Viscosupplementation: Managed Care Issues for Osteoarthritis of the Knee

BACKGROUND: Osteoarthritis (OA) affects an estimated 49 million adults in North America, or nearly 1 of every 6 adults. More than 8 million North Americans have limited mobility to some extent because of OA. By 2030, an estimated 71 million North Americans will be diagnosed with OA, an increase of 45% over current figures. For one group-model health maintenance organization (HMO), the average cost of care for patients with OA was $543 per member, a total annual cost to the HMO of $4,728,425. Of this total amount, 46% was for inpatient care, 32% was for medication, and 22% was for ambulatory care. OBJECTIVES: To determine the impact of OA on managed care and discuss treatment options available to those with OA, particularly of the knee. SUMMARY: OA represents an advanced stage of an active, progressive disease process. We know from medical research that OA is the endpoint of a progression in tissue degradation that results in loss of cartilage structure and function. Relief of pain and preservation of joint tissue must evolve to encompass treatments that interfere with cartilage-degrading mechanisms that follow acute or chronic injury, restore normal cartilage and joint homeostasis, and arrest the progression of disease. Optimal future treatments will also reverse existing damage and restore normal cartilage structure and function. Viscosupplementation with an elastoviscous fluid containing polymers of hylan derivatives of the natural glycosaminoglycan hyaluronan is indicated for treating pain of OA of the knee that has not responded to or is contraindicated for conservative nonpharmacologic therapy and traditional analgesics. These analgesics include acetaminophen, nonsteroidal anti-inflammatory drugs (NSAIDs), and cyclooxygenase-2 (COX-2) inhibitors. Clinicians in the managed care setting may consider using viscosupple-mentation in patients (1) who have persistent pain despite their use of conservative nonpharmacologic and pharmacologic therapy (e.g., exercise, weight loss, physician therapy, bracing/orthotics, NSAIDs, COX-2 inhibitors, and intra-articular glucocorticoids); (2) who have compromised gastrointestinal (GI) function or who are at risk for GI bleeding due to the adverse events of NSAIDs; (3) who are taking concomitant anticoagulant therapy for any condition; (4) who have cardiovascular or renal risk factors that preclude use of COX-2 inhibitors; and (5) for whom surgery is not appropriate. Further study should be conducted with larger numbers of patients to help identify a subgroup of patients with OA in whom viscosupplementation may have even greater effects. Additional research should also concentrate on assessing the risks and benefits of extended treatments, because limited data are available concerning the effectiveness of multiple courses of therapy. CONCLUSIONS: OA is an important public health issue as the leading cause of disability in North America. As populations age, socioeconomic costs of OA will dramatically increase. Among available treatment options, viscosupplementation is a valuable alternative to more conservative therapy and has the benefit of circumventing the possible side effects of systemically administered pharmacologic agents. Viscosupplementation demonstrated efficacy in OA of the knee, and its use in the managed care arena may generate savings in hospitalizations and other costs.