Fractures and fracture dislocations of the vertebrae are uncommon in the newborn. Typically, when they occur, they do so through excess force being applied, with the vertebral column and cord being hyperextended, or when the direction of pull is lateral, or when there is forceful longitudinal traction on the trunk, while the head is ﬁrmly engaged within the pelvis, especially when combined with ﬂexion and torsion of the vertical axis.
These fractures are most commonly associated with breech presentations, delivering the shoulders in cephalic presentations, and face presentation. In cephalic presentations the injury occurs most commonly at the level of the fourth cervical vertebra, whereas with breech presentations the injury occurs at the lower cervical-upper thoracic vertebrae. Although vertebral injury occurs most commonly at the level of the fourth cervical vertebra with cephalic presentations, in both cephalic and face presentations you can see high cervical fractures, such as those involving the odontoid and spinous processes. Also, difﬁcult forceps rotations can cause fracture dislocations of the high cervical vertebrae. Typically, injury to the cervical spinal cord occurs when the neck is hyperextended during delivery or when there is forceps rotations of 90 degrees or more. Usually, all of these fractures are the result of excessive application of force (Figs. 1-4).
Fig. 1. The above illustration shows the ﬁrst two cervical vertebrae, the atlas (C1), which supports the head, has no vertebral body. It is the upper articulation of the atlas with the skull that allows the head to nod, as when saying the word “yes”. The axis (C2) has a unique vertical shaped projection called the dens, or odontoid process, that acts as a pivot for rotation of the atlas and skull, as when a person turns their head to each side to indicate the word “no”. (hjd.med.nyu.edu)
Fig. 3. This schematic shows the various fractures of the vertebral column. (1) this shows a displacement of the vertebral bodies. (2) depicts the spinous processes being out of line. (3) displacement of the pedicles. (4) transverse process is broken off. (5) wedge fracture. (6) burst fracture. (7) forward displacement of a vertebra. (www.primary-surgery.org)
Fig. 4. This image is of a cervical spine MRI showing a C4 fracture and dislocation with compression of the cervical spinal cord. (en.wikipedia)
Fractures above C3 can lead to paralysis of the diaphragm, which is associated with immediate fatality unless the infant receives ventilatory support. Fractures and fracture dislocations that involve the lower cervical and upper thoracic vertebrae can be associated with ﬂaccidity of the legs and portions of the arms manifested by paraparesis (partial paralysis affecting the lower limbs) or quadriparesis (muscle weakness affecting all four limbs, which may be ﬂaccid or spastic). Typically, quadriparesis due to injury between C1-C4 affects arm movement more so than a C5-C7 injury; however, all quadriparetics have some kind of ﬁnger dysfunction. Consequently, it is not uncommon to have a patient with quadriparesis with fully functional arms, but no nervous control of their ﬁngers and thumbs.
There is another condition that can occur due to fractures or fracture dislocations of the cervical vertebrae, neurogenic shock. Neurogenic shock can result from severe CNS damage including brain injury, cervical or high thoracic spinal cord injury (T6 and above) In neurogenic shock there is a sudden loss of background sympathetic stimulation of blood vessels. This causes the vessels to relax, that is they undergo vasodilation, resulting in a sudden decrease in blood pressure due to a decrease in peripheral vascular resistance. Such loss of sympathetic tone can lead to organ dysfunction and death if not promptly treated.
If the fractures related to birth trauma are not diagnosed until late in the neonatal period, less than 28 days, than whether the fracture occurred at birth or was the result of child abuse must be addressed. What is of considerable help in making this differentiation is an observation made by Cumming who pointed out that calciﬁcation of most birth associated fractures are apparent on imaging by 9-10 days of life. If no calciﬁcation is present later than 10 days after birth, there is a high likelihood the fractures represent trauma after birth (child abuse).