The accuracy of blind glenohumeral injections has been the subject of many studies.^{1, 2and 3} Ultrasound guidance significantly improves the accuracy of the intra-articular injections. In addition, ultrasound-guided glenohumeral injections can be less time-consuming and more successful on the first attempt compared to fluoroscopic guidance. More imporTantly, misplaced injections can result in tendon injections (which can lead to a tendon weakening), skin depigmentation, soft-tissue damage, and dissatisfaction. Several methods of intra-articular injections have been described such as an anterior, anterior rotator cuff interval, superior rotator cuff interval, and posterior approach.^{4, 5and 6} If the injection is planned for the purpose of an arthrogram, extra caution should be exercised to avoid the tissues of interest, such as the tendon of the subscapularis. For this purpose, a rotator cuff interval or posterior approach is typically preferred. Regardless of the approach, it is imporTant to avoid traversing the cartilaginous glenoid labrum. Typically, musculoskeletal practitioners prefer a posterior approach, although a modified rotator cuff interval approach can be used as an alternative. Both approaches are described as follows.

Transducer: A linear high-frequency broad-band transducer (anterior approach) or a curvilinear low-frequency transducer (posterior approach).

Needle: 2 in to 3.5 in 22-gauge to 25-gauge spinal or echogenic needle.

Local Anesthetic: 5 mL of 1% ropivacaine, procaine, or other suitable local anesthetic with 40 mg of triamcinolone.

Anatomy: The posterior approach is considered the safest because no neurovascular structures are lying at the needle path. The tendon infraspinatus extends over the glenohumeral joint to the posterior greater tuberosity. A needle directed to the glenohumeral joint from the posterior approach will traverse the tendon or muscle infraspinatus. The target for the intraarticular posterior glenohumeral injection is a region overlying the humeral head just distal to the glenoid labrum as noted by the asterisk in Figure 60.1. One should avoid traversing the glenoid labrum for the intra-articular injection. The bevel of the needle should be directed downward as contact is made over the humeral head.