Abstract
BACKGROUND: To assess the efficacy and safety of perimysium dissection for posterior shoulder myofascial pain. METHODS: This retrospective single-arm study was performed at a medical center between April 2016 and August 2017. Fifty-seven participants with refractory chronic posterior shoulder pain of myofascial origin underwent ultrasound (US)-guided perimysium dissection with hypertonic dextrose solution. Visual analog scale (VAS) scores and complication rate were evaluated before treatment and 4 weeks after treatment. RESULTS: US-guided perimysium dissection with dextrose solution resulted in excellent treatment efficacy and safety. Nineteen participants (33.3%) were free of pain after treatment, and 32 (56.1%) had >50% improvement in pain score. Forty-nine participants had complete VAS records. Overall mean pre- and posttreatment VAS scores were 7.18 ± 1.60 and 1.91 ± 2.04 (mean difference -5.27, 95% CI -5.99 to -4.55, p < 0.0001), respectively, including 7.26 ± 1.44 and 1.84 ± 1.98 (mean difference -5.43, 95% CI -6.33 to -4.52, p < 0.0001) for those with infraspinatus myofascial pain, and 7.00 ± 1.96 and 2.07 ± 2.26 (mean difference -4.93, 95% CI -6.23 to -3.62, p < 0.0001) for those in the teres minor subgroup. No complications were reported in any of the participants. One participant received retreatment for teres minor myofascial pain. CONCLUSION: US-guided perimysium dissection is an easy, safe, and effective injection method to manage posterior myofascial shoulder pain.