Joost Peerbooms

55 PRP in upper limb conditions Currently, injections with corticosteroids have been used as a nonsurgical method. However, this method only has a temporary effect. 10 Furthermore, concerns for atrophy and adverse structural changes, including tears, have limited the use of corticosteroids. PRP has been used in vivo as a potential alternative to corticosteroids. In vitro studies have found that the use of PRP in tendinopathy and human mesenchymal stromal stem cell proliferation can strengthen. The quality of the tendon. 11 The use of PRP has shown that the macrophage proliferation and IL-1 production within the first 72 hours after exposure suppressed. 12 This difference in induction of the cells has important implications for tendon and muscle healing. Initially, PRP is able to inhibit the inflammatory process, whereas it stimulates the proliferation and maturation process. This is particularly important in preventing the formation of fibrous scar tissue that occurs macrophage-mediated tendon to bone healing. Animal studies have shown that the PRP can strengthen tendons. 13,14 A study by Hall et al. 15 showed that human tenocytes treated with PRP increased the collagen and endothelial expression for vascular repair. Moreover, an increased concentration of the growth factors described above was shown, creating a synergistic regulation of fibrosis, which promotes full muscle and tendon function. 15 Sanchez et al. 9 concluded that PRP facilitated the proliferation of human tendon cells, stimulating the release of multiple repair factors, especially an abundance of hepatocyte growth factor, which help reduce scar formation around tendon tissues. Other studies have also shown promise that local delivery of PRP shortened the recovery time after injury in small animal models, expediating myogenesis and tendinous repair. 16 Histologically, PRP appears to promote cellular repair that would otherwise be limited. HOW TO PREPARE PRP Several systems are available for the preparation of PRP in outpatients (Table 2). As an example, we describe the Biomet Biologics III GPS system (Biomet Biologics. LLC, Warsaw, IN, USA). This device uses a desktop-size centrifuge with disposable tubes for the various parts of blood separation. Thirty millilitres to 60 mL of whole blood is increased. An 18- or 19-gauge butterfly needle is recommended so as to avoid irritation and damage of the platelets, which are in a resting position. Thereafter, 3 mL to 6 ml of 8.4% of sodium bicarbonate is added to the blood to avoid clotting. The blood is then placed in a Food and Drug Administration approved device and centrifuged for 15 minutes at a speed of 3200 r.p.m. Subsequently, the blood is separated into platelet- poor plasma (PPP), red blood cells and PRP. Then, the PPP is removed through a special portal from the centrifuge tube. Finally, the PRP can be withdrawn. Depending on the blood, approximately 3 mL to 6 mL of PRP is available. After isolation, the PRP can be administered with or without an activating agent. Combination with calcium chloride and / or injection of trombine initiates platelet activation, clot formation and growth factor release at the injection site. Administration of PRP without an exogenous activator 4