الفهرس 
AnatomyOnly 14 pages are availabe for public view
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 sex-based difference in the average coracohumeral interval, with females having a space measuring 3 mm smaller than that in males. 79% sensitivity and 59% specificity for coracoid impingement was reported when the coracohumeral interval measured <10.5 mm on axial MRI.
Surgical intervention for coracoid impingement has been described using both open and arthroscopic approaches.
The intra-articular approach provides several advantages. First, the posterolateral aspect of the coracoid is easily palpated and approached through the rotator interval. This allows a direct assessment of the prominence of the coracoid process, the space available for the subscapularis tendon, and the coracohumeral space.
The other major advantage of the intra-articular approach is the ability to resect the coracoid in line with the insertion of the subscapularis tendon and the lesser tuberosity. The use of the 70° arthroscope provides an excellent aerial view of the subscapularis tendon and coracoid. The posterolateral aspect of the coracoid can then be specifically bevelled to prevent impingement in various degrees of forward elevation, adduction, and rotation. This allows a precise decompression tailored to each individual case. Unlike the open anterior approach in which the lateral 1.5 cm of the coracoid is routinely resected, an intra-articular (posterior) approach does not require release or reattachment of the conjoint tendon.
In conclusion, arthroscopic coracoplasty can be performed intra-articularly through the rotator interval. We have found that this technique is easy to perform, allows the appropriate orientation of the coracoplasty, and permits assessment of the adequacy of decompression without difficulty.