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Findings in this case: 1) Fracture in the central sternum. sternomanubrial joint is intact. There is no significant displacement of fracture fragments. 2) Increased attenuation is present in the deep subcutaneous tissues. 3) There is increased density in the anterior mediastinum. 4) There is patchy increased attenuation in the fat around the aorta however there is no focal fluid collections and the pericardial spaces or pericardium.
Diagnosis: 1)Sternal fracture without significant displacement. 2) Subcutaneous contusion/hematoma along the anterior margin of the sternum. 3) Contusion and/or hematoma in the anterior superior mediastinum. 4) Contusion and/or edema and the fat around the aorta and great vessels. No evidence of aortic injury is definitely demonstrated on these images.
File: 8A.
Organ system: 8. Musculoskeletal system
Organ: A. Bones.
Information:
Etiology and incidence: 1) Fracture of the sternal segment is the most common with manubrial fractures being less common. 2) Nearly 2/3 of fractures are nondisplaced with an additional 20-25% minimally displaced. Incomplete fractures of the anterior cortex of the sternum are also possible. 3) 3-5% of individuals who said that blunt chest trauma will have associated sternal fractures. 4) 60-90% of sternal fractures are associated with MVA. Other injuries including those associated with assault, motor vehicle vs. pedestrian/biker/motorcycle etc. and contact sports are also at risk for acute fractures. Weightlifters and golfers are at an increased risk for stress fractures of the sternum. These are rare however. 5) With CPR, up to 20% of patients are reported to have sternal fractures. 6) Associated injuries include: Vascular injuries (aorta (4% in one series), subclavian and brachiocephalic arteries, venous injuries), myocardial contusion (6-12%), fractures of the ribs (49.6% in one series ) and spine (depending upon mechanism of injury, fractures can be seen at the thoracic lumbar junction – Chance fractures, or anterior compression fractures), pulmonary injuries including pneumothorax and contusion.
Diagnosis: 1) Clinical: Nearly all patients will have point tenderness in the area of the fracture. The presence of multiple injuries may make this specific finding difficult however. Only 40-50% will have visible contusion to examination. 2) Radiographic: a; Plain films of the sternum are difficult technically to obtain, particularly in trauma patients who may not be able to cooperate with the examination; b) CT provides the most accurate diagnosis and is also able to evaluate associated injuries. CT trauma studies with IV contrast administration to evaluate the vascular structures should be obtained in all cases of known or suspected sternal injury due to the possible presence of associated vascular injuries; c) Due to the likelihood of finding nondisplaced or minimally displaced, and the variation I can be seen in the sternum, MPR reconstructions should be obtained to evaluate the sternum. 3-D/volume rendering and MIP images are typically not helpful as they can obscure subtle fractures and nondisplaced fractures; d) Differential diagnosis: Even in the presence of trauma, consideration for pathologic fracture should be considered. Nonunited segments of the sternum may simulate fractures and fractures which are in the inferior sternum may be difficult to differentiate from the xiphoid irregularities which are frequently seen. Pectus excavatum is a developmental deformity which may make evaluation for fracture more difficult. Evaluate for associated findings of subcutaneous and her mediastinal hematoma/contusion/edema.
Prognosis:1) Due to the numbers and types of associated injuries, mortality associated with the presence of a sternal fracture is reported as between 25 and 45%. 2) Fractures of the sternum can be extremely painful and it may take extended periods of time to heal. This is particularly true in elderly patients. The average healing time is 9-12 weeks. 3) Uncommonly to rarely, injuries or considered unstable and required surgical fixation. 4) Nearly all patients require pain medication.
References:
CT in blunt chest trauma: indications and limitations. Radiographics September 1998 18:1071-1084.M L Van Hise, S L Primack, R S Israel, and N L Müller
Abstract http://radiographics.rsna.org/content/18/5/1071.abstract?sid=2a8e183d-8b99-439e-a55b-aa74f19bf8f4>
Full Text (PDF) http://radiographics.rsna.org/content/18/5/1071.full.pdf+html?sid=2a8e183d-8b99-439e-a55b-aa74f19bf8f4>
Crush Thoracic Trauma in the Massive Sichuan Earthquake: Evaluation with Multidetector CT of 215 Cases Radiology January 2010 254:285-291; Published online December 17, 2009, doi:10.1148/radiol.09090685.Zhi-Hui Dong, Zhi-Gang Yang, Tian-Wu Chen, Yuan-Chun Feng, Zhi-Gang Chu, Jian-Qun Yu, Hong-Li Bai, and Qi-Ling Wang
Abstract
Full Text
Full Text (PDF)
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Epidemiology of sternal fractures. Recinos G Inaba K Dubose J Barmparas G Teixeira PG Talving P Plurad D Green D Demetriades D
http://www.ncbi.nlm.nih.gov/pubmed/19445291
Sternal Fracture. Author: Scott Felten, MD, FACEP; Chief Editor: Rick Kulkarni, MD
http://emedicine.medscape.com/article/826169-overview
Imaging in Sternal Fractures. Author: David A Fisher, MD; Chief Editor: Felix S Chew, MD, MBA, EdM
http://emedicine.medscape.com/article/396211-overview#a23
Fracture, Sternum (Closed), ICD-9-CM: 807.2,
http://www.mdguidelines.com/fracture-sternum-closed
Sternal Fractures. Kane Guthrie ;
http://lifeinthefastlane.com/2010/10/sternal-fractures/
Sternal fracture.
http://en.wikipedia.org/wiki/Sternal_fracture
