The potential benefit of hyaluronans in alleviating pain associated with osteoarthritis (OA) in joints other than the knee is of increasing interest. This double-blind, randomized, controlled study examined the safety and efficacy of intraarticular sodium hyaluronate (Hyalgan) in the treatment of pain associated with ankle OA.
Thirty consecutive patients with ankle OA documented by X-ray were randomized to treatment with five weekly injections of either sodium hyaluronate 2 mL (HYL) or phosphate-buffered saline 2 mL (control) in the tibiotalar joint. The primary endpoint was pain on movement and weightbearing using the Ankle Osteoarthritis Scale (AOS) 3 months after injection (a 100-mm visual analog scale [VAS]). Additional measures included the Western Ontario and McMaster Universities (WOMAC) OA Index and patient global assessment through 6 months; the Short Form-12 (SF-12) Health Survey at 3 months and 6 months; and all reported adverse events (AEs).
The study groups differed only in age, baseline WOMAC pain, and AOS total scores; 80% of the HYL and 73% of the control patients completed the study. At Month 3, the primary endpoint of the study, the HYL group demonstrated a significantly greater improvement from baseline in AOS total score than did the control group (HYL: -17.4 +/- 5.0 mm;
-5.1 +/- 4.0 mm; p = 0.0407). The incidence of AEs was low, with no significant differences between the groups. There were no post-injection flares.
Our study suggests that sodium hyaluronate may be a safe and effective option for pain associated with ankle OA, although larger studies are needed.