Key points

Introduction

Clavicle shaft fractures are among the most common fractures of the upper extremity in adolescents. The incidence of clavicle shaft fractures in the pediatric population is 15% among all upper extremity injuries. Traditionally, clavicle shaft fractures in children and adolescents have been managed nonoperatively, with the exception of open or impending open fractures and fractures associated with floating shoulders or with neurovascular compromise. Most clavicle fractures occur in the shaft along the middle third; this article focuses specifically on clavicle shaft fractures. The optimal treatment of clavicle shaft fractures for older children and adolescents is a topic of major controversy because the literature has shifted more in favor of surgical treatment of displaced clavicle fractures in adults, although whether the research on outcomes in adults is applicable to this younger population remains debatable.

Introduction

Clavicle shaft fractures are among the most common fractures of the upper extremity in adolescents. The incidence of clavicle shaft fractures in the pediatric population is 15% among all upper extremity injuries. Traditionally, clavicle shaft fractures in children and adolescents have been managed nonoperatively, with the exception of open or impending open fractures and fractures associated with floating shoulders or with neurovascular compromise. Most clavicle fractures occur in the shaft along the middle third; this article focuses specifically on clavicle shaft fractures. The optimal treatment of clavicle shaft fractures for older children and adolescents is a topic of major controversy because the literature has shifted more in favor of surgical treatment of displaced clavicle fractures in adults, although whether the research on outcomes in adults is applicable to this younger population remains debatable.

Anatomy

The clavicle is an S-shaped bone when viewed from the axial plane and is a key structure to the shoulder girdle. It has 2 articulations: medially at the sternoclavicular joint and laterally at the acromioclavicular joint. The joint capsules provide stability in both craniocaudal and anteroposterior planes while allowing for rotation occurring with the arc of motion of the shoulder. The clavicle is a key structure of the shoulder suspensory complex, providing ligamentous attachments to the scapula via the conoid and trapezoid coracoclavicular ligaments. In children and younger adolescents, these ligaments attach to a thick periosteal sleeve. Six muscles attach to the clavicle, with the sternocleidomastoid, sternohyoid, and pectoralis major attaching medially; the subclavius muscle attaching along the midportion; and the deltoid and trapezius attaching laterally. Understanding the relative muscular attachments allows for appreciation of direction of displacement of fracture fragments ( Fig. 1 ). The clavicle is also an important structure that protects critical neurovascular structures, including the subclavian artery and vein, and the brachial plexus, especially along the middle third of the clavicle.

Typical displacement of clavicle shaft fracture fragments with the medial fragment pulled cephalad by the sternocleidomastoid and the lateral fragment pulled caudad by the weight of the arm.

Growth and ossification of the clavicle

The clavicle forms by both endochondral and intramembranous ossification. Its primary central ossification center appears in utero around 5 and one-half weeks, and continues to contribute to most clavicular growth postnatally via intramembranous ossification. The secondary medial and lateral epiphyseal growth centers appear in adolescence and contribute growth at the ends of the clavicle via endochondral ossification. The medial and lateral epiphyseal growth centers fuse around 25 years of age and 19 years of age, respectively. Despite the later appearance and fusion of the epiphyseal growth centers, most clavicular growth occurs earlier in life. McGraw and colleagues demonstrated that 80% of the full length of the clavicle is reached by 9 years in girls, and 12 years in boys. Nonoperative treatment of displaced fractures in children relies heavily on the growth and remodeling potential of the fractured bone. Proponents of surgical treatment of severely displaced clavicle fractures may view the diminished remodeling potential of the clavicle in adolescents as a major factor in proposing treatment plans analogous to those in adults.

Mechanism of injury and evaluation

The clavicle shaft is most commonly injured by an axial load to the clavicle transmitted through a fall onto the shoulder. Less common mechanisms of fracture include a direct blow to the clavicle or fall onto an outstretched hand. The middle one-third shaft of the clavicle is the most commonly injured location due to its transitional location leading to a stress riser, where the shape of the clavicle transitions from concave to convex, and from tubular to flat. The direction of displacement depends on both the location of the fracture and the initial force causing the injury. Superior displacement of the medial fragment is common due to the pull of the sternocleidomastoid and can lead to tenting of the skin ( Fig. 2 ) or, in rare instances, open injuries when there is severe displacement. The lateral fragment often displaces inferiorly due to the weight of the shoulder and arm. A thorough neurovascular examination of the injured extremity should be performed to due to the proximity of the subclavian vessels and brachial plexus. Severe displacement or comminution of the clavicle fracture should alert the clinician to a high-energy mechanism, and one should be vigilant in looking for potential associated injuries, including pneumothorax, or fractures of the scapula and ribs. Anteroposterior and 30-degree cephalic tilt radiographs (serendipity view) with the patient in an upright position are sufficient to characterize clavicle shaft fractures. In cases of significant comminution, including radiographs of the contralateral side can aid in assessing the amount of shortening.

Skin tenting in a displaced midshaft clavicle fracture.

Nonoperative treatment options

Nonoperative treatment generally involves the use of a simple shoulder sling or figure-of-8 brace for approximately 3 to 4 weeks, followed by gradual increase in range of motion. There is an absence of data in the literature supporting that a figure-of-8 brace results in improved outcomes when compared with a shoulder sling, though the figure-of-8 bracing has been associated with more pain and discomfort. Consequently, a shoulder sling has become the preferred nonoperative treatment method. In the adolescent, gradual return to strengthening can be started at 6 weeks, and union should be expected by 12 weeks in most cases. In younger children, fracture healing may be more expeditious.

Surgical treatment options

Multiple surgical methods have been described for the treatment of clavicle shaft fractures. The most commonly used method is open reduction and internal fixation with an anatomically contoured plate and screw construct. Several studies have also demonstrated excellent results with intramedullary pin fixation for simple fracture patterns. Specific advantages of plate fixation include direct visual control of the fracture fragment and biomechanically more rigid fixation. Intramedullary fixation preserves the soft tissue around the fracture sites if a direct open reduction is not used, though complications, including hardware breakage, prominent hardware, skin breakdown near hardware, and pin migration, have been reported. Additionally, in many cases in which surgical stabilization is considered, the fracture patterns are more complex and thus not amenable to intramedullary stabilization. Consequently, this article focuses on open reduction and internal fixation with plate fixation as the primary surgical treatment because this is the method of stabilization in most the recent literature in both adults and adolescents.

Surgical technique for plate and screw fixation

For open reduction and internal fixation of clavicle fractures, a superior or anterior plating location can be chosen based on surgeon preference. The patient is positioned in a beach chair or supine position, based on the surgeon’s preference. An approximately 7 to 9 cm horizontal skin incision is made centered along the clavicle. The subcutaneous tissue and platysma is dissected and, if visible, the crossing supraclavicular nerves are identified and preserved. Occasionally, a supraclavicular nerve branch is sacrificed to gain adequate exposure for the open reduction and internal fixation, and it is important to counsel the patient about small regions of potential superior chest wall numbness before surgery. The clavipectoral fascia and surrounding muscle is dissected in a clean plane to allow for eventual closure. The bone is exposed with the periosteal elevator. If 1 large comminuted fragment is present, it is reduced to 1 of the major fragments with a small fracture reduction clamp and a lag screw (generally 2.7 mm or 3.5 mm) is inserted to secure the fragment. The surgeon should be careful to preserve some periosteum on the comminuted fragment to help maintain its viability and facilitate fracture healing. Next, the major bone fragments are directly held by fracture reduction clamps and reduced anatomically. If the fracture configuration allows, it is helpful to either place a 1.6 mm k-wire to hold this reduction or place 1 or more lag screws away from the plane of the intended plate to hold the major fragments together. An anatomically contoured plate is assessed for overall fit along the clavicle, with a goal of at least 3 screws on each of the major fracture fragments. Occasionally, the plates require subtle bending to match the clavicle shape and prevent loss of reduction as the screws are affixed to the plate. The screw holes are drilled with care not to plunge in order not to injure lung or underlying neurovascular structures. Screws are sequentially placed on each side of the fracture, the fixation verified fluoroscopically, and routine irrigation and closure is performed. A sling is used postoperatively for comfort for a maximum of 2 weeks and pendulum exercises to the shoulder are allowed. From 2 to 6 weeks range of motion is gradually progressed. From 6 weeks, gradual strengthening of the shoulder can commence and contact sports can be performed once full radiographic union and strength is achieved.

Current controversy

Most clavicle fractures in adolescents have been typically treated nonoperatively. The absolute indications for surgery involve open fractures, impending open fractures with skin tenting, and displaced clavicle fractures in the setting of floating shoulders or neurovascular compromise. In the past 10 years, the trends in treating middle third clavicle fractures in adults have changed drastically in favor of open reduction and internal fixation, with an increased annual incidence of clavicle shaft fracture open reduction and internal fixation of 61.5% from 2007 to 2011. This trend was initially spearheaded by a randomized controlled trial by the Canadian Orthopedic Trauma Society, which demonstrated significantly improved functional outcome scores and decreased rates of nonunion with plate fixation of displaced clavicle shaft fractures compared with those of nonoperative treatment (10.8% nonoperative group, 2.98% plate fixation group). In the adult population, clavicle fractures treated nonoperatively have been associated with poorer outcomes and significantly decreased strength and endurance. Fractures, particularly with 2 cm of initial shortening, have been shown to be more prone to nonunion. Furthermore, several studies have demonstrated that plate fixation and corrective osteotomy after initial malunion of nonoperatively treated fractures results in significant improvement of subjective and functional outcomes. Hence, based on the trifecta of superior strength and endurance, improved functional outcome scores, and decreased rates of nonunions, surgical treatment of more than 100% displaced or 2 cm shortened clavicle fractures has become the preferred treatment method in adults. Recent treatment trends of clavicle fractures in adolescents have mirrored the enthusiasm of surgical treatment in adults. A national insurance database study demonstrated similar trends in adolescents with significantly increased operative treatment of adolescent clavicle fractures in the 10- to 19-year age group from years 2007 to 2011 (12.5% in 2007 compared with 21.9% in 2011). A major controversy remains about whether the increased trend toward surgical treatment of clavicle shaft fractures in adolescents results in improved clinical outcomes as in adults.