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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_6025_Библиотеки_им_академика_М_И_Перельмана
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18 Lum bar Spinal Stenosis 207
f g
Fi g . 1 8 . 7 ( a ) Standard midline incision made for a lumbar laminectomy. (b) The spinous processes
have been removed. The shaded area depicts the lamina needed to be removed to accomplish a central decompression. (c) A curet te is used to rem ove t he ligam entum avum from the unde rsurface of
the lamina to gain access to the spinal canal. (d) A Kerrison rongeur is use d to rem ove t he lam ina in a
piecemeal fashion. (e) The Kerrison rongeur is then used to undercut and rem ove bone and the liga-
mentum avum within the lateral recess. (f) A Ke rriso n ro n g e u r is g e nt ly p lace d int o the ne u ro fo ra me n
to undercut the superior-articular process to create space for the exiting nerve root. (g) The shaded
areas represent the area of bone and soft tissue needed to be removed to ensure a thorough central
and lateral recess decompression.
iv. Lateral listh esis.
v. Flexible cu r ves.
vi. Patients with radicular symptom s on the concave side of the
curve.
(b) Degen erative spondylolist h esis.
(c) Iatrogenic instability.
i. Greater th an 50% facet resection bilaterally.
ii. Rem oval of one com plete facet com plex.
(d) Recurrent sam e-level or adjacent-level decom pressions.
(3) Motion preservation.
(4) Interspinous spacers.
(a) Approved by the Food and Drug Adm inistration.
(b) Th e m echanism of act ion is local distraction and kyphosis th at
theoretically reduces soft tissue infolding into the central canal
(ligam entum avum ).
(c) Indications:
i. Neurogenic clau dicat ion pain that is relieved when th e spine
is exed .
ii. Spondylolisth esis up to grade 1.5 (Table 18.1).
208
18 Lumbar Spinal Stenosis
Ta b l e 1 8 . 1 Co m p aris o n o f va sc u la r a nd n e u ro ge nic c la ud icat io n
Fi n d i n g s Va s c u l a r N e u r o g e n i c
Cla u dica t io n d ist an ce Fixe d Va r i a b l e
Re l ie f a f t e r c e s s a t i o n o f a c t i vi t y Im m e d ia t e De l a y e d
Re l ie f o f p a i n St a n d in g Fl e x io n o r s i t t i n g
Up h ill wa lkin g Pa in No p a in
Bic y clin g Pa in No p a in
Lo c a t i o n a n d r a d i a t i o n D i s t a l t o p r o x i m a l P r o x i m a l t o d i s t a l
At r o p h y Ra r e O c c a s i o n a l
Ba c k p a in Un c o m m o n Co m m o n
Skin Lo ss o f h a ir Norm al
b
Fig . 1 8 . 8 ( a . b ) Mag ne t ic re so n an ce im ag ing fo l-
lowing a fora m in a l decom pressio n in t h e lum bar
a
spine.
C. Sp in e p at ie n t o u tco m e s r e s e a r ch t r ia ls ( SPORT) .
1. Patient populations.
a. Spinal stenosis without spondylolisthesis.
b. Minimum 12 weeks of symptoms.
c. Random ly assigned to operative and nonoperative cohorts.
2. Operative versus nonoperative outcomes in patients with spinal stenosis.
a. The majority of patients (89%) underwent decompression surgery
without fusion.
18 Lum bar Spinal Stenosis 209
b. As-treated analysis demonstrated that patients treated surgically
reported greater improvem ent in pain and function through 2 years
compared with those treated nonoperatively.
3. Controversies.
a. High crossover rate:
(1) Forty-nine percent of patients in the nonoperative cohort underwent
surgery.
(2) Thirty-two percent of patients in the surgical cohort did not undergo
surgery.
b. Nonoperative management was not standardized.
(1) Included physical therapy, chiropractic, injections.
c. Intent-to-treat versus as-treated analysis:
(1) The intent-to-treat analysis compared patients according to their
assigned cohort.
(a) This demonstrated no di erence in primary outcom es between
groups in patients w ith disk herniation.
(b) In th is an alysis, if a patien t was assign ed to the nonoperat ive
treatment arm, but went on to have surgery, that patient was
coun ted as a nonoperative pat ient .
(2) The as-treated analysis compared patients according to the treatm ent
ultimately received regardless of their assigned treatment arm.
(3) Patients who underwent surgery dem onstrated improved and
sustained outcomes compared with those treated nonoperatively at
4 years.
Sugg este d Reading
Kre iner DS, Sha er WO, Baisden JL, et al; North Am erican Spin e Societ y. An eviden ce- based
clinical guidelin e for the diagnosis an d treatm ent of degenerat ive lum bar spinal stenosis (u p d ate). Spine J 20 13;13(7 ):734–7 43
Pea rson A, Lu rie J, Tosteson T, Zhao W, Ab d u W, We in st e in JN. W h o sh ou ld h ave su r-
gery for spinal sten osis? Treatm ent e ect predictors in SPORT. Spine 2012;37(21):
1791–1802
Skid m o r e G, Acke r m an SJ, Bergin C, et a l. Cost -e e ct ive n e ss o f t h e X-STOP® in t e rsp in ou s
spacer for lu m bar sp in al st en osis. Spin e 2011 ;36 (5):E345 –E356
Weinstein JN, Tosteson TD, Lurie JD, et al; SPORT Investigators. Surgical versus nonsurgical
therapy for lum bar spin al ste n osis. N Engl J Med 2008;358 (8):794 –810
Weinstein JN, Tosteson TD, Lurie JD, et al. Surgical versus nonoperative treatm ent for
lum bar spinal stenosis four-year result s of the Spine Patien t Outcom es Research Trial.
Spine 20 10;35(14):1329 –1338
19 Lumbar Spondylolisthesis
19.1 General Considerations
I. In t r o d u ct ion .
A. De n it ion s.
1. Spon dylolist hesis—d i s p l a c e m e n t o f o n e v e r t e b r a o n a n o t h e r .
2. Spon dylolysis—l y t i c d e f e c t i n t h e p a r s i n t e r a r t i c u l a r i s .
a. Bone between the superior and inferior articular processes.
II. Ge n e r a l con sid e ra t ion s.
A. He re d it a r y fa ct o r s .
1. The familial tendency is stronger in dysplastic type (94%) compared with
isthm ic type (32%).
2. More common in white males (6.4%), less common in black females (1.1%).
a. Higher incidence among Eskimo population (up to 45%).
3. Association with spina bi da of the sacrum and dysplastic changes of the
bony elements in high dysplastic types.
B. Ep id e m io lo g y.
1. More common in men than in women.
2. Higher incidence among football players, female gymnasts, and soldiers
carrying heavy backpacks.
3. Lower incidence among nonambulatory patients.
III. Bio m ech an ics.
A. Abr u p t ch an ge in st i n ess a cr oss t h e lu m b o sa cr al ju n ct io n .
1. The pars interarticularis is strong but susceptible to fatigue fractures.
a. Especially with extension injuries.
2. Shear stress at the pars can be increased by exion contractures of the hip
and secondary hyperlordosis.
a. Pincerlike e ect on L5 pars from the superior articular process of S1 and
inferior art icular process of L4.
IV. Classi cat ion s.
A. Mo d i e d W ilt se (Table 19.1).
B. Sp in al d efo r m it y s t u d y g r ou p L5– S1 cla ss i c at io n (Fig. 19.1).
1. Based on the sacropelvic morphology, slip grade, and spinal balance.
2. Type 1 and 2 spondylolisthesis carry a lower risk of progression compared
210
with type 3.
3. Reduction is likely warranted for types 5 and 6.
C. Cla ssi ca t io n o f sp on dylo list h es is (Ma r ch et t i– Ba r t oloz z i).
1. Developmental.
a. De cient “bony hook,” anatomical abnormalities of the L5 pedicle, pars,
inferior facets.
(1) High dysplasia.
(a) Severe bony anom alies with signi cant kyphosis.
19 Lumbar Spondylolisthesis 211
Ta b l e 1 9 . 1 Wilt se spondylolisthesis classi cat ion
Ty p e N a m e D e s c r i p t i o n A ected level
I Co ng e nit a l/ d ys p la st ic Dysp las ia o f t h e s a cr u m , ft h
L5 – S 1
lum ba r a rch, fa ce t s, o r b ot h
II Ist h m ic / sp o n d ylo lyt ic Pars int erart icu laris d e fe ct L5 – S1
III De g e n e ra t ive De g e n e ra t io n o f t h e fa ce t s
and disk
IV Tr a u m a t i c Fr a c t u r e o f t h e n e u r a l
L4 – L5 ( 9 0 %)
L3 – L4 o r L5 – S 1 ( 1 0 %)
L5 – S 1
arch excluding the pars
int e rart icu la ris
V Pat holog ica l Pat ho log ical lesio n o r
An y le v e l
generalized metabolic
disturbance
VI Ia t ro g e n ic Ia t ro g e n ic d isru pt io n o f t h e
facet , ligam e nt , d isk, or bone
An y le v e l
Fi g . 1 9 . 1 Sp inal de fo rm it y st ud y gro u p L5 – S1 classi cat ion fo r sp o n dylolist h e sis.
212
19 Lumbar Spondylolisthesis
(b) Com m on during 7 to 20 years of age.
(c) Com pensatory lum bar hyperlordosis.
(2) Low dysplasia.
(a) Slower progression.
(b) Frequ ently asym ptom atic.
(c) Disk degeneration aggravates the motion segm ent instability.
(3) Acquired.
(a) Traumatic (acute vs. chronic stress fractures).
(b) Post surgical.
(c) Pathological.
(d) Degenerative.
(e) Speci c entities (modi ed Wiltse classi cation).
2. Congenital or dysplastic (14%).
a. Epidemiology.
(1) Displacem ent occurs early.
(a) Typically during the adolescent grow th spurt.
(b) Tw o:one fem ale:m ale ratio.
(c) Genetic component.
i. In creased risk am ong all a ected rst-degree relatives.
b. Etiology.
(1) Congenital or dysplastic abnorm ality of the L5–S1 facet joint:
(a) Prevents proper articulation.
(b) Displacem ent is early but limited based on the int act posterior
neural arch.
i. Increased rate of neurological symptom s (25–35%).
(2) The pars interarticularis is intact but poorly developed or elongated.
c. Clinical ndings.
(1) Pain radiating into lower extrem ities.
(a) Little or no back pain.
(2) Cauda equina.
d. Treatment.
(3) Most congenital spondylolisthesis patients with progression of the
slip require decompression and arthrodesis.
3. Isthmic spondylolisthesis.
a. Epidemiology.
(1) Most comm on spondylolytic disorder am ong children and young adults.
(a) Com mon from 7 to 20 years.
(b) On set usually coincides w ith adolescent spurt, and progression
occurs between 10 and 15 years of age.
(2) Most com m on at L5 over S1 vertebrae (95%).
(3) Most often asym ptom atic.
(a) Low back pain and radiculopathy (L5 nerve root) may develop.
b. Clinical ndings.
(1) Restricted forward exion of the hips and back.
(2) Tight hamstrings.
(3) Flat buttock (vertical sacrum).
(4) Lum bosacral kyphosis.
(5) Compensatory lordosis.
(6) Anterior protrusion of the pelvis.
(7) Pelvic waddle gait.
c. Roentgenographic ndings (Fig. 19.2).
(1) Defect at the pars interarticularis:
(a) Seen at the neck of the “Scottie dog” projection on oblique view.
(2) Trapezoidal L5 vertebral body:
(a) Rounded sacral dom e.
i. On an anteroposterior (AP) view this appears as the reverse
“Nap ole on ’s h at ” sign .
19 Lumbar Spondylolisthesis 213
(3) Com puted tom ographic scan dem onstrates the pars defects and stenosis.
(a) Single-photon em ission computed tom ography (SPECT) can detect
metabolic activity in the region of the pars interarticularis defect.
(4) Magnetic resonance im aging (MRI) is the study of choice for assessing
spinal stenosis.
(a) May dem onstrate “w ide canal sign.”
i. Suggestive of a bilateral pars defect.
(5) Radiographic measurem ents:
(a) Meyerding classi cation.
i. Grade I: 0 to 25% slip.
ii. Grade II: 26 to 50% slip.
iii. Grade III: 51 to 75% slip.
iv. Grad e IV: 76 to 100% slip.
v. Grade V: sp on dyloptosis or > 100% slip .
Fig . 1 9 . 2 An L4 – L5 s p o n d ylo lis t h e s is w it h n e u roforaminal impingement of the L4 nerve root
within the foramen.
214
19 Lumbar Spondylolisthesis
(b) Slip angle (Fig. 19.3).
i. Th e angle of kyphosis is m easured as the angle between
the superior end plate of L5 and a line perpendicular to the
posterior border of the sacrum.
ii. Most sensit ive indicator of p otential instability.
iii. Correction of the slip angle is th e m ost import an t goal of
surgical reduction.
iv. Cor rect ion of th e slip is not im por t an t in ach ievin g clin ical
success.
v. In h igh -gr ad e sp on dylolist h esis, a n in terbody m ay h elp
achieve reduction.
(c) Lum bar index.
i. Measu rem ent of the wedging of the anterior L5 vertebral body
• Rat io of t he p osterior an d an ter ior heigh t of th e slipp e d
vertebra.
d. Treatment
(1) Activity modi cation (nonoperative).
(a) Back and abdom inal strengthening exercise.
(b) Ham st ring st retching.
(c) Brace if persistent pain despite activity modi cation.
(d) A positive bone scan or SPECT scan im plies the potential for
osseous healing via imm obilization.
Fi g . 1 9 . 3 Me a su re m e nt o f slip a n g le.
(2) Operative.
(a) Goals of surgery.
i. Pain reduction.
ii. Prevention of further slippage.
iii. Restorat ion of norm al posture.
iv. Prevention of neurological de cits.
(b) Surgical techniques.
i. Direct pars repair.
ii. Posterolateral fusion w ith or w ith out decom pression.
• Possible slip re d u ct ion.
• Possible in st r um en t at ion .
19 Lumbar Spondylolisthesis 215
iii. Possible interbody fusion (anterior lum bar interbody fusion ,
posterior lumbar interbody fusion, transforaminal lumbar
interbody fusion) (Fig. 19.4).
(c) Pseudarthrosis.
i. Fusion rate decreased in sm okers (57%) versu s nonsm okers
(95%).
ii. Com m on in in situ fusions without instru m en tation.
• Increased st ress across fusion m a ss.
• Di cu lt y in exp osing L5 transverse p rocess.
(d) Slip progression.
i. Occurs in 33% of cases regardless of the presen ce of a solid
fusion (u n instrum ented).
ii. In creased risk of progression .
• High -grad e slip s.
• Gill lam in ectom y.
• No p ost operat ive im m obilizat ion .
(e) High-grade slip reduction.
i. May cause L5 nerve root neu rapraxia.
ii. Full correction is not needed.
iii. Correction of the kyph osis is m ost import ant.
iv. Reduction im proves th e fu sion rate.
D. Dege n erative sp on dylolist h esis.
1. Epidemiology.
a. Most often occurs at the L4–L5 level.
b. Five times more common in women.
c. Symptom s usually appear after age 40.
2. Clinical ndings.
a. Low back pain with bilateral lower extremity radiation.
(1) Fifty percent of patients have radiculopathy, most comm only in the
L5 n e r v e r o o t d i s t r i b u t i o n .
b. Sti ness is not a common nding.
(1) Most patients are hyper exible.
c. Associated complaints of stenotic symptom s.
(1) Proximal m uscle weakness.
216
19 Lumbar Spondylolisthesis
b
a
cd
Fi g . 1 9 . 4 Im a g e s d e m o ns t ra t in g t h e m in im a lly in va sive
transforaminal lumbar interbody fusion and percutaneous
pedicel screw placement. (a) Int ra op e ra t ive a n t ero p ost e rio r
(AP) uorosco pic im age de m onst rating placem ent of the
guidewires along the medial wall of the pedicle. (b) Intraoperative image demonstrating removal of the ligamentum
avum and coagulation of the epidural veins overlying the
disk space via the tubular retractor system. (c) Intraoperative “bulls-eye” view uoroscopic image demonstrating the
advancement of guidewires for percutaneous pedicle screw
placement. (d) Intraoperative lateral uoroscopic image
demonstrating pedicle screw placement in the L4 and L5
pedicles. (e) Postoperative lateral radiograph demonstrating p e d icle scre w p lace m en t in t he L4 a n d L5 p e d icles wit h
e
posterior instrumentation.
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