3 The procedure
3.1 Platelet-rich plasma injections aim to promote cartilage repair and relieve osteoarthritic symptoms, potentially delaying the need for joint replacement surgery. Platelets produce growth factors that are thought to stimulate chondrocyte proliferation, leading to cartilage repair.
3.2 Platelet-rich plasma is usually prepared by a clinician or technician. Blood is taken from the patient and centrifuged to obtain a concentrated suspension of platelets. Platelet-rich plasma can be prepared by carrying out 2 spin cycles using a standard bench-top centrifuge, or by using commercially available single-step preparation systems. Different preparation methods may affect the concentration of platelets. Agents such as calcium chloride may be added to activate the platelets. The final platelet-rich plasma product is injected into the joint space in the knee, usually under ultrasound guidance.