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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6022_Библиотеки_им_академика_М_И_Перельмана
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restricted are somewhat more limited than those in the cervical spine.
Compressionfracturesarecommoninjuriesthat result in loss of height of the
vertebral body, anteriorly more than posteriorly. In mild cases, radiographic
findingsincludedeformityofthecorticalmarginsandend-plates.Axialloading
can cause a burst fracture, in which the force transmitted through the
intervertebral disk results in bursting of the centrum below. Posterior element
fractures are usually present, there is nearly always a prominent sagittal
component of the vertebral body fractures, and displacement into the spinal
canal is variable. CT is usually helpful to define the extent of fractures and
posterior element involvement (Figure 6.32). Fracture dislocations involve
complex, severe forces, variable amounts of dislocation of one vertebra on
another, and usually multiple fractures. Neurologic deficits from spinal cord
compression are common. Multiple imaging modalities are often helpful in
management. The dislocation is usually initially demonstrated on plain
radiographs,whichareexcellentfordemonstratingalignment.CToftheaffected
vertebrae,especiallyhigh-resolutionmultidetectorCTwithmultiplanarand3D
reconstructions,can be very helpful for planning surgicalintervention. MRI is
thebestimagingmethodtoevaluatethespinalcord(Figures6.33–6.35).Finally,
inanyinjuryinwhichthesurgicalapproachmaybeaffectedbythelocationof
thearteryofAdamkiewicz,spinalangiographymaybeindicated.
FIGURE 6.29 Avulsion of the transverse ligament attachment.
Previous lateral cervical spine radiograph of a young woman in a
motorvehicleaccidentshowedwideningofthe anterioratlantodental
intervalto 5 mm. CT shows fracture through the tubercle where the
transverseligamentattachesonthepatient’sleft(arrow).
FIGURE 6.30 Atlanto-occipital dissociation in a 22 year old in a
motorvehiclecollision.SagittalmidlinereconstructedimagefromCT
(A)showabnormaldistancefromthetipoftheclivustothetopofthe
dens (dashed line), 13 mm in this case. Parasagittal reconstruction
from CT (B) shows the disruption and widening of the atlantooccipitaljoint(arrow).
A combination of flexion and distraction results in a distinctive type of
injury,usuallyintheupperlumbarorlowerthoracicspine.TheclassicChance
fracture extends horizontally through the vertebral body and through both
pediclesand may occurinautomobile accidents whenthepatient is wearinga
lap belt but not a shoulder harness. It is often best demonstrated on plain
radiographs,becauseaxialCTislesswellsuitedtoidentifyingaxiallyoriented
fractures (see Figure 6.19). However, other patterns of flexion–distraction
injuriescanalsooccur,stillwithanaxialorientationandposteriordistraction.In
these injuries, shearing may occur through the disk space, with posterior
subluxationordislocationofthefacetjoints(63,64).
Inadditiontomechanicalnarrowingofthespinalcanalby displacedbone,
the spinal cord can be compromised by traumatic disk protrusion, hematoma,
transient hyperextension, hyperflexion, distraction, or ischemia. In allof these
conditions, MRI is the best imaging test. Many cases of injury that would
otherwise be considered spinal cord injury without radiographic abnormality
(SCIWORA) have obvious abnormalities on MRI (65,66) (Figure 6.36).
UnexplainedneurologicdeficitsshouldbeassessedwithMRIwhenpossible.In
addition, MRI may aid in planning surgery by disclosing traumatic disc
herniations that can compromise the spinal cord after reduction of fracture or
dislocation(67).Intheauthors’experience,MRIwithinthefirst2to3daysafter
injurycanexcludeanymajorligamentousinjurythatmaythreatenthestability
ofthecervicalspine(68).
FIGURE6.31Atlanto-occipitaldissociation.MRIwasperformedona
patient who was in a high-speed motor vehicle accident. Midline
sagittal T2-weighted IR image (A) shows high signal intensity of
severe anterior and posterior paraspinal soft tissue edema at the
cervicocranial junction. Heterogeneous signal intensity within the
spinalcanalreflectssomebloodpresent.Parasagittalimage(B)shows
subluxation of the atlanto-occipital joint, with high signal intensity
fluidbetweentheoccipitalcondyleandlateralmassofC1(arrow).
Penetratingtraumaofthespinecanalsodamagethespinalcordandmaybe
more difficult to image if bony injuries are minor. MRI can sometimes
demonstratespinalcordinjuryinthesecases(Figure6.37).
FIGURE 6.32 Burst fracture of T12 suffered in a parachuting
accident. The patient had incomplete paraplegia. Axial CT shows
numerousfracturesinthebodyofT12,withposteriordisplacementof
fragmentsintothespinalcanal.
FIGURE6.33Thoracicfracture-dislocation.SagittalT2-weightedIR
image of a young adult who suffered severe T10–T11 fracturedislocation in a logging accident shows dislocation and spinal cord
transection.
FIGURE6.34SagittalSTIRMRimageofthecervicalspineshowing
notonlyanteriordisplacementofC3onC4butdisruptionofthedisk,
anterior and posterior longitudinal ligaments, and interspinous
ligament,andswellingandhighT2signalwithinthecordfromedema.
ThelatesequelaeoftraumaticspinalcordinjuryarebestassessedbyMRI.
Syrinx appears as a region of fluid within the spinal cord, with CSF-signal
intensityon both T1-weighted and T2-weightedimages.MRIcan demonstrate
thesizeandextentofaposttraumaticsyrinxandcanbeusedtofollowtheresults
ofintervention.Posttraumaticmyelomalaciaappearsasathinningofthespinal
cord,oftenwiththeappearanceofstrand-likeareasofsofttissue(Figure6.38).
Adhesionsorcyststhatmayfurtherlimitspinalcordfunctioncanbevisualized.
FIGURE6.35AcuteinjuryatC5andC6resultsinprevertebraledema
and extensive spinal cord edema seen on sagittal STIR image (A).
Axial T2-weighted image with fat saturation (B) adds evidence of
hemorrhagewithinthespinalcordasdarkfocusintheleftsideofthe
cord(arrow).
DEGENERATIVEDISEASEAND
POSTOPERATIVESPINALIMAGING
Spinal degenerative disease is part of the normal aging process (Figure 6.39).
Disc degeneration and associated end-plate osteophyte formation, as well as
facet hypertrophy and the prominence of the ligamenta flava, may result in
centralorneuralforaminalstenosisandspinalcordornerverootcompression.
However, about 30% of all asymptomatic adults will have MRI findings of
lumbar spinal degenerative disease, and 19% of asymptomatic people were
foundtohavesignificantabnormalitiesoncervicalspineMRI(69,70).Thus,itis
essentialforthephysiciantocarefullyinterprettheimagingfindingsinlightof
thepatient’ssymptoms(69).Moreover,the naturalhistoryof backpainis that
about 80% of patients recover within 2 months without any treatment (71);
therefore,spinalimagingforbackpainshouldnotbeobtainedemergentlyexcept
incasesofknownorsuspectedcancer,spinalinfection,trauma,andthelike.
Discogenic degeneration may be classified as disc bulge, protrusion,
extrusion, and sequestered fragment in order of increasing size and clinical
symptomatology(72).Bulgesareextremelycommon(onestudy[72]founddisc
bulgesin52%ofasymptomaticnormaladults)andaregenerallyasymptomatic.
ThesebulgesareseenonMRIasadiffuse,nonfocalbulgingofthediscbeyond
the normal contours of the disc and end-plate.Bulgesmay narrow the central
spinalcanalandinferioraspectoftheneuralforamina,butunlesstheyarevery
large,theydonotcausesymptoms.Centralcanalstenosisandmyelopathymay
resultfromadvanceddisease;thesedisorderspresentwithverylargediscbulges
andarecommonlyassociatedwithmarginalend-platebonyosteophytes(Figure
6.40).
FIGURE 6.36 Spinal cord contusion without fracture. Sagittal T2weightedIRMRimageofamanwhohadupperextremityweakness
after a motor vehicle accident shows stenosis of the cervical spinal
canal,discbulgeorprotrusionatC4–C5,andedemawithinthespinal
cordatthesamelevel(arrow).
Disc protrusions are defined as focal posterior deformities of the anulus
fibrosuscaused by posterior herniation of the nucleus pulposus, and generally
have an intact posterior ligamentous complex (Figure 6.41). Disc protrusions
havebeenincidentallyfoundin27%ofasymptomaticvolunteers(72);however,
protrusions may also be symptomatic, causing spinal cord compression and
resultant edema or gliosis within the spinal cord, which is manifested as T2-
bright signal (Figure 6.42). Again, the physician must confirm the correlation
between patient symptomatology and the MRI findings before intervening
surgically.
FIGURE6.37Stabinjuryofthespinalcord.AxialT2-weightedMR
imageshowslinearhighsignalintensityalongtheknifetrackthrough
theposteriorsofttissues,leftlaminaofT10,andleftsideofthespinal
cord(arrows).The patient had left lower extremity sensoryloss,but
intactstrength.
Disc extrusions are generally larger than protrusions and are generally
associatedwithrupture of the posterior anuloligamentous complex. Extrusions
are more likely tobe symptomatic; only 1% of asymptomatic adults had disc
extrusions (72). Sequestered fragments result when a disc extrusion becomes
separatedfromtheparentdisc.
FIGURE6.38Posttraumaticchanges.Thepatientwhopreviouslyhad
aC5–C6dislocationandsubsequentanteriorinstrumentationreturned
after a new episode of more minor trauma. Sagittal T2-weightedIR
image (A) shows loss of spinal cord contour at the level of the old
injury.MyelomalaciaiscorroboratedonaxialT2-weightedimage(B);
therearemultiplestrand-likeareasofsofttissuewithasuggestionof
possibleseptationsandcysticchange.
FIGURE6.39Stenosisofthecervicalspinalonadevelopmentalbasis
shownonlateralradiograph(A)bynarrowAPdiameterofthespinal
canalandonsagittalT2-weightedMRI(B)withverylittleCSFaround
thespinalcord.
CSF,cerebrospinalfluid.
Ossification of the posterior longitudinalligament (OPLL) is another lesscommon degenerative disorder most common in Japanese but also seen in
others, which can cause central stenosis and spinal cord compression (71)
(Figure6.43).
PostoperativeComplications
Postoperative complications include postoperative hematomas,
pseudomeningocele,infection,recurrent discherniation,andarachnoiditis(73).
Recurrentdischerniationcanbedistinguishedfrompostoperativescartissuein
whichunlikenormalscartissue,recurrentdischerniationsdonotenhancewith
IVgadolinium-DTPA(74).
FIGURE 6.40 Sixty-seven-year-old man with multiple thoracic disc
protrusions.(A)AxialimagefrompostmyelogramCTshowsabroadbased central disc protrusion flattening the ventral thecal sac,
compressingthespinalcord(blackarrow),whichisoutlinedbywhite
contrast-ladenCSF.(B)SagittalreconstructionfromtheaxialCTdata
showstwothoracicdiscprotrusions(arrows)effacingtheventralCSF;
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