary role of platelets is to bring about blood clotting, but they also release bioactive substances such as growth factors, which can stimulate healing and tissue regeneration.


PRP injections can be used to treat many musculoskeletal conditions

Achilles tendinopathy

Patella tendinopathy

Hamstring tendinopathy

Gluteal tendinopathy

Ligament injuries

Tennis elbow

Golfer's elbow

Plantar fasciitis

Rotator cuff tears

Muscle tears

Knee osteoarthritis

Hip osteoarthritis

Shoulder arthritis

Ankle arthritis

PRP isn’t suitable for patients who have advanced osteoarthritis, or who may be considering joint replacement surgery in very near term. It’s also contraindicated in pregnant patients, or patients who are on anticoagulation therapy or who have a bleeding disorder.


What happens during the PRP injection procedure?

Blood is drawn off from a patient’s vein, and is spun in a centrifuge to separate out the heavy red blood cells from the plasma and platelets. It's then passed through a special sieve to remove the red blood cells, leaving a concentrate of plasma that contains a high amount of platelets, glycoproteins, growth factors and cytokines. The PRP is then injected into the joint or soft tissues that are being treated.

spinning whole blood in a centrifuge

Spinning whole venous blood in a centrifuge

PRP from whole spun blood

PRP separated off from whole spun blood

What are the advantages of PRP?


PRP is entirely natural and drug free, which significantly reduces the risk of adverse side effects (such as allergic reactions). The risk of an infection occurring after a PRP injection is less than one in a thousand, and PRP can be repeated on several occasions. Minimal discomfort might occur in the first 48 hours after a PRP injection, but patients consider it to be highly tolerable. PRP is quick to act; results can be expected after just two weeks, and I recommend that a course of 3 injections are administered, spaced at weekly intervals.


Traditional injections such as cortisone can be helpful to reduce pain and swelling in joints, but multiple injections can lead to weakening of soft tissues, damage to articular cartilage and systemic effects, such as a reduction in bone mineral density.


PRP can be a good alternative to painkilling medications such as anti-inflammatory medications (NSAIDS), and PRP injections are particularly helpful for patients who are suffering from mild osteoarthritis and who wish to avoid surgery. It can also be a good option for patients who are not responding to physiotherapy.



How successful is PRP injection therapy?


There is an increasing amount of research data to support the use of PRP, particularly its used in treating knee osteoarthritis. Patients with knee osteoarthritis who were treated with PRP injections experienced a reduction in pain and stiffness, and an increase in knee function which lasted for six months. Additionally, one year after undergoing in the PRP injection treatment, most patients had less pain than they did they year before, and MRI imaging showed that the arthritis process hadn’t progressed in the majority of the patients.


PRP has been used to treat many high-profile athletes such as Tiger Woods, Kobe Bryant and Alex Rodriguez, and it’s permitted by the World Anti-Doping Agency (WADA) in professional sport.


PRP tends to work best as a treatment that complements a rehabilitation programme, and because it has almost no long-term disadvantages, many patients choose to repeat the PRP injections as part of a long-term strategy for managing their condition.


Professor Ali Ghoz is a Consultant Knee & Hip Trauma and Orthopaedic Consultant.

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