Scapula Fractures

The Problem

Scapula fractures are high-energy injuries and are usually associated with other injuries to the shoulder girdle or chest wall. These fractures may range from small avulsion fractures of the acromion to comminuted body fractures, to intra-articular glenoid fractures with associated shoulder instability, to potentially fatal scapulo-thoracic dissociation.

Clinical Presentation

Patients present with pain and difficulty with shoulder range of motion secondary to an injury sustained as a result of a high energy trauma like motor vehicle accidents, a fall from height, or direct trauma with a blunt object. In most cases the vector of injury is directed from lateral to medial, often from a position superior to the plane of the shoulder. This mechanism of injury is associated with high rates of concomitant injuries – in up to 90% of patients in some reports. Concomitant injuries include those occurring in the ipsilateral extremity (50%), thoracic injuries (80%), head injuries (48%), and spine fractures (26%). Clinical examination will reveal tenderness and swelling with possible ecchymosis over the scapula. Injuries to the scapula may be missed in polytrauma and obtunded patients and will often be diagnosed on chest CT scans and during secondary or tertiary injury surveys after the patient is extubated. Scapular fractures should be suspected in the setting of hemopneumothorax and multiple rib fractures.

Diagnostic Workup

Standard radiographs of the scapula include anteroposterior (AP) (true AP view will avoid overlap of humerus with glenoid), lateral views, and an axillary view of the shoulder joint to rule out dislocation. A view with a 45 degree cephalad tilt is needed for identifying coracoid fractures. Chest radiograph is important to evaluate for chest injuries or scapulothoracic dissociation. Dissociation should be suspected if the medial edge of the scapula is displaced > 1 cm from the spinous process when compared to the opposite normal side. There may be associated widely displaced fractures of the clavicle and scapula itself.

A CT scan with 2D and 3D reconstructions are mandatory for understanding the injury pattern, identifying associated injuries, and formulating a treatment plan. Complex injuries to the scapula are difficult to classify without these advanced imaging studies. The 3D CT can be rotated to the optimal AP and lateral planes for an accurate assessment of displacement and angular deformity.

Classification commonly used for scapula fractures is the Ideberg classification which divides injuries into types ranging from extra-articular to complex combined fracture patterns. Most common are fractures of the scapula body, followed by those involving the glenoid, acromion, and the coracoid process. (See Table I)

Non-Operative Management

Indications For non-operative management:

Fractures of the scapula body i.e. those that are extra-articular.
Isolated fractures of the coracoid or acromion with minimal displacement (< 1 cm).
Fractures with intra-articular extension, but with < 4 mm displacement.
The above with associated clavicle fractures (floating shoulder) may also be treated non-operatively as long as the shoulder suspensory complex is intact.

These patients are managed with a sling and allowed early pendulum exercises and shoulder range of motion. They are usually maintained non-weight bearing for 4-6 weeks as the healing of the scapula is rapid secondary to the vascularity. As progressive deformity of scapular fractures is a concern in the early post-injury period once the patients are upright and mobile, serial radiographs should be obtained on a weekly basis for the first 3 weeks.

Indications for Surgery

Indications for operative management:

Fractures extending into the glenoid with articular incongruity of >4 mm.
Shoulder instability due to large glenoid fragment, typically >25%.
Fractures of the acromion and coracoid with displacement of >1 cm.
Multiple injuries to the shoulder suspensory complex with medialization of the glenoid (>2 cm) and associated clavicle fractures with shortening and/or multiple rib fractures.
Greater than 45 degrees of angulation of the glenoid.
Glenopolar angle of less than 20 degrees.

It is common to have fractures with multiple deformities/displacements and more than one indication noted above may be seen in various combinations. This represents the high energy nature of injury to the scapula.

Surgical Technique

Implants

A combination of mini fragment (2.0 mm and 2.7 mm) and small fragment (3.5 mm-4 mm) screws and plates as well and cannulated screws (3.5-4.0mm) are used in the surgical fixation of these fractures (Figure 1).

Post-operative radiograph of a scapula fracture demonstrating multiple small and mini fragment plates used for fixation including areas of plate placement.

The most common approach used is a modified Judet posterior approach with the interval between infraspinatus and teres minor without elevating the muscles off the bone if possible, to allow protection of the neurovascular bundle (suprascapular nerve).

An anterior deltopectoral approach is used for glenoid fossa injuries involving the anterior part or rim. Smaller avulsion fractures with instability can also be treated arthroscopically with debridement and re-attachment using suture anchors.

Patient Set-Up and Surgical Tact

It is important to assess the CT scan for the primary injury that needs fixation and the approach is tailored to the same.

For a posterior approach, the patient is positioned in the lateral position using a bean bag and the fluoroscopy machine is bought in from anteriorly. The arm is draped free to allow manipulation of the shoulder and assist in fracture reduction.

The modified Judet approach is used with a transverse incision; the longitudinal limb is used if exposure of the medial scapula body is needed; however, the majority of fractures can be fixed with only the transverse incision. Once the deltoid is elevated, the infraspinatus fascia over the tendon is partially incised and the interval developed between it and the teres minor. Once the fracture is exposed, the capsule is opened to allow articular visualization and aid in the reduction and hardware placement. Care is taken to minimize stripping of the bone of soft tissue except posteriorly and where plates need to be placed.

The scapula body is very thin and the only areas for plate placement are along its edge, with the best fixation at the lateral border and spine of the scapula. The scapula is covered by large muscles and is vascular, which will cause bleeding and oozing throughout the procedure; care must be taken to achieve adequate hemostasis as the surgery progresses. The suprascapular neurovascular bundle is at risk with retraction and during elevation of the infraspinatus.

The plates used are typically small fragment reconstruction (3.5 and 2.7mm) plates with screws. Cannulated screws are helpful when fixing intra-articular glenoid fractures. Locking plates may be useful for spanning comminuted body fractures; these are mini fragment (2.4 and 2.0 mm) plates and screws.

If there is an associated clavicle fracture, it may be beneficial to fix the clavicle in the supine position as this will allow restoration of length, before turning the patient to address the scapular fracture.

If anterior fixation is required, the patient is placed supine, usually using a beach chair position. A deltopectoral approach is used and the anterior capsule incised to expose the joint; the exposure may be carried out through the fracture, and the capsule may be incised if needed for visualization of the articular reduction. Humeral head retractors are needed to visualize the glenoid and check the articular reduction. Large fragments are fixed with screws and buttress plates (small fragment one third tubular or reconstruction 3.5 and 2.7 mm plates); while smaller comminuted fragments may require labral repair using suture anchors 92.5-3.5 mm anchors with braided non-absorbable #2 sutures).

Fractures of the acromion require a direct posterior approach and open reduction; these can be fixed with small fragment low profile plates or using tension band technique. Isolated fractures are rare, but can be addressed satisfactorily using this approach. Again the plates used here are small fragment plates (3.5 or 2.7 mm tubular or reconstruction plates and screws)

Pearls and Pitfalls of Technique

As the scapula is very vascular, attempts at reduction and fixation after 3 weeks may be difficult and associated with significant blood loss and higher risk of injury to neurovascular structures.

If needed, the infraspinatus can be elevated from the lateral and superior aspects to improve scapular body exposure.

Use of a humeral head retractor in the shoulder joint will improve the articular visualization. Provisional K-Wires inserted for fracture reduction should be those such that they can be used as guide wires for cannulated screws (appropriate size for screw diameter selected).

Multiple fluoroscopy views must be obtained to confirm extra-articular placement of all hardware and direct visualization into the shoulder will also help.

Potential Complications

The surgical approach with extensive dissection has the potential for neurovascular compromise, especially the suprascapular nerve and artery, and the medial circumflex artery. Hematoma formation and infection are potential complications secondary to soft tissue stripping.

Finally, shoulder stiffness and pain can occur even with optimal fixation and early mobilization will help prevent this to a certain extent.

Long term outcome may include shoulder arthritis, which may require future replacement. Having a well-aligned scapula and glenoid is helpful in orientation when performing the joint replacement.

Heading

Post-operative Rehabilitation

Patients are given a sling and advised non-weight bearing for a period of 6-8 weeks. Early range of motion out of the sling is recommended and restriction of shoulder rotation is based on whether an anterior or posterior glenoid fracture is present.

Once radiographs show fracture healing, weight bearing and restricted exercises are allowed and by 12-16 weeks, full motion and activity are permitted.

Heavy lifting and return to contact sports may require up to 6 months of healing time and physical therapy to strengthen the shoulder girdle muscles.

Outcomes/Evidence in the Literature

These complex injuries require treatment of both the scapula fracture and the associated injuries. When indicated, surgical treatment results in satisfactory outcomes and most authors have reported small series of patients. The common problems include shoulder stiffness and the need for removal of hardware; malunion is more of a problem while nonunion is rarely seen.

Jones, CB, Cornelius, JP, Sietsema, DL, Ringler, JR, Endres, TJ. “Modified Judet approach and minifragment fixation of scapular body and glenoid neck fractures”. J Orthop Trauma. vol. 23. 2009. pp. 558-64. (Using the modified approach and 2.7 mm plates, 37 patients underwent fixation. No wound or muscle dehiscence problems were noted. At a minimum of 1 year follow-up, average range of motion was 158 degrees (range 90-180 degrees). There were no fixation failures or instances of implant loosening.)

Zelle, BA, Pape, HC, Gerich, TG, Garapati, R, Ceylan, B, Krettek, C. “Functional outcome following scapulothoracic dissociation”. J Bone Joint Surg Am. vol. 86-A. 2004. pp. 2-8. (Nineteen of twenty-five patients had a complete or incomplete brachial plexus injury and those patients had a poor outcome as compared to those without in a 12 year average follow-up.)

Zlowodski, M, Bhandari, M, Zelle, BA, Kregor, PJ, Cole, PA. “Treatment of scapula fractures; systematic review of 520 fractures in 22 case series”. J Orthop Trauma. vol. 20. 2006. pp. 230-3. (Ninety percent of fractures had associated injuries; 82% of glenoid fractures treated surgically had good to excellent results while 14% of the body fractures treated non-operatively had fair or poor results.)

Lantry, JM, Roberts, CS, Giannoudis, PV. “Operative treatment of scapular fractures: a systematic review”. Injury. vol. 39. 2008. pp. 271-83. (Seventy-eight percent of scapula fractures were treated using a posterior approach, 18% had an anterior approach and 4% a combined approach. Risk of infection was 4.2% and that of suprascapular nerve injury was 2.6% of all patients. Overall 83.4% reported good to excellent results.)

Romero, J, Schai, P, Imoff, AB. “Scapular neck fracture – the influence of permanent malalignment of the glenoid neck on clinica outcomes”. Acta Orhop Traum Surg. vol. 121. 2001. pp. 313-6. (Retrospective review of 19 patients with scapula fractures at 8 year follow up showed that all healed and poor outcomes were seen in patients with glenopolar angle of less than 20 degrees.)

Hill, BW, Anavian, J, Jacobson, AR, Cole, PA. “Surgical movement of isolated acromion fractures: Technical tricks and surgical experience”. J Orthop trauma. 2013. (The authors report their experiences of treating 13 acromion fractures using plating or tension band with good results.)

Cole, PA, Gauger, EM, Herrera, DM, Anavlan, J, Tarkin, IS. “Radiographic follow-up of 84 operatively treated scapula neck and body fractures”. Injury. vol. 43. 2012. pp. 327-33. (Eighty-four high-energy injuries with displaced scapula fractures had associated injuries on 94% of the patients with the commonest being chest (70%) and ipsilateral shoulder girdle (43%). Almost half the fractures had more than one indication for surgery (45%) and all fractures healed with satisfactory outcomes and no infection. Seven patients required removal of hardware and three needed shoulder manipulation.)

Summary

Scapula fractures are high-energy injuries; however most of them are treated non-operatively with a sling and early range of motion. Intra-articular displacement and shoulder instability are indications for surgical treatment and the modified Judet approach is used for most cases. Scapulothoracic dissociation is potentially fatal and is associated with brachial plexus, vascular, and chest wall injuries and must be watched for in multiply injured patients.

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