For patients with knee arthritis that are not ready for joint replacement, what is the right treatment? Studies have shown that corticosteroid injections are a good treatment for acute flare-ups, giving short term symptomatic relief. Corticosteroids work as an anti-inflammatory, immunosuppressive agent, and can lead to increased hyaluronic acid concentration in the joint. They found that hyaluronic acid (gel) injections gave a longer lasting effect compared to corticosteroid injections, up to 6 months. Hyaluronic acid works to increase the viscosity of the joint fluid and works as an anti-inflammatory, analgesic, and helps to protect cartilage. PRP was only found to have improved benefit compared to gel injections in patients younger than 50 years of age with early or mild arthritis. PRP stimulates healing in the joint by bringing growth factors and other active molecules. In animal studies, PRP was shown to prevent progression of arthritis;however, effects were related to the arthritis severity (improved benefit with less severe arthritis).
From our experience, there is no easy answer. Patients respond differently to each of the injections. We have had patients get great long-lasting benefit from corticosteroid injections, but we have also had patients who had no relief with steroids but had great improvement with gel injections. Things to keep in mind: 1) insurance companies usually require a trial with a corticosteroid injection before approving hyaluronic acid injections, 2) PRP is still considered experimental and is therefore not covered by insurance.