Chiropractor Chandler AZ
PRP VS. CORTISONE INJECTION IN KNEE
The knee joint is the largest and most complex joint in the body. It helps to perform basic daily activities like walking, standing, running and jumping. It is also the most widely used part of our body and it is very easily prone to injury. Any injury to the knee can make it difficult to carry out basic daily activities.
A study conducted in Scandinavia showed that sports-related knee injuries are the leading cause of permanent disability. Around 10.4 million people suffered from knee-related injuries such as fracture, dislocation, sprains and ligament damage in 2014. These knee-related injuries lead to severe knee pain.
To treat knee pain, the conventional methods are patient management, self-education, exercise, weight management, walking support, bracing, shoe modification, heat, ice, acupuncture, physical therapy and surgery. If these methods fail to relieve pain, drugs like paracetamol, non-steroidal anti-inflammatory drugs, opioids, and slow-acting drugs are prescribed.
When the oral treatment is ineffective, intra-articular (IA) injections are prescribed to treat the pain. Intra-articular injections are directly administered into the joint. Most widely used Intra-articular injection treatments include Platelet-rich plasma Prolotherapy and Cortisone injections.
The main goals of knee pain treatments are:
- Conservation of knee structure
- Reduce pain
- Improve quality of life
The knee joint is made up of three bones, two different types of cartilages and four major ligament groups. Damage to any part of the knee can lead to severe pain, discomfort, and reduces the quality of life. The most common cause of knee pain is knee osteoarthritis which is an inflammatory, degenerative disease. Osteoarthritis is a whole joint disease that affects cartilage, damages ligaments and menisci, and causes hypertrophy of the joint capsule. There is no treatment for arthritis, only symptoms are treated.
Other causes of knee pain include chondromalacia patellae (Runner's knee), meniscus tears, knee sprains, Osgood-Schlatter disease, osteochondritis dissecans and Plica syndrome.
Treatment options available for knee pain only treat symptoms and not the real cause of pain. Therefore, PRP Prolotherapy and Cortisone injections are gaining importance as they resolve the underlying cause of pain and offer long-term pain relief.
CORTISONE INJECTIONCortisone belongs to a class of medication known as corticosteroids. It is an anti-inflammatory drug and reduces inflammation caused by different diseases. The Food and Drug Administration (FDA) has approved 5 cortisone injections:
- Methylprednisolone acetate
- Triamcinolone acetate
- Betamethasone acetate and Betamethasone sodium phosphate
- Triamcinolone hexacetonide
- Dexamethasone
The mechanism of action of cortisone is very complex. It acts as an anti-inflammatory and immunosuppressive drug. It binds directly to nuclear steroid receptors and interrupts the inflammatory and immune reactions at several levels. By this, it inhibits the accumulation of inflammatory cells and stops the secretion of inflammatory mediators such as prostaglandin and leukotriene. This then leads to a decrease in swelling, pain, redness and inflammation.
The effectiveness of different cortisone injections was evaluated by research; however, the results were indecisive. It seems that these injections have similar potency if administered with a correct indication, dose and timing.
Short-term side effects of cortisone injection are:
- Soreness and lightening of skin color at the site of injection
- Tendon damage
- Elevated blood sugar level in diabetic patients
- Infection
Long-term side effects depend on dose and frequency of injections and they can be:
- Weight gain
- Skin thinning
- Acne
- Osteoporosis
- High blood pressure
PRP Prolotherapy is a non-surgical, minimally invasive method that uses the person's own blood to treat the cause of pain. The blood consists of RBCs, WBCs, and platelets. The ratio of these components in blood is 93%, 1%, and 6%. In platelet-rich plasma therapy, the ratio of blood components is reversed. In a PRP injection, the ratio is 6%, 1% and 93% respectively.
The functions of platelets are:
- Clotting
- Haemostasis
- Connective tissue repair
Connective tissue repair is the property of platelets manipulated in PRP Prolotherapy. PRP Prolotherapy is based on the principle "when the platelet concentration is increased in a certain area of the body, it accelerates the healing process." When the PRP is injected, it releases alpha granules which contain growth factors. These growth factors activate and accelerate the cell migration at the site of injury and heal the damaged area in the following steps:
- Inflammation phase: It lasts for 2-3 days. In this phase, transforming growth factor betas are released which help regulate cell migration and replication at the site of injury
- Proliferation phase: It lasts for 2-4 weeks. Vascular endothelial growth factors, platelets derived growth factors and epithelial growth factors are released in this phase and they stimulate the formation of blood vessels at the site of injury and tissue damage as well as increase the tendon formation and collagen synthesis and stem cell replication.
- Remodelling phase: It lasts over a year. In this phase, collagen is matured and strengthened and the injury is healed
PRP Prolotherapy uses the patient's own blood; therefore, the chances of blood-borne disease transfer and immunogenic reaction are zero. Other side-effects are:
- Neural trauma
- Needle breakage
- Pain at injection site
A cortisone injection is a most commonly used method with consistent and satisfactory results. Therefore, it is used as a gold standard for comparison of new methods. It uses steroids to relieve pain immediately.
The effectiveness of cortisone was tested through 13 randomized controlled trials and the results showed that the cortisone injection is effective in pain relief as compared to conventional methods.
Cortisone injection improves knee pain caused by osteoarthritis and the pain-relieving effect lasts for more than 16 weeks. A meta-analysis showed improvement in pain, knee flexion and extension, knee circumference and stiffness in knee up to 22 weeks in the cortisone treated group as compared to the placebo group and there was no evidence of any side-effect.
Two experiments were performed to evaluate the effect of a cortisone injection in knee osteoarthritis. Results showed a significant pain reduction after 1 week of injection and the effect could last for 3-4 weeks.
On the other hand, platelet-rich plasma Prolotherapy uses autologous blood to treat the cause of pain. It releases a large amount of platelet-derived growth factors at the site of injection which kick-starts the healing process. Within one hour of activation, platelets release more than 95% of the pre-synthesized growth factors. After this, growth factors are constantly synthesized and released for the remaining lifespan.
A study published in the Journal of Prolotherapy showed that PRP has amazing pain relieving effects in patients with knee osteoarthritis. Another study showed significant functional improvements in patients with knee cartilage pathology and the effect lasted for 12 months.
In 2010, in a meta-analysis, the effectiveness of cortisone injection and PRP injection were compared in patients with knee osteoarthritis. The results showed that a cortisone injection provides only short-term pain relief while PRP injection was effective for pain relief in the long-term.
Another study that compared the effectiveness of PRP to cortisone treatment for lateral epicondylitis showed improvement in pain in both groups at short-term follow-up. In the long-term follow-up, the pain and functional score was returned to baseline for cortisone injection but for PRP, it remained high. The researchers commented a better response for cortisone in initial visits but at 3 months, the improvement was significantly better in the PRP group.
A recent double-blind randomized control study reported that the effect of cortisone injection lasts for 3 months and the effect of PRP injection lasts for up to 6 months. The difference in the duration in these two types of research can be due to formulation differences of injection.
Cortisone injection therapy is FDA approved, it has been used for quite a long time and it offers quick pain relief, but the effect of this therapy is short term. Also, it only masks the pain. It does not treat the cause of the pain. It also prevents the ligaments and tendons to heal fully, thus increasing the damage in the long run. The physician needs to be careful in cortisone injection as an increased amount can lead to the ligament, tendon and joint damage, and skin thinning.
On the other hand, PRP Prolotherapy is not FDA approved. It uses the patient's own blood, therefore the risk is very limited and side-effects are minimal. The only drawback of PRP when compared to cortisone injection is that it is a very slow method and the pain relief takes a very long time, sometimes up to 2-3 months. But it heals the cause of pain thus the pain relief is long-term and the structure of the joint is repaired as well. It is more expensive than the cortisone method though.
PRP Prolotherapy is superior to cortisone in long-term effects, but more research is required in this area to establish the fact that PRP Prolotherapy is better than cortisone in treating musculoskeletal pain in the knee.
Conservative treatments of physical therapy, exercises, and Graston Technique often enhance knee healing and reduce future bouts of knee pain. Read for more information on knee pain treatments and Graston Technique.
Class IV Low Level Lasers are newer treatments that can enhance knee healing and repair. Cold lasers utilize specific wavelengths to speed healing processes within cells and tissues. Many patients respond well to laser treatments when combined with conservative therapy treatments, Graston Technique, stability exercises, PRP, Stem cells and cortisone injections.
BIBLIOGRAPHY:
Cheng, O. T., Souzdalnitski, D., Vrooman, B., & Cheng, J. (2012). Evidence based knee injections for the management of arthritis. Pain Med, 740–753.
Raeissadat, S. A., Rayegani, S. M., Babaee, M., & Ghorbani , E. (2013). The Effect of Platelet-Rich Plasma on Pain, Function, and Quality of Life of Patients with Knee Osteoarthritis. Pain Res Treat, 10.1155/2013/165967.
Yadav, R., Kothari, S. Y., & Borah, D. (2015). Comparison of Local Injection of Platelet Rich Plasma and Corticosteroids in the Treatment of Lateral Epicondylitis of Humerus. J Clin Diagn Res, RC05–RC07.