Comparison of Peritendinous Hyaluronan Injections Versus Extracorporeal Shock Wave Therapy in the Treatment of Painful Achilles' Tendinopathy: A Randomized Clinical Efficacy and Safety Study

Abstract

Objective: To compare the safety and efficacy of hyaluronan (HA) injections with standard extracorporeal shock wave therapy (ESWT) in the treatment of painful midportion Achilles' tendinopathy.

Design: Multinational, prospective, randomized controlled, blinded-observer trial.

Setting: Ambulatory care.

Participants: Adults (N=62) with Achilles' midportion tendinopathy for ≥6 weeks and a pain score of at least 40mm (Huskisson visual analog scale [VAS], 100mm) were randomized, and 59 were analyzed in the intention-to-treat data set. There were no withdrawals because of adverse effects.

Interventions: Two peritendinous HA injections versus 3 ESWT applications at weekly intervals.

Main outcome measures: Primary efficacy criterion was changed from the Victorian Institute of Sports Assessment-Achilles' questionnaire (VISA-A) score to the percent change in pain (VAS) at 3 months posttreatment, compared with baseline values. Main secondary parameters were VISA-A, Clinical Global Impression (CGI), and clinical parameters.

Results: HA treatment provided a clinically relevant improvement in Achilles' midportion tendinopathy. A large superiority of the HA group, compared with ESWT application, was observed for percent change in pain (VAS), and this superiority was proven to be statistically significant (Mann-Whitney statistic [MW]=.7507 with P=.0030 lower than required α=.025 significance level 1-sided; Mann-Whitney U test) at 3 months posttreatment. Similar findings for HA were also observed at 4 weeks (MW=.6425, P=.0304) and 6 months (MW=.7172, P=.0018). Advantage of HA treatment was confirmed by VISA-A questionnaire, CGI, and clinical parameters. Ten adverse events, 4 in the HA group and 6 in the ESWT group, were reported, but none were classified as serious.

Conclusions: Two peritendinous HA injections showed greater treatment success in Achilles' midportion tendinopathy compared with standard ESWT.

Trial registration: ClinicalTrials.gov NCT01954108.

Keywords: Achilles tendon; High-energy shock waves; Hyaluronic acid; Rehabilitation; Tendinopathy.