Inspection of an anterior dislocation will present with a prominent medial clavicle. The integrity of the skin overlying this anterior prominence should be taken into consideration to ensure that the injury is not open from concurrent laceration or at risk of becoming open from excessive pressure on the skin. Signs of “at-risk” skin include taut, blanched, or even necrotic skin changes. If the skin displays any of these signs, the urgency to reduce the clavicle and save the soft tissue is increased. Palpation of the prominence will often be painful but can help the clinician delineate between a palpable medial clavicle and soft tissue swelling. Lying the patient supine and moving the ipsilateral extremity in an extended position will often exacerbate the anterior deformity. Anterior dislocations of the SC joint can often be reduced with gentle posteriorly directed pressure over the medial end of the clavicle. Such a reduction may be possible upon presentation , but there is a risk of recurrent dislocation as anterior SC dislocations tend to be more unstable than their posterior counterparts.

Inspection of a posterior dislocation may be less obvious than an anterior dislocation. Patients with a posterior SC dislocation may still display an anterior prominence as the soft tissue swells over the underlying dislocation. Palpation of this anterior fullness can help discern between a prominent medial clavicle, corner of the sternum, or/and swollen soft tissue [3, 12]. As with an anterior dislocation, movement of the ipsilateral upper extremity can also result in increased pain but is less able to accentuate the deformity as posterior dislocations tend to be a fixed deformity. The most concerning aspect of examining a patient with a posterior SC dislocation is the appreciation of the mediastinal structures that lie posterior to the SC joint. The trachea, esophagus, great vessels, and brachial plexus are all in close vicinity to the SC joint. Ponce et al. performed a radiographic anatomical study measuring the distance between the posterior SC joint and the adjacent mediastinal structures [13] (Fig. 3.3). The authors found that many of the important cardiopulmonary structures all lay within 3 cm of the posterior SC joint with such structures as the carotid artery and brachiocephalic vein as close as 1 mm of the articulation [13]. It is important for the treating clinician to appreciate this anatomy and have serious concern for any symptoms such as venous congestion, dysphagia, dyspnea, or hoarseness. These symptoms can be a result of compromised structures of the mediastinum and increases the urgency for immediate closed versus open reduction.

Although the SC joint is readily visible on routine anteroposterior (AP) chest radiographs, the interpretation of its position is often hard to discern. Standard AP chest radiographs are typically part of the trauma primary survey and, on occasion, can suggest displacement of the medial clavicle when compared to the contralateral side. Overlap of the ribs and vertebrae, however, make accuracy of diagnosis quite low [2, 12]. McCulloch et al. looked at a series of three SC dislocations and reported that a difference in the craniocaudal position of the medial clavicles that measured greater than 50% the width of the clavicular heads was suggestive of dislocation. The authors acknowledged that when the diagnosis remains unclear, adjunctive imaging is indicated [14].

For plain radiography, the most common adjunctive imaging option is the “serendipity” view as described originally by Rockwood in 1975 (Fig. 3.4). For this view, the patient lies supine with the X-ray tube aimed directly at the manubrium at a 40°–45° cephalic tilt (Fig. 3.5). The X-ray cassette must be large enough to accommodate the medial halves of both clavicles [12]. On the film, a horizontal line can be drawn along the axes of both clavicles. In the case of an anterior dislocation, the medial half of the affected clavicle will project above the horizontal line drawn along the axis of the unaffected clavicle. If the patient has a posterior dislocation, then the medial half of the affected clavicle will project below this line (Fig. 3.6). Since it is impossible to accurately project the X-ray beam perpendicular to the anteroposterior plane, this view affords the clinician the view closest to this perspective.

Computed tomography (CT) scans are capable of achieving the axial images that are perpendicular to the anteroposterior plane that makes them unequivocally the best technique to identify an SC dislocation (Fig. 3.7). This has made CT the modality of choice for evaluating the anatomic detail of SC joint and its surrounding soft tissues [15]. In addition to providing multiple axial images that are perpendicular to the plane of dislocation, CT scans are also better able to discern between sprains, dislocations, and medial clavicle fractures [6]. Besides becoming the gold standard for SC dislocation diagnosis, many authors support the use of the CT scan in the operating room during the time of reduction. Sullivan et al. reported on two cases of posterior SC dislocation in which an intraoperative O-arm was used to verify reduction [16]. The added benefit of performing a CT scan with intravenous (IV) contrast enhancement allows for higher quality assessment of the mediastinal vasculature that may be compromised with such an injury .

Magnetic resonance imaging (MRI) can also be used as an imaging technique for SC dislocations. Its most useful application is in the treatment of children and young adults for determining the diagnosis between SC dislocation and medial clavicle physeal injury [12, 17]. Like the CT scan, the MRI also gives great detail of the surrounding soft tissues, gives structures within the mediastinum, and has the capability of being used with IV contrast. However, the speed of the CT scan compared to MRI makes the CT scan a more favorable imaging modality in the acute setting .

The original classification system of clavicle fractures was created by Allman who based grouping on the position of the fracture along the shaft of the clavicle:

For fractures in Group I, further description has simply divided fractures as nondisplaced and displaced. Similarly, medial fractures in Group III are further divided into only two types: anteriorly displaced and posteriorly displaced. This classifies them similarly to SC dislocations as previously discussed. For Group II fractures, the concern of a high-nonunion rate led Neer to divide these lateral clavicle fractures even further. This classification has since been modified by Craig and Rockwood to classify fracture patterns based on their relationship to the nearby coracoclavicular (CC) ligaments and acromioclavicular (AC) joint (Fig. 3.8):

The majority of clavicle fractures occur due to a direct blow to the shoulder. This is typically the result of a high-energy mechanism with being thrown from a bicycle serving as one of the most common etiologies. Typically, the patient’s ipsilateral upper extremity is adducted at the time of impact allowing for the force of impact to occur directly to the superior aspect of the shoulder (Fig. 3.9). Stanley et al. looked at the mechanism of over 100 clavicle fractures and found that 87% were a result of a fall directly onto the shoulder, 7% were caused by a direct blow to the point of the shoulder, and 6% resulted from a fall on an outstretched hand [31]. Even among those patients who described their injury as involving an outstretched limb, the authors suggested the secondary impact occurring directly at the shoulder. For most patients, the history of a high-energy fall will correlate with injury findings. Low-energy mechanisms , such as a fall from standing height, are less likely to cause a clavicle fracture except for in the elderly, osteoporotic, or pathologic setting.

Physical examination of the clavicle is best performed with the patient in the standing or seated position to allow gravity to exaggerate the deformity of the shoulder girdle. Patients will typically have swelling, ecchymosis, and potentially an abrasion overlying the area of the fracture. The integrity of the skin should be carefully considered, as a sharp end of a fracture fragment can tent the overlying soft tissue. Any open lacerations, blanching, or necrosis of the skin should raise concern for an open fracture and increase the urgency for irrigation and reduction to reduce the risk of infection. Despite its superficial location in relation to the skin, open fractures of the clavicle are a rare injury. When they do occur, they typically are a result of a high-energy mechanism such as a motor vehicle collision. Taitsman et al. examined 20 patients with open clavicle fractures and found that the vast majority had an associated high-energy injury including closed head trauma, pneumothorax, vertebral fractures, or scapulothoracic dissociation [32].

The deformity of medial and lateral clavicle fractures may be little more than a prominence of the fragments at the fracture site. In the case of severely displaced midshaft fractures or lateral fractures with disruption of the CC ligaments, the shoulder may present as inferiorly displaced, shortened, and anteriorly rotated. Some authors have described this posturing as shoulder “ptosis.” [21, 33, 34] The forward rotation of the shoulder girdle can often be appreciated by standing behind the patient and observing a slight prominence of the inferior border of the scapula as it rotates forward with the unsupported distal clavicle. Lastly, as mentioned at the beginning of this chapter regarding all clavicle injuries, a thorough neurovascular examination of the ipsilateral upper extremity should be conducted as injuries to the subclavian vessels and brachial plexus can also result from the mechanism of injury.