Subtalar joint injection is used to treat inflammation secondary to rheumatoid arthritis and other inflammatory arthritides.
After informed consent is obtained, the patient is placed in the prone position with the feet extending over the end of the examination table and the foot flexed to about 90 degrees. The location of the subtalar joint, about 1 to 2 cm distal to the tip of the lateral malleolus and posterior to the sinus tarsus, should be palpated and marked. 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-gauge needle is inserted perpendicular to the skin at the mark and advanced medially into the subtalar joint. Aspiration is attempted until the needle has entered the synovial space. If there is an effusion of the joint, the aspiration is completed. If the aspirated fluid is noninflammatory (clear and viscous), the joint should be injected with a 2-mL mixture of 10 mg of triamcinolone acetonide (or equivalent) and local anesthetic (Fig. 67-56).
FIGURE 67-56. Subtalar (talocalcaneal) joint injection. Approach for subtalar (talocalcaneal) joint aspiration and injection.
Injection of this joint is usually secondary to osteoarthritis resulting from trauma or from repetitive overuse injury such as from ballet dancing. Gout is not an indication for injecting this joint.
Corticosteroids should not be injected if there is any suspicion that the joint is infected. If the fluid appears infected, then it should be sent for culture and sensitivity and the patient treated appropriately for the infection.