By David K. Lisle, M.D.
Platelet rich plasma or PRP has been used for decades by plastic surgeons and maxillofacial surgeons to augment healing and improve the quality of their patient outcomes. It was not until 2006 when Mishra and Pavelko, et al. introduced a study using PRP for tendon injuries.
They investigated the use of PRP for tennis elbow (lateral epicondylosis) and noted a significant improvement in those treated with PRP compared to those treated with an anesthetic injection. From that study, multiple investigations have been done looking at the effect of PRP on all types of tendinoses – degenerative changes to the substance of tendons due to maladaptive response to stress and overuse.
What is PRP?
First, we should ask what is a platelet?
Most know that platelets aid in coagulation to stop bleeding. Platelets do much more. They are powerful cell signalers that are activated at the time of injury. This leads to the initiation of a healing response as growth factors rush to the area and begin to fix what is wrong. The platelet is critical in initiating the first of three stages of healing, inflammation.
Platelet rich plasma is any platelet concentration that is higher than normal physiologic levels. Typically, this level is greater than 5 times what is found in the body, however the true definition of platelet rich plasma has not been clarified. Platelet rich plasma used for injection can be found from our own blood and, for many, the idea of using one’s own blood to help heal a chronic injury is very appealing.
COMMON USES FOR PRP
As mentioned before, PRP was first used to help with healing during surgery. It was much later that PRP was used for chronic tendon injuries.
Now, PRP is used for many common tendinopathies that have failed to heal with typical first-line treatments such as rest, said medications and physical therapy. PRP can be used for lateral epicondylosis (tennis elbow), medial epicondylosis (golfer’s elbow), Achilles tendinosis, patellar tendinosis (jumper’s knee), gluteus medius tendinosis (outer hip pain) as well as ligament injuries and chronic muscle injuries.
For most of these chronic tendon problems, the underlying pathology is one of tendon “disrepair” where the tendon with relatively poor blood supply has undergone multiple small injuries from overuse and thus has become stagnant in a non-healing state. This can cause pain and disability in the area of concern.
The theory behind using PRP is to jump start the healing response by introducing platelets to create inflammation in an area of chronic injury. By causing inflammation, the healing cascade may begin and the platelets can start the process of signaling for reparative cells to come to the area. For most, this is a successful treatment option, but should only be considered when other treatments have failed.
What are the results?
The literature is very promising regarding the success rates for platelet rich plasma with percentages between 60 percent and 80 percent success rate. Success is typically gauged by lessening pain and improved functioning of the injured area.
However, PRP does not work for everyone.
It is not clear how many platelet treatments are needed to maximize the healing response. It is also not clear how concentrated PRP should be, however recent studies reveals that more is not necessarily better and that a concentration that is six times the physiologic (normal) level seems to be ideal.
Platelet rich plasma injections can be done in the office and should be performed using ultrasound to guide the injection to the area of tendinosis or injury. The most common post-treatment concern is pain given that the platelet creates an inflammatory response. The area that is treated is immobilized for a few days to allow the platelet injection to remain undisturbed. After a few days, every day activities with no additional heavy use are typically fine to introduce. All patients should start a focused physical therapy protocol at about two weeks.
HEALING TIME & COST
Tendon healing from PRP takes time and the response is not often noticed until 6 – 12 weeks after the treatment. On occasion, a second treatment is performed at 12 weeks. Some physicians have used a series of two or three treatments at the beginning, however this can be costly and there is no evidence at this point to suggest this is more helpful.
Unfortunately, at this time, only Worker’s Compensation insurance covers PRP so most platelet treatments are self-pay. The cost can vary depending on where one lives between $500 and $3,000. This cost typically covers the entire procedure, including blood draw, centrifugation, ultrasound evaluation and PRP injection.
Platelet rich plasma is a promising treatment for chronic overuse injuries, especially those involving tendons. There is still much that needs to be understood and more well-designed studies are necessary to help clarify how best to optimize the use of PRP.