Platelet Rich Plasma Therapy for Knee Osteoarthritis
In this article, Ross Hauser MD discusses the use of Platelet Rich Plasma Therapy for the treatment of knee osteoarthritis, also known as PRP Knee Injections.
Some research is now moving away from trying to prove or not prove Platelet Rich Plasma Therapy is effective for knee osteoarthritis. Now research is more trying to explain how PRP works and move forward with treatment guidelines from there.
A new study acknowledges that Platelet-rich plasma (PRP) contains high concentrations of autologous (from you) growth factors that can repair the knee. Further they found that PRP may also provide the lubrication needed to protect the cartilage. The study researchers summarized that intra-articular injections of PRP have the potential to relieve the symptoms of osteoarthritis in the knee and that there is an influence on superficial zone protein (SZP) which is a boundary lubricant in articular cartilage and plays an important role in reducing friction and wear and therefore is critical in cartilage regeneration.
Further, bovine cartilage explants (injection) were found to be influenced by PRP’s ability to stimulate natural knee lubricants. They concluded that PRP significantly stimulates cell proliferation and SZP secretion by articular cartilage and synovium of the human knee joint1.
In other words PRP is acting like hyaluronic acid, except it is healing and regenerating the knee which hyaluronic acid is not designed to do.
When treating the knee, our medical team utilizes a Comprehensive Prolotherapy injection technique which may include a combination of healing factors. PRP is commonly used in conjunction with Dextrose Prolotherapy and Stem Cell Therapy. If stem cells are used, they would be drawn from the patient and then re-injected into the knee to stimulate tissue regrowth, such as in instances of knee osteoarthritis. This is to ensure that a more thorough treatment is given to the weakened area, versus a one-shot PRP approach. Please see this article for a discussion on the general treatment of osteoarthritis including a detailed description of the PRP therapy injections and for a comparison of types of knee osetoarthritis injection therapy.
PRP and Osteoarthritis of the knee
Dextrose Prolotherapy alone has been shown to improve the quality of life in patients with knee osteoarthritis, “suggesting that Prolotherapy may have a pain-specific disease-modifying effect.”2 With the addition of PRP the results are even more remarkable.
The PRP affects repair of the damaged cartilage, and the Dextrose Prolotherapy strengthens the supportive structures such as the weakened ligaments and tendons that most likely led to the cartilage degeneration in the first place. The goal of this type of Comprehensive Prolotherapy treatment is to repair the entire knee.
While Platelet Rich Plasma therapy is a very promising regenerative treatment, it must be utilized by physicians who are experienced in its use. Some physicians may use PRP as a single dose treatment rather than as part of a comprehensive treatment program. Used this way PRP may not be as effective. For this reason, some researchers see the components, healing mechanisms, and outcomes of PRP as challenging, and though the treatment has repairative functions in osteoarthritis of the knee even with the single dose usage, they would like to see a standardized protocol.3
More than one PRP injection needed
Testing whether or not Platelet-rich plasma (PRP) provides symptomatic relief in early knee osteoarthritis in athletes, researchers looked at 78 patients with bilateral knee osteoarthritis. The patients were then divided randomly into three groups.
- Group A (52 knees) received a single injection of PRP
- Group B (50 knees) received 2 injections of PRP 3 weeks apart
- Group C (46 knees) received a single injection of normal saline
The three groups were compared with each other and no improvement was noted in group C as compared with groups A and B.
The next part is interesting: there was no difference between groups A and B, which means that a single dose of PRP is as effective as two injections to alleviate symptoms in early knee osteoarthritis. The results, however, deteriorate after six months. Both groups treated with PRP had better results than did the group injected with saline only.
Other than the fact that the PRP was found effective at alleviating symptoms of osteoarthritis in the knee is the subsequent findings. Two PRP injections were no more effective than one and that the results deteriorated after six months.4
Now these findings are somewhat in agreement with other recent research that suggests a single dose of PRP worked very well for a six-month time period but the results deteriorated.5
Can PRP Prolotherapy help the patient who has already undergone knee surgery?
Yes, PRP is effective at decreasing pain and improving symptoms and quality of life in patients with chronic knee pain after surgery. Surgery entails cutting and the removal of structures. The knee joint requires these structures for cushion and stability and proper functioning. Without them, knee instability occurs. Knee ligament instability is the main cause of knee pain before and after a total knee replacement. “Instability of the knee is one of the most common causes of failure in knee arthroplasty,” because of “intraoperative injuries or excessive release of important coronal stabilizers such as the medial collateral ligament.”6 Another researcher reports, “Ligament instability is the primary reason for revision total knee arthroplasty.”7
PRP Prolotherapy strengthens the weakened ligaments and tendons that are causing instability and stabilizes the knee. PRP Prolotherapy helps the body repair the weakened structures and tissue so the knee can function optimally.
PRP Knee Injection
1. Sakata R, McNary SM, Miyatake K, Lee CA, Van den Bogaerde JM, Marder RA, Reddi AH. Stimulation of the Superficial Zone Protein and Lubrication in the Articular Cartilage by Human Platelet-Rich Plasma. Am J Sports Med. 2015 Mar 26. pii: 0363546515575023. [Epub ahead of print]
2.Rabago D et al. Association between disease-specific quality of life and magnetic resonance imaging outcomes in a clinical trial of prolotherapy for knee osteoarthritis. Arch Phys Med Rehabil. 2013 Nov;94(11):2075-82. doi: 10.1016/j.apmr.2013.06.025. Epub 2013 Jul 10.
3. Chang KV, Hung CY, Aliwarga F, Wang TG, Han DS, Chen WS. Comparative Effectiveness of Platelet-Rich Plasma Injections for Treating Knee Joint Cartilage Degenerative Pathology: A Systematic Review and Meta-Analysis. Arch Phys Med Rehabil. 2013 Nov 27. pii: S0003-9993(13)01212-4. doi: 10.1016/j.apmr.2013.11.006. [Epub ahead of print]
4. Patel S, Dhillon MS, Aggarwal S, Marwaha N, Jain A. Treatment With Platelet-Rich Plasma Is More Effective Than Placebo for Knee Osteoarthritis: A Prospective, Double-Blind, Randomized Trial. Am J Sports Med. 2013 Jan 8. [Epub ahead of print]
5. Halpern B, Chaudhury S, Rodeo SA, Hayter C, Bogner E, Potter HG, Nguyen J. Clinical and MRI Outcomes After Platelet-Rich Plasma Treatment for Knee Osteoarthritis. Clin J Sport Med. 2012 Dec 12. [Epub ahead of print]
6. Del Gaizo DJ, Della Valle CJ. Instability in primary total knee arthroplasty. Orthopedics. 2011 Sep 9;34(9):e519-21. doi: 10.3928/01477447-20110714-46.
7. Graichen H, et al. Ligament instability in total knee arthroplasty–causal analysis. Orthopade. 2007 Jul;36(7):650, 652-6.