Gluteal muscle injection is a useful diagnostic and therapeutic procedure for myofascial pain.
After informed consent is obtained, the patient is placed in the lateral position with the unaffected side down, or in the prone position. The gluteus maximus, minimus, and medius muscles are 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. 67-30).
FIGURE 67-30. Gluteal trigger points and referred pain patterns.
The referred pain pattern for the gluteus maximus usually involves the sacroiliac joint, hip, and buttock. The referred pain pattern for the gluteus medius often involves the iliac crest, sacroiliac joint, and buttock. The referred pain pattern for the gluteus minimus muscle usually involves the buttock and lateral aspect of the lower extremity. The patient should be fully familiar with the stretching program for the gluteal 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 gluteal trigger point injections; however, the anatomy of the region, including the sciatic nerve, must be carefully considered with these injections. Intraneural injection may result in nerve damage. Severe pain on injection suggests the possibility of an intraneural injection, and the needle should be immediately repositioned. Temporary lower extremity weakness is possible from regional spread of the local anesthetic.