Trigger point injection of the trapezius muscle is used to treat myofascial pain.
After informed consent is obtained, the patient is placed in the sitting or prone position. The trapezius muscle is palpated. The injection sites are identified as points of maximal tenderness to deep palpation reproducing the patient’s pain complaint. This may or may not result in referred pain. The patient is prepared in a standard aseptic fashion over an area large enough to allow palpation of landmarks, and sterile technique is used throughout the procedure. A 1½-in. (4-cm), 21- to 25-gauge needle is inserted at the point of maximal tenderness and advanced to the area of the trigger point. After negative aspiration, the trigger point area is injected with 4 mL of local anesthetic (Fig. 67-22).
FIGURE 67-22. Trapezius. Trigger points and referred pain patterns.
The referred pain pattern for the upper trapezius is often along the posterior lateral aspect of the neck, as well as periarticular and temporal regions. The referred pain pattern for the mid trapezius often involves the shoulder and paraspinal region. The referred pain pattern for the lower trapezius usually involves the paraspinal region. The patient should be fully familiar with the stretching program for the trapezius muscle and be instructed in a home program. Failure to include a home stretching program usually results in short-term relief.
Significant complications are uncommon with trapezius trigger point injections.