Rheologic behavior of osteoarthritic synovial fluid after addition of hyaluronic acid: a pilot study.

Viscosupplementation is a symptomatic treatment of osteoarthritis (OA) intended to restore rheologic homeostasis of the synovial fluid by injecting hyaluronic acid intraarticularly. Despite the long history of this therapy, little is known about its mechanisms of action and differences between commercial preparations. We investigated the rheologic behavior of OA synovial fluid with time, when stored at 4 degrees C, before and after the addition of two hyaluronic acid commercial preparations (linear and cross-linked).

Factors predicting long-term efficacy of Hylan GF-20 viscosupplementation in knee osteoarthritis.

Objectives: To describe the long-term effects of Hylan GF-20 viscosupplementation in patients with knee osteoarthritis and to identify factors predicting efficacy.

Methods: One hundred and fifty-five patients (80 women and 75 men; mean age, 69 years) with symptomatic knee osteoarthritis each received three intraarticular Hylan GF-20 injections. Effectiveness, safety, and satisfaction were evaluated 7-14 months later based on a physician's examination and a five-item questionnaire.