Patient Outcomes on Treatment of Insertional Achilles Tendinopathy with Extracorporeal Shockwave Therapy: A Retrospective Study

Abstract

Category: Ankle; Other Introduction/Purpose: Insertional achilles tendinopathy (IAT) affects approximately one-third of patients who report achilles tendon pain during their lifetime. It is characterized by stiffness and pain that are aggravated by prolonged rest and physical activity, respectively. Known treatments for IAT include eccentric exercises, night splints, pharmacologic or biologic injections, and extracorporeal shockwave therapy (ESWT). However, pain and functional outcomes following ESWT treatment for IAT vary throughout the literature. In addition, ESWT protocols have varied across studies. This retrospective study aimed to collect information on patient outcomes following ESWT treatment for IAT at a single institution to better characterize patient-reported pain and functional outcomes and to determine if patient-reported outcomes differ according to varying ESWT protocols. Methods: 44 patients who presented with IAT and received ESWT from 2/1/2016 to 10/1/2021 were included. Confirmation of IAT was determined by a review of each patient's chart. Patient-reported outcomes included NRS or VAS scores and PROMIS-10 were collected prior to ESWT sessions and at follow-up time points. Additionally, demographic information for each patient was collected including age, gender, race, ethnicity. Information regarding their achilles tendinopathy included symptom duration, laterality, prior interventions before ESWT, concurrent foot or ankle injuries on the same side, pain (baseline and follow-ups), PROMIS-10 (baseline and follow-ups) was also collected. Finally, ESWT information was reviewed including focused vs radial, number of sessions, number of pulses, energy intensity, frequency, any adverse outcomes after ESWT (e.g., tendon rupture, increase in pain; immediate or delayed), and if any interventions were needed during or after ESWT (physical therapy, cortisone injection, PRP, surgery, medications, orthotics). Results: Out of the 44 patients who were included in the study, 27 were female and 17 male. Mean symptom duration was 23.3 months (SD 26.7 months). 34 patients had unilateral pain while 5 had bilateral pain. Every patient had undergone previous treatment with a majority having tried physical therapy (n=33) and bracing (n=21). Mean number of ESWT sessions between patients was 3.3 (SD 1.5 sessions). 30 patients received focused shockwave therapy, 3 received radial shockwave therapy and 1 received both. The remaining 10 patient charts were inconclusive as to which type of shockwave was performed. 13 patients reported no improvement whereas the remaining 31 patients reported improvement, with a majority (n=18) reporting at least 50% improvement or greater. Conclusion: Insertional achilles tendinopathy can be treated with a wide variety of modalities, therapies and adjuncts. When considering treatment for cases that do not respond to the traditional methods including physical therapy, bracing and injections, ESWT shows promising data to be an effective treatment option, regardless of type or intensity. Most patients require more than 1 ESWT to be effective.