Background: Tears of the rotator cuff typically begin in the supraspinatus tendon.¹ A corticosteroid injection into the tendon may cause a potential weakening of the tendon, and therefore, these procedures are deemed inappropriate.

As new injection technologies and applications emerge such as platelet-rich plasma, bone marrow aspirate, growth factor supplements, as well as cell- and gene-modified cell therapies, musculoskeletal practitioners will need to develop injection skills to deliver these new therapeutic interventions via injection.² Advances in both ultrasound technology as well as emerging subsTances that augment tissue proliferation and enhance healing are in its infancy. The use of percuTaneous tendon decalcification procedures (Fig. 61.1) will also require skills of needle guidance into the rotator cuff tendons.³

Anatomy: The supraspinatus muscle originates in the supraspinatus fossa extending under the acromion to attach in a triangular footprint on the greater tuberosity. The muscle has a long tendinous portion in the anterior half of the muscle, which typically inserts in the anterior-most area of the highest impression on the greater tuberosity (Figs. 61.2 and 61.3).