A spinal fracture, also called a vertebral fracture or a broken back, is a fracture affecting the vertebrae of the spinal column. Most types of spinal fracture confer a significant risk of spinal cord injury. After the immediate trauma, there is a risk of spinal cord injury (or worsening of an already injured spine) if the fracture is unstable, that is, likely to change alignment without internal or external fixation.
Risk of spinal cord injury
Vertebral fractures of the thoracic vertebrae, lumbar vertebrae or sacrum are usually associated with major trauma and can cause spinal cord injury that results in a neurological deficit.
Thoracolumbar injury classification and severity score
The thoracolumbar injury classification and severity score (TLICS) is a scoring system to determine the need to surgically treat a spinal fracture of thoracic or lumbar vertebrae. The score is the sum of three values, each being the score of the most fitting alternative in three categories:
- Compression fracture - 1 point
- Burst fracture - 2 points
- Translational rotational injury - 3 points
- Distraction injury - 4 points
Posterior ligamentous complex
- Intact - 0 points
- Suspected injury or indeterminate - 2 points
- Injured - 3 points
A TLICS score of less than 4 indicates non-operative treatment, a score of 4 indicates that the injury may be treated operatively or non-operatively, while a score of more than 4 means that the injury is usually considered for operative management.
- ^"Fracture". MDguidelines by the American Medical Association. Retrieved 2017-10-26.
- ^Augustine, J.J. (21 November 2011). "Spinal trauma". In Campbell, J.R. International Trauma Life Support for Emergency Care Providers. Pearson Education. ISBN 978-0-13-300408-3.
- ^ abClark West, Stefan Roosendaal, Joost Bot and Frank Smithuis. "Spine injury - TLICS Classification". Radiology Assistant. Retrieved 2017-10-26.
- ^Mirghasemi, Alireza; Mohamadi, Amin; Ara, Ali Majles; Gabaran, Narges Rahimi; Sadat, Mir Mostafa (November 2009). "Completely displaced S-1/S-2 growth plate fracture in an adolescent: case report and review of literature". Journal of Orthopaedic Trauma. 23 (10): 734–738. doi:10.1097/BOT.0b013e3181a23d8b. ISSN 1531-2291. PMID 19858983.
- ^ abBuck Christensen. "Thoracolumbar Injury Classification and Severity (TLICS) Scale". Medscape. Retrieved 2017-10-26. Updated: Dec 09, 2014
The upper cervical spine is defined by the two most cephalad cervical vertebrae, C1 (the atlas) and C2 (the axis). This region is distinct in anatomic shape and is more mobile than the lower cervical spine, the subaxial cervical spine. The occipital condyles of the head (or the globe) rest upon the lateral masses of C1 (the atlas). These articular facets allow most of the flexion and extension of the head on the neck as the occipital condyles articulate on the atlas. [3, 4, 5, 6]
The ring of C1 has no vertebral body; the vertebral body that would correspond to C1 is connected or contiguous with the vertebral body of C2 and projects up as the dens (the tooth), also known as the odontoid of C2. Most of the lateral rotation of the neck actually occurs at the C1-2 junction; the remaining motion of the cervical spine is distributed among the subaxial spine vertebral motion segments as a fractional amount (~7%) per level and is less in total than the C1-C2 lateral rotation.
This area of the upper cervical spine is extremely mobile, and its stability is dependent on ligamentous structures. In unresponsive patients or those who are unable to report symptoms or pain, a C1 fracture or an occipital cervical dislocation must be excluded by radiographic screening. Also, displacement of the C1 ring may occur if the capsule or ligaments are disrupted, even without a C1 fracture; hence, the head may be displaced on the neck, and the atlas may also rotate around the odontoid or sustain a fracture of the dens.
The care of any fracture requires attention to the joint above and below. This cervical complex has often been treated as two separable articulations, C0-1 and C1-2, but the three-unit occipitoatlantoaxial complex (C0-C1-C2) articulation is much more functionally relevant.
The significance is the proximity to the brain, brainstem, and upper cervical spinal cord, but that is contrasted with the very significant motion that occurs in this area. Although patients are routinely asked to flex and extend their necks to determine range of motion, some of the motion observed is between the occiput and the atlas, and as the patient rotates laterally, at least 50% of that motion is atlantoaxial.
The stability of the injury depends on the ligaments between the bony structures. On the frontal view, the projecting occipital condyles are supported by the lateral masses (observed as wedges, narrow medially and expanding laterally), resting on the corresponding superior articular surface of C2. Consequently, the lateral masses provide inherent stability because of this bony shape and also illustrate the extent of the instability when this bony structure is disrupted, particularly when these wedges displace laterally.
The projecting condyles of the occiput are stabilized with the occipitoatlantal capsule, as well as anterior and posterior atlanto-occipital membranes. The ligamentum nuchae is a significant stabilizing structure; its specific relevance to the atlanto-occipital axial complex is controversial but should be considered. Connections from the occiput to the axis are the tectorium membrane and the alar and apical ligaments, which do not appear to be bulky enough to be independently significant restraints.
The dentate ligaments (ie, the alar ligament and the apical ligaments) attach to the dorsal lateral surface of the dens and run obliquely to the medial surfaces of the occipital condyles. In 1974, Anderson and D'Alonzo classified a type 1 odontoid fracture as an avulsion fracture of the odontoid tip caused by the apical ligament, suggesting that these ligaments impart a significant degree of stability.  Modifications aimed at expanding the Anderson-D'Alonzo classification have been proposed.  The Roy-Camille system has also been used to classify odontoid fractures. 
The transverse ligament goes from the medial surface of one side of the atlas to the other side and essentially constrains the axis to rotate around the odontoid in a closed ring of bone and the transverse ligament. As a consequence, the atlas can displace and embarrass the brainstem and spinal cord if this ligament ruptures or if an associated fracture of the odontoid is present as a result of this specific anatomic arrangement.