Effectiveness of Dextrose Prolotherapy Versus Normal Saline in Myofascial Trigger Points in the Trapezius Muscle: A Single Blinded Randomized Controlled Trial

Background

Muscular Trigger points is a major contributor to chronic musculoskeletal pain, leading to significant disability, reduced quality of life, and socioeconomic burden. Despite the high prevalence, its management often remains empirical, with inconsistent results from conventional therapies such as oral medications, physical therapy, and blind trigger point injections.

By systematically evaluating the outcomes of ultrasound-guided dextrose injection versus normal saline in patients with MPS, this study aims to generate robust clinical evidence to guide treatment selection and standardize interventional protocols. The findings are expected to help clinicians adopt evidence-based, safe, and cost-effective management strategies that can enhance pain relief, restore function, and improve overall quality of life in patients suffering from chronic myofascial pain.

Specific Objectives

Primary Objective: To compare the reduction in pain intensity between dextrose prolotherapy and normal saline injection groups at 1 week, 1 month, and 3 months post-intervention using the Numeric Pain Rating Scale (NPRS).

Secondary Objective: To compare improvement in Quality of Life using the World Health Organization Quality of Life Questionnaire-BREF (Hindi version).

Methodology

Design: Single Blinded Randomized control trial

Duration: 2 years

Setting: Outpatient Department (OPD) of Department of Physical Medicine & Rehabilitation, AIIMS Raebareli.

Participants:

Inclusion criteria

Age group Eighteen to sixty five years

Diagnosis based on international consensus criteria.

Palpable taut band and hypersensitive spot reproducing pain.

Duration of disease more than three months

NPRS more than or equal to five

Exclusion criteria

Cervical radiculopathy, fibromyalgia, systemic infection, coagulopathy.

Pregnancy and lactation.

Prior injection in same area

Prior steroid injection within six months

Rheumatological disorders

History of injury in neck or shoulder region

Undergoing or recently taken any medication or therapy related to psychiatric or psychological issues

Uncontrolled Hypertension and Diabetes

Refusal to give consent or take part in study

Sample Size: 36

Procedure

After obtaining informed and written consent, each participant will receive a detailed explanation regarding the purpose of the procedure, potential benefits, risks, and post-procedural care. They will be randomly divided in two groups

Group A (Experimental group): Injection 4 mL of 5% dextrose solution + Standard Rehabilitation

Group B (Control group): Injection 4 mL of 0.9% normal saline + Standard Rehabilitation

The intervention will be performed in a controlled clinical setting (Minor OT) under full aseptic precautions.

Using a high-resolution ultrasound probe (5–12 MHz linear transducer), the affected muscle will be scanned to identify the myofascial trigger point (MTrP), characterized by a focal hypoechoic or stiff nodule within the muscle belly associated with local tenderness on palpation. The skin will be sterilized using 2% chlorhexidine solution, and a 25-gauge, 1.5-inch needle attached to a 5 mL syringe will be introduced under real-time ultrasound guidance using the in-plane approach.

Once the needle tip reaches the target point (Muscle twitch may occur), negative aspiration will be performed to rule out intravascular placement. The injectate (Injection 4 mL of 5% dextrose solution ) will then be administered using the fanning technique, in which the needle tip is redirected in multiple directions within the same tissue plane without complete withdrawal from the skin. Approximately 0.5–1 mL of injectate will be delivered at 3–4 sites within the identified trigger point to ensure uniform distribution of the solution and adequate muscle coverage.

Both the groups will receive standard rehabilitation services that include postural care or correction, activity modifications or ergonomic changes and therapeutic exercises (Stretching of trapezius muscle)

Post-procedure care

After injection, the participant will be observed in the recovery area for 2–4 hours for any immediate complications such as bleeding, dizziness, or allergic reactions. A cold pack may be applied to the injection site if localized soreness occurs. Participants will be advised to avoid vigorous activity on the day of the procedure and to begin gentle stretching exercises after 24 hours to maintain muscle flexibility and prevent stiffness. Analgesics will be avoided unless rescue medication is required; in such cases, acetaminophen 650 mg may be taken on a SOS (as-needed) basis.

Follow-up and Outcome Assessment

Follow-up assessments will be conducted at baseline, 1 week, 1 month, and 3 months post-procedure.

Pain intensity will be evaluated using the Numeric Pain Rating Scale (NPRS) at all four time points (baseline, 1 week, 1 month, 3 months).

Quality of life will be assessed using the WHOQOL-BREF questionnaire at baseline, 1 month, and 3 months. Any adverse events, recurrence of pain, or need for additional interventions will be documented during each follow-up visit.

This standardized protocol aims to ensure uniformity, procedural safety, and reproducibility of ultrasound-guided trigger point injections for comparative evaluation between dextrose and normal saline.

Randomization and Blinding: Participants randomized 1:1 using computer-generated sequence. Participants will not know about their group allocation and type of intervention therefore it will be Single Blind study. Both injections are transparent in nature. Participants will be informed about both procedures. Assessor will also not know about intervention group. Patient will be informed about their management.