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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_5259_Библиотеки_им_академика_М_И_Перельмана.pdf
Question 11
The blood supply of the cervical cord arises from which
arterial supply?
A. Vertebral artery
B. Deep cervical artery
C. Ascending cervical artery
D. All of the above
Response (D) All the vessels listed supply the spinal cord
in the cervical region.
Question 12
What range of angulation in degrees is considered normal for
thoracic kyphosis?
A. 15° to 30°
B. 25° to 55°
C. 20° to 40°
D. 30° to 60°
Response (C) The typical range for thoracic kyphosis is
20° to 40°. The other choices are incorrect.
Question 13
Which of the following includes all thoracic vertebral bodies
with costotransverse facets on their transverse process?
A. T1 to T12
B. T2 to T11
C. T1 to T10
D. T2 to T9
Response (C) All the thoracic vertebrae have a costotrans-
verse facet on their transverse process except T11 and 12.
Question 14
What artery runs through the anter ior median fi ssure of the
spinal cord and originates from the vertebral and radicular
arteries?
A. Anterior intercostal artery
B. Anterior spinal artery
C. Posterior spinal artery
D. Ascending cervical artery
Response (B) The anterior spinal artery is the only artery
that runs through the median fissure [8 ].
Fig. 2.2 Artist’s rendering
demonstrating the different layers
of the posterior cervical
musculature
36 A. Khan et al.
Question 15
At what vertebral level and anatomical side does the artery
of Adamkiewicz most commonly arise from?
A. Left T7
B. Left T9
C. Right T7
D. Right T10
Response (B) In 80% of people, this artery originates on the
left side of the body. Of those people, a large majority of them
have the artery extend from T9 to L2 vertebral bodies [9].
Question 16
Which of the following is considered the posterior border of
the intervertebral foramen?
A. Posterior borders of the adjacent vertebral bodies and
discs
B. Inferior border of the pedicle for the superior vertebrae
C. Pars interarticularis and facet joints
D. Superior border of the pedicle of the inferior vertebrae
Response (C) The pars interarticularis is located posteri-
orly along with the facet joints, and they serve as the pos-
terior border of the intervertebral foramen [10].
Question 17
The cauda equina receives blood from all of the following
EXCEPT:
A. Lumbar arteries
B. Lateral sacral arteries
C. Anterior sacral arteries
D. Median sacral arteries
Response (C) The cauda equina receives blood from the
lumbar arteries, the lateral sacral arteries, and the median
sacral arteries [11].
Question 18
Which of the following is an indication for a posterior cer-
vical foraminotomy?
A. Cervical instability
B. Cervical myelopathy
C. Severe kyphosis
D. Recurrent surgery, with cervical root compression
Response (D) Recurrent surgery with cervical root com-
pression is an indication for posterior cervical foramino-
tomy. It provides the greatest improvements for patients who
have repeated cervical spine problems [12].
Question 19
Of the following surgical complications after an Anterior
Lumbar Interbody Interbody Fusion (ALIF), which can
cause retrograde ejaculation?
A. Deep vein thrombosis
B. Injury to the superior hypogastric plexus
C. Injury to the testicular artery
D. Abdominal hernia
Response (B) The superior hypogastric plexus controls the
process of ejaculation, and damage to it leads to the retro-
grade flow of sperm. The remaining options could be sur-
gical complications of the ALIF approach but do not change
the pattern of ejaculation [13].
Question 20
What anatomical landmark should serve as the lateral marker
during a lumbar laminectomy?
A. Bilateral transverse process
B. Bilateral pedicle
C. Bilateral pars
D. Bilateral lamina
Response (C) The correct lateral anatomical landmark for a
lumbar laminectomy is the pars located on both sides of the
lamina to minimize the potential for instability [14].
Question 21
The most common complication following transoral
odontoidectomy:
A. Injury of the vertebral artery
B. Injury of the hypoglossal nerve
C. CSF leakage
D. Infection
2 Surgical Anatomy and Techniques to the Spine 37
Response (D) Infections from the oral flora due to the poor
pharynx and soft palate closure is the most common com-
plication following the transoral approach [15].
Question 22
Regarding Spinal Cord Stimulation (SCS), all of the fol-
lowing are true
EXCEPT:
A. In cases of extensive scarring, laminectomy is recom-
mended to pass the lead without resistance
B. Cervical and upper extremity stimulation is attainable at
the level of C1-C2
C. SCS lead is usually placed at T8-9 epidural space
D. Active infection is a contraindication for the technique
Response (A) While multiple laminotomies may be needed
with extensive epidural scarring, a total laminectomy is
avoided, as there will be no remaining bone to keep the lead
apposed snuggly against the dura.
Question 23
Regarding Closed Cervical Traction (CCT), all of the fol-
lowing are true
EXCEPT:
A. Coexistence of skull fracture may contraindicate the
technique.
B. Posterior pin placement will apply an extension to the
cervical spine.
C. Correct pin placement is ½ an inch above ear pinna in
line with the external auditory meatus.
D. Too superior pins are at high risk of pullout.
E. If over distraction or neurologic deterioration occurs,
the wei ghts should be immediately removed.
Response (B) Posterior pin placement will apply a flexion
(not extension) to the cervical spine [16].
Question 25
Regarding retroperitoneal approach to the lumbar spine,
which one of the following is true:
A. It can easily provide exposure above L2
B. Muscle sparing is more painf ul than muscle incising
approach
C. Placement of graft cannot be done utilizing this
approach
D. This approach is indicated for patients with moderate
spine deformity in the form of scoliosis < 40° or
kyphosis < 25°
Response (D) This approach can expose from L2-S1.
Muscle sparing is less painful than muscle incising
approach. The direct anterior exposure facilitates graft
placement and anterior decompression [17].
Question 26
Regarding vascular injury in anterior lumbar approach, all of
the foll owing are true,
EXCEPT:
A. The middle sacral artery and vein usually lie directly
over the L5-S1 disc
B. The great vessels bifurcate at the level of L4 vertebral
body
C. The incidence of vascular injury during anterior lumbar
spine surgery is 1–15%
D. Exposure for pathology at the L5-S1 level needs
extensive vascular exposure.
Response (D) If exposure of only the L5–S1 disc is nee-
ded, this can be easily achieved typically without mobilizing
any great vessels (see Fig. 2.3). However, extensive vascular
mobilization is required if exposure is needed to the L4–L5
level or to multiple anterior disc levels, and the exposure will
be more complex [18].
Question 27
Regarding cervical degenerative disease, which one of the
following is true:
A. The rate of pseudoarthrosis is higher when an anterior
plate is not used in single-level fusion.
B. Dislodgment of graft is the most common complication
following Anterior Cervical Discectomy and Fusion
(ACDF).
C. The posterior approach is associated with a longer
hospital stay after surgery.
D. Four-level involvement is a contraindication for the
anterior approach.
Response (C) The rate of pseudoarthrosis for single-level
fusion is the same 0–5% with or without plate. Dysphagia is
the most common complication following ACDF. Four-
levels involvement is not a contraindication of anterior
approach [19].
38 A. Khan et al.
Question 28
Regarding spinal cord tracts, which one of the following is
true:
A. Sensory fibers directed to the dorsal columns entering the
spinal cord below T6 enter the gracilis and travel medially.
B. The posterior column transmits pain and temperature
sensations.
C. The tectospinal tract, arising from the superior collicu-
lus, contr ols the muscle tone of flexor muscle groups.
D. The rubrospinal tract, arising from the red nucleus,
mediates reflex postural movements in response to
visual stimuli.
Response (A) The anterolateral system transmits pain and
temperature sensations; the tectospinal tract mediates reflex
postural movements in response to visual stimuli; the
rubrospinal tract colliculus controls muscle tone of flexor
muscle groups.
Question 29
All of the following ligaments connect C1 to the occipital
bone,
EXCEPT:
A. Anterior atlanto-occipital membrane
B. Posterior atlanto-occipital membrane
C. Cruciate ligament
D. Tectorial membrane
Response (D)The tectorial membrane runs from the pos-
terior aspect of the body of C3, C2, and the dorsal aspect of
the odontoid process to the anterior aspect of the foramen
magnum [20].
Fig. 2.3 Artist’s rendering of the
bifurcation of the aorta below
which the anterior surface of
LS-S1 is visualized (adapted with
permission, Watkins) [18]
2 Surgical Anatomy and Techniques to the Spine 39
Question 30
Regarding nerve roots, all of the following are true,
EXCEPT:
A. C3, C4, C5 form the phrenic nerve
B. L3 root exits through the L3/4 foramen
C. C4 root exits through the C4/5 foramen
D. T7 root exits through the T7/8 foramen
Response (C) C5 root exits through the C4/5 foramen.
Unique to the cervical spine, the nerve roots exit above their
respective vertebral level except C8. There are eight nerve
roots, with the first one exiting between the occiput and the
atlas. From T1 downwards, the nerve root exit below its
corresponding vertebral body pedicle [21].
Question 31
In the following image, the instrument's tip is located under
which structure (see Fig. 2.4)?
A. Pedicle
B. Spinous Process
C. Superior Articulating Facet
D. Lamina
E. Inferior Articulating Facet
Response (D) The tip of the angled curette is resting just
under the lamina of L2. This is a method of intraoperative
level localization comm only utilized.
Question 32
Which of the following is not considered a risk or disad-
vantage unique to anterior lumbar interbody fusion (ALIF)
compared to posterior interbody fusion techniques?
A. Risk of injury to the iliac vein
B. Venous thromboembolism secondary to venous retraction
C. Postoperative ileus due to manipulation of abdominal
viscera
D. Retrograde ejaculation
E. Postoperative neuropraxia
Response (E) Answers A-D are all complications, risks, or
disadvantages considered unique to the approach of the
ALIF. Though postoperative neuropraxia is possible after
ALIF, the risk is far less than poste rior interbody techniques
as retraction of neural elements is not required to insert the
interbody graft or expose the disk space.
Question 33
Damage to which structure during anterior lumbar interbody
fusion (ALIF) can lead to retrograde ejaculation?
A. Superior hypogastric nerve plexus
B. Genitofemoral nerve
C. Obturator nerve
D. Pudendal nerve
E. Common peroneal nerve
Response (A) The superior hypogastric plexus is seated
just inferior to or along the bifurcation of the aorta. Damage
to these nerves results in regulatory issues with the internal
vesicular sphincter resulting in semen entering the bladder
during ejaculation leading to retrograde ejaculation in males.
It is often due to thermal injury from the monopolar elec-
trocautery during exposure and dissection.
Question 34
The anterior longitudinal ligament extends from the anterior
sacrum to C1 then continues rostrally as which named
ligamentous structure?
Fig. 2.4 Lateral intraoperative XR demonstrating the placement of a
curette to localize the level of interest
40 A. Khan et al.
A. Cruciate ligament
B. Anterior atlanto-occipital membrane
C. Ligamentum flavum
D. Accessory tectorial membrane
E. Transverse ligament
Response (B) The anterior atlanto-occipital membrane
extends from the anterior ring of C1 to the ventral skull base.
It serves as a continuation of the anterior longitudinal liga-
ment of the spine.
Question 35
A 40 years old male presents to your clinic for surgical
consultation for severe radicular pain refractory to medical
management. He describes to you pain originating in his
low back radiating down his right leg into the dorsal aspect
of his right foot and great toe. Based on this description,
what is the location of the disc herniation if the patient were
to have a single disc herniation that resulted in all of his
symptoms?
A. Far lateral disc herniation at L5-S1
B. Paracentral disc herniation at L5-S1
C. Far lateral disc herniation at L4-5
D. Paracentral disc herniation at L3-4
E. Far lateral disc herniation at L3-4
Response (A) It is important to distinguish which nerve
root is affected by the different types of disc herniations. Far
lateral disc herniations affect the exiting nerve root, while
paracentral disc herniations affect the traversing nerve root.
The patient, in this case, is describing a classic L5 radicu-
lopathy. Therefore, a far lateral disc herniation at L5-S1
would explain this as the disc would impinge upon the
exiting L5 nerve root at this level.
Question 36
In a patient undergoing minimally invasive microdiscectomy
for a far lateral disc herniation at L4-5, what anatomical
structures are used as docking points for the retractor?
A. L5 pars interarticularis and transverse process
B. L4 lamina and superior articulating process
C. L4 pars interarticularis and transverse process
D. L4 lamina and inferior articulating process
E. L4 lamina and pars interarticularis
Response (C)When performing a minimally invasive far
lateral microdiscectomy, the retractor is docked on the pars
and transverse process at the level of the impinged exiting
nerve root. This offers a lateral working corridor to visualize
and protect the exiting nerve root and offer room for disc
removal [22].
Question 37
Which cranial nerve controls the most superficial muscle
encountered during an anterior cervical discectomy and
fusion (ACDF)?
A. Cranial nerve XI
B. Cranial nerve VII
C. Cranial nerve XII
D. Cranial nerve VIII
E. Cranial Nerve IX
Response (B) The platysma is the most superficial neck
muscle seen during an ACDF dissection. This muscle is
innervated by the cervical branch of the facial nerve (cranial
nerve VII) [23].
Question 38
In what percentage of people does the vertebral artery enters
the trans verse foramen at C6?
A. 75%
B. 25%
C. 90%
D. 5%
E. 50%
Response (C) In 90% of people, the vertebral artery enters
the transverse foramen at C6. However, there are anatomic
anomalies, with 1% entering at C3, 2% entering at C4, 5%
entering at C5, and 2% entering at C7.
Question 39
How many degrees of kyphotic correction does a
Smith-Peterson Osteotomy typically achieve?
A. 5–10 degrees
B. 10–15 degrees
2 Surgical Anatomy and Techniques to the Spine 41
C. 15–20 degrees
D. 15–30 degrees
E. 20–25 degrees
Response (A) A Smith-Peterson Osteotomy typically
achieves 5–10 degrees of correction of kyphotic deformity in
the sagittal plane [24].
Question 40
How many degrees of kyphotic correction does a Pedicle
Subtraction Osteotomy typically achieve?
A. 5–10 degrees
B. 10–12 degrees
C. 12–20 degrees
D. 15–30 degrees
E. 20–25 degrees
Response (D)A Pedicle Subtraction Osteotomy typically
achieves 15–30 degrees of correction of kyphotic deformity
in the sagittal plane (see Fig. 2.5)[25].
Question 41
When performing a Smith Peterson or Ponte Osteotomy
(SPO) at L2, which of the following structures is preserved?
A. Inferior articulating process of L2
B. L2 pedicle
C. Superior articulating process of L3
D. L2 spinous process
E. L2 lamina
Response (B) During an SPO or Ponte osteotomy, the
following bony structures are removed to complete the
osteotomy: At the osteotomy level, the spinous process,
lamina, and inferior articulating process and at the level
below, the superior articulating process. The pedicles are
removed in pedicle subtraction osteotomy [26].
Question 42
During a transoral odontoidectomy, the exposure of which
ligamentous structure indicates the maximal depth of dis-
section has been reached?
A. Apical ligament
B. Anterior atlantooccipital membrane
C. Posterior atlantooccipital membrane
D. Tectorial membrane
Response (D) When performing a transoral odontoidec-
tomy the tectorial membrane lies deep to the odontoid and is
the ligamentous structure that is just ventral to the thecal sac.
It marks the deep extent of exposure for this procedure as
visualization of this structure typically signifies adequate
spinal cord decompression has been achieved.
Question 43
Which diagnosis requires a sympathectomy procedure
involving resection of the sympathetic chain only at the
second and third rib?
A. Palmar hyperhidrosis
B. Craniofacial hyperhidrosis
C. Axillary hyperhidrosis
D. Clavicular hyperhidrosis
Fig. 2.5 Lateral drawing of PSO angulation and shape of the
osteotomy
42 A. Khan et al.
Response (A) Palmar hyperhidrosis is the only approach
that is limited to the second and third rib. Craniofacial
hyperhidrosis involves the 2nd, 3rd, and 4th ribs resection.
Axillary hyperhidrosis involves the 3rd, 4th, and 5th ribs
resection. Clavicular hyperhidrosis is not associated with the
second or third ribs [27].
Question 44
What is the external anatomic landmark used to help identify
the locat ion of the C4-5 disc space?
A. Hyoid bone
B. Thyroid cartilage
C. Cricoid cartilage
D. Chassaignac’s tubercle
E. Midpoint of the sternocleidomastoid
Response (B) The thyroid cartilage approximates the
location of the C4-C5 disc space [28].
Question 45
When performing lateral trans-psoas approach to the lumbar
spine, which of the following is considered a safe working
zone?
A. Middle of the L1/2 disc space
B. Middle of the L2/3 disc space
C. Middle of the L3/4 disc space
D. Middle of the L4/5 disc space
E. Posterior third of the L4/ 5 disc space
Response (D) The safe working areas during lateral
trans-psoas approach to the lumbar spine are the posterior
third of the disc space from L1-L4 and the middle for the
disc space at L4-5. The operation here decreases rates of
retraction-related morbidity of the lumbar plexus such as
thigh numbness and hip flexor weakness [29].
Question 46
What is the most common complication following lateral
trans-psoas lumbar fusion?
A. Retrograde ejaculation
B. Transient thigh numbness or hip flexor weakness
C. Ileus
D. Retroperitoneal hematoma
E. Bowel perforation
Response (B) Following lateral transpsoas approaches,
patients commonly experience transient anterior thigh
numbness or hip flexor weakness secondary to traction on
the psoas muscle as well as branches of the lumbar plexus.
The rate of weakness has been reported at 0.7–33.6%, and
the rate of sensory changes was reported at 0–75%. There
have been few organ- or vascular-related complications in
the published literature on this approach.
Question 47
When Smith-Peterson osteotomies (SPO) performed in con-
junction with transforaminal lateral interbody fusion (TLIF),
how many degrees of lordosis per level can be achieved?
A. 0–5 degrees
B. 5–10 degrees
C. 10–15 degrees
D. 15–20 degrees
E. 20–25 degrees
Response (D) According to data from Shaffrey and col-
legues, performing an SPO at the level undergoing TLIF can
increase lordosis approximately 5–10 degrees at each level.
This gain in lordosis is additive, meaning that this 5–10
degree is in addition to the lordosis achieved by the TLIF
itself. Shaffrey reports a total increase in lordosis at 15–20
degrees per level when using this technique [30].
Question 48
For which of the following spinal levels is lateral lumbar
interbody fusion (LLIF) not recommended?
A. L1-2
B. L3-2
C. L3-4
D. L4-5
E. L5-S1
Response (E) It is suggested to refrain from using the LLIF
approach for fusion at the L5-S1 level due to the risk of
damage to the iliac vessels as well as unfavorable access to
the disk space due to the iliac crest.
Question 49
Which of the following is not considered an advantage of
cervical laminoplasty over anterior cervical discectomy and
fusion (ACDF)?
2 Surgical Anatomy and Techniques to the Spine 43
A. Lower incidence of complications compared to ACDF
B. Lower incidence of adjacent segment disease compared
to ACDF
C. Preserved cervical range of motion
D. Allows foraminotomy to be performed simultaneously
if needed
E. Allows for correction of alignment
Response (E) Cervical laminoplasty does not allow for the
correction of alignment as opposed to ACDF, which can
help rest ore cervical lordosis.
Question 50
Which of the following are types of laminoplasty?
A. Open door laminoplasty
B. Double open-door laminoplasty
C. Closed-door laminoplasty
D. A and B
E. B and C
Response (D) The two types of laminoplasty include the
open door and double open-door approaches. The open-do or
approach involves drilling a trough on one side of the ver-
tebra to create a hinge and then drilling out an open area of
the lamina on the contralateral side. The spinous process is
also removed at the base and is used as a graft on the open
side to expand the canal. In the double open-door lamino-
plasty, bilateral laminar troughs are drilled. Additionally, a
trough is drilled in the spinous process until dura is exposed.
Finally, either iliac or artificial graft is placed within the
spinous process window [31].
Question 51
Which of the following is not true regarding posto perative
C5 palsy post cervical decompression?
A. Patients whose muscle power is antigravity often have a
low likelihood of recovering function.
B. Patients with poor motor exams as a result of the palsy
have a low likelihood of recovering function.
C. It is thought to be due to dorsal migration of the spinal
cord resulting in traction of the C5 nerve root.
D. It is most likely to occur after laminectomy and fusion.
E. The mean recovery time is 21 weeks.
Response (A) All of the above are true regarding postop-
erative C5 palsy except answer A. Patients with preserved
antigravity function often recover to full strength, unlike
patients with significant postoperative deficits.
Question 52
Which of the following is the most suitable surgical
approach for a patient with central and calcified thoracic disc
herniation but has bronchiectasis?
A. Traditional open thoracotomy
B. Retro-pleural approach using a tubular retr actor
C. Transforaminal endoscopic approach
D. Mini-thoracot omy approach
E. Oblique paraspinal approach using tubular micro-
endoscopic discectomy
Response (B)The traditional open thoracoscopy and
mini-thoracotomy approaches are considered the gold stan-
dard for central disc herniations. However, both procedures
require entry into the chest cavity, increasing the risk of
postoperative pulmonary complications such as atelectasis,
pneumonitis, pleuritis, and intercostal neuralgia. An oblique
retropleural approach using a tubular retractor is developed
to overcom e this difficulty. It uses a smaller incision site and
provides equally good access to the disc as the transthoracic
approaches [32].
Question 53
Which of the following condition is not a contraindication
for late ral lumbar interbody fusion (LLIF)?
A. History of diverticulitis
B. L5/S1 disc space access
C. Lumbar spinal stenosis of Schizas grade D
D. Rising psoas sign at L4-L5 level
E. Nerve root anomaly
Response (E)LLIF is suitable for degenerative diseases that
require the restoration of the disc height and has a particular
advantage in revision cases. Contraindications are mainly
secondary to conditions that prevent safe lateral approaches.
These can include prior retroperitoneal surgery, L5–S1 dis-
ease, high-grade spondylolisthesis, and extreme spinal canal
stenosis. However, nerve root anomaly is a relative
44 A. Khan et al.
contraindication for the transforaminal approach, as it can
increase the risk of iatrogenic nerve injury in the nerve roots
[33].
Question 54
Which of the following is not a benefit of performing
image-guided punctate midline myelotomy (PMM) in com-
parison to the traditional approach?
A. Less disturbance to the posterior structures of the spine
B. Decreased the possibility of subarachnoid hemorrhage
C. Decreased the risk of respiratory dysfunction after the
surgery
D. Decreased the length of hospital stay
E. Decreased neurological complications because patients
are capable of reporting abnormal sensation or motor
function intraoperatively
Response (B) PMM is a surgical procedure that damages
the ascending fibers of the postsynaptic dorsal column
pathway to interrupt visceral pain transmission. It has the
potential to be performed using a minimally invasive
approach. However, the feasibility of this technique is still
questionable. The percutaneous needle may pierce the
meandering dorsal spinal vein, leading to subarachnoid
haemorrhage [34].
Question 55
A selective dorsal rhizotomy is one of the oldest standard
surgical techniques in treating spasticity. What is the most
common perioperative complication after selective dorsal
rhizotomy?
A. Bladder dysfunction
B. Paraplegia
C. Lower extremity hyperesthesia
D. Incidental durotomy
E. Deep wound infection
Response (C) Selective dorsal rhizotomy is a procure that
divides the posterior nerve rootlets in the lumbosacral region
to reduce the level of spasticity, in particular muscle groups
of the lower extremity. Despite uncommon, complications of
selective dorsal rhizotomy still occur, including paraplegia,
sensory loss, hyperesthesia, bowel or bladder incontinence,
cerebrospinal leak, and infection. Among these complica-
tions, hyperesthesia in the legs is the most common that can
last for several months.
Question 56
How many primary ossification centers do C1, C2, and C3
vertebrae contain, respectively?
A. 3, 5, 3
B. 3, 3, 3
C. 5, 3, 1
D. 2, 4, 2
E. 4, 2, 2
Response (A) C1 (atlas) and C2 (axis) vertebrae show
unique patterns of ossification. The atlas develops from three
primary ossification centers: one anterior arch and two neural
arches. The axis develops from five primary ossification
centers: two vertically oriented odontoid centers, two neural
arches, and one centrum. C3 through L5 vertebrae have a
similar pattern of development. Each of these vertebrae has
three primary ossification centers: one centrum and two neural
arches; however, the shapes of the ossification centers vary
between the cervical, thoracic, and lumbar spine.
Question 57
Punctate midline myelotomy (PMM) can be valuable for
patients with chronic, intractable visceral pain associated
with malignancy of the abdominal or pelvic regions. In
managing the pelvic visceral pain that originates from gen-
italia, rectum, and colon cancer, the incision is commonly
made at which spinal cord level?
A. T2
B. T5
C. T9
D. T12
E. L2
Response (C) It is well known that the level of the thoracic
spinal cord is usually several segments higher than the cor-
responding vertebral level. The lesion level is better placed
several segments above the innervating segment of the spinal
cord. Genitalia, rectum, and colon are innervated by spinal
cord segments S2 to S4. An incision at the T9 spinal cord is
remote from the spinal segments innervated by afferents of the
pelvic organs and thus is generally successful in managing
intractable pain associated with these malignancies.
Question 58
Which of the following is not a contraindication for per-
forming an anterior lumbar interbody fusion?
2 Surgical Anatomy and Techniques to the Spine 45