GENERAL HEALTH Over the last three years, there have been a number of high quality research studies published which have shown Platelet Rich Plasma (PRP) therapy to be a valid treatment option for patients with knee osteoarthritis. Multiple well-conducted randomised clinical trials have shown superiority of PRP intra-articular injections over a variety of other injections including: placebo injections, Synvisc (Hyaluronic Acid) and intra-articular steroids. A systematic review of this literature, recently published in the March 2016 Journal of Arthroscopy, concluded that for patients with symptomatic knee OA, PRP injection results in significant clinical improvements up to 12 months post injection. Clinical outcomes and measures of patients’ pain, stiffness and functioning of the joints were significantly better after PRP injection versus HA visco-supplementation injections (Synvisc), at three to 12 months post injection. Another important recent study published in the February 2016 edition of the American Journal of Sports Medicine, the leading journal for sports medicine in the world, demonstrated that PRP is safe and provides benefit for pain relief and functional improvement for knee OA. In this study, the patients who received a PRP intraarticular knee injection had improvements of 78% in function, pain and stiffness compared to the placebo control group who had improved by only 7%, at one year after injection. Additionally, no serious complications due to the PRP injections were observed. These promising outcomes have led to the increasing popularity of PRP therapy. The exact mechanism of how PRP relieves the symptoms of osteoarthritis is uncertain, but is thought that it likely alters the metabolism of the cells within the joint in response to the growth factors released by the platelets. This in turn alters the intra-articular biology and reduces the osteoarthritic symptoms. Ideal patients for PRP are those who have failed other non-surgical options or are unable to tolerate NSAIDs (eg: Nurofen, Voltaren), and suffer mild to moderate osteoarthritis. Patients with severe osteoarthritis may also benefit, but the research has shown that the improvement in this patient group will be lessened. Maximum benefit is gained when PRP therapy is used in combination with a weight loss and quadriceps strengthening program. PRP can also be used to assist healing for specific knee surgeries, and in our practice it may be used in conjunction during surgery for chondral surfacing cartilage defects. The PRP procedure is very simple and is performed as an out-patient. The patient has a blood sample collected just like a normal pathology blood test. This blood is placed into a special PRP device, is spun in a centrifuge where the platelets in the blood are concentrated into a small volume of plasma, which is then injected into the patient’s knee. The intra-articular injection must be performed using meticulous sterile technique, with or without imaging guidance as needed. By using subcutaneous local anaesthetic initially, the intra-articular injection can be pain free. After the injection, patients are encouraged to apply ice intermittently and plan minimal activities the following day. The risk of side effects of PRP injections are very low as the patient receives an injection of a component of their own blood, within 10 minutes of the blood sample being collected. Because the injection is the patient’s own biology, there is virtually no risk of rejection or an allergic reaction and the procedure is considered very low risk. Some patients will experience some local pain within the injected knee for 24-48 hours after the injection, due to the body’s response to the PRP. It is important that patients understand that the PRP injection is not a “quick fix” and is meant to be used as part of a rehabilitation and comprehensive program supervised by their GP, physiotherapist or specialist. There are a variety of ways to create PRP, from using a simple plain tube and centrifuge, to expensive commercial systems. One of the difficulties in assessing PRP studies is the significant variation in these preparation techniques. Simple PRP preparations can be inexpensive to prepare but result in variable or low platelet concentration, sterility issues, high number of white cells and red cell cellular debris. Various sterile, TGA approved, commercial systems exist that can produce far higher platelet concentrations while simultaneously removing white cells. White cells, such as neutrophils, can release local mediators once in the joint that have a potentially negative effect on the synovial cells. It appears when PRP has been depleted of white cells, the injection leads to better outcomes for knee osteoarthritis than PRP that has a higher white cell concentration. The protocols for best preparation method, PRP volume and number of injections are still being researched. There is no medical technique, product or device that can guarantee it can ‘cure’ injured or degenerative tissue, nor is there any guarantee of PRP therapy providing the desired healing outcome for every patient. Published studies have shown that 85% or greater of the patients observed gain benefit of 50- 80% reduction in symptoms for six to twelve months. A minority of patients will still have benefit at 24 months. Repeat injections can extend the beneficial effect, usually spaced six months apart. Research has also demonstrated a beneficial effect from PRP for some tendinopathies such as patella tendinopathy and tennis elbow; and for plantar fasciitis. However somewhat inconclusive results have been found in other tendon studies which is probably due to the wide variety of preparation & application techniques. Continued research in PRP and patient’s own biologics will provide further insight for the evolving field of regenerative cellular medicine. For more information, visit www.prpclinic.com.au 12 Pindara Magazine 2016
Pindara Private Hospital Magazine - Issue Seven
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