SLR - February 2022 - Sara Sadeghi
Reference: Gatz M, Schweda S, Betsch M, Dirrichs T, de la Fuente M, Reinhardt N, Quack V. Line- and Point-Focused Extracorporeal Shock Wave Therapy for Achilles Tendinopathy: A Placebo-Controlled RCT Study. Sports Health. 2021 Sep-Oct;13(5):511-518. doi: 10.1177/1941738121991791. Epub 2021 Feb 13. PMID: 33586526; PMCID: PMC8404720.Level of Evidence: Level 1
Scientific Literature Review
Reviewed By: Sara Sadeghi, DPM
Residency Program: East Liverpool City Hospital – East Liverpool, OH
Podiatric Relevance: Achilles tendinopathy is a common pathology encountered in the field of podiatric medicine. The utilization of extracorporeal shockwave therapy can help expand the podiatric physician’s conservative treatment modalities of Achilles tendinopathy prior to surgical intervention. The hypothesis of the study was that point- and line-focused ESWT would have a superior outcome than placebo ESWT and that ESWT would cause morphological tendon changes detectable with ultrasound.
Methods: This was a single-blinded placebo-controlled randomized controlled trial. The study was divided into three cohorts: ESWT point (n=21), ESWT line (n=24), and ESWT placebo (n=1). VISA-A scores were measured before intervention, six weeks after intervention and 24 weeks after intervention. Ultrasound was performed with B-mode, power Doppler, shear wave elastography, and with ultrasound tissue characterization. Data was then collected with a mixed analysis of variance and t test.
Results: All groups showed significant VISA-A improvement over time (P<0.001). ESWT point had the strongest VISA-A score improvement +23 (ESWT line: +18, ESWT placebo: +15). However, there was no significant interaction shown between time and any of the groups. Ultrasound tissue characterization, power doppler, and B-mode did not indicate any significant changes over time. Shear wave elastography displayed a significant increase of elastic properties for ESWT point in the insertion (t= -3.113, P=0.03) and mid portion (t= -2.627, P=0.02) of the Achilles tendon over time.
Conclusions: The authors concluded that there was a significant VISA-A score improvement for all study groups without a statistically significant benefit for ESWT point or ESWT line compared with ESWT placebo. Tendon adaptation was only detected with shear wave elastography for ESWT point. Line-focused ESWT allows for greater tendon volume to be treated versus point-focused ESWT. However, maximum energy density is higher in point-focused ESWT versus line-focused. The ESWT point cohort had the strongest VISA-A score improvement throughout the whole study period and a significant score change directly after six weeks. However, it’s difficult to compare the variation in technologies because of the different energy distributions. Regardless of method, all groups appeared to improve overtime, which suggests that extracorporeal shockwave therapy is an acceptable method for conservative treatment of Achilles tendinopathy. The study also suggested that shear wave elastography could partly show significant increased elastic tendon properties which correlated with score improvement. Therefore, shear wave elastography could prove to be useful in helping to monitor clinical symptoms while conservatively treating Achilles tendinopaty with the use of ESWT. The information provided in the study could help benefit the podiatric patient that encounters tendinopathy and is seeking conservative treatment.