Sodium hyaluronate in the treatment of hallux rigidus. A single-blind, randomized study.

Background: The purpose of this study was to evaluate the effectiveness and safety of intra-articular sodium hyaluronate (Ostenil)mini) compared to intra-articular triamcinolone acetonide (Trigon depot) in the treatment of painful hallux rigidus.

Methods: Thirty-seven patients (ages 40 to 80 years) with painful early stage hallux rigidus were enrolled in the study. One group received an intra-articular injection with 1.0 ml sodium hyaluronate (SH); the other received an intra-articular injection of 1.0 ml triamcinolone acetonide (TA). Patients were evaluated on days 0, 14, 28, 56 and 84. Effectiveness was measured using the following parameters: joint pain at rest or on palpation (VAS), with passive motion, and gait pain; AOFAS hallux metatarsophalangeal score; use of analgesics and global assessment of the treatment by the patient and investigator. Safety was evaluated by the outcome of tolerance to treatment and observation of adverse events. Statistical analyses were performed using the Chi-square test, Mann-Whitney U test, Wilcoxon test and Friedman test.

Results: Thirty-seven patients (40 feet) were evaluated. Pain at rest or with palpation and pain on passive mobilization decreased significantly in both treatment groups in comparison to baseline (p<0.01), but no significant between-group differences were observed (p>0.05). Gait pain improved substantially in the sodium hyaluronate group with significant differences compared to the triamcinolone group at days 28 and 56 (p<0.05). The AOFAS total score improved significantly in the SH group compared to the TA group (p<0.05). This was mainly due to improvements in the pain subscale. No between-group differences were seen regarding the use of analgesics. Global assessment of treatment by patients was good in both groups, and there was a significant between-group difference favoring SH when areas under the curves (AUC) were calculated (p < 0.05). Tolerance was good in both groups. Adverse events occurred in three patients.

Conclusions: Intra-articular injections of sodium hyaluronate are effective and safe in decreasing hallux rigidus pain. The AOFAS scores in the SH group were significantly better than in the TA group.