This article reviews the various pharmacological modalities for the treatment of osteoarthritis (OA) of the knee, with a particular emphasis on the use of intra-articular (IA) hyaluronic acid (HA).
A literature review of the pharmacotherapy of OA of the knee was performed. Reviewed studies included those involving acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), topical analgesics, IA corticosteroids, and IA HA.
According to American College of Rheumatology (ACR) guidelines, acetaminophen should be used as first-line oral therapy. NSAIDs can be tried if nonpharmacological therapy and acetaminophen fail to provide adequate symptom relief. Topical capsaicin cream, either as monotherapy or as adjunctive therapy, is recommended for patients who do not respond to analgesics or who do not wish to take systemic therapy. IA corticosteroids are recommended for patients who have an effusion and local signs of inflammation. IA HA preparations are indicated for the treatment of pain in patients with OA of the knee who have failed to respond adequately to conservative nonpharmacologic therapy and to simple analgesics. Clinical trials show that IA HA therapy results in improvement in knee pain and function that is superior to placebo and comparable to NSAIDs.
Treatment with IA HA products appears to offer a significant advantage over aspiration and placebo injections for up to 6 months. It also may have an advantage over IA glucocorticoids.