Clavicle Fracture Case File

Clavicle Fracture Case File

Eugene C. Toy, MD, Andrew J. Rosenbaum, MD, Timothy T. Roberts, MD, Joshua S. Dines, MD

CASE 11

A 31-year-old competitive cyclist reports right shoulder pain after falling during a race. He presents to your office with his right arm guarded and held close to his body. He did not lose consciousness and denies other injuries. Findings on physical examination include a visible “bump” over his right clavicle without skin breakdown. He has intact sensation to light touch in his axillary, radial, ulna, and median nerve distributions. His motor examination of the extremity is normal below the shoulder, but passive and active motion at the shoulder itself is limited, secondary to pain. He has a palpable radial pulse. An anteroposterior (AP) radiograph of the injury site is obtained ( Figure 11–1 ).

Figure 11–1. An AP chest radiograph, cropped to show the right clavicle. (Reproduced, with permission, from Simon RR, Sherman SC, Koenigsknecht SJ. Emergency Orthopedics the Extremities. New York, NY: McGraw-Hill; 2007:297;Fig. 11-54.)

► What is the most likely diagnosis?

► What additional concerns do you have regarding this injury?

ANSWER TO CASE 11:

Clavicle Fracture                              

Summary: A 31-year-old cyclist fell from his bicycle directly onto his right shoulder. An AP shoulder radiograph reveals a midshaft clavicle fracture that is angulated superiorly.

• Most likely diagnosis: This is a right midshaft clavicle fracture, specifically, an Allman group I injury.
• Concerns for additional injuries: Given the proximity of the brachial plexus and subclavian vessels to the clavicle, a careful neurovascular exam must be performed to rule out injury to these vulnerable structures.

ANALYSIS

Objectives

1. Understand the anatomy of the clavicle with regard to its ligamentous, muscular, and neurovascular relationships with the thorax and upper extremity.
2. Understand the indications and options for the treatment of clavicle fractures.
3. Understand the differences in outcomes for operative versus nonoperative management of clavicle fractures.

Considerations

Clavicle fractures are common, comprising approximately 5% to 10% of all fractures. They may be in isolation, as experienced by the cyclist in this case, but are also found in high-energy, poly-traumatic events such as motor vehicle accidents. Such patients are more likely to have thoracic cage injuries, scapula fractures, and pneumo- or hemothoraces. Low-energy mechanism injuries such as simple falls are unlikely to be associated with other fractures or intrathoracic injury.

    Although the patient in the vignette sustained an isolated injury, careful attention must be focused to the neurovascular status of the extremity. The subclavian vein runs directly between the subclavius muscle and the first rib. Posterior to the subclavian vein lie the subclavian artery and brachial plexus. The plexus is closest to the clavicle in its midportion and is at greatest risk for injury at this location.

APPROACH TO:

Clavicle Fracture                                             

DEFINITIONS

SERENDIPITY VIEW: A radiographic image of the sternoclavicular joint obtained like an AP chest film with 40 degrees of cephalic tilt. Typically used to assess the sternoclavicular joint.

ZANCA VIEW: An AP radiographic image of the shoulder performed by centering the x-ray beam over the acromioclavicular joint with 15 degrees of cephalic tilt. Good for assessing the distal clavicle and the acromioclavicular joint.

SUPERIOR SHOULDER SUSPENSORY COMPLEX: A conceptual bone and soft-tissue complex comprising the glenoid, coracoid process, coracoclavicular ligaments, distal portion of the clavicle, acromioclavicular joint, and acromion process. Together, these structures form a supportive, stable ring from which the arm is suspended.

FLOATING SHOULDER: This may occur when two or more components of the shoulder suspensory complex (most commonly a concomitant clavicle and ipsilateral scapula neck fractures) are injured. Represents a theoretical increase in instability and displacement of the glenoid that, at least historically, was considered an indication for operative fixation.

CLINICAL APPROACH

Anatomy and Mechanism of Injury

The clavicle is an “S”-shaped bone with its medial portion apex anterior and its lateral portion apex posterior. It is wider in the axial dimension laterally where it forms the acromioclavicular joint. The clavicle acts as a strut connecting the upper extremity to the axial skeleton. It functions as part of the suspensory complex of the upper extremity and has multiple muscular and ligamentous attachments. The major muscular attachments include the sternocleidomastoid, which originates at the superomedial aspect of the clavicle; the pectoralis major, which originates anteriorly and inferomedially; the trapezius, inserting posteriorly and superolaterally; and the deltoid, originating anteriorly and inferolaterally. The medial articulation of the clavicle, the sternoclavicular joint, is supported by sternoclavicular (SC) ligaments. Its lateral articulation, the acromioclavicular joint, is supported by acromioclavicular (AC) ligaments. Additional attachments include the coracoclavicular ligaments, composed of both the conoid and trapezoid ligaments and considered the suspensory ligaments of the upper extremity, providing vertical support to the AC joint. 

Clavicle fractures are deformed by the following forces:

• The sternocleidomastoid displaces the proximal fragment superiorly and posteriorly.
• The pectoralis major and latissimus dorsi displace medially, pulling the shoulder toward the midline and resulting in clavicle shortening.
• The weight of the arm displaces the distal fragment inferiorly.
• Such forces result in the typical presentation: the distal fragment being inferiorly displaced and medially shortened. A superficial bony “bump” may be appreciated on physical exam as a direct result of this mechanism.

Radiographic Evaluation

Standard AP radiographs are generally sufficient to evaluate and treat clavicle fractures. Additional Serendipity and Zanca views may help further evaluate proximal and lateral clavicle fractures, respectively. A computed tomography (CT) scan may be beneficial in assessing clavicle fractures when the fracture pattern is unclear or if the fracture is intraarticular. CT may also be performed later in follow-up to assess bony healing.

Classification

Clavicle fractures are commonly classified using the Allman classification as later modified by Neer. Allman originally divided the clavicle into 3 anatomical groups, based primarily on frequency of injury: middle, distal, and proximal. Neer subsequently sub-characterized group II fractures based on integrity of the coracoclavicular ligaments.

• Group I: Middle third of clavicle (approximately 80% of fractures)

    ° May be nondisplaced or displaced (>100% displacement; ie, no cortical contact between ends)

• Group II: Distal third of clavicle (approximately 15% of fractures)

    ° Type I: Distal clavicle fracture with the coracoclavicular ligaments intact

    ° Type II: Coracoclavicular ligaments detached from the medial fragment with the trapezoid ligament attached to the distal fragment

    ° Type IIA: Both conoid and trapezoid attached to the distal fragment

    ° Type IIB: Conoid detached from the medial fragment

• Group III: Proximal third of clavicle (approximately 5% of fractures)

TREATMENT

Most clavicle fractures are successfully treated with simple immobilization in a sling or a figure-of-eight bandage for 4 to 6 weeks. During immobilization, active range of motion of the elbow, hand, and wrist is allowed to preserve joint motion. Passive range of motion and active assisted range of motion of the shoulder are typically initiated at approximately 2 to 3 weeks. There are no significant differences in outcomes after sling immobilization versus figure-of-eight bandages.

    Surgical management of clavicle fractures is controversial. Absolute indications for operative intervention include open fractures, skin tenting with the potential to progress to open fracture, and associated neurovascular injuries. Relative indications for surgical fixation include displacement or shortening greater than 2 cm, significant fracture comminution, the presence of a floating shoulder, or bilateral clavicle fractures. Common fixation methods include plate and screw fixation and intramedullary pinning.

    Postoperatively, the patients are allowed to perform pendulum exercises or gentle active ranging of the suspended arm with a limited motion arc for 2 weeks. At 6 to 8 weeks, muscular strengthening exercises may begin if follow-up radiographs show signs of healing. A full return to sports is generally not recommended until 12 weeks postoperatively.

    When deciding between operative versus nonoperative management, there is an increasing amount of evidence supporting operative intervention for displaced midshaft clavicle fractures, especially in young, active patients. Potential benefits to operative management include decreased time to bone union, decreased rates of non- or malunion, and a faster return to work. To some patients, cosmetic factors may influence decision making. Patients, for instance, may prefer a permanent visible “bump” between partially displaced but united fractures versus prominent scars and palpable hardware from surgical intervention.

Complications

Adverse outcomes associated with management of clavicle fractures include nonunion, malunion, posttraumatic arthritis at the AC joint, infection with surgical intervention, and refracture. A common complication of surgical management is chronic irritation from prominent hardware: Plate and screw constructs placed on the superior aspect of the clavicle are notorious for needing removal in up to 30% of patients.

COMPREHENSION QUESTIONS

11.1 A 30-year-old professional football player gets tackled on his right shoulder and sustains a distal clavicle fracture. The patient has no neurologic or vascular abnormalities on physical exam and has no other injuries on physical exam. Initial radiographic evaluation should include:

A. CT scan

B. Bone scan

C. Chest x-ray

D. AP clavicle including Zanca views

E. Shoulder x-rays

11.2 A 17-year-old high school tennis player trips while returning a serve and sustains a right midshaft clavicle fracture. Which of the following increases the risk of nonunion in the nonoperative treatment of clavicle fractures?

A. Sling treatment

B. Figure-of-eight bandage treatment

C. Displacement and comminution

D. Male sex

E. Age <20 years

11.3 A 53-year-old intoxicated man crashes his motorcycle into a pole. In the emergency department, he is hemodynamically stable and complains of right shoulder pain. Radiographs of the affected site are seen in Figure 11–2 . Which classification best describes his injury?

Figure 11–2. An AP radiograph of the left clavicle. (Reproduced, with permission, from Simon RR, Sherman SC, Koenigsknecht SJ. Emergency Orthopedics the Extremities. New York, NY: McGraw-Hill; 2007:286;Fig. 11-35.)

A. Allman group I, type IIA

B. Allman group II, type I

C. Allman group III, type IIB

D. Allman group I, type II B

ANSWERS

11.1 D. The best initial imaging choice to evaluate clavicle fractures is an AP view of the clavicle with Zanca views to further evaluate distal clavicle fracture pattern.

11.2 C. Displacement and comminution have been shown to increase risk of nonunion in nonoperative management. There are no significant differences between outcomes when using sling immobilization versus a figure-of-eight bandage.

11.3 B. This is a right distal clavicle fracture (group II) with coracoclavicular ligaments intact (type I): an Allman group II, (Neer) type I. Allman group I and III fractures describe the middle and proximal clavicle, respectively, and do not apply to this distal clavicle injury. Because the injury is medial to both coracoclavicular ligaments, they are intact, and thus it is a type I and not type II group II injury.

    CLINICAL PEARLS    

► The clavicle is distinct in being the first bone in the body to ossify (fifth week in utero) and the last to fuse its ossification center (22-25 years). ► Clavicle fractures occur in both low- and high-energy settings. ► The vast majority of clavicle fractures may be managed nonoperatively in a sling or figure-of-eight bandage.

REFERENCES

Andersen K, Jensen PO, Lauritzen J. The treatment of clavicular fractures: figure-of-eight bandage versus a simple sling. Acta Orthop Scand. 1987;58:71-74. 

Buchholz RW, Court-Brown CM, Heckman JD, Tornetta P, eds. Clavicle fractures. In: Rockwood and Green’s Fractures in Adults . 7th ed. 2 vol. Philadelphia, PA: Lippincott Williams & Wilkins; 2010:1106-1130. 

Canadian Orthopaedic Trauma Society. Nonoperative treatment compared with plate fixation of displaced midshaft clavicular fractures: a multicenter, randomized clinical trial. J Bone Joint Surg . 2007;89:1-10. 

Khan LA, Bradnock TJ, Scott C, Robinson CM. Fractures of the clavicle. J Bone Joint Surg. 2009;91: 447-460.

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