Download 8 Vertebral

LECTURE 8 THE SURGICAL ANATOMY OF
THE VERTEBRAL COLUMN THE
OPERATIONS ON THE VERTEBRAL
COLUMN
The spine is a part of the locomotor system that provides the important
vital functions.The well-known phrase “Motion is life” proves that without
mobile activity a full value life is impossible. Man who suffers from the spinal
disease feels how much does this ailments does him out of enjoying life and
brings down the capacity to work The spinal disease and attached illnesses pull
into the pathologic process other organs (the heart, lungs, stomach, liver). The
functions of the adoptative (hypophyseal-adrenal and sympatho- adrenal) are
decreased when this pathology. That is why very important to know the clinical
anatomy of the spine to base topical diagnosis and determine the ways of
spreading of the process, the surgical treatment of the spinal trauma.
Considering the spine one should remember about the soft tissues
adjoining to the spinal lateral surfaces. The operations at the spinal cord are
possible only while spinal cord baring from the muscles, aponeuroses. The spine
is a support for trunk and skull. It participates the movements of these
departments. It carries out the amortizative function because there is the
extinction of the oscillations in it. The vertebral column contains and protects
the spinal cord. The vertebral column consists of the separate vertebras and has
a methameric structure. It starts from the base of the skull (from the occipital
bone and goes to the coccyges bone. The lateral borders of the spine are the
vertical lines those pass across the transverse process. The spine adjoins the
lateral regions of the neck, breast, abdomen (the lumbar region) and pelvis with
its own lateral surfaces.
The posterior cervical region is trapezoideum. It is prominent
transversally and concaved longitudinally.That”s why it is compared with a
saddle.
There is an occipital fossa at the upper part of the region in the median
line 2-3 cm lower than inferior occipital protuberance. It prolongs downwards
like a gently slopping gutter, where the cervical spinous processes may be
palpated.
There is an important surgical triangle there. The extracranial portion of
the vertebral artery is situated in it. The accesses to the posterior cranial fossa
are dangerous because of the possibility of damaging. it. The borders of the
triangle are the superior oblique muscle of the head from the superior; the
inferior oblique muscle of the head from the inferior; the great posterior rectus
muscle of the head from the middle.
The dorsal region is an arch smoothly curved to the behind. The vertical
sulcus passes downwards. It is a prolongation of the cervical gutter but more
narrow and deep. The sulcus becomes flat while going downward.
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The spinous processes go to the behind and form the relief of the serratus
crest.
The lumbar region is concaved more from above to bottom in woman,
fat patients and patients with a large abdomen. The concaved shape of the
lumbar region levels while the horizontal position on the back.
When the concaved shape is expressed and a hand may pass between the
bed amd back the pathologic process is going on.
The sulcus is expressed the best at the lumbar region. The tonicity of the
sacrospinous muscles grows and their borders become reliefed distinctly while a
great overloading of the back. The hypertonicity of the muscles is observed
while the pathology (the tuberculous spondilitis) or an excessive straightening of
the back. The muscular rollers enlarge from the damaged vertebras to the
scapula. That is Kornev”s symptom or also termed the symptom of the reins.
The vertebras are situated profoundly so just the spinous processes are at
the reach to palpate. The occipital protuberance is at the upper region at the
place of head and neck border.
The nuchal fossa is little lower at the median line. The spinous process
of the 7 cervical vertebra is lower. The 6 superior cervical vertebras are not
within the reach because of the profound localization and nuchal ligament. The
spinous processes of the thoracal and lumbar vertebra are easy to reach
especially when the patient is bent forward. The spinous process of the sacrum
are consolidated at the median line and form the medial crest. The sacral orifice
is 5 cm higher than coccyges top and is a point of the extradural space ending.
The vertebral bodies are not at the reach. The bodies of the 2-4 cervical
vertebras and the anterior facet of the atlas’ body may be palpated. The inferior
cervical and the superior thoracic vertebras can’t be palpated in that way. The
lumbar vertebras may be reached through the anterior abdominal wall. The
anterior facet of the sacrum and coccyges bone may be palpated through the
rectum or vagine.
The upper lateral parts of the breast are covered with scapular muscles.
The scapula is at the level from the 1 to 7 rib. Its superior angle is situated at the
level of the 1 thoracic vertebra and its inferior angle is situated at the level of the
7 thoracic vertebra, its crest is at the level of the 3 thoracic angle.
The pelvic bones and gluteal muscles form the inferior lateral parts of
the back. The line that connects the supreme points of the iliac bone crest
crosses the spinous process of the 4 lumbar vertebra. The line that connects the
posterior superior spines of the iliac bones goes between the 1 and 2 sacral
foramens.
The spinal cord ends at the level of the inferior border of the spinous
process of the 1 lumbar vertebra in growns-up. The subarachnoideal space with
spinal liquor reaches the inferior border of the sacral vertebra that lies at the
level of the posterior iliac spine.
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The vertebral column is rather flexible. It consists of the vertebra of
various shape those are the 1\4 of the vertebral column length. The vertebras are
divided into 5 groups. These are cervical (7), thoracic (12), lumbar (5), sacral
(5), and coccyges (4-3) vertebras.
The general characteristic of the vertebras.
In spite of the differences between the vertebras, there may be created a
common model. The typical vertebra consists of the body and arch. The arch
borders the space that is called the vertebral foramen through what the spinal
cord with its coverings passes. The vertebral arch consists of a pair of the
cylinders shaped as peduncles those form its sides; and a pair of plates those
border the arch from the behind. The vertebral arch splitting is a pathology that
is called spina bifida occulta. This pathology at the thoracic level is
incompatible to life. The spinal cord and spinal roots traumatization leads to the
spinal shock (a cardiovascular dysfunction and death in neonates). The partial
splitting of the arches at the lumbar level is followed by different dysfunction,
especially the posturnal enuresis (bed-wetting). But those symptoms may
disappear after the plastic of the defect. The vertebral arch has 7 processes. 1 is a
spinous process, 2 are the transversal, and 4 are the articular processes. The
spinous process directs to the behind, the transversal processes direct to the sides
from the articular surfaces jointing. All the processes are the levers while
movements. The muscles and ligaments joint to the processes. The articular
processes are situated vertically. There are two inferior and two superior
articular processes. Their surfaces are covered with the hyaline cartilage. The
superior articular processes of the lower vertebra are jointed with the inferior
articular process of the upper vertebra and are forming the synovial articulations.
There are incisures at the superior and inferior edges of the peduncles those
form the intervertebral foramens. The spinal nerves and vessels pass through
them. While its narrowing (ostheochondrosis, spondyloarthrosis) there is spinal
nerves roots compression. The algesic syndrome develops. The foramen stenosis
appears while salt deposition with acute spines formation. The easiest movement
leads to the spinal roots and vessels traumatization and sharp pain appearing in
such cases.
There are foramens in the transversal processes for the vertebral artery.
The narrowing of these foramens or dislocation of the vertebra leads to the
breaking of the cerebral blood circulation, its hypoxy, cerebrovascular syndrome
appearing (headache, dizziness, and disturbance of memory and walk).
The vertebral arteries give to the brain about 28% of the blood. The
vertebral bodies and spinous processes are small, but the vertebral foramen is
large and triangle-shaped.
The first vertebra or atlas has no body and no spinous process. There are
the anterior and posterior arches and lateral masses where are the anterior and
superior articular facets. The atlas joints the occipital condyles and forms the
atlanto-occipital joint. The second cervical vertebra, the axillar one, has an
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odontoid process that forms the atlantoaxial articulation with the inferior facet of
atlas.
There may occur congentional pathology at the cervical part of the spinal
column that is called Klippel-Fail’ssyndrome (that is developing while
embriogenesis manifest as a short neck extensive fusion of the cervical vertebras
as an integral bone.
There are differed two types of the deformation. The first type means
lessing of the vertebras number from 7 to 4 and their fusion into an integral
bone. The second type means that the atlas forms the synosthosis with the
occipital bone and the other cervical vertebras form the integral conglomerate.
There is a triad: a short neck, a low border of the hair growth, limitation of the
movements of the head. There is also the curvature of the neck axis, the
asymmetry of the face, skoliosis, cleft palate, muscular pareses, the functional
and organic changes of the other organs (heart, lungs, liver).
The syndrome goes on the dominant heredity. The cervical vertebras
are approximately of the equal height. The thoracic vertebras enlarge from the
first to twelfth one. The vertebral foramens on the contrary are small in
thoracic vertebras. The spinous processes are long and leaned down
overlapping each another. That’s why the spinal puncture is impossible here.
The lumbar vertebras are short, square and horizontally directed. That is
optimal for the puncture.
The vertebral bodies are the support for the upper portions. The cervical
vertebras have the smallest vertebral bodies; the largest are the lumbar
vertebral bodies, where the pressure on the area unit is the greatest.
The sacral and coccygeal vertebras’ height is lesser from up to down
because the pressure heaves on to the legs.
The sacrum consists of the five rudimental fused bones. The superior
part of the sacrum forms the articulation with the fifth lumbar vertebra. The
fifth lumbar vertebra may be knotted with the sacrum. The phenomenon is
termed sacralization.
When the first sacral vertebra is free (disjointed with the sacrum) there
is lengthening of the lumbar part of the vertebral column. The phenomena is
termed lumbalization. There are 6 lumbar vertebras.
The inferior part of the sacrum forms the articulation with the coccyx
bone; the lateral facets of the sacrum are jointed with the iliac bone. (That is
the sacroiliac articulation the most powerful pelvic articulation that is called
“the key of the pelvis”. The breaking of the ligaments of this articulation makes
walking impossible.
There are discs between the vertebral bodies those are the 1\4 of the
vertebral column length. They are thick at the cervical and lumbar parts (the
more mobile parts). The loading on the vertebras is leveling while walking,
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springing because of the discs' elasticity. Every disc consists of the fibrous ring
that covers the central part that is nucleus pulpous. When the fibrous ring
breaks the nucleus pulpous moves to the periphery and presses the spinal
nerves roots. The corresponding neurologic symptoms develop. This disease is
called Shmorle’s body (discal hernia). The surgical intervention is necessary
than.
The superior and inferior surfaces of the vertebral bodies those are in
contact with the disc are covered by the hyaline cartilage. The fluid
consistention of the pulpous nucleus lessens with years passing and than the
fibrous cartilage substitutes for it wholly. The elasticity lessens. The dystrophic
changes in discs leads to the approaching as vertebras as intercartilage joints
(just for microns sometimes).
The first case is the ostheochondrosis; the second is the
spondyloarthrosis. The spondyloarthrosis appears as a result of the prolonged
microtraumatization of those articulations and is a sign of the ostheochondrosis.
The patients complain on the headache crunching while bending and unbending
and turning of the head when the process is going on at the cervical part.
There are also a cardialgia, arthralgia, aching of the hands because of the
ischemia and compression of the spinal nerves roots.
The discs are absent between the both first cervical vertebras, in sacrum
and coccygeal bone.
The vertebral ligaments.
The vertebral column is strengthened with ligaments good. The anterior
and posterior longitudinal ligaments pass along the anterior and posterior facets
of the vertebral bodies. They run from the scull to sacrum. The anterior
longitudinal ligament is broader and tougher. It intersperses into the vertebral
bodies and discs. The supraspinous ligament connects the apexes of the spinous
processes. The neighbour processes are connected by the interspinous ligament.
The nuchal ligament is formed by the supraspinous and interspinous ligament at
the cervical part. The flavum ligament passes between the vertebral arches.
The anterior and posterior atlanto-occipital ligaments strengthen the
atlanto-occipital articulation. Those ligaments connect the anterior and posterior
arches of the atlas with the anterior and posterior borders of the great occipital
foramen. The atlantoaxial articulation is strengthened by:
1) the ligament that runs from the apex of the odontoid process to the anterior
border of the great occipital foramen;
2) the alate ligament that runs between the odontoid process and medial facet of
the occipital epicondyles;
3) The cruciform ligament. Its tight transversal portion connects the odontoid
process and the anterior atlas arch. The vertical portion connects the posterior
facet of the 2 vertebral body with the anterior border of the great foramen;
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4) The covering membrane is the prolongation of the posterior longitudinal
ligament that is stretched between the occipital bone and the posterior facet of
the odontoid process.
The vertebral column has physiologic curvatures at the sagital plane.
Those are the cervical and lumbar lordoses (curvature to the front) and thoracic,
sacral, coccygeal kyphoses (the curvature to the behind). The neonates have on
curvatures of the vertebral column. The lordosis appears when the child can hold
and rise its head (3-4 month after the birth). The thoracic kyphosis appears when
a child can sit (4-6 month after the birth). And later after the first independent
steps the lumbar lordosis appears. The lordosis may be expressed in grownupsup better when the person has a great abdomen, or pathology, or a tumor of the
lumbar vertebras. The kyphosis extends because of the back muscle weakness or
structure changes of the vertebral bodies and/or discs.
The impacted fracture of the tuberculous affection of the vertebral bodies
is followed by the development of the acute kyphosis. The cervical, thoracic,
lumbar parts of the vertebral column become kyphotic because of the age
degenerative changes. The lateral curvature of the vertebral column is termed
skoliosis. It may be at the thoracic part often because of the muscular or
vertebral defects or continued wrong carriage (in schoolchildren, sportsmen and
others). The skoliosis may appear as a result of shortening of the leg or coxal
articulation disease. The pathologic curvature of the vertebral column as well as
a great cosmetic defect is a locomtor system defect followed by its and other
organs (cardiovascular system) dysfunction.
The movements of the vertebral column are possible in different ways.
These are bending to the front, to the behind, to the sides, rotation. But
according to the anatomical structure of the movements between two neighbour
vertebras are rather limited. But the articulations between the vertebras are not at
the same plane, that’s why movements at one of the articulations influent the
amplitude in others. The synchondrosis of the head is mobile just
correspondingly to the elasticity and pliancy of the intervertebral cartilage. The
numerous ligaments limit the amplitude of movements. But because of a great
number of elements from which the vertebras consist, the smallest their
movements give a good pliability in summary in all directions. But the mobility
of the different parts of the vertebral column isn’t equal. It is expressed the best
in cervical part. The softness and thickness of the inter vertebral cartilages,
saddle-like curvatures of the congruent facets of the vertebral bodies and their
localization nearly at the same horizontal plane make them more mobile and
lead to the extension of the oscilative movements along the whole cervical part
of the vertebral column. The thoracic part mobility is rather limited. The thin
intervertebral cartilages and their rather free joints with the breast lead to the
oscilative amplitude to minimal. But the mobility range is much higher at the
lumbar part. The amplitude there is maximal. The axis of the gravitation passes
from the odontoid process along the anterior facets of the vertebral bodies while
standing. The good development of the posterior vertebral muscles is necessary
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for this posture keeping. The profound back muscles form a rather massive
column that lays from both sides of the spinous processes from the sacrum to the
base of the skull and are covered by the well developed thoracolumbal fascia.
The spinous and transverse processes are the levers for the muscular
work. The longest portion of the muscles lies superficially from the sacrum to
the transverse and spinous processes (the erectors of the vertebral column). The
transversospinal muscles are of the medial length. These muscles go obliquely
from the transverse to the spinous process. The profound and short muscles are
the intertransversal muscles. They lay between the transverse and spinous
processes of the neighbor vertebras. The posterior branches of the spinal nerves
innervate the back muscles.
The spinal canal goes from the occiput to the coccygeum. It is bordered
by the discs of the vertebral bodies from the front and by the vertebral arches
from behind and sides. It is the prolongation of the cranial cavity and it is the
container of the spinal brain as well as its maters, roots, tissues, and venous
plexes. The posterior longitudinal and interarch ligaments transform the canal
into the closed tube with a smooth even walls and intervertebral foramens at the
lateral facets.
The intervertebral foramens are bordered with the articular processes
from the posterior; with the cervixes of the arches from the superior and inferior;
with the vertebral bodies from the anterior. The intervertebral foramens are
called sacral foramens in the sacral bone. The opening of the vertebral column is
more broaden than the spinal diameter. The most broaden is the cervical part,
than it becomes thinner from the 7 cervical vertebra and it is the thinnest at the
10-11 thoracic vertebra level. It is broadened again at the lumbar part. One can
see that the aperture is the most broaden at the most mobile parts. This structure
provides the lesser traumatization of the spinal cord.
The spinal cord lies within the vertebral column together with its maters
and vessels. The spinal cord is a flattened at the sagittal plane band that starts
higher the great occipital foramen and ends at the inferior edge of the lumbar
vertebra level in grownups-up. The first year infants have the discorrespondensy
of the spinal cord and vertebral column length. The spinal cord reaches the
superior edge of the 4 lumbar vertebra. One should remember that the spinal
cord grows more slowly than the vertebral column. So the spinal cord gradually
lifts while growing. The length of the spinal cord corresponds the length of the
vertebral column at the third month of the embryogenesis and the spinal cord is
situated at the level of the 4 lumbar vertebra neonates and it is much higher in
grownups-up. The oblique direction of the spinal nerves sets up as a result. This
should be remembering while the spinal puncture to prevent the traumatization
of the spinal cord and spinal roots. The puncture is performed between the 3 and
4 lumbar vertebras in grownups and lower than 4 lumbar vertebra in children.
The spinal cord is thickened at the cervical part where the brachial plexus is
forming and as well in the lumbar and sacral parts where the lumbosacral plexus
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is formed. The lowest part of the spinal cord is the medullar cone that ends with
the terminal filament. The spinal nerves are formed of the spinal segments ( 31).
The nerve consists of the anterior effector and posterior sensitive roots. There
are 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal nerves starting off the
spinal cord. But the level of the divergence of the nerves and segments is of
certain discordance. It should be remembered while definition of the level of the
spinal cord injury and operations at the spinal cord and roots.
3-4 superior cervical nerves are formed of the roots in a certain
horizontal direction. The roots of the next nerves go obliquely from above to
down at an acute angle to the spinal cord. The angle is acutest at the lowest
spinal segments. The segments are one vertebra higher at the lower cervical and
upper thoracic part. The medial thoracic part gives the disaccording for 2
vertebras. The inferior thoracic part disaccords for 3 vertebras. The lumbar
segments occupy the interval between the 10th, 11th, 12th thoracic vertebras; the
sacral segments occupy the interval between the inferior part of the 12 th thoracic
and 1st lumbar vertebra. The inferior lumbar, sacral, coccyx roots are the longest.
The complex of the roots between the L2-S2 is called the horse’s tail.
The spinal segments (myelomers) are considered as partially
independent functional centers those corresponds the certain parts of a human
body. The comparative anatomy of a spinal cord proved that the appearing and
growing of the cervical and lumbar enlargements of the spinal cord is observed
while embryogenesis and phylogenesis. These start to differentiate at the 2-3
month of embryogenesis and are closely timed to the appearing and developing
of the upper and lower limbs. The formative process depends of the mass of the
limbs and the physiologic activity, movements differentiation and sensitiveness
development. That’s why the enlargements are called the functional centers of
the limbs control.
The spinal cord like the brain is covered with the dura mater, arachnoid
mater and pia mater. The dura mater is a tough fibrous membrane that rounds
the spinal cord and horse’s tail. It ends at the level of the inferior edge of the
second sacral vertebra. It consists of the two layers. The external plate plays the
role of the periosteum. The internal plate is separated with the external by a
friable connective tissue. The space between those plates is called the epidural
space. There is the internal venous plexus here. It forms the cases for the spinal
nerves up to their leaving off the intervertebral foramens. That’s why the dura
mater is fixated, extended and keeps on a permanent shape within the vertebral
column even while movements.
The arachnoid mater is a membrane that covers the spinal cord and it is
situated between the dura mater and the pia mater. There is a wide subarachnoid
space between the pia mater and arachnoid.
There is a cerebrospinal fluid. The subdural space of the encephalon at
the great occipital foramen level. The arachnoid mater is closely applied to the
dura mater connected with the short fibrous bands. It is tied especially tightly at
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the cervical and superior thoracic level. Where it is impossible to separate them.
So the subdural space is practically absent at the superior portion of the vertebral
canal. But it is much like fissure at the inferior portions and contains a little of
the cerebrospinal fluid, because the bag of the arachnmoid mater is too strained
by the fluid and closely pressed to the dura mater. The arachnoid mater may
form the adhesion and thickening with the dura mater while inflammation.
That is the difference of the spinal and cerebral arachnoid mater (the
cerebral arachnoid mater never form the adhesion with the dura mater. the
cerebral arachnoid mater nowhere touches the pia mater because the
subarachnoid space is expressed here and filled with the cerebrospinal fluid. The
subarachnoideal space is pierced with connective tissue fibresand plates those
have the spongious structure. Those fibres and plates are isolated and situated in
a certain order. There are serratus ligaments at the lateral facets of the brain in a
frontal plane. They start off the pia mater from the every side at the space
between the anterior and superior roots of the spinal nerves. They go to the place
of the arachnoideal and dura mater adhesion then. The serratus ligaments
alternate with the spinal nerves they are from 20 to 23 .the superior serratus
ligaments are fastened to the great occipital foramen at the place of the vertebral
artery perforating the dura mater. The inferior serratus muscle is fastened at the
place between the two last thoracic and prime spinal nerves.
The serratus ligaments divide the subarachnoideal space into anterior and
posterior parts. The anterior part is free the posterior part is penetrated with
some membranes those connects the pia mater and the arachnoid mater. One of
the membranes goes from up to down at the median line from the posterior
median fissure of the spinal cord to the posterior part of the arachnoid mater and
dura mater. This membrane is very thin and with many foramens. It diverges
into isolated bands and fibres at the cervical and lumbar parts. There are
additional membranes those cover the posterior spinal nerves’ roots and go to
the behind at the dorsal part of the subarachnoid space. They divide the
subarachnoid space into stores connected with each other. The arachnoid mater
reaches the top of the dura mater cone and joins with it at the place of its
transforming into the filum terminale.
The pia mater is a vascular membrane and is closely applied to the
exterior of the spinal cord. There are two plates those are connected by a friable
connective tissue where the small blood vessels pass. The araachnoid mater
forms a vagina for the spinal nerves’ roots as well as the dura mater does.
The cerebrospinal fluid circulates between the arachnoid mater and pia
mater. It is secreted by the choroid plexus that is the structure consisting of a
network of the blood vessels those are situated at the lateral (3-4) ventricles of
the brain. It flows through the three foramens in the roof of the 4th ventricle and
communicates with the subarachnoid space. The spinal part of the subarachnoid
space prolongs downwards to the level of the second sacral vertebra. The
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pressure of the fluid reaches 180-200 mm of wat. col. while sitting and 150-180
mm of wat. col. while lying at one side.
Blood supply.
The cerebrum is supplied by 4 great arterial trunks. These are the pair of
the internal carotid and a pair of the vertebral arteries. The blood supply of the
spinal cord, its coverings and vertebral column is providing by a number of
different range arteries those penetrate the vertebral canal at every vertebra
levels.
The branches of the subclaviar and vertebral arteries pass through the
spinal column and spinal cord. These branches arise from the cervicobrachial
trunc that is the ascending branch of the thyrocervical trunk.
The thoracic and lumbar parts are supplied by the thoracic and lumbar
branches of the aorta. The lumbar arteries diverge into the anterior (the
intercostal and lumbar arteries) and posterior (the dorsal spinal arteries) parts.
The spinal arteries arise from the lateral sacral artery (the branches of the
internal iliac artery) at the sacral part. The dorsal spinal arteries divide into two
branches independently of the place of arising. The thicker branch that diverges
in the muscles around the spinal column; the finer branch is the radicular artery
and passes together with the corresponding spinal nerve through the
intervertebral foramen to the vertebral canal. It is called a radicular artery
because it follows the root through the whole length. 31 radicular arteries go
through the intervertebral foramens into the intervertebral canal. There are 3
types of vessels.
1) The certain radicular arteries those end in roots’ border.
2) The arteries reaching the vascular network of the pia mater those are called
radicular-maters arteries.
3) The radicular arteries those supply the substance of the spinal cord those are
called the radiculospinal arteries.
There are 3 great arterial basins.
The first (superior) is a cervicothoracic portion that contains the cervical
segments of the spinal cord and the 1st, 2nd, 3rd thoracic segments. The first and
second anterior spinal arteries supply the 3 and 4 superior cervical segments
those arise from the intracranial part of the vertebral artery. The anterior spinal
arteries converge into a trunk lower or higher than C1 – C2 level. The second
and third anterior radicular arteries supply the middle cervical segments (4-7)
those arise from the intracranial portion of the vertebral artery. The anterior
radiculospinal arteries those arise from the right and left cervicocostal trunks
supply the inferior cervical and superior thoracic segments. These arteries are
the mostly the main blood supply of the cervical enlargening of the spinal cord.
The collaterals of the profound and ascending cervical arteries (the subclavial
arterial system) occipital (the external carotid artery system) that is
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communicated by the broaden anasthomosis with the horizontal suboccipital
segment of the vertebral artery may participate the blood supplying of the spinal
cord.
The second (intermediate) thoracic basin goes from the third to the ninth
segments of the spinal cord. The single anterior radiculospinal artery supplies it.
The artery passes together with the 5th and 7th thoracic nerves and 1/3 is supplied
by the 4 posterior radiculospinal arteries. It seems to be the poorer arterial blood
supply of the middle part of the spinal cord comparing to the upper and lower
portions of the spinal cord. That’s why this part is especially vulnerable and is
the most frequent place of injuring by ischemia, because the collateral blood
supply is non-significant here.
The third lower or lumbothoracic basin is formed by three or four lower
thoracic segments, the lumbar enlargement and medullar cone. The significant
blood supply is provided with the only anterior radiculospinal artery that is the
branch of the last thoracic artery or one of the initial lumbar arteries. A.
Adamkevich described its arising and localization in details in 1882 and termed
it “the great anterior radicular artery.» 3-5 posterior radiculospinal arteries end
at the lumbothoracic basin. There is a regular anastomosis at the medullar cone
level that is called “ the anastomotic loop of the cone”. It connects the anterior
and both posterior spinal arteries.
The superficial arterial network is around the spinal cord within the pia
mater. The radiculo-meningeal and radiculospinal arteries form it. The
vascularization is more significant, partially at the cervical and lumbar
enlargements level. The density of the arteries is greater at the posterior facet of
the spinal cord than at the anterior one. The vertical arterial vessels are identified
at the superficial network. They are going along the spinal cord from up to
down. There are also transverse vessels those communicate the vertical arteries.
All the vessels form the arterial corona where the arteries arise those are
supplying the white substance of the spinal cord. Three main vertical arterial
trunks are defined. These are the anterior trunk and two posterior ones.
The anterior median vessel is situated at the anterior facet of the spinal
cord and is termed the anterior spinal artery (or trunk). Two posterior vessels
pass on symmetry at the line of entering in the posterior radicles. They are
termed the posterior spinal arteries (trunks). The distribution of the
intramedullar arteries is similar for every segment at contrary to the superficial
blood supply.
The arteries pass to the center of the spinal cord from the meningeal
superficial artery, much like spokes in the wheel.
The blood supply of the dura mater and spinal column is providing by
the radicular arteries those arise variably. The vertebral and profound cervical
arteries are constant at the cervical part of the spinal cord. The additional blood
supply might be the ascending cervical, inferior thyroidal arteries and
thyrocervical trunk.
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The branches supplying vertebrae and dura mater are the intercostal
arteries at the thoracic part. The superior intercostal artery, thyrocervical and
thyrointercostal trunk supplies three initial vertebrae.
The lumbar, medial and lateral sacral arteries supply the vertebrae and
dura mater at the lumbar and sacral levels.
The methameric (segmental) vascularization is typical at the thoracic and
lumbar parts. The methamerism isn’t so expressed at the cervical and sacral
parts because of the vertical situation of the blood vessels (vertebral ascending
and profound cervical, median lateral sacral arteries). The best blood supply is at
the C3-C5 and L5-S1 level.
Veins situation copies the arterial angioarchitectonic. The most powerful
venous plexus lies between the walls of the vertebral column and dura mater.
They have fine walls and no valves. They are the very important clinical
structure and are communicated with the intracranial venous sinuses from above
and with veins of thorax, ribs, abdomen, and pelvis segmental. The venous
blood flows out not only to the inferior Cava vein but to the vertebral plexus as
well.
The numerous communications of the venous vessels causes the
extension of the methastatic spreading of the carcinoma of the prostate (uterus,
ovarian) or mammarian tumors into the spin e and cranium.
The blood supply is considered as attentively because of a great
importance of the vessels’ factor at the pathology of the spinal cord. It may
occur independently and may combine with any other diseases. The injury of the
large artery occurs often while the trauma of the spinal cord. The sharp strong
unbending of a head while a car accident leads to the folding of the flavum
ligaments those come forward and compress the spinal cord and vessels. The
intervertebral disc while too strong unbending may compress the spinal cord and
vessel. The ischemia of the spinal cord leads to the myelomalacia.
The spinal deformation is complicated with the paraplegia often. The
vascular factor is significant in the pathogenesis.
The arterial and venous blood circulation fails here because of the angle
of bending of the spinal cord, its poor lengthening because of the tightening of
the spinal roots an tension of the dura mater that makes come close the spinal
cord and vertebral bodies. All these factors lead to the ischemia and dysfunction.
The surgical interventions.
The surgical interventions are mostly the spinal puncture and
laminectomia.
The spinal puncture is the injection of the needle into the vertebral canal
with the next reaching of the subarachnoid to get the cerebrospinal fluid. That
may be performed with the diagnostic (measuring of the pressure, the
cytological or bacterial analysis) or treating aim (the injection of medicines).
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The puncture is performed in sitting or left side lying posture. The
lumbar puncture is performed in interval between 3-4 or 4-5 lumbar vertebrae
after the cleansing pretreatment. The needle perforates the skin, subcutaneous
fat, supra and infraspinous ligaments, flavum ligament and than dura mater.
While favum ligament and dura mater perforating the surgeon feels the elastic
resistance and falling in. The surgeon draws out the mandrene and gradually
gets into the subarachnoid space. The sign of the correct puncture is flowing out
the cerebrospinal fluid from the cannula. The needle (cannula) should be drawn
out and the place of the puncture should be treated by the ethyl spirit after the
puncture.
It is necessary to bend the back that makes the interspinous intervals
wider and the procedure easier. The accuracy of the needle direction provides
success of the puncture.
The needle should be drawn out when the bone barrier appears.
The complications are possible:
1) The respiratory center paralysis while law situating of the head when
puncture.
2) Wedging of the cerebellar tonsil into the great occipital foramen that is
followed by the compression of the medulla oblongata. That’s why the
spinocerebellar fluid is flown gradually in small portions.
The puncture is applying for the peridural and spinal anesthesia often.
Pajee has applied this anesthesia clinically for the first time in 1921.
The great interest appeared to this type of the anesthesia just after
describing of the employed technique of this performing by the Doliotty in
1931.
The great spreading of the spinal and epidural anesthesia may be
explained by the convincing arguments those persuade that the block of the
impulsation from the operative field in segmental range is more effective and
selective comparing to the general narcosis.
But this type of the anesthesia is combined with narcosis often. It is
applied independently while surgical interventions at the lower limbs and pelvic
organs.
The patient is in a sitting position or at one side.
There are two accesses to the vertebral column these are median and
paramedian ones. The needle is advanced at the interval between the spinous
process, taking account of the angle of the spinous process and vertebral axes at
the thoracic and lumbar part while median access.
The needle perforates the skin, subcutaneous fat, supraspinous and
interspinous ligaments. Elderly patients have tight or even calcinated ligaments
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that make the advancing of the needle into the interval between the vertebral
arches much slower.
While the paramedian access applying the needle should be injected at
the border between the vertebrae from the point in 1,5-2 cm distance from the
median line. The tip of the needle goes medially up to the interarchal interval at
median line. This access is applied while the median access is impossible. It has
advantages in patients with rather sklerosed ligaments or a great fatness.
Peridural (epidural) anesthesia has some technique peculiarities. That is
necessary to remove the mandrene and join the syringe that is filled with the
isotonic solution (NaCL 0,9 %) with a ball of air before the needle injecting
through the flavum ligament. While gradual advancing of the needle one can see
the pressing of the ball of the air. The ball gets smoothed out and the surgeon
feels free flowing of the liquid from the syringe just after the ligament
perforation. This is convincing that the needle is within the epidural space. The
depth of the needle injection is orientated by the no flowing out of the
cerebrospinal fluid through the needle after the mandrene removal, the negative
aspiration test, no recurrent flowing of the 2,0-4,0 ml of the isotonic chloride
solution after removing of the syringe, negative menisk and even absorption of
the drop at the top of the cannula inside the needle. In case of prolonged
cathetrization necessarity of the continued radicular anesthesia the special
needles with a cut are applied. Tuohy’s needle)/
The catheter should be graduated and the point o injection has to b
applied. After the injection into the epidural space the needle should be
removed. The anesthetic spreads from up to down within the epidural space and
onto the paravertebral fat partially through the lateral intervertebral foramens.
The sacral epidural (or caudal anesthesia differs with its techique of
performing; the anesthetic should be injected into the lowest point of the space.
It is performed at one of three positions/ these are on abdomen with legs
are hanging down of the bed, knee-elbow position or at one side with bent leg
(which is superior).
The treatment of the operative field and local anesthesia are performing
between the cornues of the sacrum where the deepening is palpated that
corresponds to the place of inlet into the sacral canal. The needle is abducting
upwards for 20 degrees from the conventional perpendicular line to the skin
surface at the sacral region. The angle has no to be extended more than to 40-50
degrees after the puncture of the sacrococcugeal membrane. The needle is
injected on 4,0-4,5 cm depth. One can orientate by the point that is 1 cm lower
than the line connecting the superior spines of the iliac bones. The inferior
border of the bag of the dura mater is projecting there. The needle has not to be
lower this level to prevent the dura mater injury. The depth of the needle should
be increased while bleeding.
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The solution of the trymecaine hydrochloride or xycaine hydrochloride
1,5-2% is applied. The test dosage of 5 ml is injected firstly. If there is no signs
of the spinal anesthesia during 5 minutes the whole dosage is injecting (20,025,0 ml of the anesthetics for grownups). Th superior border of the anesthesia
reaches the level of the 4-5 lumbar segments.
One should remember that injecting of novocaine with adrenaline is
followed by the spinal arteries' constriction that causes the spinal ischemia. And
the complication that is termed the ”caudal syndrome “ is possible. There are
typical paresthesias and pareses of the lower limbs and even pelvic organs. That
is the result of the direct injury of the spinal radicles by the needle.
Laminectomia.
It is an important surgical intervention. That means the opening of the
vertebral canal. The essence of the operation is the resection of the spinous
processes and corresponding vertebral arches. It is applied most often to remove
the compression of the spinal cord that is caused by the foreign body, tumor, and
varicose vessels. The patient is at the position an abdomen or at the right side.
The general anesthesia is applied but it is possible to operate on under local
anesthesia. The skin incision should be for 1 vertebra higher and for 1 vertebra
lower than border of the expected vertebral canal opening. The incision of the
skin, subcutaneous fat and fascia is performed up to the top of the spinous
processes on median line. The wound edges should be retracted and spinous
processes are making naked.
The greeze bandage wet with a hot saline solution (70%) is applied to
stop bleeding. The muscles are separated in consecutive order. The spinous
process are nipped off with Liston’s bone cutting forceps, the arch is nipped off
with the laminectom of Luer’s forceps. One can see the dura mater with its
venous plexus within the vertebral canal. One should remember that the veins'
injury leads to the air or fat embolism.
The dura mater is dissected with the scissors or scalpel in a short
distance than follows the incision on grooved probe. The laminectomia isn’t the
end of the operation. That is necessary sometimes to reset the articular processes
those are situated at the center of the compressions to extract the extradural
radicles and at last to free the spinal cord and its arteries off the compressive
agents.
The wound should be closed in layers after the resection. The dura mater
is closed solidly with the continuous suture. The sutures should be hermetic,
especially at the corners to prevent the liquorrhea. The great defects of the dura
mater are covered with the transverse fascia graft or fibrous sponge.
The soft tissues are suturing in layers. One should remember the danger
of the vessels injury as well a while the cerebral operations. Especially
vulnerable are the arteries while tumor resections or freeing and crossing of the
radicles. The crossing of the anterior radicles is more dangerous than posterior
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because the anterior radiculospinal arteries pass here. Just single radiculospinal
artery incision goes on without complications; some arteries incision leads to the
myelomalacia. The Adamkevich’ artery incision (that supplies a great territory
of spinal segments, lumbar enlargement) leads to the irreversible changes in
spinal cord and radicles that causes limbs paralysis.
The injury of the vertebral column is of a great importance in a surgical
practice.
The simplest orthopedic manipulation is unloading and traction. While
cervical vertebra injury. The unloading of the vertebral column performed by the
immobilization of the cervical part with plaster-of-Paris high collar, traction of
the Glissons’ loop or stirrup.
The total discectomia with the corporodesisis performed when acute
breaking of the intervertebral discs, cervical osthechondrosis with the prolabs of
the nucleus pulposus. The operation is goaled to remove the compression of the
spinal cord. The operative access is the anterior edge if the
sternocleidomastoideus muscle. The anterior facet of the cervical vertebra
bodies and intervertebral discs should be nude. The H-shaped incision is made at
the certain level at the anterior longitudinal ligament and it should be exfoliated
to the side.
The surgeon incises the anterior part of the fibrous ring and than
removes the injured disc with Folkman’s spoon. The autotransplantant from the
spine of the iliac bones is applied to form the block between the neighbor
vertebrae. The wound is closed in layers.
While comminuted compression fractures of the vertebral bodies the
anterior spondylodesis is performed. The fragments of the vertebral bodies and
intervertebral discs are extracted firstly and the rectangular compact spongious
autoplastic graft is advanced to that place. The access is the similar while the
cervical vertebrae injury.
The access to the thoracic vertebrae goes through the pleural cavity with
rib resection.
While lumbar vertebrae fracture there are possible the anterior and
posterior accesses. The posterior access is during the operations at the spinous,
transversal, and articular processes and arches of the lumbar vertebrae. The
posterior-external access (lumbotransversectomia) is performed by the surgeonsbecause of the tuberculous spondylitis at the lumbar level. The anterior
extraperitoneal accesses by Chaclin are optimal.
But the essence of the operation is the removal of the injured fragments
of the vertebral bodies and discs with the next replacing by the autoplastic graft
from the iliac bone or the superior metaphysis of the fibula. The technique of
these operations (because of the trauma or pathologic process injury) is
described in details at the neurosurgery, orthopedy and traumatology courses.