Monitoring symptom improvements after the treatment of active myofascial trigger points with ultrasound elastography

Abstract

Purpose: Ultrasound elastography (UE) is a recently developed technique and is used to determine the mechanical properties of tissues. We aimed to assess the usefulness of axial-strain UE for pre and post treatment evaluation of patients with active myofascial triggerpoints (MTrPs) of the upper trapezius.Materials and Methods: The study included 49 patients (66 MTrPs) with myofascial pain syndrome. Patients were randomized into two treatment groups, group 1 (trigger point injection with stretching exercises) and group 2 (trigger point injection). The groups were evaluated with UE before, 2 and 14 days post-treatment. Disability, pain, and pressure pain threshold (PPT) were also assessed. Results: All clinical parameters were strongly correlated with strain ratio (SR) value at baseline, 2 and 14 days post-treatment. Both groups demonstrated significant improvements with respect to Neck Pain and Disability Scale , VAS, and PPT scores post-treatment. However, group 1 had better scores than group 2 in 14 days post-treatment. Conclusion: Our study demonstrated that SR values for MTrPs in the upper trapezius correlated with clinical parameters at baseline and after treatment. According to these results, axial-strain UE, which is non-invasive and semiquantitative method may be usefull to evaluation and monitor improvement in patients with active MTrPs.