What are the indications for a tendon sheath injection, and what are the potential complications?
The indications for tendon sheath injection include chronic or intractable pain that is recalcitrant to physical therapy. A tendon sheath injection may be performed with US guidance for diagnostic purposes, to localize the patient’s pain preoperatively, or for therapeutic purposes to provide symptomatic relief in an effort to delay surgery. The tendon sheath injection may be performed either in the long axis or the short axis of the tendon ( Figure 75-3 ). The major potential complication of a tendon sheath injection is tendon rupture, with a greater risk in patients with severe tendinosis or high-grade partial tears. The risk of tendon rupture in a previously intact tendon is very low. In the setting of superficial tendon sheath injection such as in the feet and hands, there is a risk of fat necrosis/skin depigmentation secondary to corticosteroid infiltration of the subcutaneous soft tissues.