What is Platelet Rich Plasma?
Platelet rich plasma is platelet plasma fraction of blood drawn from patient [autologous blood] which contains concentrated platelet and used as orthobiologics to treat many musculoskeletal conditions. It appears promising and popular therapy.
In this article, we try and look for effectiveness and recommendations as based on evidence available in the literature.
Platelet rich plasma is also known by the names of
- Platelet-enriched plasma
- Platelet-rich concentrate
- Autogenous platelet gel.
Normal platelets in Human Body
The normal platelet count in whole blood in a healthy individual is between 150,000 to 450,000 platelets per microliter of blood
Platelet rich plasma contains 4-5 times of the baseline platelets.
Platelet are formed from megakaryocytes in the bone marrow.
How is Platelet Rich Plasma Prepared?
For preparation of platelet rich plasma, blood is drawn into a bag or tube containing an anticoagulant. Then it is centrifuged to separate the red cells from rest of components.
Then the platelets are separated from the red cells and platelet poor. This is platelet rich plasma which is also rich in white blood cells. It is termed as leukocyte- rich platelet rich plasma.
This concentrate when passed through a leukocyte filter gives us leucocyte poor platelet rich plasma.
Both kinds of platelet rich plasma are used though few studies have suggested that use of leucocyte poor platelet rich plasma may be associated with lesser pain as leucocyte induce inflammation at the injection site.
Platelet rich plasma can be used in activated and non activated form.
The activation process consists of simultaneous application of calcium chloride.
In case of use of nonactivated platelets, the platelets get activated after they come in contact with collagen of the tissue.
How does platelet rich plasma act
Platelet rich plasma is a kind of orthobiologic substance. That means it supplies the essential growth factors that hasten the tissue healing.
Applications in Musculoskeletal Conditions
Platelet rich plasma has been used in diverse orthopedic and non orthopedic conditions. It has been used in variety of orthopedic conditions
- Lateral epicondylitis
- Rotator cuff tears
- Sub-acromial impingement
- Shoulder osteoarthritis
- Patellar tendinosis
- Osteoarthritisof the knee
- Tendo- Achilles tears
- ACL reconstruction
- Plantar fasciitis
- Fracture nonunion of bones
Few conditions, where more work has been done in literature are discussed below.
Common orthopedic usage of platelet rich plasma is discussed below.
Lateral epicondylitis is a kind of tendinosis. A significant number of patients do not respond to conventional treatment in spite of good response rate.
The patients who could potentially have significant benefit from platelet rich plasma. Many studies have reported it to be effective.
An ideal candidate for this treatment is one who does not show improvement with conventional treatments and in whom a surgical treatment option is being considered.
Rotator Cuff Injuries
Rotator cuff tears occur in young as well as old persons. But there is a difference of causation.
Hyperactiviry or repetitive injuries are thought to cause rotator cuff tear in young people and is most common in young sports persons.
In the older population, degenerative changes are responsible for the tear.
Distal part of the rotator tendon has inherently poor healing capabilities. Platelet rich plasma with its growth factor may thus be an attractive option for the stimulation of the healing of this tendon.
Some physicians use platelet rich plasma after performing rotator cuff repair.
But the enough evidence and thus recommendation for this use are yet not available.
Osteoarthritis of knee
Osteoarthritis of knee is a degenerative disease resulting from gradual and progressive destruction of the articular cartilage. This is meditated by metalloproteinases which are produced by chondrocytes. Growth factor contained in alpha granules of platelet have been postulated to be cartilage protective and PRP has been used in an attempt to slow down progression of the disease.
But a definite recommendation cannot be made at this stage. Longer follow ups and more studies would make the picture clearer.
Achilles tendinopathy is known to be difficult to heal and platelet rich plasma has been used in attempt to hasten the healing but the results are not very encouraging.
Still there are mixed results from different studies and bigger studies avoiding the limitations of smaller unorganized may hold the final answer.
Jumper‘s knee or patellar tendinosis in athletes is a common cause of knee pain. Though studies claim good results but level of evidence is low.
Future of Platelet Rich Plasma
A look at different conditions and plasm use shows that, platelet rich plasma cannot be recommended with confidence in any condition yet though it seems to hold a lot of promise.
Lack of adequately powered studies is an important issue preventing their recommendation for routine use.
It is still an attractive option because of
- Minimal side effects
- Relative ease of preparation
- Cost effectiveness
- Shorter hospital stay
The need of the time is to have more studies which are better organized, trials without biases which can provide high level of evidence.
- Paoloni J, De Vos RJ, Hamilton B, Murrell GA, Orchard J. Platelet-rich plasma treatment for ligament and tendon injuries. Clin J Sport Med. 2011;21:37–45.
- Alsousou J, Thompson M, Hulley P, Noble A, Willett K. The biology of platelet-rich plasma and its application in trauma and orthopaedic surgery: A review of the literature. J Bone Joint Surg Br. 2009;91:987–96.
- Filardo G, Kon E, Di Martino A, DiMatteo B, Merli ML, Cenacchi A, et al. Platelet-rich plasma vs hyaluronic acid to treat knee degenerative pathology: Study design and preliminary results of a randomized controlled trial. BMC Musculoskelet Disord. 2012;13:229.
- Edwards SG, Calandruccio JH. Autologous blood injections for refractory lateral epicondylitis. J Hand Surg Am. 2003;28:272–8.
- Thanasas C, Papadimitriou G, Charalambidis C, Paraskevopoulos I, Papanikolaou A. Platelet-rich plasma versus autologous whole blood for the treatment of chronic lateral elbow epicondylitis: A randomized controlled clinical trial. Am J Sports Med. 2011;39:2130–4.
- Sanchez M, Anitua E, Azofra J, Andia I, Padilla S, Mujika I. Comparison of surgically repaired achilles tendon tears using platelet-rich fibrin matrices. Am J Sports Med. 2007;35:245–51.
- Mishra A, Harmon K, Woodall J, Vieira A. Sports Medicine Applications of Platelet Rich Plasma. Curr Pharm Biotechnol. 2012;13:1185–95.
- Mishra A, Pavelko T. Treatment of chronic elbow tendinosis with buffered platelet rich plasma. Am J Sports Med. 2006;34:1774–8.
Dhillon MS, Behera P, Patel S, Shetty V. Orthobiologics and platelet rich plasma. Indian Journal of Orthopaedics. 2014;48(1):1-9. doi:10.4103/0019-5413.125477.