Incidence and Distribution

• two-thirds at T12, L1, and L2
• 90% between T11 & L4
• in children at T4, T5, & L2
• adjacent vertebrae
• 20% associated injuries
• calcaneus #
• sternum #

Patient evaluation

• backboard
• collar or sand bags
• resuscitation ( ATLS 1992 )
• ABC
• hypotension w/ bradycardia
• high dose methylprednisolone ( Bracken,1990 N Eng J Med )
• inspection & palpation
• localised tenderness, gaps, swelling, and gibbous
• occult fractures in more than 30%
• neurologic examination
• muscle strength
• sensory examination
• reflexes
• signs of sacral sparing
• Frankel classification A - E

Roentgenographic assessment

Plain film

AP & lateral views

• junctional areas
• coned-down view
• complete spine series
• non-contigous spine fractures occur in 10-30%
• soft tissues - paraspinous mass
• thoracic spine
• haematomas
• alignement - dislocation
• loss of height
• status of the anterior, middle & posterior elements
• interpedicular & inter-spinous process distance

Computed Tomography

• more than a simple wedge compression #
• in older patients
• osteoporotic compression or pathologic #
• wedge compression <---> burst fractures
• status of the posterior wall of the vertebral body
• fragments in relation to the spinal canal
• disadvantage
• if #-s in the horizontal plane
• three-dimensional reconstruction
• tomography
• scoliosis, kyphosis → pseudo fractures
• water-soluble contrast

Tomography

• axially oriented fractures of the posterior elements
• demonstrate alignment

MRI

• cord pathology
• contusion
• transsection
• other soft-tissue injuries & disk

indicated

• progressive neurologic deterioration
• incongruous neurologic and skeletal injury
• unexplained neurologic deficit
• also to assess the status of the posterior ligamentous complex

Myelography

• little role

Classification

• majority simple wedge compression fractures
• based on
• radiographic appearance
• forces presumed to have created the injury

Denis' three-column theory of spinal stability

• anterior column
• middle column
• posterior column
• involvement > 2 columns - instability



third or middle column as a hinge or fulcrum


middle column remains intact stable injury

Denis's classification of thoracolumbar spinal injuries

• retrospective study of 412 thoracolumbar #-s
• divided into minor & major injuries

Minor spinal injuries

• Articular process fracture : 3 (0.7%)
• Transverse process fracture : 56 (13.59%)
• Spinous process fracture : 7 (1.69%)
• Pars interarticularis fracture : 4 (0.97%)

Major spinal injuries

• Compression fractures : 197 (47.81%)
• Burst fractures : 59 (14.32%)
• Fracture dislocations : 67 (16.26%)
• Seat-belt type spinal injuries : 19 ( 4.61%)

• minor injuries ---> all stable
• four basic mechanisms of injury:
• compression
• distraction
• rotation and
• shear

Compression Fractures

• failure of the anterior column under compression forces
• middle column intact & acts as a hinge
• partial tension failure of the posterior column
• anterior & lateral

Radiographic Characteristics

• lateral film:
• decreased height of the anterior vertebral body
• posterior height unchanged, posterior cortex intact
• no subluxation
• interspinous distance increased

AP film

• buckling of the lateral vertebral cortex
• lateral wedging

Characteristics on CT Scan

• vertebral ring (posterior wall, pedicles & lamina) intact
• rupture of the anterior end-plate

Osteoporotic Compression

• in older individuals associated with osteoporosis
• more common & earlier in females ( postmenopausal ) than in males
• whites » blacks
• peak incidence in mid-dorsal spine & thoracolumbar junction ---> classic kyphotic deformity (dowager's hump)
• distinguish between compression of a vertebra d/t OP & that d/t acute trauma
• acute trauma
• evidence of cortical disruption
• increase in density beneath the endplate of an involved vertebra indicate impaction of bone due to acute fracture

• osteoporotic compression
• the deformed vertebral body similar in density to adjacent vertebrae
• frequently show evidence of osteophytic spurs
• radioisotopic bone scan of little use
• CT scan may be useful

Pathologic Fracture of the Spine

• metastatic disease

radiographic feature

• bony destruction - pedicle erosion
• any component of the vertebra
• the fractures are multiple, discontiguous, or both
• surrounding soft tissue mass

history

• trivial trauma
• fracture of osteoporosis or with metastatic disease
• CT or MRI examination helps

Burst Fractures

• axial load
• failure of the anterior & middle columns
• neurological deficit

Radiographic Characteristics
lateral film

• failure of the middle column
• fracture of the posterior wall cortex
• loss of posterior height
• retropulsion of a fragment of bone into the canal

AP film

• increase of the interpediculate distance
• vertical laminar fracture
• splaying of the posterior joints

CT Scan

• break of the posterior wall of the vertebral body
• retropulsion of bone into the canal

• five different types of burst fractures
• Type A - E

Seat-Belt-Type Injuries

• failure of both the posterior and middle columns
• tension forces by flexion and distraction
• anterior column acts as a hinge

Radiographic Characteristics

• increase of interspinous distance
• horizontal split of the transverse processes, pedicles
• pars interarticularis fractures
• increased height of the posterior vertebral body & posterior opening of the disc space

CT Scan

• not much information
• may totally miss the fracture - lateral tomograms
• subtypes

one-level lesions

• Chance fracture
• ligamentous disruption

two-level lesions

Fracture Dislocations

• failure of all columns under compression, tension, rotation or shear
• this leads to subluxation or dislocation
• may present in a reduced position - high index of suspicion
• subtle signs (multiple rib #, multiple transverse process #, horizontal laminar or spinous process #s)
• Types and Subtypes
• type A - flexion rotation
• type B - shear type
• type C - fracture dislocation

Correlation of the classification with neurological deficits

• close link between mechanism of injury, type of # & neurological deficit
• Isolated transverse process fractures
• T1 and T2 ---> brachial plexus injuries
• L4 and LS ---> pelvic fractures with lumbosacral plexus injuries
Isolated spinous process fractures
• temporary conus contusions
• Isolated facet and pars interarticularis fractures
• Compression fractures
• Seat-Belt Type Injuries
• no neurological injury

Burst fractures

• 50% were neurologically intact at first examination
• Hx leg numbness, tingling and/or weakness
• impact to conus or cauda equina
• 50% with neurological deficits
• high proportion of incomplete paraplegia (96.45%)
• Fracture dislocations
• Flexion rotation type
• neurologically intact in 25%
• when neurologically injured, 50% of them were complete
• Shear type
• all cases were complete paraplegics on admission (Frankel A)
• Flexion-distraction type
• were incomplete paraplegics in 75% cases
• intact in one case 25%

Correlation of the classification with instability and basic rationale for treatment

Stable injury

• minimal & moderate compression #s w/ an intact posterior column

Rx

• early ambulation w/ or w/out external immobilisation
• degree of compression
• kyphosis & the age of the patient

Instability of the first degree (mechanical instability)

• clinical instability
• "the loss of the ability of the spine under physiologic loads to maintain relationships between vertebrae in such a way that there is neither damage no subsequent irritation to the spinal cord or nerve roots and, in addition, no development of deformity with excessive pain"( Panjabi )
• severe compression fractures and seat-belt-type injuries
• disruption of the posterior ligamentous
• flexion allows buckling around the hinge of the anterior column
• does not acutely threaten the neural elements

Rx

• bedrest in hyperextension
• brace
• ORIF

Instability of the second degree (neurological instability)

• burst fractures
• middle column ruptured under axial load
• continued compression by the fragment of the middle column against the neural elements
• early ambulation leads to axial load
• may develop neurology if treated conservatively

Rx

• controversial

non-operative

• neurologically intact
• angle of kyphosis < 15°
• angle of scoliosis < 15°
• displacement in any direction < 5 mm

surgical

• if > any of above
• pt. should be informed of the neurological risk
• posterolateral instrumentation & fusion
• anterior or posterior decompression

Instability of 3rd degree (mechanical & neurologic)

• fracture-dislocation & severe burst fracture w/ neurological deficit
• 2°displacements & progression of neurological deficit may occur

Rx

• prevention of both complications
• surgical decompression and stabilisation