Comparison of the Effects of Physiologic Saline Interfascial and Lidocaine Trigger Point Injections in Treatment of Myofascial Pain Syndrome: A Double-Blind Randomized Controlled Trial

Abstract

ObjectiveTo compare the effects of physiological saline interfascial and lidocaine trigger point injections in the treatment of myofascial pain syndrome (MPS). DesignDouble-blind randomized controlled study. SettingDepartment of Rehabilitation Medicine. ParticipantsEighty patients (N=80; 15 men, 65 women; mean age, 40.4±10.9y) with MPS in the upper trapezius muscle. InterventionsPatients were randomly assigned to 1 of 2 groups: group 1 (n=40) received ultrasound-guided interfascial injection with physiological saline, and group 2 (n=40) underwent ultrasound-guided trigger point injection with lidocaine. Main Outcome MeasuresThe primary outcome was pain scores measured by the visual analog scale (VAS). Secondary outcomes included cervical range of motion (ROM) and adverse effects of the procedure. The outcomes were assessed before treatment and 10 minutes, 2 weeks, and 4 weeks after treatment. ResultsLidocaine trigger point injection showed higher VAS score improvement at 10 minutes after the procedure (P=.037). However, there was no statistically significant difference at other follow-up points. Pain scores significantly decreased at 10 minutes, 2 weeks, and 4 weeks from baseline in both groups. Cervical ROM increased significantly over time in some directions without significant differences between the groups. There were no serious adverse effects in this study. ConclusionPhysiologic saline interfascial and lidocaine trigger point injections effectively decreased MPS pain in the upper trapezius muscle at 2 and 4 weeks after treatment. However, lidocaine trigger point injection demonstrated better pain improvement at 10 minutes after treatment.