Astym treatment vs. eccentric exercise for lateral elbow tendinopathy: a randomized controlled clinical trial

Abstract

Introduction. Patients with chronic lateral elbow (LE) tendinopathy, commonly known as tennis elbow, often experience prolonged symptoms and frequent relapses. Astym treatment, evidenced in animal studies to promote the healing and regeneration of soft tissues, is hypothesized to improve outcomes in LE tendinopathy patients. This study had two objectives: (1) to compare the efficacy of Astym treatment to an evidence-based eccentric exercise program (EE) for patients with chronic LE tendinopathy, and (2) to quantify outcomes of subjects non-responsive to EE who were subsequently treated with Astym treatment. Study Design. Prospective, two group, parallel, randomized controlled trial completed at a large orthopedic center in Indiana.

Inclusion criteria: age range of 18-65 years old, with clinical indications of LE tendinopathy greater than 12 weeks, with no recent corticosteriod injection or disease altering comorbidities. Methods. Subjects with chronic LE tendinopathy (107 subjects with 113 affected elbows) were randomly assigned using computer-generated random number tables to 4 weeks of Astym treatment (57 elbows) or EE treatment (56 elbows). Data collected at baseline, 4, 8, 12 weeks, 6 and 12 months.

Primary outcome measure: DASH; secondary outcome measures: pain with activity, maximum grip strength and function. The treating physicians and the rater were blinded; subjects and treating clinicians could not be blinded due to the nature of the treatments. Results. Resolution response rates were 78.3% for the Astym group and 40.9% for the EE group. Astym subjects showed greater gains in DASH scores (p = 0.047) and in maximum grip strength (p = 0.008) than EE subjects. Astym therapy also resolved 20/21 (95.7%) of the EE non-responders, who showed improvements in DASH scores (p < 0.005), pain with activity (p = 0.002), and function (p = 0.004) following Astym treatment. Gains continued at 6 and 12 months. No adverse effects were reported. Conclusion. This study suggests Astym therapy is an effective treatment option for patients with LE tendinopathy, as an initial treatment, and after an eccentric exercise program has failed. Registration/Funding. Ball Memorial Hospital provided limited funding. Trial registration was not required by FDAAA 801. Known about the Subject. Under the new paradigm of degenerative tendinopathy, eccentric exercise (EE) is emerging as a first line conservative treatment for LE tendinopathy. EE and Astym treatment are among the few treatment options aiming to improve the degenerative pathophysiology of the tendon. In this trial, Astym therapy, which has shown success in the treatment of tendinopathy, is compared to EE, which has also shown success in the treatment of tendinopathy. Clinical Relevance. There is a need for more effective, conservative treatment options. Based on the current efficacy study, Astym therapy appears to be a promising, non-invasive treatment option.

Keywords: Astym; Lateral epicondylitis; Tendinitis; Tendinopathy; Tennis elbow; Treatment.

Conflict of interest statement

Thomas L. Sevier is the Medical Director of the Astym program.

Figures

Figure 1. Flow sheet of number subjects enrolled, retention and drop-outs through the course of the study.

Figure 2. Astym treatment.

(A) Astym treatment of tendinopathy of the lateral elbow. (B) Astym treatment of tendinopathy of the lateral elbow, distal kinetic chain. (C) Astym treatment of tendinopathy of the lateral elbow, proximal kinetic chain

Figure 3. Mean and standard deviations of the DASH scores of the Eccentric and Astym Groups at Baseline (DASH 0) and at the closure of the 4 week randomized phase of the study (DASH 4).

Figure 4. Mean and standard deviations of DASH scores for the Astym Delayed Entry Group. Astym treatment started at 8 weeks for recalcitrant eccentric subjects who opted to receive Astym therapy.