Efficacy of intraarticular botulinum toxin A and intraarticular hyaluronate plus rehabilitation exercise in patients with unilateral ankle osteoarthritis: a randomized controlled trial

Background There was an increasing requirement for novel treatments of osteoarthritis (OA). The aim was to compare the efficacy of intraarticular Botulinum toxin type A (BoNT‐A) and intraarticular hyaluronate plus rehabilitation exercise in patients with ankle OA. Methods This was a prospective, randomized, assessor‐blinded study with a 6‐month follow‐up period, conducted in the outpatient rehabilitation department at a university‐affiliated tertiary care medical center. Seventy‐five patients with symptomatic ankle OA (Kellgren‐Lawrence grade 2) were randomized to receive either a single 100‐unit BoNT‐A injection into the target ankle (n = 38) or a single hyaluronate injection plus 12 sessions of rehabilitation exercise (30 minutes/day, 3 times/week for 4 weeks) (n = 37). The primary outcome measure was the Ankle Osteoarthritis Scale (AOS). Secondary outcome measures included American Orthopedic Foot and Ankle Society (AOFAS) Ankle/Hindfoot Score, visual analog scale (VAS) for ankle pain, single leg stance test (SLS), Timed “Up‐and‐Go” test (TUG), consumption of rescue analgesics and global patient satisfaction. Results There were no significant between‐group differences in total AOS scores, pain subscale and disability subscale scores (adjusted mean difference AMD = ‐0.2, 95% CI = (‐0.5, 0.2), p = 0.39; AMD = ‐0.1, 95% CI = (‐0.5, 0.3), p = 0.57; AMD = ‐0.2, 95% CI = (‐0.6, 0.2), p = 0.36). The 2 groups showed no significant differences in AOFAS, VAS, SLS, TUG scores and consumption of rescue analgesics at each follow‐up visit, except that the hyaluronate group improved more in SLS than the BoNT‐A group at 1‐month follow‐up. Patients' satisfaction rate was high, with no serious adverse events. There was no difference in adverse events between the two groups ( p  = 1.00). Conclusions Treatment with intraarticular BoNT‐A or hyaluronate injection plus rehabilitation exercise was associated with improvements in pain, physical function and balance in patients with ankle OA. These effects were rapid at 2 weeks and might last for at least 6 months. There was no difference in effectiveness between the two interventions. Trial registration The trial was registered at clinical trials.gov (Registry number NCT01760577 ).