Introduction

The clavicle is one of the most commonly fractured bones, representing up to approximately 5% of all fractures. There is a growing body of evidence that select middle 1/3 clavicle shaft fractures in adults may benefit from operative management. Fractures of the medial 1/3 and lateral 1/3 of the clavicle are recognized as distinct clinical entities and deserve unique consideration (▶Video 18.1).

I. Preoperative

1. 
   

   History and physical examination

   
   
   
   
   1. 
      

      The most common mechanism for sustaining clavicle fractures involves a fall directly onto the lateral aspect of the shoulder, followed by bicycle accidents, direct blow to the clavicle, motor vehicle accidents, and motorcycle accidents.

      
      
   2. 
      

      The distribution of this injury follows a bimodal distribution:

      
      
      
      
      1. 
         

         One peak found in young, predominantly male, adults as a result of high-energy injuries.

         
         
      2. 
         

         Second peak in individuals over the age of 70 years, primarily as a consequence of low-energy falls.

      
      
   3. 
      

      In patients having sustained high-energy mechanisms of trauma:

      
      
      
      
      1. 
         

         Systematically assess the patient using the advanced trauma life support (ATLS) protocol to rule out associated occult and potentially life-threatening injuries.

         
         
      2. 
         

         Scapular fractures or rib fractures my herald the presence of pneumothorax or pulmonary contusion. In this setting, an upright chest radiograph is indicated.

         
         
      3. 
         

         Evaluate neurologic and/or vascular compromise.

         
         
      4. 
         

         Scapulothoracic dissociation:

         
         
         
         
         • 
           

           i. Often indicated by distraction, rather than shortening, at the clavicle fracture site.

           
           
         • 
           

           ii. High rate of neurologic and vascular injury.

      
      
   4. 
      

      Physical examination:

      
      
      
      
      1. 
         

         Inspection of the shoulder girdle may reveal abnormalities in the soft tissue envelope such as abrasion, ecchymosis, swelling, skin tenting, or open fracture.

         
         
      2. 
         

         Open fracture is uncommon.

         
         
      3. 
         

         Skin tenting may be common but skin compromise due to displaced fracture ends is rare. Skin at risk of necrosis due to fracture displacement may necessitate more expeditious management.

         
         
      4. 
         

         Palpation of the shoulder girdle may elicit focal tenderness, and gentle manipulation may result in appreciable crepitation at the fracture site.

         
         
      5. 
         

         Perform a thorough neurologic and vascular examination.

   
   
2. 
   

   Anatomy

   
   
   
   
   1. 
      

      Osteology:

      
      
      
      
      1. 
         

         It is the last bone in the body to fuse, as its medial physis closes between 20 and 25 years of age.

         
         
      2. 
         

         The clavicle is a tubular S-shaped bone, whose round and stout medial end articulates with the sternum via a synovial joint.

         
         
      3. 
         

         The lateral end of the clavicle is flat and wide, and articulates via the synovial acromioclavicular (AC) joint with the acromial process of the scapula.

         
         
      4. 
         

         Medially, the clavicle has an anterior bow that curves near its midpoint to form a posterior bow laterally.

         
         
      5. 
         

         The central, tubular portion of the clavicle represents a weak, transitional area, making it more prone to fracture. This explains why most clavicle fractures are middiaphyseal.

         
         
      6. 
         

         The intramedullary canal begins 7 mm from the sternoclavicular joint and ends 20 mm from the AC joint.

      
      
   2. 
      

      Ligamentous anatomy (▶ Fig. 18.1 ):

      

      
      
      
      
      1. 
         

         There are several important ligamentous structures which attach to the clavicle and support shoulder function.

         
         
      2. 
         

         The coracoclavicular (CC) ligament, composed of the conoid ligament medially and the trapezoid ligament laterally, plays a role in suspending the scapula and supporting the weight of the arm.

         
         
      3. 
         

         Medially, the sternoclavicular ligaments and costoclavicular ligaments affix the upper extremity to the axial skeleton.

         
         
      4. 
         

         Laterally, the AC ligaments, strongest posterosuperiorly, prevent displacement of the lateral clavicle in the anteroposterior (AP) direction.

      
      
   3. 
      

      Muscular structures attaching the clavicle (▶ Fig. 18.2 ):

      

      
      
      
      
      1. 
         

         Knowledge of the muscular attachments to the clavicle are critical in understanding the deforming forces, and subsequent patterns of displacement seen in clavicle fractures.

         
         
      2. 
         

         The muscles that attach to the clavicle include—sternocleidomastoid, trapezius, deltoid, pectoralis major, sternohyoid, plastysma and subclavius.

         
         
      3. 
         

         Resultant forces lead to:

         
         
         
         
         • 
           

           i. Superior displacement of the medial fragment.

           
           
         • 
           

           ii. Medial (shortening), inferior, and anterior displacement (rotation) of the lateral fragment.

      
      
   4. 
      

      Adjacent structures of relevance:

      
      
      
      
      1. 
         

         Subclavian vessels—lie posterior to the medial clavicle and pass underneath the middle one-third of the clavicle. Subclavian artery lies posterior and superior to the subclavian vein.

         
         
      2. 
         

         Brachial plexus—anterior and posterior divisions (continuation of the superior, middle, and inferior trunks) pass under the middle one-third of the clavicle.

         
         
      3. 
         

         Lung—inferior to the medial half of the clavicle.

         
         
      4. 
         

         Injury to these structures has been described in the course of injury to the clavicle, during the surgical approach, and from insertion of hardware.

      
      
   5. 
      

      Clavicle function: The clavicle functions as both a strut and a suspension for the upper extremity.

      
      
      
      
      1. 
         

         Strut function—the musculature of the shoulder girdle and thorax are maintained at their optimal working length due to the presence of the clavicle, thus optimizing their mechanical advantage.

         
         
      2. 
         

         Suspensory function—dynamic suspension is achieved through the upward pull of the trapezius, and static suspension is achieved via the sternoclavicular (SC), AC, and coracoclavicular (CC) ligaments.

   
   
3. 
   

   Imaging

   
   
   
   
   1. 
      

      Although a clavicle fracture can usually be diagnosed on a standard plain chest radiograph, initial imaging for clavicle fractures should include AP and apical oblique radiographs. The latter involves 25 degrees of cephalic tilt of the beam, and allows unobscured view of the clavicle.

      
      
   2. 
      

      For fractures of the medial and lateral ends of the clavicle, special films are occasionally needed:

      
      
      
      
      1. 
         

         Medial clavicle fractures displace in the axial plane, and injuries of the sternoclavicular joint can be best viewed on a Serendipity view (X-ray centered on the SC joint and angled 40 degrees cephalad with the patient supine).

         
         
      2. 
         

         Lateral clavicle fractures and injuries of the acromioclavicular joint may be best appreciated on a Zanca view (X-ray beam angled 20 degrees cephalad).

      
      
   3. 
      

      Cross-sectional imaging in the form of computed tomography (CT) scan is beneficial in delineating the fracture pattern for more complex, comminuted injuries. CT scanning is the imaging modality of choice for medial fractures.

   
   
4. 
   

   Classifications

   
   
   
   
   1. 
      

      The Allman classification of clavicle fractures is the one most commonly used. It divides fractures based on anatomic region:

      
      
      
      
      1. 
         

         Group 1: middle one-third.

         
         
      2. 
         

         Group 2: lateral one-third.

         
         
      3. 
         

         Group 3: medial one-third.

      
      
   2. 
      

      Group 2 (lateral) was further classified by Neer, based on the relationship between the fracture line and the CC ligaments. This classification was further modified by Rockwood to the classification in use today.

      
      
   3. 
      

      Another classification of clavicle fractures exists within the Arbeitsgemeinschaft für Osteosynthesefrage/Orthopaedic trauma association (AO/OTA) classification, which categorizes clavicle fractures first based on fracture location, followed by fracture characteristics and morphology.