Close
New

Medscape is available in 5 Language Editions – Choose your Edition here.

 

Imaging in Clavicular Fractures and Dislocations

  • Author: Barry Hahn, MD, MD; Chief Editor: Felix S Chew, MD, MBA, MEd  more...
 
Updated: Nov 09, 2015
 

Overview

The clavicle derives its name from the Latin word clavicula, or small key, because of its unique curvature. Despite the high frequency of injuries to the clavicle, our understanding of its injuries and function is based on only a modest amount of data. It has long been thought that the inherent reparative capacity of the bone leads to its rapid healing with little more than symptomatic treatment. Deformity has been described as merely a cosmetic concern, because function is satisfactory despite malunion.[1, 2, 3, 4, 5, 6]

Clavicular fractures are classified by their location. The most common injury is a type 1 fracture (seen in the images below), which affects the middle third of the clavicle.

Type 1 clavicular fracture (middle third). Type 1 clavicular fracture (middle third).
Type 1 comminuted clavicular fracture with skin te Type 1 comminuted clavicular fracture with skin tenting.

Type 2 fractures (demonstrated in the image below) involve the lateral third of the clavicle, distal to the coracoclavicular ligament. These can be further subdivided into fractures with or without disruption of the ligament itself.

Type 2 clavicular fracture (lateral third). Type 2 clavicular fracture (lateral third).

The least common injury, type 3 (seen in the image below), is a fracture of the proximal third of the clavicle.

Type 3 clavicular fracture (medial third). Type 3 clavicular fracture (medial third).

Preferred examination

The preferred method for radiologic evaluation of clavicular fractures varies according to the location of the injury and the need to identify potential associated injuries. In general, radiography is the only modality required, and fractures of the middle third of the clavicle are seen with an isolated anteroposterior (AP) projection centered on the midshaft of the clavicle. If clinical suspicion is high and if the AP view does not reveal a fracture, a 30° cephalic view can be helpful. On the converse, radiographs are extremely difficult to interpret when injuries to the medial clavicle and the sternoclavicular (SC) joint are being evaluated, even when both sides are included or oblique views are used. Computed tomography (CT) scanning is currently the best technique to evaluate these injuries. It provides true orthogonal views, which are unobtainable with plain radiography.[7, 8, 9, 10]

Finally, a single AP radiograph often suffices for diagnosing distal clavicular fractures and injuries to the acromioclavicular (AC) joint. However, certain clinicians prefer to obtain comparison views of the opposite shoulder or stress images. Some believe that the value of stress, or weighted, images is controversial. Use of these images has essentially been abandoned in current practice. A specialized Zanca view may help to visualize the joint by eliminating overlying structures.

Next

Radiography

The radiographic evaluation of different regions of the clavicle and assessment of the AC and SC joints are discussed in this section.

Midclavicle

Evaluation of the clavicle requires a standard AP view centered on the midshaft of the clavicle. The image should be large enough to permit evaluation of the AC joint and the SC joint, as well as of the rest of the shoulder girdle and the upper lung fields.

Oblique views can be used to further gauge the degree and direction of displacement. In practice, an AP view with a 20-60° cephalic tilt provides an adequate second view, because interference with thoracic structures is minimized. (See the image below.)

Anteroposterior view with a cephalic tilt shows a Anteroposterior view with a cephalic tilt shows a midshaft clavicular fracture.

Because of the shape of the clavicle, fractures of the midclavicle represent multiplanar deformities, and accurate estimates of shortening are difficult to obtain with plain radiographs. CT scans, especially with 3-dimensional reconstructions, improve the accuracy. However, this level of accuracy is rarely required.

Medial clavicle and SC joint

Standard projections for the evaluation of the SC joint include posteroanterior (PA), lateral, and oblique views. Medial clavicular fractures and SC joint injuries may be difficult to appreciate on standard views because of the overlap of the clavicle with the sternum and the first rib. Special projections include Rockwood, Hobbs, Heinig, and Kattan views. The most popular additional view is the Rockwood, or Serendipity, view (seen in the image below). This projection requires a 40° cephalic tilt of both SC joints centering on the manubrium.

Normal Rockwood (Serendipity) view of the sternocl Normal Rockwood (Serendipity) view of the sternoclavicular (SC) joint.

The full extent of these injuries is often unclear despite the use of additional radiographic views. The diagnosis is best confirmed with CT scanning, which has the added benefit of the depiction of rib fractures, pulmonary contusion, and pneumothorax.

Of note, the secondary ossification center at the medial end of the clavicle does not appear before the age of 12 years, and it may not unite until the age of 25 years. Therefore, a physeal fracture can be confused with a dislocation of the SC joint on plain radiographs. This possibility should be carefully considered when studies in children or adolescents are being evaluated.

Lateral clavicle and AC joint

A single AP radiograph of the injured side often suffices, but some prefer to obtain comparison views of the opposite shoulder. AP views of the AC joint are performed at 15° of cephalic inclination, along the scapular spine. Normal alignment of the joint is present on an AP view when the joint space measures less than 5 mm wide and when the undersurfaces of the acromion and the distal clavicle form an uninterrupted arc.

Type 1 AC injuries (not to be confused with type 1 clavicular fractures) consist of a minor tear in the AC ligament, with an intact coracoclavicular ligament. This injury is clinically diagnosed when radiographs appear normal but tenderness is present over the joint.

Type 2 AC injuries represent a complete tear of the AC ligaments, with partial tearing of the coracoclavicular ligament. The clavicle is superiorly displaced by less than half of its own width.(See the image below.)

Type 2 acromioclavicular (AC) dislocation. Type 2 acromioclavicular (AC) dislocation.

Type 3 AC injuries signify complete disruption of the AC and coracoclavicular ligaments. Displacement greater than half of the width of the clavicle is present. (See the image below.)

Type 3 acromioclavicular (AC) dislocation. Type 3 acromioclavicular (AC) dislocation.

Radiographic findings are evident in 75% of type 1 and 2 AC injuries but in virtually 100% type 3 injuries.

Three additional categories have been introduced to help distinguish severe injuries for which surgical treatment may be warranted. Type 4 injuries are similar to type 3 injuries, except that posterior displacement of the distal clavicle is also present. This can be verified on an axillary view.

Type 5 injuries are characterized by inferior displacement of the scapula, with an increase of the coracoclavicular interspace of 2-3 times its normal size. Such extreme displacement is usually associated with extensive stripping of the trapezius, pectoralis major, and deltoid muscles. Type 6 injuries involve inferior displacement of the clavicle. This is a rare type of injury resulting from a direct downward blow.

In the past, stress radiographs were used to differentiate type 2 and 3 injuries (partial vs complete ligamentous tears). Because most surgeons now treat type 2 and type 3 injuries nonsurgically, this distinction is no longer critical, and the use of stress views has fallen out of favor.

Previous
Next

Computed Tomography

CT scanning's most important role in clavicular fracture evaluation is in the assessment of medial clavicular fractures and injuries affecting the SC joint when plain images are not sufficient to do so. CT scans should include the SC joints and at least half of both clavicles to allow for side-to-side comparison. If vascular compromise or impingement is a concern, the study can be performed with intravenous contrast enhancement. (See the image below.)

Medial clavicular fracture without injury to the s Medial clavicular fracture without injury to the sternoclavicular (SC) joint.

CT scans for the assessment of the medial clavicle and SC joint can be acquired in a neutral position or with stress maneuvers, which increase scan sensitivity. A stress maneuver requires that the ipsilateral humerus be internally rotated and brought medially across the chest by forcefully pulling against the opposite elbow.

CT scanning is occasionally required to elucidate intra-articular fractures or stress fractures involving the AC joint. However, CT is limited in the evaluation of the surrounding soft tissues, including the capsule, ligaments, and synovium.

Previous
Next

Magnetic Resonance Imaging

In most cases, the medial clavicle and SC joint can be adequately evaluated with standard radiography or CT scanning. However, magnetic resonance imaging (MRI) is superior to CT scanning in depicting bone marrow abnormalities, disk or cartilaginous injury, and joint effusions. MRI is also better than other methods for evaluating extra-articular soft tissues. Furthermore, MRI does not expose patients to radiation and it directly provides multiplanar data rather than reformations. Coronal, sagittal, axial, and oblique axial planes have been used in the MRI evaluation of the SC joint, depending on the specific area of concern.

When vascular injury is a concern, magnetic resonance angiography (MRA) may be performed.

MRI is occasionally required to elucidate intra-articular fractures or stress fractures involving the AC joint. MRI is now well established as an important modality in the assessment of rotator cuff disease.

Previous
Next

Ultrasonography

Katz et al suggested that ultrasonography is a sensitive diagnostic tool for the evaluation of clavicular fractures in newborn infants and should be the procedure of choice in the diagnosis of neonatal clavicular fracture. In a study, the authors examined 41 clavicular fractures in newborns, using radiography and ultrasonography. The investigators found no substantial difference between the modalities.[11] Further, a prospective study of 58 pediatric patients found that ultrasonography accurately diagnosed clavicle fracture with 89.5% specificity and may reduce length of stay in the emergency department.[8]

The role of ultrasonography in examination of the SC joint is limited. Although ultrasonography has been suggested as a screening tool for the identification of SC joint dislocation, it is, in practice, used only if other modalities are not readily available.

Ultrasonography has been reported to be a useful intraoperative study to guide relocation of a dislocated joint, and Doppler ultrasonography can be used for a quick assessment of vasculature.

Research indicates that ultrasonography contributes to information on soft tissues in the examination of the AC joint in suspected high-grade injuries and that it may be useful in the delineation of type 3 injuries.[12]

An ultrasonogram of a clavicular fracture is seen below.

Ultrasonogram of a clavicular fracture Ultrasonogram of a clavicular fracture
Previous
 
Contributor Information and Disclosures
Author

Barry Hahn, MD, MD Assistant Professor, Department of Emergency Medicine, SUNY Downstate Medical Center/Kings County Hospital; Attending Physician, Department of Emergency Medicine, Staten Island University Hospital

Barry Hahn, MD, MD is a member of the following medical societies: American College of Emergency Physicians, American Medical Association, Society for Academic Emergency Medicine

Disclosure: Nothing to disclose.

Coauthor(s)

Mark Raden, MD Director of Radiology, Chief of Neuroradiology, Co-Chief of Vascular and Interventional Radiology, Department of Neuro/Interventional Radiology, Staten Island University Hospital

Mark Raden, MD is a member of the following medical societies: American Society of Neuroradiology

Disclosure: Nothing to disclose.

Specialty Editor Board

Bernard D Coombs, MB, ChB, PhD Consulting Staff, Department of Specialist Rehabilitation Services, Hutt Valley District Health Board, New Zealand

Disclosure: Nothing to disclose.

Thomas Lee Pope, MD, FACR Radisphere National Radiology Group

Thomas Lee Pope, MD, FACR is a member of the following medical societies: American Roentgen Ray Society, International Skeletal Society, Radiological Society of North America, South Carolina Medical Association, Society of Breast Imaging

Disclosure: Nothing to disclose.

Chief Editor

Felix S Chew, MD, MBA, MEd Professor, Department of Radiology, Vice Chairman for Academic Innovation, Section Head of Musculoskeletal Radiology, University of Washington School of Medicine

Felix S Chew, MD, MBA, MEd is a member of the following medical societies: American Roentgen Ray Society, Association of University Radiologists, Radiological Society of North America

Disclosure: Nothing to disclose.

Additional Contributors

Michael A Bruno, MD, MS, FACR Professor of Radiology and Medicine, Pennsylvania State University College of Medicine; Director, Radiology Quality Management Services, The Penn State Milton S Hershey Medical Center

Michael A Bruno, MD, MS, FACR is a member of the following medical societies: American College of Radiology, American Roentgen Ray Society, Association of University Radiologists, Radiological Society of North America, Society of Nuclear Medicine and Molecular Imaging, Society of Skeletal Radiology

Disclosure: Received royalty from Oxford Press for book author/editor & reviewer; Received royalty from Elsevier Press for book author / editor.

References
  1. Browner BD, Jupiter JB. Skeletal Trauma: Basic Science, Management and Reconstruction. 3rd ed. Philadelphia, Pa: WB Saunders; 2003.

  2. DeLee JC, Drez D. DeLee and Drez's Orthopaedic Sports Medicine. 2nd ed. Philadelphia, Pa: WB Saunders; 2003.

  3. Marx JA. Rosen's Emergency Medicine: Concepts and Clinical Practice. 5th ed. St Louis, Mo: Mosby; 2002.

  4. Roberts JR, Hedges JR. Clinical Procedures in Emergency Medicine. 4th ed. Philadelphia, Pa: WB Saunders; 2004.

  5. Khan LA, Bradnock TJ, Scott C, Robinson CM. Fractures of the clavicle. J Bone Joint Surg Am. 2009 Feb. 91(2):447-60. [Medline].

  6. Shen JW, Tong PJ, Qu HB. A three-dimensional reconstruction plate for displaced midshaft fractures of the clavicle. J Bone Joint Surg Br. 2008 Nov. 90(11):1495-8. [Medline].

  7. Ernberg LA, Potter HG. Radiographic evaluation of the acromioclavicular and sternoclavicular joints. Clin Sports Med. 2003 Apr. 22(2):255-75. [Medline].

  8. Chien M, Bulloch B, Garcia-Filion P, Youssfi M, Shrader MW, Segal LS. Bedside ultrasound in the diagnosis of pediatric clavicle fractures. Pediatr Emerg Care. 2011 Nov. 27(11):1038-41. [Medline].

  9. Balcik BJ, Monseau AJ, Krantz W. Evaluation and treatment of sternoclavicular, clavicular, and acromioclavicular injuries. Prim Care. 2013 Dec. 40 (4):911-23, viii-ix. [Medline].

  10. Bonz J, Tinloy B. Emergency department evaluation and treatment of the shoulder and humerus. Emerg Med Clin North Am. 2015 May. 33 (2):297-310. [Medline].

  11. Katz R, Landman J, Dulitzky F, et al. Fracture of the clavicle in the newborn. An ultrasound diagnosis. J Ultrasound Med. 1988 Jan. 7(1):21-3. [Medline].

  12. Heers G, Hedtmann A. Correlation of ultrasonographic findings to Tossy's and Rockwood's classification of acromioclavicular joint injuries. Ultrasound Med Biol. 2005 Jun. 31(6):725-32. [Medline].

 
Previous
Next
 
Type 1 clavicular fracture (middle third).
Type 1 comminuted clavicular fracture with skin tenting.
Type 2 clavicular fracture (lateral third).
Type 3 clavicular fracture (medial third).
Anterior sternoclavicular (SC) dislocation.
Anteroposterior view with a cephalic tilt shows a midshaft clavicular fracture.
Normal Rockwood (Serendipity) view of the sternoclavicular (SC) joint.
Type 2 acromioclavicular (AC) dislocation.
Type 3 acromioclavicular (AC) dislocation.
Medial clavicular fracture without injury to the sternoclavicular (SC) joint.
Ultrasonogram of a clavicular fracture
 
 
 
All material on this website is protected by copyright, Copyright © 1994-2016 by WebMD LLC. This website also contains material copyrighted by 3rd parties.