Study Guide

Scapula Fractures

Key Points:

Scapula fractures are uncommon in children
They are classified according to the portion of bone involved (i.e. body, glenoid, acromion, coracoid)
The majority of fractures are treated non-operatively
There is a high incidence of associated chest and lung injuries such as rib fractures, pneumothorax, and pulmonary contusion
Scapulothoracic dissociation is infrequently seen in children but is associated with severe neurologic and vascular injuries

Description:

Scapula fractures are classified based upon their location. Fractures of the scapular body account for the majority of injuries but fractures of the glenoid neck or cavity, acromion, coracoid, and scapular spine are also encountered.

Glenoid neck fractures are classified based upon the degree of displacement and angulation. Type I fractures are displaced less than 1cm and angulated less than 40°. Conversely, Type II fractures are displaced more than 1cm or angulated greater than 40°.

Glenoid cavity fractures are classified based upon location and degree of comminution (Ideberg classification). Type I fractures involve either the anterior (Ia) or posterior (Ib) glenoid rim. Types II, III, and IV fractures are all transverse glenoid fractures with the fracture line exiting inferiorly through the lateral scapular border (II), superior through or near the notch (III), or medially through the medial scapular border (IV). Type V fractures have more than one fracture line and are a combination of the other types. Type VI fractures have severe comminution.

Acromion fractures are classified based upon displacement. Type I fractures are nondisplaced or minimally displaced. Type II fractures are displaced but do not reduce the subacromial space. Type III fractures are displaced and do reduce the subacromial space.

Scapulothoracic dissociation describes a traumatic disruption of the scapulothoracic articulation. This is an uncommon injury in children. There is no specific classification system.

Epidemiology:

Scapula fractures are uncommon in children. Body fractures are usually the result of high-energy trauma such as motor vehicle collisions or falls. There is a high incidence of associated injuries including other shoulder girdle fractures, rib fractures, head injury, and lung injury, such as pneumothorax or pulmonary contusion. Additionally, there is a strong association of scapula fractures with non-accidental trauma (NAT). One study showed that aside from rib fractures, scapula fractures were the most likely injuries to be associated with NAT.

Glenoid fractures are often due to a direct blow to the lateral shoulder or a fall onto a flexed elbow with the humeral head being driven into the glenoid. The position of the arm dictates whether an anterior or posterior rim fracture occurs. Similarly, acromion fractures are usually due to a direct blow to the lateral shoulder. Coracoid fractures are usually an avulsive injury resulting from pull of the acromioclavicular ligaments or the conjoint tendon. Scapulothoracic dissociation is often due to a severe traction injury.

Clinical Findings:

The primary symptom is often pain about the shoulder or back and difficulty with motion. Numbness or weakness may be present with a concomitant brachial plexus injury (associated with scapulothoracic dissociation). Difficulty breathing may be encountered with associated rib fracture or lung injury.

Physical exam findings may include abrasions, ecchymosis, swelling, and tenderness about the shoulder. Open injuries are uncommon. A complete vascular or neurologic examination of the upper extremity is mandatory. Scapula fractures are frequently the result of high-energy trauma thus there should always be concern for associated injuries and a complete physical exam should be performed.

Imaging Studies:

The recommended radiographic views for a suspected scapula fracture are a true AP of the scapula, scapular Y, and axillary lateral views. A Stryker notch view radiograph can also be obtained when evaluating for potential coracoid fractures. A chest radiograph is mandatory when concerned for scapulothoracic dissociation. A CT scan is also indicated with intra-articular fractures, fractures with significant displacement, or for preoperative planning.

Treatment:

The majority of fractures are treated non-operatively. Treatment includes immobilization for 3-4 weeks followed by pendulum exercises and protected range of motion. Progression of activity is based upon symptoms and evidence of healing on radiographs.

Indications for operative treatment include: open fractures, fractures with associated neurovascular injuries, scapulothoracic dissociation, Type II glenoid neck fractures, and glenoid cavity or coracoid fractures with significant displacement. Significant displacement is defined as greater than 5 mm for glenoid cavity fractures and greater than 2 cm for coracoid fractures.

An anterior deltopectoral approach and open reduction internal fixation is utilized for displaced coracoid fractures as well as displaced Type Ia and III glenoid cavity fractures. Alternatively, Type Ia glenoid cavity fractures may be treated with arthroscopic reduction and suture anchor fixation.

A posterior approach with open reduction internal fixation is utilized for displaced glenoid neck fractures as well as displaced Types Ib, II, and IV glenoid cavity fractures.

Complications:

Nonunion and malunion are potential complications associated with nonoperative treatment. Treating large glenoid rim fractures nonoperatively or failure to achieve an anatomic reduction may lead to articular incongruity and early arthritis or recurrent subluxation or dislocation. Malunion of a displaced acromion fracture may lead to symptomatic impingement. Another potential complication is nerve injury due to aggressive retraction during surgical fixation, specifically the musculocutaneous nerve during retraction of the conjoint tendon.

References:

Abzug JM, Waters PM. Clavicle and Scapula Fractures. In: Flynn JM, Skaggs DL, Waters PM, eds. Fractures in Children. 8^th ed. Philadelphia: Wolters Kluwer; 2015:822-7.
An HS, Vonderbrink JP, Ebraheim NA, Shiple F, Jackson WT. Open scapulothoracic dissociation with intact neurovascular status in a child. J Orthop Trauma. 1988;2(1):36-8
Bullock DP, Koval KJ, Moen KY, Carney BT, Spratt KF. Hospitalized cases of child abuse in America: who, what, when, and where. J Pediatr Orthop. 2009 Apr-May;29(3):231-7.
Herring JA, Ho C. Upper Extremity Injuries. In: Herring JA, ed. Tachdjian’s Pediatric Orthopaedics. 5^th ed. Philadelphia: Elsevier Saunders; 2014:1251-3.

Top Contributors:

Jeremy Rush, MD