Injection Technique for Scapulocostal Syndrome

Indications and Clinical Considerations

Scapulocostal syndrome describes a constellation of symptoms consisting of unilateral pain and associated paresthesias occurring at the medial border of the scapula, referred pain radiating from the deltoid region to the dorsum of the hand, and decreased range of motion of the scapula ( Fig. 51.1 ). Scapulocostal syndrome is commonly referred to as traveling salesman’s shoulder because it frequently is seen in individuals who repeatedly reach backward over a car seat to get something from the back seat of the car. It is an overuse syndrome caused by repeated improper use of the muscles of scapular stabilization, namely the levator scapulae, the pectoralis minor, the serratus anterior, the rhomboids, and, to a lesser extent, the infraspinatus and teres minor.

Physical examination reveals decreased scapular range of motion on the affected side. Pain is reproduced by reaching backward with the affected extremity. A prominent infraspinatus trigger point is present in almost all patients with scapulocostal syndrome ( Fig. 51.2 ). This infraspinatus trigger point can be demonstrated best by having the patient place the hand of the affected side over the deltoid of the opposite shoulder. This maneuver laterally rotates the affected scapula and allows palpation and subsequent injection of the infraspinatus trigger point. Other trigger areas along the medial border of the scapula also may be present and may be amenable to injection therapy.

Plain radiographs are indicated for all patients with suspected scapulocostal syndrome to rule out occult bony pathology, including metastatic lesions. On the basis of the patient’s clinical presentation, additional testing may be indicated, including complete blood cell count, prostate-specific antigen, sedimentation rate, and antinuclear antibody testing. Magnetic resonance imaging scan of the shoulder is indicated if a rotator cuff tear is suspected. Electromyography is indicated in patients with scapulocostal syndrome to help rule out cervical radiculopathy or plexopathy. The injection technique described later serves as both a diagnostic and a therapeutic maneuver.