Clavicle Fractures

Individualizing Treatment for Fracture Type

Jeffrey A. Housner, MD; John E. Kuhn, MD

Practice Essentials Series Editors:
Kimberly G. Harmon, MD; Aaron Rubin, MD

THE PHYSICIAN AND SPORTSMEDICINE - VOL 31 - NO. 12 - DECEMBER 2003

In Brief: Clavicle fractures are common injuries in both children and adults. In most cases, the diagnosis can be made readily from the patient's history and physical examination. X-rays are helpful to confirm the diagnosis, to assess the severity of the fracture, and to follow interval healing. Most fractures are treated nonoperatively, and surgical intervention is typically reserved for unstable distal clavicle fractures. Nonoperative options involve either a sling-and-swathe or figure-of-eight splint. Return-to-play decisions should be individualized based on the age of the patient, location and severity of the fracture, degree of clinical and radiographic healing, and the sport in which the athlete will be participating.

The diagnosis of a clavicle fracture is relatively straightforward, but management decisions may present a greater challenge. Understanding the classification, injury mechanism, and diagnostic work-up of clavicle fractures will help physicians recommend appropriate treatment and return-to-play options.

Classifying Fractures

Fractures of the distal clavicle (group 2) have been further subclassified into three main types, according to the location of the coracoclavicular ligaments (ie, conoid and trapezoid) relative to the fracture fragments (figure 2).² Type 1 fractures are the most common and are nondisplaced, in type 2 fractures, the coracoclavicular ligaments remain attached to the distal fragment, and type 3 fractures occur distal to the ligaments and enter the acromioclavicular joint.

Anatomy, Incidence, and Mechanisms

The clavicle has a unique shape and function that make it a likely candidate for fracture when it is subjected to excess stress.

Anatomy. Embryonically, the clavicle develops by a combination of intramembranous and endochondral ossification, with the central part of the clavicle ossifying first and providing most of the growth of the clavicle for the first 5 years of life. After that time, the medial and lateral epiphyseal plates develop, and the medial physis is responsible for most clavicle growth until adulthood. This physis closes when individuals are about 25 years old.

The S-shaped clavicle serves as a strut that is the only bony connection between the torso and the arm. The medial portion has a tubular cross section, resists axial loading, and protects the brachial plexus (especially the medial cord) and other structures in the costoclavicular space. The flat lateral portion provides sites for muscle and ligament attachment. The transition between the two sections is relatively weak and is thought to place the middle portion of the clavicle at risk of fracture when the bone is overstressed.³

Fracture incidence. Clavicle fractures account for approximately 1 in 20 of all fractures and 44% of all injuries to the shoulder girdle.⁴ The incidence appears to be increasing, most likely because of the growing popularity of contact sports and the increasing number of motor vehicle accidents.⁵ An epidemiologic review by Nordqvist and Petersson⁶ of all clavicle fractures (adult and pediatric) found an overall incidence in Sweden of 64 per 100,000 population per year. Other studies found a lower incidence but included only adult patients: Robinson⁴ noted an incidence of 50.3, and Nowak et al⁷ found an incidence of 29.2 per 100,000 population per year. Approximately 20% to 25% of all clavicle fractures result from athletic activity.^4,6

Mechanism of injury. The most common mechanism of injury is a fall on or direct blow to the point of the shoulder.^8-10 A fracture can also occur following a fall on an outstretched hand, although this mechanism of injury has been shown to be much less common.^9,10 Fowler⁸ has reported that a blow to the bone itself rarely causes a fracture, except in sports that use sticks such as lacrosse and hockey. No correlation has been found between fracture location and mechanism of injury.¹⁰

The Patient, the Exam, and Diagnostic Tips

Physicians should note several details in examining patients suspected of having clavicle fractures.

Symptoms and presentation. Patients typically report a history of a significant injury, such as falling or being struck with a heavy object. They usually report hearing a snapping or cracking sensation at the time of injury, followed by immediate and well-localized pain. Pain is exacerbated with any arm motion. The patient may also describe rapid swelling or crepitus at the fracture site.

Associated injuries to underlying structures may produce symptoms to alert the clinician. Dyspnea should raise suspicion of a pneumothorax, and upper-extremity paresthesias may indicate injury to the brachial plexus.

Physical exam. The patient usually presents with the affected arm supported or held straight against the side, and physical examination typically reveals an obvious bump at the fracture site. Gentle palpation over the fracture will usually elicit pain, crepitus, and (occasionally) motion. The physician may feel a grinding sensation when the patient attempts to raise the affected arm. The skin may be "tented" over a fracture fragment, but the fragment rarely penetrates the skin. Nondisplaced fractures and fractures of the distal clavicle may not produce any deformity and can easily be overlooked. Neurovascular disruption is rare, although brachial plexus, subclavian artery, or pulmonary damage should be ruled out, especially when the injury results from high-energy impact.

The examining physician should perform a thorough neurologic examination of the involved extremity, with particular attention to dysesthesia or lack of sensation in an ulnar nerve distribution, since the medial cord of the brachial plexus is at higher risk. Occasionally in high-energy injuries, cervical root damage will occur, and nerve damage results in a poor prognosis. Medial cord brachial plexus symptoms may develop late if abundant callus or deformity associated with nonunion or malunion of the clavicle impinges on the brachial plexus.¹¹

A pneumothorax may occur in as many as 3% of clavicle fractures,¹² so the exam should also include auscultation of the upper lung fields. If concern exists, a standing chest x-ray will assist in detecting subtle collapse of upper lung fields. This radiograph is especially warranted in high-energy injuries with ipsilateral scapula or rib fractures that increase the likelihood of a pneumothorax or hemothorax.

Imaging and differential diagnosis. Plain radiographs are useful to: (1) confirm the diagnosis, (2) evaluate fragment position and alignment, (3) classify the fracture, and (4) assess the extent of healing on follow-up examinations. In general, a trauma shoulder series consists of a true anteroposterior (AP) view of the scapula with the humerus in internal rotation and another radiograph with the humerus in external rotation; an axillary lateral view; and a true scapulolateral view (scapular Y-view).¹³

A routine AP view of the clavicle will identify most fractures (figure 3A).¹⁴ In cases in which the diagnosis is in question, a 30° caudal tilt view (figure 3B) and a 30° cephalad tilt view (figure 3C) can facilitate the evaluation.¹³ The latter views direct the x-ray beam either superior or inferior and reduce the overlying rib and chest shadows that may obscure the clavicle on an AP view. Proximal clavicle fractures are difficult to see on AP radiographs, so adding a serendipity view (40° cephalic tilt view) is warranted when that injury is suspected.¹³ Computed tomography (CT) can be helpful to identify these fractures and assess the risk to neurovascular structures at the base of the neck if the fracture is displaced posteriorly. Distal clavicle fractures can be seen especially well with an axillary lateral view and a 10° cephalic tilt view. Other diagnoses to consider include an acromioclavicular separation, sternoclavicular dislocation, rotator cuff injury, labral pathology, or shoulder contusion.

Treatment Options

The ultimate goal is to achieve bone healing with minimum morbidity, loss of function, and residual deformity (see the Patient Adviser, "Steps to Take for Clavicle Fractures").

General considerations. Most clavicle fractures have been successfully treated by nonoperative methods; operative intervention has been discouraged.¹⁴ Nonoperative treatment should attempt to reduce motion at the fracture site and consists of relative rest, pain control, and free mobilization with either a sling (figure 4A) or figure-of-eight bandage (figure 4B). Treatment outcomes are nearly identical for the two methods^15,16; however, the figure-of-eight treatment has an advantage in that it leaves the elbow and hand free for daily activities. The patient should be instructed to tighten the figure-of-eight splint regularly to maintain tension but cautioned against overaggressive tightening that can lead to skin problems, edema from venous obstruction, and brachial plexus palsy.¹¹ During immobilization, the patient may use the extremity as symptoms allow but should avoid strenuous activity. Patients using sling immobilization should be instructed to perform elbow range-of-motion exercises to maintain normal elbow function. Immobilization should be continued until there is no crepitus or tenderness over the fracture site.

Follow-up visits should be scheduled 1 to 2 weeks after injury to assess clinical symptoms and then every 2 to 3 weeks until the patient is asymptomatic. Repeat radiographs are not necessary at each return visit, but when clinical union has occurred, a final radiograph aids in assessing callus formation. Clinical union is demonstrated by a resolution of pain, full range of motion, and return of normal strength.¹⁷ Radiographic calcification of the fracture callus is typically seen 4 to 6 weeks after the injury. Complete radiographic union, as demonstrated by calcified bridging callus, occurs approximately 4 to 6 weeks after clinical union.

Closed reduction by a skilled physician is sometimes used if patients have several displaced fragments with neurovascular compromise or are at risk of skin tears.⁵ After preparing the skin, the physician injects the area of the fracture hematoma with local anesthetic. With the patient seated, the physician places a knee between the patient's scapulae, grasps the shoulders, and then gently retracts them, manipulating the fracture into place.

Adults should be cautioned that a permanent visible prominence over the fracture site is a common outcome. Parents can be reassured that, at least in younger children who still have significant growth potential, the raised area formed at the fracture site during the healing phase usually remodels with growth.¹⁷

Midclavicle fractures. Fractures in the middle third, in particular, respond extremely well to closed treatment. Surgical intervention is usually reserved for the rare cases of delayed union or nonunion. Neer¹⁸ reported that only 3 of 2,235 patients (0.1%) with midclavicle fractures did not heal after treatment by closed methods. Nordqvist et al¹⁹ reviewed 225 midclavicle fractures that had an average follow-up of 17 years. Initial treatment consisted of either a figure-of-eight splint (197 cases), sling immobilization for an average of 3 weeks without any attempt at reduction (4 cases), or immediate free shoulder mobilization (24 cases). Only 1 patient was determined clinically to have had a poor outcome, and almost all fractures healed without complications. These investigators found no evidence to recommend surgical treatment based on the initial appearance of the fracture. However, they did caution that surgical consideration should be given to injuries that involved neurovascular interference or skin at risk of puncture (tented over the fracture). Typically, healing takes 6 to 12 weeks in adults and 3 to 6 weeks in children.¹⁷

Distal clavicle fractures. These fractures should be approached with vigilance. Type 1 and type 3 fractures are treated similarly, with sling immobilization for comfort. These fracture types are usually minimally displaced, are extremely stable, and heal well with conservative treatment. Type 2 fractures, however, may lead to significant morbidity. They have a high rate (22% to 33%) of nonunion when treated nonoperatively.^2,20 A sling does not reduce the fracture, and the use of a figure-of-eight bandage is contraindicated, because it can further displace the deformity. Nonunion in type 2 fractures is likely to be related to the penetration of the medial fragment through the trapezius ("button-hole" injury), coupled with the weight of the dependent arm, which acts to maintain displacement at the fracture site.²¹

Primary surgical stabilization should be considered for all displaced type 2 distal clavicle fractures, and, therefore, these fractures should be referred to an orthopedic surgeon.⁵ It should be noted that nonunion may be asymptomatic in 80% of patients,²⁰ and that the results of surgery may not be optimal.⁴ Because type 3 distal clavicle fractures may lead to future degenerative changes of the acromioclavicular joint, some primary care providers refer these intra-articular fractures for orthopedic management; however, we usually do not do so unless some other sign is present. Healing for a type 1 or type 3 distal clavicle fracture takes about 6 to 8 weeks.¹⁷ A type 2 distal clavicle fracture may take up to 12 weeks to heal if it is treated conservatively.¹⁷

Proximal clavicle fractures. Because the sternoclavicular ligaments usually remain intact in proximal clavicle fractures, essentially all are successfully treated with sling immobilization. After an initial period of rest, patients may use the arm as much as symptoms permit. Healing generally occurs within 6 to 8 weeks.¹⁷ Most authorities recommend nonoperative treatment, reserving surgery for fractures that fail to heal.¹¹ Patients with displaced fragments should undergo CT to assess posterior displacement of fragments and the potential risk of neurovascular compromise.¹¹

Orthopedic referral. In addition to type 2 distal clavicle fractures, other indications for orthopedic evaluation and surgical consideration include: (1) painful nonunion, (2) an open fracture, (3) an unstable fracture with accompanying neurovascular injury, (4) severe displacement causing tenting of the skin, (5) floating shoulder (concomitant fracture of clavicle and scapular neck), (6) the rare patient in whom the cosmetic lump over the healed clavicle is intolerable, and (7) displaced fractures in skeletally mature elite athletes who engage in throwing or overhead activities or competitive cycling, or in patients who use backpacks extensively.

Complications to Note

Although treatment complications are rare, they should not be missed.

Malunion, which results in angulation, shortening, and poor appearance, is the most common complication (figure 5). A nonanatomic union is typical of most displaced middle-third clavicle fractures, and many authors suggest that such malunion results in acceptable function.¹⁹ In a review of 118 patients with clavicle fractures followed for 2 years, Eskola et al²² found that 27 (23%) had pain or limited motion with exercise, and 4 (3%) had major functional problems. Criteria associated with a poor outcome were displacement greater than 15 mm and shortening of the clavicle.²²

Nonunion is typically defined as failure to show clinical or radiographic progression of healing after 4 to 6 months.⁵ Several risk factors for nonunion have been identified, including the extent of initial trauma, fracture comminution, fracture displacement, inadequate immobilization, distal-third fractures, primary open reduction, and refracture.¹⁴

Despite identification of such risks, the precise indications for open reduction and fixation of acute clavicle fractures are not well defined. While most patients with a middle-third clavicle fracture will heal in a nonanatomic position, it is conceivable that elite competitive or professional athletes who engage in overhead or throwing activities (eg, baseball pitcher) may not do well with a malunited clavicle. Consequently, treatment recommendations must be individualized. Neurovascular complications associated with nonunion, including subclavian artery and vein compression, thoracic outlet syndrome, and brachial plexus palsy, have also been reported.^11,14

Return-to-Play Considerations

The return-to-play decision is highly individualized. A literature search did not reveal any studies that have been conducted to determine the optimum time to allow an athlete to return to his or her sport following a clavicle fracture. Even professional recommendations are few and, when given, are quite variable. The decision, however, must take into account the age of the patient, the location and severity of the initial fracture, the degree of clinical and radiographic healing, and the sport in which the athlete participates. For example, an 8-year-old with a mild cortical break of the midclavicle (figure 6A) will be able to return to a noncontact sport much sooner than a collegiate level hockey player who sustains a displaced, comminuted fracture (figure 6B).

Athletes should not return to sport until they have regained full range of motion, normal strength of the shoulder, and radiologic and clinical evidence that bone healing is sufficient to allow participation. In addition, athletes should not have any pain with forceful palpation over the fracture site. Athletes can then be allowed to resume upper-extremity sport-specific movements as tolerated. This may include such motions as throwing, swimming, racket or golf club swinging, and ball shooting. Gradually, the athlete can be allowed to increase the intensity and duration of each motion. A return to noncontact sports routinely takes at least 6 weeks from the time of the injury.²³

Collision sports obviously increase the likelihood for refracture at the healed site; therefore, a more conservative time frame is recommended for these athletes. A return to contact sports may take 8 to 12 weeks. Most treating physicians will allow a return to collision sports after radiographs demonstrate union of the fracture. Because clinical union occurs before radiographic union, it is conceivable that an athlete could return to play before radiographic union has occurred if that athlete has no pain, full range of motion, and normal strength. In this scenario, however, the athlete and the treating physician must be willing to accept the potential risk of refracture.

While some physicians have allowed patients with fixation hardware to return to collision sport, including football, Schlegel and Hawkins²⁴ recommend removing any such hardware before permitting these athletes to return to play. The athlete must allow adequate time (6 to 8 weeks) for the screw holes to fill with bone to reduce the risk of refracture. Hardware is typically removed 1 year after it is placed and at a time that fits the athlete's schedule.

Successful Outcome

Most clavicle fractures heal without any functional impairment. With appropriate rehabilitation, return to full competition with strenuous and demanding use of the upper extremities is clearly the rule. The decision as to when an athlete can return to sporting activities should be based on sound clinical judgment.

References

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19. Nordqvist A, Petersson CJ, Redlund-Johnell I: Mid-clavicle fractures in adults: end result study after conservative treatment. J Orthop Trauma 1998;12(8):572-576
20. Nordqvist A, Petersson CJ, Redlund-Johnell I: The natural course of lateral clavicle fracture: 15 (11-21) year follow-up of 110 cases. Acta Orthop Scand 1993;64(1):87-91
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Dr Housner is clinical assistant professor in the departments of orthopaedic surgery and family medicine at the University of Michigan and team physician for the University of Michigan and USA Hockey National Development Team. Dr Kuhn is an associate professor and chief of shoulder surgery in the department of orthopedic surgery at Vanderbilt University in Nashville, Tennessee. Address correspondence to Jeffrey A. Housner, MD, MedSport Domino's Farms, 24 Frank Lloyd Wright Dr, Ann Arbor, MI 48106-0363; e-mail to jhousner@umich.edu.

Disclosure information: Drs Housner and Kuhn disclose no significant relationship with any manufacturer of any commercial product mentioned in this article. No drug is mentioned in this article for an unlabeled use.