Type 2 Jefferson Fracture with Vertebral Dissection

81 F with trauma due to falling down stairs. Neck pain • Xray of the Week

Figure 1. What is the important finding on this CT scan and potential serious complication.

Figure 2. A. Axial CT scan with thick slab MPR. Type 2 Jefferson fracture with bilateral fractures of anterior arch of C1 (orange arrows) and bilateral fractures of posterior arch of C1 (red arrows). B. Coronal CT showing lateral subluxation of left lateral mass due to the burst fracture and possibly due to transverse ligament rupture.

Figure 3. Axial CT Angiogram of the upper neck. Sequential images (1-6). Short segment occlusion of the right vertebral artery at the level of the C1 fracture, compatible with vertebral artery dissection (green arrows). Note how there is no enhancement of the right vertebral on images 4 and 5 with retrograde filling seen on image 6. Normal completely opacified left vertebral artery (red arrows).

Discussion:

C1 or atlas is the first part of the cervical vertebrae and articulates between the occiput above and C2 or the axis below. It is secured firmly with 3 ligaments around its ring-like structure, the anterior atlantoaxial ligament, the posterior atlantoaxial ligament, and the transverse ligament connecting the dens of C2 to C1 allowing the joint great stability and mobility [1]. Fractures of the C1 vertebrae account for 7% of all acute cervical spine. An important type of C1 fracture is the Jefferson fracture which involves damage to 4 portions of both the anterior and posterior arches of the C1 ring (Figs. 1-2). The mechanism of injury is axial loading on the skull resulting in the occipital condyles being driven into the lateral masses of C1, typically seen with motor vehicle trauma, falls or diving injuries. Rarely it may occur in isolation, but is most commonly associated with fractures of the axis [2,3] and is frequently associated with head injuries.

Due to the close proximity of nearby vessels and nerves, such fractures may cause severe neurologic deficits if they involve the vertebral artery or displace posteriorly into the spinal canal [4]. In fact, this patient did suffer dissection of the right vertebral artery with short segment occlusion at the level of the C1 fracture (Fig. 3). Since retropulsion of fracture fragments is rare in these types of injuries, neurologic deficit is uncommon [3].

Plain films may not be helpful in demonstrating the severity of cervical spine injury or extent of instability hence it is recommended to proceed with CT imaging for an accurate diagnosis [5]. Instability depends on whether or not the transverse ligament is intact. Transverse ligament integrity can be assessed with flexion and extension radiographs and MRI is useful in defining the anatomy [6-8].

Table1. Types of Jefferson fractures. From Mead, et al. C1 fractures: a review of diagnoses, management options, and outcomes. Curr Rev Musculoskelet Med. 2016;9(3):255-262. doi:10.1007/s12178-016-9356-5

A classification system of Jefferson fractures based on fracture location has been proposed by Mead et al. (Table 1) [3]. If not displaced and stable, type 1 and type 3 Jefferson fractures can be managed with the use of rigid cervical collar or other external immobilization [3]. Type 2 is most often unstable and if there are signs of instability or neurologic compromise, it warrants internal fixation and surgical management [9]. Atlanto-occipital dislocation is by definition unstable and requires surgical immobilization [3,7,8]. This patient was treated with halo traction and ultimately had a full recovery.

References:

1. Waxenbaum JA, Reddy V, Futterman B. Anatomy, Back, Cervical Vertebrae. In: StatPearls. Treasure Island (FL): StatPearls Publishing; July 27, 2020. https://pubmed.ncbi.nlm.nih.gov/29083805/

2. Hadley MN, Dickman CA, Browner CM, Sonntag VK. Acute traumatic atlas fractures: management and long term outcome. Neurosurgery. 1988;23(1):31-35. doi:10.1227/00006123-198807000-00007

3. Mead LB 2nd, Millhouse PW, Krystal J, Vaccaro AR. C1 fractures: a review of diagnoses, management options, and outcomes. Curr Rev Musculoskelet Med. 2016;9(3):255-262. doi:10.1007/s12178-016-9356-5

4. Payabvash S, McKinney AM, McKinney ZJ, Palmer CS, Truwit CL. Screening and detection of blunt vertebral artery injury in patients with upper cervical fractures: the role of cervical CT and CT angiography. Eur J Radiol. 2014;83(3):571-577. doi:10.1016/j.ejrad.2013.11.020

5. Lee C, Woodring JH. Unstable Jefferson variant atlas fractures: an unrecognized cervical injury. AJNR Am J Neuroradiol. 1991;12(6):1105-1110. https://pubmed.ncbi.nlm.nih.gov/1763734/

6. Radcliff KE, Sonagli MA, Rodrigues LM, Sidhu GS, Albert TJ, Vaccaro AR. Does C1 fracture displacement correlate with transverse ligament integrity?. Orthop Surg. 2013;5(2):94-99. doi:10.1111/os.12034

7. Nidecker AE, Shen PY. Magnetic Resonance Imaging of the Craniovertebral Junction Ligaments: Normal Anatomy and Traumatic Injury. J Neurol Surg B Skull Base. 2016;77(5):388-395. doi:10.1055/s-0036-1584230

8. Riascos R, Bonfante E, Cotes C, Guirguis M, Hakimelahi R, West C. Imaging of Atlanto-Occipital and Atlantoaxial Traumatic Injuries: What the Radiologist Needs to Know. Radiographics. 2015;35(7):2121-2134. doi:10.1148/rg.2015150035

9. Joaquim AF, Ghizoni E, Tedeschi H, et al. Upper cervical injuries - a rational approach to guide surgical management. J Spinal Cord Med. 2014;37(2):139-151. doi:10.1179/2045772313Y.0000000158

Muhammad Hammad Malik is a recent graduate from CMH Lahore Medical College, Pakistan. He is interested in neuroradiology and interventional radiology and is currently doing research at the Mayo Clinic Rochester, Minnesota in the Neurovascular Research Lab with Dr. Waleed Brinjikji. Stroke and identification and management is important to Dr. Malik as his grandfather suffered a massive stroke and unfortunately was not able to get the medical care he needed. Because of this, Dr. Malik was inspired to one day bring expertise back to his home country of Pakistan in order to improve the healthcare of his fellow citizens. In his free time he likes to read and write short stories, travel, play basketball and is an avid gamer. Follow Hammad Malik on Twitter @HammadM43666973

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Kevin M. Rice, MD is the president of Global Radiology CME

Dr. Rice is a radiologist with Renaissance Imaging Medical Associates and is currently the Vice Chief of Staff at Valley Presbyterian Hospital in Los Angeles, California. Dr. Rice has made several media appearances as part of his ongoing commitment to public education. Dr. Rice's passion for state of the art radiology and teaching includes acting as a guest lecturer at UCLA. In 2015, Dr. Rice and Natalie Rice founded Global Radiology CME to provide innovative radiology education at exciting international destinations, with the world's foremost authorities in their field. In 2016, Dr. Rice was nominated and became a semifinalist for a "Minnie" Award for the Most Effective Radiology Educator.

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