The application of thermal oscillation method to augment the effectiveness of autologous platelet rich plasma in treating elderly patients with knee osteoarthritis

Elderly patients with knee osteoarthritis (OA) are often troubled with joint soreness, swelling, weakness, and pain. Knee intra-articular (IA) injection of autologous platelet rich plasma (PRP) is one of the options that can be used in treating knee OA. However, there are doubts on the effect of PRP when used in treating elderly patients with moderate to severe degrees of knee OA. In this study, 47 elderly patients with moderate degree of knee OA combined with supra-patellar bursitis were recruited. Musculoskeletal ultrasound was used for accurate needle placement for the aspiration of bursa synovial fluid SF followed by PRP injections. In group 1, 23 patients received conventional liquid-form IA PRP injections. In group 2, 24 patients received IA injections of thermal oscillation prepared PRP injectants. It was discovered that when the liquid-form PRP was heated up to a temperature of 75 °C and simultaneously oscillated under 200 revolutions per minute (rpm) for 15 min, the end product became paste-form like and with a viscosity similar to that of an anti-cough syrup. Under incubation, the highest number of platelet-derived growth factor (PDGF) was obtained on the 8th day. At one month after the completion of PRP injections, group 2 patients revealed significant decreases in SF total protein concentrations, SF volumes, and Lequesne index values. Proteins associated with inflammation, such as apolipoprotein A-I, haptoglobin, immunoglobulin kappa chain, transferrin, and matrix metalloproteinase also decreased significantly. Therefore, the thermal oscillation preparation method can augment the effectiveness of autologous PRP in treating elderly patients with moderate knee OA. It may be recommended that the PRP injectant should be prepared first using the thermal oscillation method to increase its viscosity, enabling prolonged release of growth factors once it is injected into the knee joint.