The level of evidence is downgraded by study quality (several issues) and imprecise results.
A Cochrane review [Abstract] 1 included 6 studies with a total of 240 subjects. The primary analysis included three RCTs (109 participants) which compared HA to placebo. One study compared HA to exercise therapy, one compared HA combined with exercise therapy to an intra-articular injection of botulinum toxin and one compared four different dosages of HA.
Primary analysis: a pooled analysis of two trials (45 participants) found that the Ankle Osteoarthritis Scale (AOS) total score (measuring pain and physical function) was reduced by 12% (95% CI −24% to −1%) at six months (MD −12.53 (95% CI −23.84 to −1.22) on a scale of 0 to 100; number needed to treat for an additional beneficial outcome (NNTB) = 4 (95% CI 2 to 205). It is unclear if a mean difference of 12.53 points on a 100 point scale is clinically relevant. Pain and function outcomes were not reported separately. Radiographic joint structure changes were not investigated. There were a few adverse events (AEs) 5/63 (8%) in the HA group and 2/46 (4%) in the placebo group.
For comparing HA to exercise therapy (30 participants) the results for pain on a Visual Analogue Scale (VAS 0 to 10) at 12 months are inconclusive (MD 0.70, 95% CI −2.54 to 1.14). The American Orthopedic Foot and Ankle Society score (AOFAS score) was 13.10 points (MD) higher in favour of HA (95% CI 2.97 to 23.23) on a scale of 0 to 100.
For the comparison of HA injection combined with exercise therapy to an intra-articular injection of botulinum toxin A (BoNT-A) (75 participants), the outcome of the AOS pain score of the affected joint at six months is inconclusive (MD 0.10, 95% CI −0.42 to 0.62). The physical function (the AOS disability score) at six months is inconclusive (MD 0.20, 95% CI −0.34 to 0.74). The same number of AEs were found in both groups; HA 2/37 (5.9%), BoNT-A 2/38 (5.8%) (RR 1.03, 95% CI 0.15 to 6.91).
The RCT comparing four different dosing schedules for HA (26 participants) showed the best median decrease in pain on walking VAS (on a scale of 0 to 100) for 3 x 1 ml at 27 weeks with a median decrease of 30.
Date of latest search: 2014-11-09
Primary/Secondary Keywords