Feasibility of Ultrasound-Guided Trigger Point Injection in Patients with Myofascial Pain Syndrome.

We compared the feasibility of ultrasound (US)-guided myofascial trigger point (MTrP) injection with that of a blind injection technique following the use of shear wave elastography (SWE) for the measurement of stiffness at the MTrPs in patients with trapezius myofascial pain syndrome (MPS). A total of 41 patients (n = 41) were randomized to either the trial group (n = 21, SWE combined with US-guided injection) or the control group (n = 20, SWE combined with blind injection). At baseline and four weeks, they were evaluated for the manual muscle test (MMT), the range of motion (ROM), pain visual analogue scale (VAS) scores, Shoulder Pain and Disability Index (SPADI) scores and Neck Disability Index (NDI) scores during the abduction, adduction, flexion, extension, external rotation and internal rotation of the shoulder joint. Differences in changes in pain VAS scores, NDI scores and SPADI scores at four weeks from baseline between the two groups reached statistical significance (p = 0.003, 0.012, and 0.018, respectively). US-guided MTrP injection is a more useful modality as compared with a blind injection in patients with MPS.