Treatmentofmyofascialpainsyndromewithlidocaineinjectionandphysicaltherapy,aloneorincombination:asingleblind,randomized,controlledclinicaltrial

Myofascial pain syndrome (MPS) of the shoulder girdle and cervical region is a common musculoskeletal problem that is often chronic or recurrent. Physical therapy (PT) and lidocaine injections (LI) into trigger points are two treatments that have shown effectiveness when compared to control groups, but little was known about whether combining these treatments would produce better results than either treatment alone. This matters because clinicians and patients want to know if adding an invasive procedure (injections) to a non-invasive program (physical therapy) is worth the extra time, cost, and potential risks.

The researchers conducted a single-blind, randomized, controlled clinical trial with three parallel groups at two urban hospitals in Medellín, Colombia. They enrolled 127 patients who had shoulder girdle MPS for more than 6 weeks with pain greater than 40 mm on a 0-100 visual analog scale (VAS). Patients were randomly assigned to one of three groups: physical therapy alone (43 patients), lidocaine injection alone (43 patients), or the combination of both (41 patients). The PT program consisted of 12 sessions over 4 weeks (3 times per week), each including hot packs, ultrasound, manual trigger point compression, deep stroking or strumming, muscle stretching and strengthening exercises, and joint range of motion exercises.

The lidocaine injection used 0.5% lidocaine without epinephrine, injected once into identified trigger points using a 25 or 26 gauge needle. The combination group received both interventions, starting with the injection and beginning PT 2-3 days later. A nurse who was blinded to treatment group assessed outcomes at baseline, 1 month, and 3 months post-treatment. The primary outcome was VAS pain score at 1 month.

Secondary outcomes included VAS at 3 months, function (hand-back and hand-mouth maneuvers), quality of life (SF-36 subscales), and depressive symptoms (PHQ-9).

There were no statistically significant differences between any of the three groups for the primary outcome of pain at 1 month. The mean VAS scores were: PT+LI group 40.8 (SD 25.3), PT group 37.8 (SD 21.9), and LI group 44.2 (SD 24.9). The p-values for comparisons were p=0.560 (PT+LI vs PT) and p=0.545 (PT+LI vs LI). At 3 months, pain had improved in all groups (PT+LI: 21.6, PT: 28.2, LI: 28.8), but again with no significant differences between groups.

For secondary outcomes, there were no significant differences in PHQ-9 depression scores or any SF-36 quality of life dimensions at either time point, except for one SF-36 item: the PT+LI group reported significantly better "change in health" quality of life compared to PT alone at 1 month (70.0 vs 60.9, p=0.03). The only other significant finding was that both the PT and PT+LI groups had better right upper limb hand-back maneuver scores compared to LI alone at 1 month (p=0.013) and 3 months (p=0.016). Left upper limb function did not differ between groups. Complications were minimal: 6 patients total had localized hematomas (4 in PT+LI, 2 in LI), with a complication rate of 2.66% for injections.

Analgesic use was similar across groups (36.6% PT+LI, 53.0% PT, 51.2% LI; p=0.10).

For patients with myofascial pain syndrome of the shoulder girdle and cervical region, adding lidocaine injections to physical therapy does not provide additional pain relief compared to either treatment alone. This suggests that patients can achieve similar pain outcomes with physical therapy alone, avoiding the invasiveness and small risks of injections. However, physical therapy — whether alone or combined with injections — may offer slight functional advantages for specific upper limb movements compared to injections alone. For clinicians, this means that physical therapy should be considered a first-line treatment, and the decision to add lidocaine injections should not be based on expected superior pain outcomes.

The finding that all groups improved over time also suggests that MPS can improve with structured treatment, but the specific modality may matter less than previously thought. The lack of a sham or placebo control group means we cannot determine how much of the improvement was due to natural history or placebo effects, which is an important limitation for interpreting the magnitude of improvement seen in all groups.