Arthroscopic Management of Coracoid Impingement

Abstract

Coracoid impingement has been the topic of debate for a century. Most authors have identified coracoid impingement as a potential cause of anterior shoulder pain, particularly with movements requiring forward flexion, internal rotation, and horizontal adduction of the humerus. Subcoracoid pain can occur as a result of compression of the subscapularis tendon or biceps tendon between the bony structures of the lesser tuberosity and the coracoid process. Underlying coracoid impingement is associated with dull pain in the anterior shoulder that may refer distally through the biceps area. Multiple etiologies of coracoid impingement have been described, resulting in primary or secondary impingement. Idiopathic causes include the presence of a congenitally elongated or angled coracoid tip and calcification within the subscapularis tendon.Ganglion cyst formation has also been described as a cause of coracoid impingement. Traumatic etiologies include fracture of the humeral head and neck,malunion of previous coracoid or glenoid fracture, and displaced fracture of the scapular neck. The patient should be carefully examined for anterior glenohumeral instability because this clinical entity can cause secondary coracoid impingement, resulting in anterior shoulder pain. Identification of abnormal scapular mechanics, such as winging or dyskinesia, is vital. Coracoid decompression in a patient with underlying instability or scapular malposition will likely lead to a poor outcome.Iatrogenic causes of coracoid impingement include previous anterior shoulder surgery, such as coracoid transfer and posterior glenoid osteotomy. Meticulous physical examination is required in the patient with coracoid impingement, along with proper use of imaging studies to assess the anatomic structures in the anterior shoulder and their relationship to the coracoid process. Coracoid impingement is a rare finding. Identification and proper management of this condition can yield excellent pain relief and functional outcomes in the patient with ongoing anterior shoulder pain. MRI appears to be more sensitive than CT for diagnosis of coracoid impingement. MRI provides greater sensitivity in identifying concomitant soft-tissue lesions of the rotator cuff and biceps as well as soft-tissue contribution of coracoid impingement, such as a thickened fibrous falx near the confluence of the coracoacromial ligament and coracobrachialis. Studies have identified a s