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CHAPTER 19 • Clavicle and Scapula Fractures and Acromioclavicular and Sternoclavicular Injuries

fracture. 89 If necessary, comparison radiographs of the contra- lateral side can be obtained to confirm this. Coracoid fractures occur due to the pull of either the AC lig- aments or the conjoint tendon. When the AC ligaments avulse the coracoid from the remainder of the scapula, the fracture occurs at the physis through the base of the coracoid and upper quarter of the glenoid. 58 In contrast, when the conjoint ten- don avulses the coracoid from the scapula, the fracture occurs through the tip of the coracoid. 34 INJURIES ASSOCIATED WITH SCAPULA FRACTURES Whether scapula fractures occur due to high-energy mech- anisms or nonaccidental trauma, associated injuries are com- mon, including life-threatening injuries. Such injuries include closed head injuries, pneumo- or hemothorax, rib fractures, ruptured viscera, and concomitant long-bone fractures. 53,65,145 A recent analysis of high-energy pediatric scapula fractures due to motorized vehicle accidents found a higher Injury Severity Score (ISS) in the scapula fracture patients compared with a cohort of patients with similar high-energy motor vehicle acci- dents that did not have scapula fractures. 136 Almost half of all children admitted to the hospital for nonaccidental trauma have at least one fracture and approximately one-third had a diagno- sis of contusion. 22 Concomitant neurovascular injury may also occur involving the brachial plexus, subclavian artery/vein, or axillary vessels. Finally, additional fractures or dislocations can occur about the shoulder girdle, particularly clavicle fractures, leading to a floating shoulder. 136 SIGNS AND SYMPTOMS OF SCAPULA FRACTURES Because of the large amount of force required to sustain a scapula fracture, a complete head-to-toe survey should be per- formed by either the trauma team or emergency room physi- cian. Associated rib fractures or lung injury may cause difficulty breathing, whereas ruptured viscera will lead to an acute abdo- men. In cases of suspected nonaccidental trauma, a complete evaluation needs to be performed including a head CT scan, an ophthalmologic examination, a skeletal survey, and a social work consultation. Patients with scapula fractures will often complain of sig- nificant pain about their chest, back, and shoulder region. Numbness may be present because of concomitant brachial plexus injury or significant swelling. Observation for signifi- cant swelling and ecchymosis should begin the examination. Subsequently, a complete neurovascular examination of the involved upper extremity is necessary. Palpation should then be performed to determine the location of maximal tenderness as well as additional areas of tenderness, as concomitant shoulder girdle fractures can be present. A secondary survey should be performed by the orthopedic surgeon to ensure there are no additional musculoskeletal injuries.

imaging is necessary to fully evaluate the fracture. Plain radio- graphs including true AP and lateral scapula views as well as a glenohumeral axillary view should be obtained when a scap- ula fracture is suspected. In addition, because of the significant amount of overlying bony and soft tissue structures, a CT scan will enable the surgeon to fully understand the fracture pattern. The addition of reconstructions, including three-dimensional reconstructions, will aid in preoperative planning if operative intervention is being considered. CLASSIFICATION OF SCAPULA FRACTURES Scapula fractures are classified according to the fracture location within the scapula: body, glenoid cavity, glenoid neck, acro- mion, and coracoid. In addition, scapulothoracic dissociation is a term utilized to describe complete separation of the scapula from the posterior chest wall.

Glenoid Neck Fractures: CLASSIFICATION

• Displaced < 1 cm and angulated < 40 degrees

Type I

• Displaced > 1 cm and angulated > 40 degrees

Type II

Glenoid neck fractures are further classified based on their dis- placement and angulation. A type I fracture is displaced less than 1 cm and angulated less than 40 degrees, whereas a type II fracture has more than 1 cm of displacement and is angulated greater than 40 degrees. 52 Type I fractures account for 90% of glenoid neck fractures. 2,164

Glenoid Cavity Fractures: CLASSIFICATION

• Fracture involving the anterior glenoid rim

Type Ia

• Fracture involving the posterior glenoid rim

Type Ib

• Transverse fracture line that divides the superior and inferior aspects of the glenoid and then exits inferiorly through the lateral scapular border • Fracture line dividing the superior and inferior aspects of the glenoid, but exits superiorly near or through the scapular notch • Fracture line dividing the superior and inferior aspects of the glenoid, but exits medially through the medial border of the scapula • More than one fracture line involving a combination of types II and IV fractures • More than one fracture line involving a combination of types III and IV fractures • More than one fracture line involving a combination of types II, III, and IV fractures

Type II

Type III

Type IV

Type Va

Type Vb

Type Vc

• Severely comminuted fractures

Type VI

IMAGING AND OTHER DIAGNOSTIC STUDIES FOR SCAPULA FRACTURES

Glenoid cavity fractures are classified into six types based on the location of the fracture within the glenoid cavity and their severity (Fig. 19-11). 51,64 Type I fractures involve either the

Scapula fractures may initially be discovered on the chest x-ray obtained during the trauma work-up; however, additional