Scapula fracture is an uncommon injury. The scapula is a bone that sits congruently against the ribs and stabilizes the upper extremity against the thorax. It links the upper extremity to the axial skeleton through the glenoid, the acromioclavicular joint, clavicle, and the sternoclavicular joint.
The low incidence of scapula fracture has been attributed to thickened edges of the scapula, great mobility with recoil, and its layers of muscle around it. Scapula fracture generally occurs in young patients.
Mechanisms of Injury of Scapula Fracture
This occurs when the load is transmitted axially through the arm on the outstretched arm
Direct trauma from a blow or fall may cause a fracture.
Pull by muscles or ligaments may cause avulsion fractures.
Types of Scapula Fracture
For ease of classification and discussion, scapular fractures are broadly classified based on their anatomical location.
- Coracoid and acromion
- The glenoid and neck
- Scapular body fractures.
Coracoid and Acromion Fractures
Fracture of Acromion
- Type I are minimally displaced and can be treated nonoperatively.
- Type II fractures are displaced but do not cause a reduction in the subacromial space. Can be treated non operatively.
- Displaced type III fractures with reduction of the subacromial space. These fractures would need surgical intervention
- Proximal to coracoclavicular ligaments
- Distal to the coracoclavicular ligaments
The former type is more severe and may require surgical fixation.
Glenoid and Neck
Extraarticular Glenoid neck Fractures
These might be associated with acromioclavicular separation or clavicular fracture.
Intrarticular Glenoid Neck Fractures
They are further classified into six subtypes
- Type I, fractures of the glenoid rim
- type IA, Anterior rim fracture;
- type IB, Posterior rim fracture
- Type II – Fracture line through the glenoid fossa exiting at the lateral border of the scapula
- Type III – Fracture line through the glenoid fossa exiting at the superior border of the scapula
- Type IV – Fracture line through the glenoid fossa exiting at the medial border of the scapula
- Type IV fracture in combination with other fracture patterns
- Type V
- A – Combination of types II and IV
- B – Combination of types III and IV
- C – Combination of types II, III, and IV
- Type VI – Comminuted fracture
Usual history of a patient with scapula fracture is of motor vehicle accidents which led to falling. There is a complaint of pain in the shoulder region and movements of the arm are painful. Selling and bruises may be evident.
Associated injuries to other points in the shoulder girdle, the thoracic cage, and soft tissues are common. Often the physician may miss the scapular fractures due to associated and more obvious injuries.
Because of its complex anatomy and superimposition of the thorax and other structures, scapula fracture may be difficult to visualize. Therefore, multiple views in different planes may be required to adequately evaluate them.
Following views are helpful
- A true anteroposterior view of the scapula
- True scapular lateral view
- The axillary lateral view
The computed tomographic scan is important in evaluating glenoid or coracoid fractures. CT reconstruction helps to assess displacement of glenoid intraarticular fractures.
Treatment of Scapula Fracture
Mostly, the scapular fracture can be treated nonoperatively. Results have in general been satisfactory with conservative treatment. A sling support for 3-4 weeks and early rehabilitation is the key to successful nonoperative treatment.
However few might require surgical treatment.
Intraarticular Glenoid Fractures
These fractures may require surgical treatment due to intraarticular nature and high chances of arthritis developing with conservative treatment.
A nondisplaced fracture of the acromion should respond well to conservative treatment. Displaced fractures require reduction and fixation with tension-band wires or screws.
For isolated coracoid fracture, no specific treatment is needed. A sling to support would suffice. For the coracoid fracture with acromioclavicular separation, surgical and nonsurgical treatment can be equally be used depending on the individual demands.
Scapular Body Fractures
Nonoperative treatment yields good results
Extraarticular glenoid neck fractures
Sling immobilization is enough. Reduction of the fracture is not necessary. Mobilization should begin early.