Viscosupplementation of osteoarthritic knees with hylan: A treatment schedule study

Double-blind, randomized, 12-week studies, which included 6-month follow-up, were conducted to compare the efficacy and safety of hylan versus physiologic saline administered intra-articularly to the affected joint of 80 patients with degenerative osteoarthritis of the knee. During a 2-week preinjection washout period and for the duration of the studies, patients received no steroidal or nonsteroidal anti-inflammatory drugs or analgesic medication. Two intra-articular injections administered 2 weeks apart were compared with three intra-articular injections given 1 week apart. Outcome measures included pain under weight-bearing movement, pain at night, reduction of activity while performing daily tasks, improvement of the most painful knee movement, and overall evaluation of therapeutic efficacy. Most parameters were evaluated by both the patient and the investigator. Compared with the control group, the two-injection and three-injection hylan treatment groups both showed statistically significantly greater improvement for the pain outcome measures as well as overall evaluation of treatment at the 12-week evaluation. The three-injection group showed statistically significantly greater improvement for all outcome measures compared with the two-injection group at the 12-week evaluation. At the 6-month follow-up, results in both hylan treatment groups were significantly superior to those in the control group in terms of reducing weight-bearing pain and night pain and restoring joint function. No generalized adverse events were observed, and only one local, transient adverse event (muscle pain) was reported. The results suggest that hylan is an extremely effective and safe viscosupplementation therapy for the management of degenerative osteoarthritis of the knee. Beneficial results can be maximized using a treatment schedule of three hylan injections administered at l-week intervals.