DISORDERS AF THE LUMBAR /À/TER VERTEBR,AL FONTMEIT (LIF)

AF THE LUMBAR
DISORDERS
FONTMEIT(LIF):
/À/TERVERTEBR,AL
A,ryDTREATMENT
DIAGIT/OSIS
ABOLA",11DOUSSET''"
].-AT.VITALI"F' F-AZA]N
Frauce
Peilegrin Unirersitr Hospital Borcleartr'
', Lnir of Spirral Disorclers,
Borcleaul France
,:r,Depirrtf,rentof Neuroracttolog\ p.'fiaS,:,"Unirersitr Hospital
of the
lal recessiledial to il-ie pedicle
is
Tl-re lumbar inten'eltebral foramen
ntlnber as
canai u=t*t tu that i-rasthe saile
;;;;*d as the pat't of tl-reradicular
the same
the r:oot,ar-rdthe LIF betu'eer-i
nenre root
that sttrrottt'tclsthe lttmbar
pedicle
lvir-ig
rindel
the
of adja- o.ai.t. ar-id
oi-ie
,'it,,r"t"a betrireentl're pedrcles
sections'
imaging
arial
distir-Lgui- ifig. f l. On
.lnt t'"rt.b,,ae It sl-roulclbe
liues' one
u'hicl-l .ni't dru,r' t\{o anteropostelior
,i-,.a t.on-, the vertebral folamen'
pedicie' the
the
of
edge
canal oi'iù.-t".aiui
.orr.tponat to the central spinal
the larelal edge Anv lesion
àir*.
the
of
pedicles
ti*^,.a bett'eeu tire tri:o
is desi"
tii.*,.à n-rechalto tlie pedicle.
designatedit
;'in,tuforar,inal", straight r-rncier
,0,*.,.rt.bta. MacNab[1]
;i.iâà.t zoue",becar-tse
of i1-redifficultv *oi.à
ttro lines ''fotair-ua- ift.'o.ai.f. betureenthe
either
bi'
regioi-t
ti-ris
"er'tra'
erploting
in
and latelal to the peclicle
anatotr-n' ;ri;i;
The
sllrgern"
or
stuclies
sine
re'ier"red'
.inJ pnt'tiologl' 'eed to be
eatellt'
greai
becarrsethev erpiain' to a
T-l-ie
rt'ot-lt-up
ihe cl i nical m anifestatioi-ts,
anclthe surgical
.-o*inn,ions calieclFot-'
pi-ocedr-rt'es
AHæ
F\T{AT*IVEV
FF{YSïÛ€,*GYtul
: Radicularcanal anatomy'
Fia.1
'^l"oosie,rior
Tl-ie racliclilar cana1, u'l-rich sr-tn'or-inc1s
view : b) endocanalar view
leal'es
it
before
root
1 = retrodiscal Part
ihe irtn'rbarneil'e
oI lhree 2 = iaieral recess
ti . u.rt.trtot forai-i-retl'cot-tsisis
forcfien (LtF)
space'ti-relate- S = ti*:'g^, intervertebral
fo,-,ionr, lhe lett'ociiscal
49
T:-:..
NICE SPINE COURSE 2007 - Current ConcejrLs
foraminal" (fig 2) Of cour-se,lesions
erist that go bevond the limirs of the
pedicle,as u'e shallseein the chapteron
foraminal herniated discs. On sagittal
slices,the LIF is ear"shapedrvith a bony
upper portion, is inertensible and rvider.
than the lower portion. The spinal
nen/e,01'tobe more pr-ecise,
its ganglion
Iies in the upper parl of the foramen.
crest.The closerone comesto the lumbosacral junction, the mor.e later-althe
crest. One might say that the more cau_
da1 the iun-rbarsegment, the more the
roof cover"sthe foramen (fig. 3).
F i g .2 :S p o rt i ons.
a) axial view; b) posterior view (rigth side)
A = intraforaminal
B = foraminal
C = extraforaminal
The lor.r'erpart o[ the foramen is nan-ower, and mobile becauseit is bor-dered
by the inten'er1ebralsegment,r.i'hereit
rs more exposedto herniated disc and to
degenerative osteoarlhritis. The transvertebral veins pass through the lora,er.
parl of the foramen. The LIF is rine shaped in the upper lumbar spine anà shaped like a gutter oriented dolrmurard in
the iower lumbar"spine, becauseof the
same orientation of the pedicles,r.r'hich,
in the lower lumbar spine,are not ol-tented horizontally as are the pediclesof L1
andL2, The r"oofof the LIF and its poste ri o r-l i m i La r e i mporranrbecausei herconceal rhe foraminal r-egion.These
edgesconsist of the articular processof
the underlying rrerlebraand the isthmus
slightly abovethe facet joint. The lateral
limit of the isthmus often appearsas a
50
Fig. 3 : Latera! Iimits of LIF.
The more caudat the lumbar segment, the
more the root covers the toramen.
The dolsal loot ganglion is the main element of the LIF. it is situated in the for"arnen in most cases,but it can also lie
intraforaminally (notably at S1) or
extraforaminally the foraminal ratio is
the ratio of the surface area of the ganglion to the surface ar-eaof the LIF: it
fanges fiom 250/oat L1 to 51a/aat L5.
This ganglion is verryrich in large-diameter cells (m1'elinatedAB fibers, which
transmit deeptouch and pr-essuresensa_
tion) and in celis of smaller diameter
(fiber:sC and Aô convet'lng pain, light
touch and temperatul-ediscriminatron).
D ls ollDE R So F 7 ' L r E
L L , t \ t B ! ,rR^ T ER\.' ERT EBR.IL
F OR]I/EN
tL t[) :Dr .) GN estsA N DTR E .A .)]E ^'T
The dorsal l'oot ganglion is \/erysensitile [o vi b r aiions .hr por ia a n d p h o s p h o l i pases.In the folamen it coursesbeside
the t'adiculomedullan,artel"ies(the n-rost
important
beilig tire DesprogesGottelon ladiculomedullarv arterr,:
rvhich follou's the L,5root and feedsthe
teln-rinalcone) and the venousplerus.
During movements, there is a 20a/o
reduction in the sr_rrface
area of the LIF
in ertension t3l (fig. 4) and a marked
reductjon during ipsilaterallateral beno rn s (n g . 5) .
CLINICAL SIGI{S
The clinical signs of foraminai nen,e
loot pain generallvlack specificitvThev
are tvpicallvvetrypainfi-rland associated
urith notor cleficit.A pain-fi-eeposition
has been descr-ibed:later-aldecLrbitus
contralateral to the contpressionand
flerion of the ipsilateral hip and knee.
The lesr,rltingpain r-adiatesin the terr"itorv of the r-ootu'hich bears the number
of the supelior pedicle of the LIF. In
casesof foran-rinalcompressionof L4L5, u'e have often noted that the pain
radiates to the lateral aspect of the br_rttock, thigh and calf, r,vhichdoesnot correspond 1othe specificterriton- of either
L5 or L4. This territon,r,r,ouldappear.to
str"addlethesetrvo distributrons(fig. 6).
Fig. 4 :2A/" reduction in the surtace areaof
the LIF in extension (according to Revel).
a) flexion ; b) extension
Fig. 5 : Reduction in the surîace area of the
LIF in the ipsitaterat bending (according to
Panjabi).
Fig. 6 : ln cases foraminal compression of
L4'L5, we have often noted that the pain
radiates to the lateral aspect of the b uttock,
thigh and calf, which does not correspond
to the specific territory of either tS orLS.
51
N 1C F SPI\t tOLT R SE1007 C r r r r c rrtC o u c e p L "
ELECTROPHYSIOTOGTCRADTOTOGICAÏ,
EXAMTNIATIÛI{S
At STGNS
signs are essentialElectrophl'51o1ogica]
study of sensorfl
the
ir- dominated b1'
potentials in electromyography.Sensorl
in casesof prepolenrialsat'ept-esen-ed
ganglionic iuvoh'ement in r'r'hich the
centrai spinal canal is compromised,
bLrtther at'ealteted when thei-eis gangiion ol post-ganglionic compt'ession
(fig 7)tal.
of
Plain films shou fired displacemettts
spondylolistl-resisor letrospondylolisthesis (rvhich compressesthe LIF more,
as u'e sirall see beior^.')or lateral imbaiance (asymmetlic disc disease).
Computedtomographl'permits exploration of the bony upper porlion of the LIF
and of its lolr,er pot'tion next to the disc
on classic axial slices (fig 8) Sagittal
reconstr-uctionsare useful in cases of
by spondylolysis.
spond.tlolisthesis
Myelographv is of little usefulnessbecauseit only exploresthe root, not the ciorsai
root ganglion,the dural envelopeending
at the plolimal sjde of the ganglion.
Fig.7 : Sensory potentials (5'P') are altered
in ganglionic and Post lesions'
a) normal
b) preganglionic lesion
c) postganglionic Iesion
d) ganglionic lesion
Magnetic resonance imagrng (MRl) is
the most useful examination. With the
various slices it plorrides, MRI best establish the anatomy of the contentsof this
lirdden zone.The inextensiblepal-lscan
particular'lythe state of the
be assessed,
carlilaginous endplates and subchondral
bone, neal the foran'rinalstenosis.Modic
type-1 signal changes cotlesponding ro
hlposignal in T1-rveighted sequences,
h1pelsignalin T2-r.,eigirtedsequences,a
ulhite signal in fat saturation sequences
and jncreasedsignalintensiryafterinjection of gadolinium, are caused bY
inflammatory edema and are oflen associaLed uith an acule painful phase'
Modic type-2 signal changescol'l'espondlng to hypersignalin T1- and T2-rveighted sequences,decteasedsignai in fat
saturation sequencesand no incleasein
intensit--vby gadohnir-rm enltaircement
are causedb1'lessactive fattl changes
and are found more fi"equently
D/sOR'[R.SOF THE LL']IBAIIINTER|ERTEBII-IT
[O,R-.J,.]/ËN
ILIF].
DI,)()NOSI5
-I,\' r,RE,]rI;;
r-ingof the dor"salrooi ganglionbr, the
colrtl"astmedmm. Using thrs pr.otocol,
Belger reportedimprovement qLralified
as acceptablebv 64ai of the patients,
S rv e e np e t-cenl
of rhe pati ents\\erc opelated, amons u'honr 90% had good or
vern good lesr,rlts'if the pain repr.odr,rction test bv injectionu,aspositive,
Fig.B:CTscan.
a) fixed LtF; b) mobite LtF
1:
!
,,'
t,t
i
TREATMENTS
Conset vativ e treatnænt
The conseir,atirretr eatmeni of classic
foraminal neta,eroot pain consistingin
rest, antiinflammatola,ch-ugs,and analgesics,can be attemptedin nost cases
e\cept in patientsr.r'ithneural deficits.
'-i,
:
Forantinal injections
,'-.a
Foraminal injections irave a pr-edominant lole. Thev can be guided bv flr_roroscopy01-errenbetter-br,computedtomo., .. :.
graphri Belger 15] published u,ith us a
Fig. 9 : Foraminal infittration guided by CT
ser"ies
of 160folaminai injections,139of
scan. Note the contrast medium contourina
u'hich u,ele in the lumbar"spine(fig. 9)
the ganglion.
Lumbar foraminal compressionu,asdue
to disc disorders,osteoar-tllitis,ot both.
In a smali number of patients there u,as
no irnage of patent compressiolr.
Surgical treatrnent
Tl-rror,rgl-r
a size 22 needle, tl-re patient
r"eceived75 rng of hvdrocot"tisone,1 ml
of i i d o c aine and 1 n l o f c o n tr-a s t The sr,rrgicaltreatruentof for-aminalstemedir-rn-r.Ideallrl one should r"epr-odr-rcer-rosisu'as anah'2".6bv Razanabola[2] in
the samepain that ptonpted the patient l-rismedicaithesison 116 patrentsirospito corrsr-rltand to obserle clear conton- talized foi" for-aminal nen'e root pain.
53
NICE SPINE COURSE 2007 - Current ConcePls
Clinicalln the average age is 50 vears:
Men ale invohtedtwo times out of thr-ee.
Lumbal stiffiess and pain exacerbated
hv effo'rs or corrqlrinpare ]'are(25 oo\'.a
There u'ere tl-rreeprinicipal indications rmh'positite straight-leglaising sign is
observed in only one ollt of three
for surgetl:
- for aminal herniated discs: 76 cases patients. Hou'e\rer, a nrotol' deficit is
in23o/oof cases.Surgeryby the
obser-ved
(7 2 .l a /o ),
possible is perfolmed
(11,44h),
access
closest
12
cases
- bony stenosis:
canal in cases of
the
spinal
tlt"ough
17
cases
- isthmic spondviolisthesis:
intrafolaminal and foraminal discs, In
(l0.2Eo).
such cases,one should begin ar.t'avfion
ihe disc flagment rtorking.in a catrdalto
Foranùnalhenùateddiscs
cephaladdirection, even if this means
of the lamina (fig. 11).In cases
resectior-t
In the ser"iescited above they wel:e as of purell' foraminal disc hei"niations,
follorvs:
thel can be approachedihrough the spi- intraforaminal and foraminal tn 25a/o nal canal or u'ithout going thror:gh it. In
of cases,
some cases, r'elativelv ertensive tesec- foraminal tn20o/oof cases,
tion of the facetsis necessatl to pl"oper- foraminal and extlaforaminalin30%
ly erpose the folamen.
of cases,
of cases(fig. 10).
- extraforaminaTtn15a/o
Eieven (9.5%) had conservative treatment (intravenolls inftlsion or- infiltra\vereoperal ed
ti o n ) a n d 1 0 5(90.5qc)
Herrriated discs that originate fi"om the
lor,i' and mobile porlion of the LIF
migr-ateupu'ard lifting the rool givrngil
a horizontal tr:ajectory'[6]. A bulging
disc mav be invoived, ol' more t'arel1'a
tme sequestrateddisc
Fig. 10 : Bight L4-L5 foraminal herniation
on MRI.
a) axial view ; b) coronal view
Fig. 11 : In case of intra and foraminal
herniation we can perform endocanalar
approach with working on opposite side
and cephaIad di rectio n'
54
.- __--:.€
DI.SON,ER.S
OF TiIE LIii\IB,AR
INTERT'ERTEBR.{L
FOR.1,I/€A
IIIF].,'14CNO.S/.S.{.{D
rÂËIr,IiTNr
In patients ll'ith ertrafor"aminaldisc her- ced becauseof ageing and the LIF has
niation, one nray consider-reutoving it _ narlou,ed, one nlav be sutprised br, the
thror-rgha latelal e\posllre, eithei"r-rsing g o o d to lel ance of thi s compressi on,
Wiltse's apploach l7l, u'hich passes rvhich n-ray der,elop verv graduallv.
thror-rghthe fatt_vspacebetrveenthe mulNonali-enedstenosesare tvpically mor-e
tifidr,rsand the longissimusmuscles(fig. poollv tolerated.Retrospondvlolistheses
12);tl-risappt-oachis easierin the upper exhibit a marked tendencv to narropalt of lumbar spine rl,here the isthn-rus u ' j n s . In degenerati tespondrl ol i thesi s,
crestis more medial (fiS. 13) [8]. The lat- conpression is sitr-ratedmainlv in the
ter approach beginsat the midline, but
r;ertebral foramen and lateral recess,
coltrsesbett'een the tr,r,ot1-ans\ret-se
pl:o- analogicalto the action of a cigar cr-rttet:
cessesafter removal of the inter-tr-âns\rer- In contrast,the LIF tendsto be oriented
se musclesand ligaments.The ganglion holizontalh, and becones mor-e oval
l'ithout actr-rallvnat't'o\\ring.Foraminal
and the spinal nen'e that ertends fr-omit
hale to be locatecl under the sr-rperior compressionis more patent in asvmepedicle; the herniated fr-a_qment
is in The tric disc disease.In a specificseriesof
angle betureenthe nele and the dr-rra. 38 cases,r,r'ediagnosed:2 casesof pr-iEndoscopic approaches provide better m a rr d e " enel arj redi sc di sease(D D D )
exposlll'ein the axis of the LIF and ideal (fi g . 1 4 ), 10 postdi scectomv D D D ,
8 rapidlv destmctivepostdiscitisDDD,
lighting.
10 casesof degenelativescoliosis,and
8 isthmic spondylolistheses.
Botry stenosis
i
Bonv stenosis can be qualified as "aligned" or" "nonaligned". In aligned stenoses in rvhich the disc height is r-edu-
Fig. 12 : ln case ot this left extra
f oraminal herniation, tatera!
approach between multifidus
and longissimus is prefered.
In degeneratjvescoliosis.compr.ession
occurs in the ]umbosacralconcaliir ormore rat-elv in the main concavitr,.In
isthnric spondvlolisrhesis,
asr-mnretn'is
Fig. 13 : The latera! limit of the isthmus often appears
as a crest. We can note the more mediat position of
this crest at L3-L4 level.
55
'..
,
,
1..,.t',.. :t.' :.1,.,,'',,,.- ,...,-'- ,,,.. , . , -r, , ,
j- ,:- .
.r: .i.. : .
-t
a :::.:-:r: :.,r :.j; i.,r,
N IC E SPIN E C OIT R SE2007 - C ur r e rrtC u rl i e p i s
Fig. 14 : Primary asymmetric disc dtsease.
right normal LIFon T1 sequence; c) Ieft patha'
Qïscending AP view-withasymmetry on the teft; b)
T2
sequence;e) left pathologic LIFon TZ sequen'
LIF
on
right
normal
d)
Iogic LtFon T1 sequence;
ci : il axiat view on T2 sequence; note theinllammation on the end plate and in the foramen'
D/,SoÂDEÂsoF Tt-E LL!lrBARTNTERYERTEB||L
(LtF):Dt.4cNosrs.AÀDrRÊAr,,1lENr
FoR.{,,r/ËN
possible rvith nen'e root pain and narrou'ing of the LIF on MRI on one side and,
iu some cases,r-rnilater.al
Modic lr,pe-l
si g n a l c hangesr r it h a n i n fl a m m a to n ,
pattern in the entjr-efol-amen.
Regalding sui'gen/ for- bonv stenosis,
decoilpression can be performed
thlough a spinaJcanal approàch(as for
herniated discs) or thror_rgha later-al
approach, notably using the pr"ocedur-e
described bv Farcv, r.vhich consists in
cutting and resectingthe tip of superior
alticuiar pt"ocessof the lo,,i,elvertebra,
Use of pedicle screlr'fixation in moder-ate distraction is the conrrentionaltreatment and the use of interbodv caees
thlor-rgh a postelior approach (pffpl
ensut:esbetter"opening of the foramens
and better stabilirrr The TLIF techniqr_re
rr,,ithinsertion of a cagethrough a postelolatelal apploach after complete facetectomv is probablv the technique best
adapted to this for-arninaldisorder.
In degenerativescoliosis,one mav consider usin,elimited sllrgenr (applied to the
compressionof the lumbosacralconcar.itv in elderlv subjects) ot- ertensirresurgery taking into accountthe entire scoliosis
(rihen compressionis in the concavityof
the scoliosisand rhe parienTis vourng).
good in 700/oof cases.The results differ
according to the disorder trealed: 780/o
of good and verJ good results in SpL,
70% in herniated cliscs(poorer-than in
posterolateralher-niateddiscs l9l), and
620/o
in casesof bonv stenosis.
IN CONCLUSION
The diagnosis of LIF compr-essionhas
been improt ed by modet.nimaging studies, br-rtelectrophvsiologicalexaminations (sensor"rrpotentials) and steroid
injection tests can also help establish
the diagnosis.
In decompr-essivesurgery, one should
avoid destabilizing this hidden zone,
notably by not hesitating to use the
ertraforaminal approach. If there is the
Ieast doubt regarding postoperative
instabiliiri one should emplov pedicle
screurfiration in some casesrvith intetbodv cages.
Mediocre clinical results can be explained bv the dulation of the disor-ders
before diagnosis and bv lesion of the
dorsal root ganglion,a fragile and sensjtirre stmctut'e.
Or,elall, the results of surgerv for for-aminal complession are good and ven'
31
:i.-|=:.=..]..::::j:-::.].-j1...::'.:.:-l.]-.-i=',i.17;.,.-ff
.--aaa-=a
N IC E SPIN E C O U R SE2007 - Cu rrc n t C o n c c p l s
REFERET\/CES
[1 ] M C NAB r .
al tten'e
al tlrc causts
att attnlt'sis
rutiot1;
,Vegatile
rlisce-rp1o
toal uttolteitt?j u l tt s i .l i r ei l r r l 1'nl i r r tts
J Bone Joinl S ur g l 97l ; 53 A: 89i - 903.
[2] vrTAl J.M.
Forailletlitùen'efiébrallottûaire: attatotttie,e.tploratiouet
de h SOFCAT.
pnthologie.Caltter d'Enseigttettrettt
2000, Elsevier,Paris, 139-63
ci'Enseignc-ment
Ccxrlérence-s
[3] RE\IEL M., MAYOIX-BEN]14']\,1OU M'A., AARON C.,
AMOR B,
\itriailons ntarylrologitluesdes itntts de cottitryoisottLottt'
et le I'allaissctttetttliscal
baircs lors ilekt lltriorrr.r/gti-sicrtl
Rel Rhum 1988r5i : 361- 6.
[4] HERAUT L.H.
et svndrotttetlu cartal lotnbaireétroit.
Electropht'siologie
Rel Chir Orthop 1996; 76 suppl 1: '{9 5 1
[5] BERGER O., DOUSSET \1, DELMER O.,
POINTILLART V., VIIAI J.M., CAILLE J.M.
Etaluariott de I'eflicacitédes inl'iLtratiottslôrantitnles de
grirlde-ssotrs lotttodertsilotttétrietlausIe trnite'
corticoi:des
par cottflil laranùtnl.
nett tles rarlicuLalg[es
J Radiol 1999 r80: 917- 23.
58
[6] ROSENBLUMB.
ttetl'ercal sign.
TlteperyctrlictrLar
S pi ne1989;l ,l :188'9.
[7] \4IILTSEL., SPENCERC.
la
Nerl rrssst|ul refiue]rttlsal rlrcparaspitnlaPprcaclt
tlrclLntùnrspiut.
S pi ne1988;1l : 696-706.
[8] POINTITLARTV., BROCG., SENEGASJ.
approaclt
A tnt'e! paraspinal
lor lunibarlûtetûle.\tralôfanti nalroati nttnpt)È tl i .
E nr S pi neJ 1991
,6: 102-5.
[9] LEJEUNEJ.P.,HLADKY J,P,,COTTEN4.,
\.INCHON M,, CHRISTIAENSJ.L.
tritlt83patietts
etperiettce
lLLbar
disclteniatiatt:
Foratttinal
19:1905-8.
S pi ne199,{;