6. BiomechanicsBiomechanics
Three biomechanical regions:Three biomechanical regions:
The upper thoracic region (T1-T8) isThe upper thoracic region (T1-T8) is
rigid due to the ribcage whichrigid due to the ribcage which
provides stability.provides stability.
The transition zone T9-L2 is theThe transition zone T9-L2 is the
transition between the rigid &transition between the rigid &
kyphotic upper thoracic part & thekyphotic upper thoracic part & the
flexible lordotic lumbar spine. Thisflexible lordotic lumbar spine. This
is where most injuries occur.is where most injuries occur.
Finally we have the L3-Sacrum zoneFinally we have the L3-Sacrum zone
which is flexible & this is the regionwhich is flexible & this is the region
where axial loading injuries occur.where axial loading injuries occur.
8. BiomechanicsBiomechanics
In the upper thoracic spine theIn the upper thoracic spine the
center of gravity is anterior tocenter of gravity is anterior to
the spine.the spine.
Axial loading will result inAxial loading will result in
compressive forces anteriorly &compressive forces anteriorly &
tensile forces posteriorly.tensile forces posteriorly.
This will result in flexion-type ofThis will result in flexion-type of
injuries.injuries.
9. BiomechanicsBiomechanics
In the lumbar spine due to theIn the lumbar spine due to the
lordosis, the center of gravity islordosis, the center of gravity is
posteriorly.posteriorly.
Flexion & extension here is theFlexion & extension here is the
product of a combination of rotationproduct of a combination of rotation
& translation in the sagittal plane& translation in the sagittal plane
between each vertebra.between each vertebra.
Flexion type of injuries will straightenFlexion type of injuries will straighten
the spine & result in axial loading.the spine & result in axial loading.
In this lumber area we will seeIn this lumber area we will see
many burst fractures.many burst fractures.
10. Ranges of segmental movementsRanges of segmental movements
L1-L2 L2-L3 L3-L4 L4-L5 L5-S1
Flexion/
Extension
12 14 15 16 17
Lateral
flexion
6 6 8 6 3
Axial
rotation
2 2 2 2 1
(White and Panjabi, 1990) are (in degrees)
12. Stable or NotStable or Not
A simple anteriorA simple anterior
wedge # or just sprainwedge # or just sprain
of the posteriorof the posterior
ligaments is stable.ligaments is stable.
A wedge # with rupture ofA wedge # with rupture of
the interspinous ligamentsthe interspinous ligaments
is unstable, becauseis unstable, because
the anterior & posteriorthe anterior & posterior
columns are disrupted..columns are disrupted..
13. Patterns of InjuryPatterns of Injury
Flexion InjuriesFlexion Injuries
• Anterior Compression
• 2 Column Burst
• 3 Column Burst
• Flexion Distraction
• Chance
• Translation
Extension InjuriesExtension Injuries
• Mechanism is rare
• Fused spine: less energy
– Ankylosing spondylitis
– Surgery
• Translation common
Rotational InjuriesRotational Injuries
• Rare
• Subset of flexion
• Facet jump
TheThe Holdsworth fractureHoldsworth fracture is an unstableis an unstable
fracture dislocation of thefracture dislocation of the thoraco lumbarthoraco lumbar
junctionjunction of the spine.of the spine.
The injury comprises a fracture through aThe injury comprises a fracture through a
vertebral body, rupture of the posteriorvertebral body, rupture of the posterior
spinal ligaments and fractures of thespinal ligaments and fractures of the
facet joints.facet joints.
14. Flexion/CompressionFlexion/Compression
FractureFracture
Occurs at the T1 & L1 levels usually.Occurs at the T1 & L1 levels usually.
The amount of anterior column failureThe amount of anterior column failure
depends on the amount of compressivedepends on the amount of compressive
force. Usually there is some loss offorce. Usually there is some loss of
vertebral height with this injury,vertebral height with this injury,
but as long as the middle and posteriorbut as long as the middle and posterior
columns are intact, this fracture is considered stable.columns are intact, this fracture is considered stable.
16. Chance fractureChance fracture
• A flexion injury of the spine, first described by GQA flexion injury of the spine, first described by GQ
Chance in 1948.Chance in 1948. It consists of a compression injuryIt consists of a compression injury
to the anterior portion of the vertebral body & ato the anterior portion of the vertebral body & a
transverse fracture through the posterior elementstransverse fracture through the posterior elements
of the vertebra the vertebral body. It is caused byof the vertebra the vertebral body. It is caused by
violent forward flexion, causing distraction injury toviolent forward flexion, causing distraction injury to
the posterior elements.the posterior elements.
• The most common site at which Chance fracturesThe most common site at which Chance fractures
occur is the thoracolumbar junction (T12-L2) andoccur is the thoracolumbar junction (T12-L2) and
midlumbar region in pediatric population.midlumbar region in pediatric population.
17. Seat Belt injurySeat Belt injury
•• Lap belt injuryLap belt injury
–– childrenchildren
•• Fulcrum is beltFulcrum is belt
•• Pure distractionPure distraction
•• Associated injuries-Associated injuries-
Up to 50% of Chance fractures have associatedUp to 50% of Chance fractures have associated
intraabdominal injuries. Injuries associated withintraabdominal injuries. Injuries associated with
Chance fractures include fractures of the pancreas; contusions orChance fractures include fractures of the pancreas; contusions or
lacerations of the duodenum; & mesenteric contusions or lacerations.lacerations of the duodenum; & mesenteric contusions or lacerations.
18. Lover’s FracturesLover’s Fractures
Usually seen in people jumping out of a window to escapeUsually seen in people jumping out of a window to escape
from the police or a jealous husbandfrom the police or a jealous husband
Burst fractureBurst fracture
Anterior and the middle
column are disrupted,
edema in the posterior soft
tissues indicating involvement
of the posterior column.
19. Burst FractureBurst Fracture
Burst fractures usually occurBurst fractures usually occur
through a high-energy axial orthrough a high-energy axial or
violent compressive loadviolent compressive load
resulting in failure of both theresulting in failure of both the
anterior and middle columnsanterior and middle columns
of the vertebrae e.g, after carof the vertebrae e.g, after car
accident or fall from greataccident or fall from great
height with all or pieces ofheight with all or pieces of
vertebra shattering intovertebra shattering into
surrounding tissues & spinalsurrounding tissues & spinal
canal.canal.
20. Burst Fracture TypesBurst Fracture Types
Type Patterns Force Applied
A Fracture of both end plates Pure axial loading
B Fracture of superior end plate Axial loading with flexion
C Fracture of inferior end plate Axial loading with flexion
D Burst Rotation Axial loading with rotation
E Burst lateral flexion Axial loading with flexion
Denis F. Clin Orthop 1984
21. Burst FractureBurst Fracture
A burst fracture is alwaysA burst fracture is always
unstable because at leastunstable because at least
the anterior & middlethe anterior & middle
column are disruptedcolumn are disrupted
Coronal reconstruction &Coronal reconstruction &
an axial imagean axial image
at the level of the fracture.at the level of the fracture.
23. Three Column BurstThree Column Burst
• Compression of all three columns
• Neurological compromise common
24. Flexion Distraction InjuryFlexion Distraction Injury
• Highly unstable
• Three column injuries
• Operative repair may
differ from burst
–Assessment of distraction
is critical
27. PredictingPredicting SoftSoft Tissue InjuryTissue Injury
Criteria to predict soft-tissue injury
from bony injury are:
•Angulation greater than 20 degrees.
•Translation of 3.5 mm or more.
29. ASIA Classification SystemASIA Classification System
Grade Motor Examination
0 Total paralysis
1 Visible or palpable contraction
2 Active movement, full range of motion; gravity
(-)
3 Active movement, full range of motion vs
gravity
4 Active movement, full range of motion vs
moderate resistance
5 Active movement, full range of motion vs full
resistance
30. Grading of Clinical InstabilityGrading of Clinical Instability
White & Panjabi Check List:White & Panjabi Check List:
Element Point Value
Cauda Equina damage 3
> 8% Relative flexion sagittal plane translation 2
> 9% extension sagittal plane translation 2
< - 9 degrees Relative flexion sagittal plane rotation 2
Destroyed anterior element 2
Destroyed posterior element 2
Antcipated dangerous loading 1
Count of five or more points to Clinical Instability
33. Key PointsKey Points
Thoracolumbar Injury Classification
& Severity Score is designed to
depict the features important in predicting-
• spinal stability,
• future deformity &
• progressive neurologic compromise.
Facilitating appropriate treatment
recommendations.
Thoracolumbar Injury Classification
& Severity Score is designed to
depict the features important in predicting-
• spinal stability,
• future deformity &
• progressive neurologic compromise.
Facilitating appropriate treatment
recommendations.
34. Key PointsKey Points
The composite injury severity score derived from
this classification system assigns between 1 and 4
points to three critical components of an injury.
•Fractures with 3 points or less are considered
nonoperative candidate.
•Fractures with scores of 4 points can be
considered for nonoperative or operative
intervention.
•Fractures with 5 or greater points are considered
surgical cases.
The composite injury severity score derived from
this classification system assigns between 1 and 4
points to three critical components of an injury.
•Fractures with 3 points or less are considered
nonoperative candidate.
•Fractures with scores of 4 points can be
considered for nonoperative or operative
intervention.
•Fractures with 5 or greater points are considered
surgical cases.
35. Key PointsKey Points
In operative candidates, features of
this classification system, such as -
•posterior ligamentous integrity & the
•neurologic status of the patient
Directs the optimal surgical approach.
In operative candidates, features of
this classification system, such as -
•posterior ligamentous integrity & the
•neurologic status of the patient
Directs the optimal surgical approach.
36. ISS Also assists Decision MakingISS Also assists Decision Making
37. ISScore was-?
The MR images show bone marrow edema in the involvedThe MR images show bone marrow edema in the involved
vertebral body, but no additional soft tissue injury.vertebral body, but no additional soft tissue injury.
Conservative treatment thoracolumbar injuriesConservative treatment thoracolumbar injuries
40. Management in the Emergency DepartmentManagement in the Emergency Department
Much attention has been given to injuries of theMuch attention has been given to injuries of the
cervical spine, but injuries to the thoracolumbarcervical spine, but injuries to the thoracolumbar
region are actually more common. Because of theregion are actually more common. Because of the
anatomy involved, these injuries are oftenanatomy involved, these injuries are often
accompanied by multiple serious injuries to otheraccompanied by multiple serious injuries to other
areas of the body and may be overlooked duringareas of the body and may be overlooked during
resuscitation and stabilization.resuscitation and stabilization.
- Sandra M. Schneider, MD, FACEP, Editor Executive Summary
Roque, Pedro MD; Feiz-Erfan, Iman MD; LoVecchio, Frank DO, MPH;
Wu, Teresa S. MD, FACEP; Falcone, Robert E. MD, FACS
Emergency Medicine Reports. 32(13):157-166, June 6, 2011.
41. Approach to Acute ThoracolumbarApproach to Acute Thoracolumbar
Spine FractureSpine Fracture
CT scan is the imaging study of choice forCT scan is the imaging study of choice for
thoracolumbar injuries.thoracolumbar injuries.
To differentiate a burst fracture from a compressionTo differentiate a burst fracture from a compression
fracture, sagittal reconstructions and axial viewsfracture, sagittal reconstructions and axial views
are necessary.are necessary.
A thorough perineal examination is indicated inA thorough perineal examination is indicated in
patients with a possible thoracolumbar injury. Thispatients with a possible thoracolumbar injury. This
includes assessment of bladder function, rectalincludes assessment of bladder function, rectal
tone, bulbocavernosus reflex, and anal wink.tone, bulbocavernosus reflex, and anal wink.
42. Surgical Intervention warrantedSurgical Intervention warranted
The posterior column is essential for spinal stability.
Radiographic findings suggestive of posterior column
disruption include -
Kyphosis > 20 degrees,
Loss of 50% of anterior vertebral height,
Facet dislocation,
Multiple adjacent compression fractures, and
Compromise of > 30% of the spinal canal.
43. Alternative to standard surgical approaches less invasiveAlternative to standard surgical approaches less invasive
procedures are becoming popular in the management ofprocedures are becoming popular in the management of
traumatic & degenerative spine diseases.traumatic & degenerative spine diseases.
STANDARD OPEN MICRODISCECTOMY VERSUS MINIMAL ACCESS TROCAR
MICRODISCECTOMY:RESULTS OF A PROSPECTIVE RANDOMIZED STUDY:
Neurosurgery 61:174–182, 2007
