As of 2015, the latest injection for knee pain is hyaluronic acid, according to Cleveland Clinic. Hyaluronic acid injections and corticosteroid injections are the most effective treatments for knee osteoarthritis. Platelet-rich plasma injections are another recent knee pain treatment, although evidence regarding their efficacy is scarce, notes WebMD.
As they do with corticosteroids, physicians inject hyaluronic acid into the knee joint directly, notes Cleveland Clinic. Healthy knees have a natural supply of hyaluronic acid, but the supply is thin in arthritic knees, explains WebMD. The injections increase the supply and help lubricate and cushion the joint. Several versions of the injection treatment are available in the United States, ranging from a single injection to five injections over a five-week period. The injections are effective for up to six months.
For platelet-rich plasma injections, a physician draws a patient's blood, uses it to create a higher-than-normal concentration of platelets, and then injects the concentrated fluid into the patient's knee. The platelets speed healing in the injured area, according to WebMD.