Clavicle fractures are common injuries and account for approximately 35% to 40% of fractures in the shoulder region. Most occur in the midshaft, and the majority are treated nonoperatively. Nonsurgical management of this injury was based on historic, retrospective, surgeon, or radiographic studies that equated union with success. These early studies concluded that the residual shoulder deformity was primarily cosmetic and that shoulder and upper limb function were satisfactory. In the past 15 years, there has been a paradigm shift in the evaluation and treatment of clavicle fractures because contemporary studies have reported that nonoperative treatment of widely displaced fractures in adults is associated with persistent anatomical deformity, residual shoulder pain and weakness, and subtle neurologic impairment. Furthermore, recent randomized clinical trials comparing nonoperative with surgical treatment of widely displaced clavicle fractures in adults have shown a 15% rate of nonunion and symptomatic malunion, respectively, in nonoperatively treated patients. These newer studies also used patient-oriented limb-specific outcome measures such as the Constant, Dash, or ASES scores and demonstrated statistically significant improvement in validated patient outcome measures following internal fixation. These studies lend support for the use of internal fixation in selected patients with widely displaced clavicle fractures in adults to decrease the incidence of nonunion and malunion. Surgery has proven to be safe and effective with the most common complication being prominent hardware necessitating removal.

Most classification schemes for clavicle fractures divide them into three basic categories. Group I are middle third fractures, Group II are lateral third fractures, and Group III are medial fractures. Neer et al. further subdivided Group II fractures into three distinct subgroups based on associated soft-tissue and ligamentous injuries. In type I injuries, the coracoclavicular ligaments remain intact; in type II injuries, this ligamentous complex is disrupted allowing superior displacement of the lateral fragment; and type III injuries that involve the articular
surface of the acromial-clavicular joint. Several epidemiological studies show that approximately 80% of all clavicle fractures occur in the middle one-third, 15% in the lateral third, and only 5% occur medially. The AO/OTA classification of clavicle fractures is seen in Figure 1.1.

A thorough knowledge of the osseous, soft-tissue, and neurovascular anatomy of the shoulder is important if surgery is planned. The clavicle is an S-shaped bone and has an anterior convex to concave curvature when viewed from medial to lateral. The lateral end of the clavicle flattens while the medial end remains cylindrical. The midportion is densely cortical with a short and narrow medullary canal particularly in young adults (Fig. 1.2). Laterally, the clavicle is anchored to the scapula by the relatively weak acromioclavicular ligaments and the more robust coracoclavicular ligaments (conoid and trapezoid). Medially, the clavicle articulates with the sternum and is supported by the thick and strong sternoclavicular, costoclavicular, and interclavicular ligaments. Although the clavicle is predominately a subcutaneous structure, the deltoid muscle arises from the anterior-inferior portion of the lateral clavicle while the trapezius muscle arises posterior and superior in its midportion. Several other upper limb muscles take all or part of their origin from the clavicle including the subclavius, sternocleidomastoid, and pectoralis major (Fig. 1.3).

From a mechanical point of view, the clavicle functions as a strut between the shoulder girdle and the thorax, and it suspends the upper limb from the chest wall. The clavicle also provides significant protection to the subclavian vessels and the brachial plexus that lie in close proximity (Fig. 1.4).

Most clavicle fractures in adults are managed nonoperatively. Nonsurgical treatment is indicated when fracture displacement is <12 to 15 mm, angulation is <10 degrees, and translation is less than a bone diameter. Treatment consists of support for the upper extremity in a sling, shoulder immobilizer, or figure-of-eight _clavicle strap to relieve pain. In adolescents, teens, and young adults, a figure-of-eight sling is simple and well tolerated. In adults, a sling or shoulder immobilizer is usually preferred. These treatment methods will not “reduce” a clavicle fracture; rather, they are intended to support the upper limb during the healing process. Within 2 to 3 weeks, most patients are able to remove their sling for simple activities of daily living, bathing, and hygiene. Serial radiographs usually show some callus by 3 weeks and substantial healing by 6 to 8 weeks. External support is discontinued when the patient has minimal pain and x-rays show progressive healing. Return to activities is dictated by local symptoms. Most patients can return to full activities by 12 weeks if the fracture is healed.

Until the turn of this century, the indications for internal fixation of clavicle fractures were very limited. Most major orthopedic textbooks supported surgery for open fractures, those with vascular compromise or progressive neurologic deficits, as well as in patients with scapulothoracic dissociation, or displaced pathologic fractures. Not surprisingly, these conditions represent a small minority of clavicle fractures seen in clinical practice. Current indications for clavicular surgery, based on recent randomized clinical trials, support the use of internal fixation in adults when there is shortening, displacement, or translation >15 to 20 mm (Fig. 1.5). Other strong indications for clavicular surgery include complex ipsilateral injuries to the scapula or proximal humerus, displaced group 2 type 2 lateral clavicle fractures, and symptomatic nonunion (Fig. 1.6).