Comparison of the Effectiveness of Dry Needling Versus the Combination of Dry Needling and Local Anesthetic Injection in Myofascial Pain Syndrome of the Upper Trapezius Muscle: A Sham-Controlled, Randomized Clinical Trial

Myofascial pain syndrome (MPS) is one of the most common causes of chronic pain among musculoskeletal disorders, leading to both individual workforce loss and a decrease in quality of life. The pathophysiological basis of MPS consists of hyperalgesic areas within the muscle tissue, known as "trigger points. These trigger points usually arise due to repetitive microtrauma, poor posture, or static muscle use, with the upper trapezius muscle being one of the most frequently affected muscle groups .

Dry needling (DN) induces local microtrauma within the muscle by directly and invasively stimulating the trigger points, thereby initiating local inflammation and achieving an analgesic effect. DN is thought to work by reducing muscle spasm, increasing oxygenation, and providing segmental pain inhibition \[1, 5]. On the other hand, local anesthetic injection (LAI), particularly with agents such as lidocaine, provides rapid analgesia by temporarily blocking nerve conduction when applied directly around the trigger point .

Although the combined use of DN and LAI has gained attention in recent years, comparative clinical data regarding their efficacy remain limited. Some studies in the literature have shown that LAI is more effective than DN in reducing pain , yet systematic data on the advantages of combined protocols are insufficient. Additionally, some randomized controlled trials have reported that DN provides functional improvement, while achieving similar pain scores compared to LAI.

The use of sham procedures is critically important for evaluating the true biological effect of treatment. Especially in invasive techniques like dry needling, the absence of placebo control increases the risk of misinterpreting the analgesic effect. Therefore, there is a need for methodologically robust study designs.

The present study aims to demonstrate the clinical superiority of combining DN with LAI, compared to DN alone and sham groups, in terms of both pain reduction and functional improvement. The combined approach may result in more lasting outcomes on muscle tension and function. Moreover, thanks to the comparison group with sham procedures, the true clinical efficacy of the interventions can be evaluated more objectively.

Inclusion criteria

• Being between 18 and 65 years of age

• Having a diagnosis of myofascial pain syndrome with at least one active trigger point in the upper trapezius muscle according to the criteria of Travell and Simons
• Having signed the informed consent form regarding the study
• Having a history of muscle pain with VAS >3 persisting for at least four weeks in the same area (upper trapezius muscle)

Exclusion criteria

• Having a diagnosis of cervical disc herniation, cervical radiculopathy, or myelopathy

• A history of central or peripheral nervous system disease (e.g., multiple sclerosis, stroke, peripheral neuropathy)
• Diagnosis of a major psychiatric disorder (major depression, anxiety disorder, bipolar disorder, schizophrenia) or receiving active psychiatric treatment
• Having bleeding diathesis, thrombocytopenia, or using anticoagulant/antiplatelet therapy for any reason (e.g., warfarin, clopidogrel)
• Presence of local infection at the injection site, dermatological lesions disrupting skin integrity, or signs of systemic infection
• Being pregnant or breastfeeding
• Having undergone injection, prolotherapy, or similar interventional treatment in the upper trapezius region within the last 6 months
• Having received dry needling treatment in any region previously
• A history of orthopedic or neurosurgical surgery involving the cervical spine, shoulder, or upper trapezius muscle region within the last year
• Having a diagnosis of uncontrolled diabetes mellitus or advanced-stage chronic disease (e.g., congestive heart failure, renal failure)
• Having a diagnosis of malignancy or systemic rheumatologic disease (e.g., rheumatoid arthritis, fibromyalgia syndrome, lupus)
• Having communication difficulties, cognitive impairment, or severe visual/hearing loss that could prevent participation in the study
• Having social/logistical barriers (e.g., transportation difficulties) that would prevent regular participation in the study process