Hyaluronic acid injection for ankle sprains: a randomised controlled trial

M. Quinn, J. O’Donnell, D. Bergin, S.R. Kearns

Introduction: A double blinded randomised controlled trial was conducted to ascertain the effectiveness of hyaluronic acid injection in acute ankle sprains, confirmed with magnetic resonance imaging (MRI). Primary end points were that of return to optimal ankle function as assessed by both visual analogue pain scores (VAS) and American foot and ankle score (AFAS). A secondary endpoint was to investigate, in the case that, peri-articular injection (PI) showed benefit, that a perhaps more technically straight forward technique of intra-articular injection (II) produced similar results.

Methods: Patients were selected through identification by either emergency department or general practice referrals on clinical suspicion of a grade 2 or 3 ankle sprains, and MRI was performed to confirm lateral ligament injury. Patients with occult fractures or other significant pathology were excluded. Those identified as having lateral ligament injury were then randomised to Hyaluronic acid (HA) or placebo (PL) injection, either peri-articular or intra-articular. Patient outcomes were assessed at day 10 and day 42, with the VAS and AFAS.

Results: Among the 4 groups of 8 patients, those who received HA injection rather than PL, showed improved pain and function scores at day 10, assessed with both, VAS (Intra-articular HA v Peri-articular placebo : Mean difference 1.63 p=0.02 CI 95% 0.3-2.95) and AFAS (IAHA v PAPL, Mean difference =13.88, P=0.0016 CI 95% 6.24-21.51) scores. However, results were similar in all groups at day 42. There was no significant statistical difference between both the PI and II groups.

Conclusion: This study finds that early identification and intervention with hyaluronic acid injection of lateral ligament complex injuries can result in a more swift resolution of symptoms, and earlier return to function, which is statistically significant. It also suggests delivery of the therapeutic agent can be either peri or intra-articular.