Both lidocaine trigger point and physiologic saline interfascial injections were found to minimize myofascial pain in the upper trapezius muscle at two and four weeks following therapy. But, lidocaine trigger point injection offered better pain relief at 10 minutes after therapy. 

To distinguish between the effects of two anesthetic ultrasound-guided injections to manage myofascial pain syndrome.

A total of 80 patients (15 males and 65 females with a mean age of 40.4 ± 10.9 years) with pain in the upper trapezius muscle were included in this double-blind randomized controlled study. Participants were divided into 2 groups as (i) Group 1 (n=40): Received interfascial injection with physiologic saline, and (ii) Group 2 (n=40): Received lidocaine trigger point injection with lidocaine.

Visual analog scale (VAS) for pain assessment was regarded as the primary outcome while the cervical range of motion and adverse effects were the secondary outcomes. The outcomes were evaluated before therapy and 10 minutes, two weeks, and four weeks after therapy. 

A higher VAS score improvement at 10 minutes was observed after the use of lidocaine trigger point injection as shown in the following figure 1:

Figure 1: Pain assessment via VAS scores outcomes in group 1 and group 2

No statistically significant difference at other follow-up time periods was found. A significant decline in pain scores was observed at 10 min, 2 weeks, and 4 weeks from the baseline. The cervical range of motion raised considerably over time in some directions without any vital differences between the two groups. No serious adverse effects were reported.

At two and four weeks, physiologic saline interfascial and lidocaine trigger point injections were successful in reducing myofascial pain. Nevertheless, lidocaine trigger point injection exhibited better pain recovery at 10 minutes following the treatment.