What size needle is used for trigger point (myofascial trigger point) injection?

From the Guidelines

A 25-gauge, 1.5-inch needle is typically used for trigger point injection, as it provides a good balance between effectiveness and patient comfort. When considering the size of the needle for trigger point injection, it's essential to weigh the factors of effectiveness, patient comfort, and potential complications. The gauge of the needle refers to its thickness, with higher gauges indicating thinner needles. A 25-gauge needle is relatively thin, which helps minimize pain during insertion, but still sturdy enough to penetrate muscle tissue effectively. The length of the needle is also crucial, as it needs to be long enough to reach the trigger point, which can be located at varying depths depending on the muscle group being treated.

• Key considerations for needle size include:
  • Effectiveness in reaching the trigger point
  • Patient comfort during the procedure
  • Risk of complications, such as bleeding or nerve damage
• The specific area being treated and the patient's body composition can influence the choice of needle size, with longer needles potentially needed for larger muscle groups or patients with more adipose tissue, and shorter needles for more superficial trigger points or leaner individuals 1.
• While the provided evidence does not directly address trigger point injections, the discussion on needle types and sizes in the context of acupuncture trials highlights the importance of considering these factors in interventions involving needle insertion, underscoring the need for a balanced approach that prioritizes both efficacy and patient comfort.

From the Research

Needle Size for Trigger Point Injection

• The size of the needle used for trigger point injection is an important consideration in the treatment of myofascial pain syndrome.
• A study published in 2009 2 compared the efficacy of 21-, 23-, and 25-gauge needles for trigger point injection in the upper- and middle-trapezius muscle.
• The results showed that all three needle sizes were effective in reducing pain and improving function, with no significant difference between the groups in terms of pain intensity during injection.
• However, the study found that injections with 21- or 23-gauge needles were more effective in improving health-related quality of life, as measured by the SF-36 score.

Comparison of Dry Needling and Trigger Point Injection

• Other studies have compared the efficacy of dry needling and trigger point injection for the treatment of myofascial trigger points.
• A systematic review and meta-analysis published in 2022 3 found that trigger point injection (wet needling) was more effective than dry needling in reducing pain intensity in the short term.
• However, the evidence was downgraded due to heterogenicity and imprecision of results, and no significant effects were observed on other outcomes such as pain-related disability, pressure pain thresholds, cervical mobility, and psychological factors.

Needle Size and Treatment Efficacy

• The optimal needle size for trigger point injection is not clearly established, and more research is needed to determine the relationship between needle size and treatment efficacy.
• The study published in 2009 2 suggests that 21- or 23-gauge needles may be more effective than 25-gauge needles in improving health-related quality of life, but further research is needed to confirm this finding.
• Other studies have focused on the comparison of dry needling and trigger point injection, rather than the specific needle size used for trigger point injection 4, 5, 6.