Fractures of the thoracic and lumbar spine and thoracolumbar transition

Böhler was the first to publish a classification system for vertebral fractures in 1929. His system differentiated 5 subtypes. In subsequent years, various classification systems for vertebral fractures were introduced with respect either to the fracture type or fracture mechanism (such as those developed by Denis or Ferguson and Allen). The bony and ligamentous structures of the anterior and posterior column area of the vertebral segment and the intervertebral disc can be involved in all spinal column injuries.

In 1994, F. P. Magerl introduced a classification system for the assessment of injuries to the thoracic and lumbar spine that is still used as the standard assessment system today.

This classification system takes into account the forces acting upon the spinal column to cause the injury (compression, distractions, and translation/rotation forces) as well as the typical injury patterns observed in the vertebrae, intervertebral discs, and ligamentous apparatus as a result of the mechanics of an injury.

There are three distinct types:

• Type A injuries are caused by compression forces
• Type B injuries by distraction forces
• Type C injuries by rotation forces

The three injury types A, B and C are each subdivided into three subtypes with three subgroups each.

Type A injuries: Vertebral body compression (compression injury)

Type A injuries are caused by axial forces. They affect the vertebral body with intact dorsal ligamentous structures:

A1: Depressed fractures (impaction fractures), with upper plate collapse and no involvement of the posterior vertebral margin. This is subdivided into the following:

A1.1: Upper plate depression

A1.2: Wedge fracture

A1.2.1: Cranial wedge fracture

A1.2.2: Lateral wedge fracture

A1.3: Vertebral body impaction

A2: Fissure fractures, characterized by fissure formation in the sagittal or frontal plane, where the degree of dislocation of the individual fragments differs.

A2.1: Sagittal fissure fracture

A2.2: Frontal fissure fracture

A2.3: Pincer fracture

A3: Burst fractures are frequently characterized by the shattering of the vertebral body with involvement of the posterior edge of the vertebra with the dorsal ligamentous apparatus intact. A3 fractures are frequently unstable and cause neurological symptoms due to the compression of the spinal cord resulting from the dislocation of the posterior fracture fragments with parts of the intervertebral disc into the spinal canal.

A3.1: Incomplete burst fracture
A3.1.1: Incomplete cranial burst fracture

A3.1.2: Incomplete lateral burst fracture
A3.1.3: Incomplete caudal burst fracture
A3.2: Burst-fissure fracture
A3.2.1: Cranial burst-fissure fracture

A3.2.2: Lateral burst-fissure fracture
A3.2.3: Caudal burst-fissure fracture
A3.3: Complete burst fracture
A3.3.1: Pincer burst fracture
A3.3.2: Complete flexion burst fracture
A3.3.3: Complete axial burst fracture

Type B injuries: Injuries of the anterior and posterior vertebral elements with distraction (distraction injuries)

In type B injuries, distraction results in the rupturing of the anterior and/or posterior elements of the mobile segment.

B1: With dorsal rupture of the intervertebral joints (flexion-distraction injuries)

B1.1: With rupture of the intervertebral disc
B1.1.1: Flexion subluxation

B1.1.2: Anterior luxation

B1.1.3: Flexion subluxation or anterior luxation with fracture of the articular processes

B1.2: With type A fracture of the vertebral body Flexion subluxation type B1.2.1 with cranial wedge fracture of type A1.2.1

Flexion subluxation type B1.2.1 with pincer fracture type A2.3

Flexion subluxation type B1.2.1 with incomplete cranial burst fracture, type A3.1.1

B1.2.2: Anterior luxation with cranial wedge fracture, type A1.2.1

B1.2.3: Flexion subluxation with fracture of the articular processes and vertebral body fracture

B2: Dorsal rupture through the vertebral arch (flexion-distraction)

B2.1: Horizontal rupture of the vertebra

B2.2: Flexion spondylolysis with rupture of the intervertebral disc

B2.3: Flexion spondylolysis with vertebral body fracture

B3: Ventral rupture, splitting the intervertebral disc (hyperextension injury)

B3.1: Hyperextension subluxation

B3.1.1: Without articular process fracture

B3.1.2: With articular process fracture or fracture of the pedicles

B3.2: Hyperextension spondylolysis

B3.3: Posterior luxation (one of the most severe spinal column injuries, often involving complete paraplegic paralysis

Type C injuries: Injuries of the anterior and posterior vertebral elements with rotation (rotation or torsion injury)

Type C injuries are either type A injuries in combination with additional rotation, or type B injuries in combination with rotation and shearing fractures. These fractures are in most cases unstable, with high rates of neurological complications.

C1: Type A with rotation

C1.1: Rotation wedge fracture

C1.2: Rotation split fracture
C1.2.1: Sagittal rotation split fracture
C1.2.2: Frontal rotation split fracture
C1.2.3: Rotation pincer fracture
C1.2.4: Vertebral body separation

C1.3: Rotation burst fracture
C1.3.1: Incomplete rotation burst fracture
C1.3.2: Rotation burst-fissure fracture
C1.3.3: Complete rotation burst fracture

C2: Type B with rotation

C2.1: Type B1 with rotation (torsion)
C2.1.1: Rotation flexion subluxation

C2.1.2: Rotation flexion subluxation with articular process fracture

C2.1.3: Unilateral luxation

C2.1.4: Anterior rotation luxation without/with articular process fracture
C2.1.5: Rotation flexion subluxation without/with articular process fracture with vertebral body fracture
C2.1.6: Unilateral luxation with vertebral body fracture
C2.1.7: Anterior rotation luxation without/with articular process fracture with vertebral body fracture
C2.2: Type B2 with rotation

C2.2.1: Horizontal rupture of the vertebral body with rotation

C2.2.2: Rotation flexion spondylolysis with intervertebral disc rupture
C2.2.3: Rotation flexion spondylolysis with vertebral body fracture
C2.3: Type B3 with rotation
C2.3.1: Unilateral hyperextension subluxation without/with articular process or pedicle fracture
C2.3.2: Unilateral hyperextension spondylolysis
C2.3.3: Posterior rotation luxation

C3: Rotation shear fractures

C3.1: Slice fracture (Holdsworth)
C3.2: Rotation oblique fracture

• Pain (local, movement-induced, radiating)
• Medullary symptoms with incomplete or complete paraplegia
• Radicular symptoms
• Spinal shock
• Specific symptoms of additional secondary injuries

The clinical and neurological examinations provide information on:

• The vertebral height of the injury (reference muscles, reflex status, sensomotor status)
• Medullary or radicular symptoms
• Any secondary injuries

Radiological diagnostics are based on conventional x-ray images of the thoracic or lumbar spine in 2 planes, though the pain experienced by the accident victim often makes it difficult to adjust the image planes with a high level of accuracy, compromising the value of the information obtained in the x-rays to a considerable degree.
Computer tomography with reconstruction images allows for exact imaging of the destroyed vertebral elements. Nuclear magnetic resonance tomography allows for the clear imaging of injuries of the spinal cord, spinal nerves, and ligamentous apparatus.

• In a complete or incomplete paraplegic syndrome, rapid decompression of the pinched spinal cord and spinal nerves must be achieved to improve the neurological symptoms or prevent further worsening.
• The stability of the spinal column must be restored.
• The correct axial position of the spinal column, in particular the sagittal profile with physiological spinal column curvatures (lordosis/kyphosis), must be reconstructed.
• The fusion length (spondylodesis segments) must be selected so as to ensure the stability of the whole while fusing as few mobile segments as possible.
• Early mobilization and rehabilitation to expedite the reintegration of the injured person into his or her private and professional environment.

Stable fractures of the thoracic or lumbar spinal column without neurological complications, such as impaction fractures of type A1, are treated conservatively. Unstable fractures, such as burst fractures of type A 3, flexion distraction injuries of type B, or rotation injuries of type C, undergo surgical treatment. Depending on the level of the injury along the spine and the extent of spinal cord and spinal nerve damage, a number of surgical options are available for the stabilization of thoracic and lumbar spine fractures with dorsal (from the back), ventral (from the front) or combined dorsoventral access.
The following surgical methods are frequently used in the surgical treatment of thoracic and lumbar vertebra fractures:

• Ventral decompression, ventral support with dorsal compression spondylodesis
• Dorsal decompression, dorsal stabilization, ventral support and dorsal compression spondylodesis
• Ventral decompression and ventrally instrumented spondylodesis