To assess the long-term efficacy and tolerability of sodium hyaluronate (Hyalgan) after 1 cycle of 5 intra-articular (IA) injections in patients with osteoarthritis (OA) of the knee. The benefits of a second treatment cycle in patients with renewed need for therapy also were examined.
One hundred eight patients with knee pain (Kellgren-Lawrence grade 1, 2, or 3) for at least 20 days per month, and a score for pain on movement of at least 3.3 cm on a 10-cm Visual Analogue Scale (VAS) were treated with Hyalgan once weekly for 5 weeks in a multicenter, observational study. A repeat course was administered if patients continued to fulfill the inclusion criteria but not earlier than month 4. The primary efficacy parameter was pain on movement measured by VAS. Secondary parameters were pain on movement and pain at rest (5-point Likert ordinal rating scale), pain at rest (VAS), knee joint function (Larson scale), walking time, and global assessment of efficacy.
The 59 patients completed the first 12-month follow-up period without the necessity for a second treatment cycle; 14 of the remaining 49 patients received a second treatment cycle. There were significant improvements in all efficacy parameters compared with the baseline values starting from 1 week after the last injection until month 12 for the 59 completed patients and also for all 108 enrolled patients (last observation carried forward). Safety and tolerability of Hyalgan were good or very good in more than 90% of patients. Of 4 patients who withdrew because of adverse events, only 1 event (knee joint effusion) was judged as possibly drug related. Two other adverse events judged to be drug related (generalized skin eruption; pruritus and knee joint effusion) resolved and did not lead to study withdrawal.
The results of this observational study suggest that Hyalgan, administered either as a single or repeat course, is an effective and well-tolerated therapy for the long-term treatment of the pain of OA.