THORACOLUMBAR SPINE INJURY

Dr. Kevin J. Ambadan

ANATOMY OF THE CORD AND CAUDA

• Spinal cord from foramen magnum to L1

• Conus at L1 for bowel and bladder (nervi eriganties S1-S5)

• Peripheral nerves for lower extremities start from T9-T12

• L1 roots start innervation of lower extremities

• Thoracic blood supply to the cord tenuous at T10-T12 (artery of Adamkowitz)

• Lumbar blood supply abundant

PHYSIOLOGICAL ANATOMY OF THE THORACIC SPINE

• Facets lie in the frontal plane- allowing rotation

• Ribs resist rotation and add 3x the normal stiffness in lateral rotation

• Kyphosis of the T spine loads the anterior column

• Lower 2 vertebra have floating ribs and no costotransverse articulations

• Canal size in thoracic spine relatively small

PHYSIOLOGICAL ANATOMY OF THE LUMBAR SPINE

• Large discs allow more ROM

• Facets prevent rotation

• Spinal canal wider

• Lordosis is natural alignment

• Lordosis loads the facets

THORACOLUMBAR JUNCTION

• Thoracic spine stiffer in flexion (ribs) than lumbar spine (stress riser)

• Lowest 2 thoracic vertebra have less extrinsic stability secondary to changes in facet orientation and floating ribs (T11-12 have frontal facets but no conjoined ribs to stabilize, therefore less rotational resistance)

• In pure axial loading, thoracic spine deforms into kyphosis and lumbar spine into lordosis leaving the transition vertebra exposed to pure compression

• Force distributed over 10 thoracic and 4 lumbar vertebra is withstood only by 2 vertebra at the thoracolumbar junction

MECHANISMS OF INJURY

• Low-Energy Insufficiency Fractures arising from comparatively mild compressive stress in osteoporotic bone

• Minor Fractures of the Vertebral Processes due to compressive, tensile or tortionalstrains

• High-Energy Fractures or Fracture-Dislocations due to major injuries sustained in motor vehicle collisions, falls or diving from heights, sporting events, horse-riding and collapsed buildings.

• Neurological complications are mainly associated with the third group.

• Flexion Compression – failure of the anterior column and wedge-compression of the vertebral body. Usually stable, but greater than 50 per cent loss of anterior height suggests some disruption of the posterior ligamentous structures.

• Lateral compression – lateral wedging of the vertebral body resulting in a localized ‘scoliotic’ deformity.

• Axial compression – failure of anterior and middle columns causing a ‘burst’ fracture and the danger of retropulsion of a posterior fragment into the spinal canal. Often unstable.

• Flexion–rotation – failure of all three columns and a risk of displacement or dislocation. Usually unstable.

• Flexion–distraction – the so-called ‘jack-knife’ injury causing failure of the posterior and middle columns and sometimes also anterior compression.

• Extension – tensile failure of the anterior column and compression failure of the posterior column. Unstable.

MECHANISMS OF INJURY

IMAGING - XRAYS

AP View:

• May show loss of height or splaying of the vertebral body with a crush fracture.

• Widening of the distance between the pedicles at one level, or an increased distance between two adjacent spinous processes, is associated with posterior column damage.

Lateral View:

• Examined for alignment, bone outline, structural integrity, disc space defects and soft-tissue shadow abnormalities.

• Evidence of fragment retropulsion towards the spinal canal.

IMAGING – CT & MRI

• Rapid screening CT scans are now routine in many accident units.

• More reliable than x-rays in showing bone injuries throughout the spine, and indispensable if axial views are necessary,

• Eliminate the multiple attempts that may be required to ‘get the right views’ with plain x-rays.

• MRI also may be needed to evaluate neurological or other soft-tissue injuries.

COBB’S ANGLE

• Used to classify sagittal plane deformity, especially in the setting of traumatic thoracolumbar spine fractures.

• Cobb angle is defined as the angle formed between a line drawn parallel to the superior endplate of one vertebra above the fracture and a line drawn parallel to the inferior endplate of the vertebra one level below the fracture.

• The Cobb angle is the preferred method of measuring post-traumatic kyphosis in a recent meta-analysis of traumatic spine fracture classifications

• Scoliosis is defined as a lateral spinal curvature with a Cobb angle of 10° or more

CLASSIFICATION SYSTEM

• Holdsworth 2 column theory

• Denis 3 column theory

3 COLUMN THEORY - DENIS 83

• Based on radiographic review of 412 cases

• 5 types, 20 subtypes• Anterior- ALL , anterior 2/3 body• Middle - post 1/3 body, PLL• Posterior- all structures posterior to PLL

• Same as Holdsworth• Posterior injury-not sufficient to cause instability

Spinal injury and Three column concept:

• One column injury is stable

• Two column injury is unstable

• Three column injury is invariably unstable

CLASSIFICATION OF INJURIES

• Simple Compression (1-2 column injury)

• Stable burst (2-3 column injury)

• Unstable burst (3 column injury)

• Flexion distraction (2 nonconjoined columns)

• Chance (3 column failure all in tension)

• Fracture dislocation (3 column injury)

• Pure Dislocation (rare) (3 column injury)

• Pathological (any and all)

• Insufficiency (any and all)

• Multiple contiguous fractures (nly 1-2 columns)

COMPRESSION FRACTURES

• Only anterior column injury

• Middle and post. OK

• Ant. column less than 30%

• No more than 10 degrees kyphosis

• No neuro injury

FLEXION DISTRACTION

• Easy to miss - may look benign

• Anterior column > 50% crushed

• Middle column mainly intact

• Significant spinous process widening

• Unstable

STABLE BURST

• Both ant and middle column involvement

• Minimal kyphosis

• No neuro involvement

• No laminar fracture

UNSTABLE BURST

• 3 column involvement

• Possible neuro involvement

• Severe communition

• Significant pedicle widening

• Look for laminar fracture (asso. with root entrapment)

CHANCE FRACTURES

• Old “Seatbelt injuries”

• Center of rotation is anterior to ALL

• May be “bony” chance or purely ligamentous

• Normally neuro intact

• “Bony” stable, ligamentous unstable even though all are 3 column injuries

FRACTURE DISLOCATIONS

• Translation in lower lumbar spine may be developmental (nly L3-S1 spondylolysthesis)

• Always abnormal in thoracic spine (ribs)

• Unstable

• Normally- neuro deficit

• Can be hidden at mid thoracic spine

• 3 column injury

PATHOLOGICAL FRACTURES

• Normally in patient with history of CA

• May be hard to distinguish from insufficiency fracture

• May be multiple levels

• Fracture out of proportion to force of trauma

• Suspicion calls for MRI and ?Bx

INSUFFICIENCY FRACTURES

• Normally in elderly females

• Osteopenia/malacia

• Bones have “washed out” appearance

• Minimal force vectors

• Multiple levels (normally)

• Kyphosis greater than 70 degrees may need surgery

• ?Vertebroplasty

THORACOLUMBAR INJURY CLASSIFICATION AND SEVERITY SCORE

(TLICS)

TREATMENT

• Injuries with 3 points or less = Non Operative

• Injuries with 4 points = Non-Op vs Op

• Injuries with 5 points or more = Surgery

EXAMPLESFLEXION COMPRESSION #

•Flexion compression (morphology) - 1

•Intact (neurology) - 0

•PLC (ligament) no injury - 0

Total Points = 1 point.

Non-Operative

COMPRESSION BURST FRACTURE

•Flexion compression burst - 2

•Intact ( neurology) - 0

•PLC (ligament) no injury (0)

Total Points = 2 point.

Non-Operative

COMPRESSIONBURST # - COMPLETE NEURO INJURY

•Axial compression burst with distraction posterior ligamentous complex -4

•Complete (neurology) - 2

•PLC (ligament) injury – 3

Total Points = 9 point.

Surgery

NON-OPERATIVE TREATMENT OF THORACIC SPINE INJURIES

Brace or Cast Treatment• Compression Fractures

• Stable Burst Fractures

• Pure Bony Flexion-Distraction Injury

SURGICAL MANAGEMENT OF THORACOLUMBAR INJURIES

• Unstable burst fractures

• Purely ligamentous

• Facet dislocations

• Translational injuries

• Neurologic deficit

ANTERIOR COLUMN # TREATMENT

• Simple compressions can be placed in a Jewett or TLSO off the shelf brace and discharged from the ED or office as long as pain is controlled, fracture is stable with new standing x-rays in brace and they don’t have an ileus. Cannot treat fractures above T6 without cervical extension

TLSO

STABLE BURSTS AND LATERAL COMPRESSION #

• Pain management

• Brace management

• Off the shelf TLSO (ThoracoLumboSacral Orthosis) for simple compressions greater than 30% and lateral compressions

• CASH (Cruciform Anterior Spinal Hyperextension) brace for insufficiency #

CASH

COMPLICATIONS FROM FRACTURE

• Pneumothorax (thoracic Fxs with asso rib Fxs)/

• Ileus (30-60%)

• Splenic, liver and vessel injury (mechanism of injury)

• DVT/PE

• Decubitis

• UTI

• Pneumonia

• Renal failure (hydronephrosis from cauda equina involvement)

SURGICAL INDICATIONS

• Neurological Involvement

• Flexion distraction injury

• Greater than 50% canal compromise with >15 degrees kyphosis

• >25 degrees kyphosis

• Failure of stress testing (severe pain, angulation above 25 degrees, neurosymptoms)

• Fracture dislocations

• Soft tissue “chance” fractures

LAMINECTOMY• Indications:

• Comminuted posterior elements causing direct neural compression

• Epidural hematoma requiring evacuation

• Repair of dural tear associated with burst and laminar fractures during posterior instrumentation and fusion

Contraindications:

• Canal compromise >67%

• Delay in operative treatment for > 4 days

• Where pedicle screw insertion is not feasible (atypical morphology, small dimension or traumatic fracture)

Requires intact PLC

VERTEBROPLASTY AND KYPHOPLASTY

Indications:

• Osteoporotic VCF not responding to conservative management

• Spinal metastatic lesions & fractures

• Hemangiomas

Goal of vertebroplasty is to improve strength and stability

Goal of Kyphoplasty is to restore vertebral body height and stability. The use of balooncreates a void for cement placement under lower pressure and thus results in lower incidence of cement extravasation

Can be safely done in patients with refractory pain to conservative treatments.

THANK YOU