I-Hsiu Liou, Shu-Fen Sun, Chien-Wei Hsu, Huey-Shyan Lin, Yi-Jiun Chou, Hsien-Pin Sun, Chen-Lun Lu, Mei-Chia Chou, Jue-Long Wang and Wei- Hsuan Lee
Purpose: Ankle osteoarthritis (OA) can cause substantial pain and functional limitations. Effective therapy has been a key therapeutic challenge. The aim of this pilot study is to investigate the effects of intra articular Botulinum toxin type A (BoNT-A) for the treatment of patients with painful ankle OA.
Methods: This was a prospective study conducted in a university-affiliated tertiary care medical center with 6- month follow-up. Patients with painful ankle OA for at least 6 months and radio graphically verified as having stage II OA according to the Kellgren-Lawrence classification were enrolled. Eligible patients received single intraarticular injections of BoNT-A (100 units). The primary outcome was the Ankle Osteoarthritis Scale (AOS) score at 6-month follow-up. Secondary outcomes measures included American Orthopaedic 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) and consumption of rescue analgesics. Patients were evaluated at baseline, 2 weeks, 1 month, 3 months, and 6 months post injection. Patients’ global satisfaction about therapy was assessed at 2 weeks, 1 month, 3 months, and 6 months post injection. Adverse events during the study period were recorded also.
Results: Thirty-six patients completed the study. All patients showed significant improvements in AOS, AOFAS, VAS, SLS, TUG scores and consumption of rescue analgesics at 2 weeks, 1, 3 and 6 months respectively after the injection (p < 0.001 for each value compared with baseline). Patients’ global satisfaction rate was high with no serious adverse events.
Conclusion: BoNT-A injection to the ankle joint is associated with improvement in pain, function and balance in patients with painful ankle OA. These effects can last for 6 months. This pilot study supports a possible role for BoNT-A as a treatment option for painful ankle OA. Future studies are needed to confirm the results.