Christiaan N. Mamczak
MICHAEL J. GARDNER
Christopher S. Smith*

*The views expressed in this chapter are those of the author(s) and do not necessarily reflect the official policy or position of the Department of the Navy, Department of Defense or the United States Government. Christopher S. Smith is a military service member and this work was prepared as part of his official duties. Title 17 U.S.C. 105 provides that ‘Copyright protection under this title is not available for any work of the United States Government.’ Title 17 U.S.C. 101 defines a United States Government work as a work prepared by a military service member or employee of the United States Government as part of that person’s official duties.

Bony Anatomy

The clavicle is an S-shaped curvilinear bone with varying degrees of curvature within adult and pediatric patients.
With articulations at the sternoclavicular (SC) and acromioclavicular (AC) joints, imaging can be challenging due to bony overlap with the ribs, vertebrae, and scapula.
Single AP views of the clavicle do not accurately depict its anatomy or intraoperative reduction. Like any other bone, multiple views are necessary to delineate the restoration of length and alignment.

Radiographic Anatomy

AP View

In traditional AP views, the intact clavicle will have a gentle S-shaped orientation sweeping cranially and laterally from the SC joint.
With displaced middle and lateral third fractures, the medial segment is typically translated cranially due to the deforming forces of the sternocleidomastoid muscle (Fig. 3-1).
Postreduction AP images should restore the gentle AP S-shaped anatomy, particularly with an apex superior bow. Flattening of the contour or apex deformity may be concerning for malreduction (Fig. 3-2).

Gardner1e-ch003-image001 — Figure 3-1 AP fluoro view of midshaft clavicle fracture with >100% displacement.

Gardner1e-ch003-image002 — Figure 3-2 AP fluoro view demonstrating anatomic restoration of the clavicular length and contour.

Inlet/40 to 45-Degree Caudal View

This view accentuates the true S-shaped degree of curvature thus demonstrating that the clavicle is not a simple, straight bone.
The x-ray/fluoro beam is directed 40 to 45 degrees caudal from the true AP with the patient supine (see figures below).
The typical anterior butterfly fragment seen in comminuted midshaft fractures can be better delineated with this view, but posterior and inferior comminution should be expected and is not uncommon (Fig. 3-3).
Proper screw lengths for anterior-inferior plating can be confirmed with the clavicular inlet view.
Postreduction inlet images should restore the S-shaped anatomy. Flattening of the contour or apex deformity may be concerning for malreduction (Fig. 3-4).

Gardner1e-ch003-image003 — Figure 3-3 Clavicle inlet fluoro view depicts fracture displacement and anterior comminution.

Gardner1e-ch003-image004 — Figure 3-4 Clavicle inlet fluoro view demonstrating anatomic restoration of the clavicular length and S-shaped contour.

Outlet/15 to 30-Degree Cranial View

The intact clavicle is typically most linear in this view.
The degree of cranial tilt is variable and predicated on patient anatomy and positioning.
The x-ray/fluoro beam is directed approximately 15–30 degrees cranial or cephalad from the true AP with the patient supine.
Medial fragment cranial displacement and inferior comminution are best imaged with the clavicular outlet view.
Reduction and displacement of far lateral clavicle fractures with and without AC joint ligamentous injury are also well visualized with the outlet view (Fig. 3-5).
Proper screw lengths for superior plating are appreciated with this view.
Postreduction outlet images should restore the linear anatomy. Apex deformity may be concerning for malreduction, although some clavicles have physiologic apex superior morphology (Fig. 3-6).

Gardner1e-ch003-image005 — Figure 3-5 Clavicle outlet fluoro view depicts fracture displacement and inferior comminution.

Gardner1e-ch003-image006 — Figure 3-6 Clavicle outlet fluoro view demonstrating anatomic restoration of the clavicular length and straight axial contour.

Serendipity 40-Degree Cranial SC View

Medial clavicular fractures and dislocations of the SC joint are best depicted on this midline view of the clavicles. Imaging technique is similar to the outlet view (Fig. 3-7).
Note that advanced imaging (i.e., CT scan) offers better anatomic orientation of SC dislocations because orthogonal views of the SC joint anatomy are obscured by overlap of surrounding medial bony and soft tissue structures. 3D CT can also better demonstrate the multiplanar deformity associated with an acute clavicle fracture (Fig. 3-8).