Position and anatomical landmarks
Infiltration is carried out with the patient in the supine position with the head in a slightly backward flexion position. The head is positioned in the midline.
The lower margin of the arcus zygomaticus is localised, and then the joint cleft is palpated and marked, just below the arcus zygomaticus and anterior to the external auditory meatus (see figure).
The surrounding area is disinfected and covered with sterile drapes. A needle (22-G) is inserted (under ultrasound guidance) just below the arcus zygomaticus until there is contact with bone.
The needle is replaced slightly caudally (' walked') until it reaches the joint cleft. The needle is withdrawn slightly, and bupivacaine 0.25% with 20 mg of methylprednisolone is injected (in 1 ml).
- The most serious complication of injection is infection.
- Small subcutaneous bleedings may result in a temporary increase in pain after the injection.