Thoracic and Lumbar SpineTrauma

MI Zucker, MD

A dr Z Lecture

• On injuries of the thoracic and lumbar spine

Radiography

• Thoracic: AP, lateral, swimmer’s views

• Lumbar: AP, lateral, coned L5-S1,

(oblique) views

In major trauma, don’t move patient! Lateral

is done cross-table and no oblique views

Thoracic Spine

• AP

• Lateral

Thoracic Spine

• Swimmer’s view to see T1-3

Lumbar Spine

• AP

• Lateral

Lumbar Spine

• Coned L5-S1

• Oblique views

Thoracic AP View: Anatomy

Thoracic Lateral View: Anatomy

Lumbar AP View: Anatomy

Lumbar Lateral View: Anatomy

Lumbar Oblique View: Anatomy

The Paraspinal Line

• Also called para-vertebral stripe, it is the junction between the posterior mediastinum and the lung.

The Paraspinal Line

• The left line hugs the vertebral column and is less than 50% of the distance to the descending aorta.

• The right line is usually not visible.

The Paraspinal Line

• Abnormal line: either diffuse displacement or focal bulge.

• In trauma, it means paraspinal hematoma and so occult spine injury.

• It is also an indirect sign of aortic injury.

Abnormal Paraspinal Line

Role of CT in Spine Trauma

• More sensitive and specific than plain films

• Can do dedicated thoracic or lumbar CT

CT

• However, an excellent screening examination can be done by reformatting from abdominal and chest CT’s without additional imaging.

• Ideal for major trauma patients

Role of MRI in Spine Trauma

• Gold standard for spinal canal, thecal sac, cord, disc, nerve roots

• Very good for detecting fractures, but not as sensitive or precise as CT

• Good for detecting ligament injuries

Thoracic and Lumbar Spine

The Specific Injuries

Fractures: Osteoporosis related

• Insufficiency Stress Fracture: Normal stress on abnormally weak bone by repetitive microtrauma

-or-

• Acute compression fracture from a single event, minor trauma on weak bone

Osteoporosis related Compression Fractures

• Most are considered stable

• Symptomatic treatment

Osteoporosis related Compression Fractures

• For intractable pain, stabilization by vertebraloplasty:

Percutanous injection of poly-methylmethacrylate cement

Complications: nerve root damage, PE

Pathologic Fractures

• Focal lesions, benign or malignant, that weaken bone and cause it to fracture with trivial forces

• Look for an osteoblastic or osteolytic underlying lesion, with special attention to pedicles and inferior end plate

Pathologic Fractures

• MRI is much more sensitive for identifying lesions and evaluating extension of tumor into the spinal canal

Minor Fractures

• Transverse process: anyone

• Pars: young adults, older adolescents

Transverse Process

• A minor fracture but occurs with major trauma: hard to break

• Do CT ABDOMEN to look for associated intraperitoneal or retroperitoneal injury

Pars Fracture

• SPONDYLOLYSIS

• Occasionally a congenital anomaly, but usually a fatigue type stress fracture: abnormal stress on normal bone. Hurdler, cheerleader, gymnast, weightlifter.

Spondylolysis

• Oblique view: the famous “Scotty Dog”

• The “dog” has a collar on its neck

Spondylolisthesis

• With bilateral spondylolysis, body slips forward: Spondylolisthesis

• Graded 1-4

Major Fractures

• Flexion

• Axial loading

• Shearing

• Extension

Flexion

• Wedge compression fractures: stable andunstable

• Chance fractures

• Dislocations and fracture-dislocations

Compression Fractures

• Stable: Isolated to body, less than 50% loss of height, 1 or 2 levels only

• Unstable: Posterior arch involved, or more than 50% loss of height, or more than 2 levels

• Look for loss of height, loss of straight or anterior concave surface of body

• Mechanism: FLEXION. Very common• Neurologic injury: Uncommon

Compression Fracture

Chance Fracture

Compression fracture of body and transverse posterior arch fracture

Most common at T10-L2UnstableNeurologic injury in 15%, abdominal injury

in 50% (tear of mesentery, bowel injury): always CT spine AND abdomen

Mechanism: FLEXION over a lap seat belt

Chance Fracture: Lateral

Chance Fracture: AP

Chance fracture: Bowel Injury

Fracture-dislocation

• Marked flexion force

• Frequently at T10-L2

• Very unstable

• Severe cord/cauda equina injury is common

Fracture-dislocation

Burst Fracture

• Compression fracture of body with superior and inferior end plate fractures, posterior arch fracture with laterally displaced pedicles

• Very unstable• Over 2/3 have cord injury from retropulsed

fragments.• Axial load/flexion combined mechanism

Burst Fracture: Lateral

Burst Fracture: AP

Burst Fracture: CT

• Mandatory to evaluate retropulsed fragments’ effect on spinal canal

Shear Injuries

• Marked shearing force causing severe fractures and dislocations, very unstable, severe cord injury.

Shear Injury

Extension Injuries

• Predisposing conditions: Degenerative spondylosis, DISH, seronegative spondyloarthropathies (e.g. ankylosing spondylitis). These are conditions that reduce spine elasticity.

• Often unstable• Central or complete cord syndromes common,

even with relatively minor trauma.

Extension Injury: DISH

GOODBYE

• Copyright 2004

MI Zucker