Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_583_Библиотеки_им_академика_М_И_Перельмана
.pdf
354
https://t.me/medicina_free
T. Bräuer
Fig.50.11 Left and right: X-ray bending pictures conrming rigidity in all three curves/ the center: X-ray supine position depicting the real exist-
ing curvatures intraoperatively in a prone position
Fig. 50.12 ALLEN operating table
and if it exceeds 40° (hyperkyphotic), the modier + is
assigned. The Lenke classication can be of great help to
Fig. 50.13 Yellow arrow: gear shift positioned prior to penetration of
the pedicle
plan the numbers of vertebrae to fuse (mostly COBB-toCOBB angle in structural curves to conserve motion in the
non-structural curve/−s also described as “selective fusion”),
50.6 Positioning
however even with optimal pre-operatively planning, reality
can show in some cases postoperatively—the need to extend
the xation in order for the patient to have proper balanced
three-dimensionally.
The patient is supported in a prone position on a radiolucent
operating table (e.g., Jackson table or Allen table) (see
Fig. 50.13). Positioning of the patient should assure least
50 Posterior Correction ofAdolescent Idiopathic Scoliosis (AIS)
https://t.me/medicina_free
355
possible pressure upon the vena cava with the intention of
minimalizing intraoperative loss of blood and preventing
possible skin lesions due to extensive duration of the operative procedure.
50.7 Surgical Technique
Surgical technique benets a great deal by better understanding the pathogenesis of AIS: when reaching puberty, the
growth in the anterior wall of the corpus vertebrae in patients
with AIS is “outrunning” the growth of the posterior wall
resulting in a at thoracic spine with an apical lordosis/
hypokyphosis. The plumb line from C7 falls eventually
behind/posteriorly to L5 with a concurrently introduction of
an unnatural rotation in the main (structural) curve/−s which
induces the growth of a hunchback. Nature’s solution to deal
with the anteriorly gain in anterior height of the vertebrae in
order to prevent imbalance in the sagittal plane appears to
give way by emerging a rotation as the minor biomechanical
drawback in contrast to sagittal imbalance. The consistent
analysis of the origin of AIS (and basically all deformities of
the spine) may be a good help in correcting them: the derotation of the scoliotic spine removes the hump but at the same
time brings back to light the original pathogenesis of AIS,
which is the relative, anterior space requirement causing the
rotation in the scoliotic spine, so that sagittal balance can be
sustained. At the same time, anatomical derotation of the
scoliotic spine produces an undesirable hypokyphosis. To
avoid this, it is recommended to elongate the posterior structures of the spine starting from the apex of the primary curve,
which can be achieved by transporting the pedicle screws on
the rods using distraction forceps—closely controlled by
intraoperative neuromonitoring.
50.7.1 Approach
A midline incision is performed with the customary subperiosteal exposure of the posterior bony elements. Scrupulous
dissection will be benecial concerning minimizing tissue
damage, blood loss, and ultimately providing best possible
fusion rate. Blunt dissection with gauze compresses instead
of exceedingly usage of wound retractors may be supportive
to complete optimal access and walking the thin line between
hemostasis and preventable in situ rhabdomyolysis.
50.7.2 Instrumentation
The use of pedicle screws in correction of deformities also in
the thoracic spine has become the gold standard in line for
reported three column control of the vertebra, improved cor-
onal, sagittal and rotational correction, minimal loss of correction over time, lower pseud arthrosis rates, lower implant
failures, and earlier return to activities. Several screw insertion techniques are described in the literature, for example,
uoroscopic assisted, Funnel technique, intraoperative navigation, electronic conductivity device, and freehand placement. The choice of the screw insertion technique is up to the
personal preference of the surgeon. In the current selected
operative case, the freehand technique was chosen which is
also a topic of this book and is described in detail. In the following gure, the yellow arrow shows the gear shift before
the penetration of the pedicle. At the given entry point for the
pedicle screw, the cortical part of the lamina dorsalis has
been removed beforehand in order to better haptically grasp
the cancellous part of the pedicle. The gear shift illustrated
here is pointed and bent. The tip points laterally in order to
guarantee the integrity of the medial pedicle wall in the best
possible way, which assures approx. 65% of the stability of
the pedicle screw inserted later, while an intact lateral pedicle wall stands for approx. 35% of the stability of the pedicle
screw. The gear shift is pushed approx. 10–15mm into the
pedicle with alternating rotations of the gear shift to the right
and left. Experience shows that light, alternating rotations
can facilitate safe and precise penetration, especially in the
usually thin, narrow pedicels on the concave side of the scoliosis. After approximately 10–5mm penetration of the pedicle with the gear shift, the tip of the gear shift is in the
immediate vicinity where the pedicle merges into the vertebral body. It is recommended to pull the gear shift directly
out of the pedicle at this point without any rotational movements. The gear shift is turned outside the pedicle with 180°
and then inserted into the preformed pedicle screw channel
with the tip pointing medially. Continue with the same pressure and rotation movements as before to the desired length
of the pedicle screw channel. Although modern pedicle
screw designs have self-tapping threads, it is preferable to
use a pre-tap with a diameter 1 millimeter minor than that of
the intended pedicle screw diameter to achieve a press-t
situation, and thus optimum stability of the pedicle screw
(Figs.50.14, 50.15, 50.16, 50.17, 50.18, 50.19, and 50.20).
The red arrow points to another gear shift that palpates the
lateral boundary of the superior articular process and is then
inserted from proximally to distally into the costo- transversal
joint and then further pushed with nimble pressure approx.
10mm. A slight movement of the gear shift from lateral to
medial allows the haptic as well as optical representation of
the lateral pedicle wall. Usually it is recommended to select
the entry point for the pedicle screw approx. 2mm medial
from the lateral pedicle wall displayed with the gear shift.
After thorough probing and integrity testing of the ve walls
that dene the screw channel (oor-superior-inferior-lateralmedial), the pedicle screw is inserted (for FAS up to the
resulting stop, i.e., when the oor of the screw head lies per-
356
https://t.me/medicina_free
Fig. 50.14 Yellow arrow: gear shift positioned prior to penetration of
the pedicle. Red arrow: indicating gear shift palpating the lateral
boundary of the superior articular process unveiling the lateral border of
the pedicle
T. Bräuer
Fig. 50.17 Ideally, the appropriate rod can be placed on the spinal pro-
cesses in the given surgical case indicating a proper t
Fig. 50.15 After thoroughly palpating of the preformed pedicle screw
channel with a probe follows the introduction of the pedicle screw
Fig. 50.16 The ttingly adjusted rod should compare to the given
anatomy in the surgical site
Fig. 50.18 Mount the rod reducer on the screw heads and insert
therod
Fig. 50.19 With the help of rod reducers, the rod is consistently and
without substantial force transfer brought into the screw heads and
secured with the set screws
pendicular to the dorsal lamina and stops). When all planned
pedicle screws are set, the rod is adjusted. For practical reasons, it may be helpful to adjust the rod at rst for the side on
which the concavity of the primary curve is found. The spinal processes are an additional aid in modifying the rod, as
can be seen in the gure, the adjusted rod follows its course.
Several rod reducers are placed on the screw heads to
50 Posterior Correction ofAdolescent Idiopathic Scoliosis (AIS)
https://t.me/medicina_free
357
Fig. 50.20 90° rotation of the rod with the rod holder clamps from
medial to lateral
minimize the load on the screws and their corresponding
mobility segments. The rod is then inserted into the rod
reducer. With the help of the rod reducers, the rod can be
guided consistently and without signicant effort into the
heads of the pedicle screws. The rod holder forceps are used
to rotate the rod by 90°. The rod is secured in the pedicle
screw heads during rotation with set screws on top. The last
plastic shape change of the rod is performed with the coronal
benders to achieve further correction in the coronal plane.
The other rod is applied in the same way on the contralateral
side and ttingly adapted in its shape. The consecutive derotation takes place directly at the motion segment which is
dened by two vertebrae with the vertebral disc between
them. Four counter- torques are placed on each of the four
attached pedicle screws in the motion segment. The extension of the relatively shortened posterior structures of the
scoliotic spine is done bilaterally with distraction forceps
between the proximal and distal pedicle screw pairs, while
the set screws are loosely attached to the pedicle screw heads.
After the distance between all four pedicle screws have been
elongated on the rods to the matching height, the two counter
torques on the convex side are carefully moved in the direction of the anterior spine, while the two counter torques on
the concave side are guided in the direction of the spinal process at the same time. The inclination angle of all four pedicle screws in the motion segment in relation to the midline
structures can be clearly seen from the long counter-torques.
Ideally, with the same inclination angle, the pedicle screws
are on the identical level in sagittal direction; in coronal
level, the screws point with the tip toward the center of the
anterior vertebral body. In this way, the achieved derotation
can be visualized before the intraoperative X-ray control.
Within the instrumented spine, all other motion segments are
derotated in the same manner. The technique with four counter torques, compared with similar derotation techniques,
may allow also a turning force within the intervertebral disc
of the motion segment, which could optimize the derotation
even more if desired. Once the three-dimensional correction
has been completed, an X-ray inspection can be carried out
(Figs.50.21, 50.22, 50.23, 50.24, 50.25, 50.26, and 50.27).
Fig. 50.21 It follows both the denite prole adjustment of the rod
and simultaneous an additional correction of the spinal deformity by
using the coronal benders
Fig. 50.22 Customized DVR technique with four counter torques
mounted on four screw heads in the motion segment
Fig. 50.23 Elongation of the motion segment by enlarging the dis-
tance of the screw heads on the rods performed with distraction
forceps
Fig. 50.24 Final check of the performed deformity correction (visual
and with x-ray)
358
https://t.me/medicina_free
Fig. 50.25 Decortication and autologous bone transplantation inside
the performed instrumentation
T. Bräuer
Operation is concluded by a consistent bilateral decortication of the lamina dorsalis within the instrumented spinal
column in order to achieve optimal spondylodesis.
50.7.3 Postoperative Treatment
The postoperative therapy involves an effective pain treatment which in turn enables an early and optimal mobilization of the patient. The intrathecal morphine instillation
carried out by the surgeon at the start of the operation and/or
the introduction of two EDAs in the spinal canal after performed decortication of the instrumented spine can provide
Fig. 50.26 Preop. X-rays showing LENKE type 4CN Triple Major
50 Posterior Correction ofAdolescent Idiopathic Scoliosis (AIS)
https://t.me/medicina_free
359
Fig. 50.27 2year postop. X-ray
360
https://t.me/medicina_free
T. Bräuer
satisfactorily postoperative pain treatment accompanied by
Paracetamol, morphine, and morphine-like drugs, as well as
short-term use of NSAIDs. Total postoperative admission
time is usually expected to be 4–7days.
50.8 Tips andTricks
• Operative 3D corrections of spinal deformities pose
highly complex challenges to the surgeon. The acquisition of the necessary skills may require a correspondingly
longer period of time and is undoubtedly made easier by
a targeted training at institutions with a sufciently high
volume of deformity interventions to be performed.
• As is so often the case in surgical disciplines, a both welldesigned and performed approach pays off in the correction of spinal deformities as well: the overview of the
surgical site considerably facilitates more precise and
easier placement of the pedicle screws, enables more
atraumatic surgery by taking into account the anatomical
structures, which in turn decreases signicantly tissue
damage— hence take down intraoperative blood loss—
and benets the patient in recovering faster.
• When placing the pedicle screw at the respective level, it
may be recommended to consider the potential entry
point of the pedicle screw on the contralateral side while
simultaneously adjusting the intended direction of the
pedicle screw channel on the ipsilateral side; ideally, the
“virtual” pedicle screw channel on the contralateral side
and the real one on the ipsilateral side should point toward
each other. This procedure deems effective in preventing
misplacement of the pedicle screw with either undesirable
proximal penetration of the pedicle into the intervertebral
disc or distal penetration which may compromise the
nerve root.
• Considering the potential entry points of the pedicle
screws before preparing the actual screw channel allows a
smoother placement of the pedicle screws in line to each
other. The subsequent insertion of the rod is then made
considerably more convenient.
• Both of the above mentioned advices for placing the pedicle screws from S1 to Th1 may be of assistance to use
polyaxial screws (MAS), as well as exclusively monoaxial screws (FAS) in extensive constructs.
• The mutually mixing of MAS and FAS in longer constructs should be carefully considered, as the signicantly
greater distance between the MAS-screw head (measured
from the lamina dorsalis to the lower border of the inserted
rod) compared to the FAS-screw head causes a hypomochlion (center of rotation of a joint) in the MAS-screw
head which may give rise to the risk of pull-out moment
in FAS.
• Self-image and self-understanding of the adolescent
patients is—at a time when physical perfection is openly
favored—far more negatively inuenced by the observable hump than by the scoliosis/spinal curvature itself.
The trade-off in the successful de-rotation of the hump
can lead to a concurrent undesired intensication of the
already preoperatively existing hypokyphosis. The extension of the spinal posterior structures with pedicle screw
transport on rigid CoCr rods can counteract the formation
of hypokyphosis but cannot completely protect against it.
An optimal and patient satisfactory derotation of the
hump has probably been achieved at the point where further derotation would fall short of the preoperative existing kyphosis, and thus threatening a stable sagittal balance
of the spine.
References
1. Akbarnia Y. Thompson: the growing spine. Berlin Heidelberg:
Springer-Verlag; 2011.
2. Danielsson AJ.Natural history of adolescent idiopathic scoliosis: a
tool for guidance in decision of surgery of curves above 50°. J Child
Orthop. 2013;7:37–41.
3. Dunn J, Henrikson NB, Morrison CC, etal. Screening for adolescent idiopathic scoliosis evidence report and systematic review for
the US preventive services task force. JAMA. 2018;319(2):173–87.
4. Konieczny MR, Senyurt H, Krauspe R.Epidemiology of adolescent
idiopathic scoliosis. J Child Orthop. 2013;7:3–9.
5. Weiss HR, Karavidas N, Moramarco M, Moramarco K.Long-term
effects of untreated adolescent idiopathic scoliosis: a review of the
literature. Asian Spine J. 2016;10(6):1163–9.
6. Wong HK, Tan KJ.The natural history of adolescent idiopathic scoliosis. Indian J Orthop. 2010;44(1):9–13.
Thoracic Vertebrectomy andSpinal
https://t.me/medicina_free
Reconstruction Via Posterior
orCombined Approaches
M.Ruf, J.Petrovics, G.Ostrowski, andT.Pitzen
51
51.1 Introduction and Core Message
Thoracic vertebrectomy and spinal reconstruction via
posterior or combined approaches is a demanding technique for surgical treatment of spinal tumors that require
a complete resection of the entire vertebra, including the
posterior structures (lamina, facet joints, transverse processes, pedicles) as well as the anterior structures (vertebral body). This entire en bloc vertebrectomy or
spondylectomy entails a complete disruption of the continuity of the spine with severe instability. Depending on
the extension of the underlying pathology, the resection
comprises one or more vertebrae, usually with resection
of the adjacent ribs within their proximal part. This technique allows for resection of tumors in one piece including a healthy layer (marginal or wide resection). There
is some evidence that local recurrence is reduced and
long-term survival is more probable [1–3]. However, the
technique creates a relevant instability necessitating a
biomechanically sound reconstruction that is able to
take loads and to withstand exion/extension, lateral
bending, and left- right axial rotation.
51.2 Indication
• Primary malignant tumors.
• Semimalignant tumors.
• Isolated spinal metastasis with long life expectancy.
M. Ruf (*) · G. Ostrowski
Center for Spine Surgery, SRH Klinikum KarlsbadLangensteinbach, Karlsbad, Germany
e-mail: michael.ruf@srh.de
J. Petrovics · T. Pitzen
Center for Spine Surgery, Orthopedics, and Traumatology,
SRH Klinikum Karlsbad- Langensteinbach, Karlsbad, Germany
51.3 Contraindication
• Tumor inltration of the spinal cord.
• Tumor inltration in essential adjacent organs.
• Multiple metastasis (relative).
• Prognosis infausta.
51.4 Technical Prerequisites
Fluoroscopy, radiolucent operating table, thoracotomy resp.
laparotomy equipment, intraoperative electrophysiological
monitoring (SSEP/MEP), vertebral body replacement
devices, adaptable to every size of defect (titanium mesh
cages (Harms), expandable cages), posterior instrumentation
with different diameters, transition rods if necessary at the
cervicothoracic region.
51.5 Planning
Conventional radiographs, computed tomography, and MRI
are essential to assess localization and extension of the
tumor. Computed tomography of brain, thoracic chest, and
abdominal cavity as well as bone scintigraphy are necessary
to exclude further tumor and metastases, so widespread disease. Using all radiographic information, the border of the
tumor is exactly identied. Every vertebra that is involved
has to be included completely into the intended resection,
also including affected ribs and surrounding soft tissue with
a wide safety distance. As the vertebra contains the spinal
cord, the area has to be dened where the bony ring can be
opened with sufcient distance to the tumor (Fig. 51.1).
Then an appropriate approach is chosen to remove the tumor
in one piece (posterior or combined). In tumors with a pronounced perfusion, segmental arteries above and below the
feeding artery, as well as the feeding artery itself, should be
embolized preoperatively. Pre- and intraoperative neuromonitoring (SSEP, MEP) is strongly recommended.
© Springer-Verlag GmbH Germany 2023
U. Vieweg, F. Grochulla (eds.), Manual of Spine Surgery, https://doi.org/10.1007/978-3-662-64062-3_51
361
362
https://t.me/medicina_free
M. Ruf et al.
A score is proposed as a tool for surgical strategy for
metastatic spine tumor, including grade of malignancy,
visceral metastases, and bone metastases. Tomita et al.
advised the surgical classication of spinal tumor
(Figs.51.2 and 51.3) based on the pattern of local vertebral
tumor progression [4].
The Spinal Instability Neoplastic Score (SINS) was
developed for assessing patients with spinal neoplasia. It
identies patients who may benet from surgical consultation or intervention. It also acts as a prognostic tool for surgical decision making [5].
Fig. 51.1 Artist’s view to illustrate preoperative planning of the open-
ing of the spinal canal with sufcient distance to the tumor. The canal is
opened at the position of the gaps, thus giving a safety margin around
the tumor mass
51.6 Surgical Technique
Total en bloc vertebrectomy is the most aggressive surgical treatment for spinal tumors. It comprises a complete
resection of the posterior structures and stabilization by a
posterior approach, as well as the resection of the vertebral body via costotransversectomy or an additional anterior approach.
51.6.1 Posterior Approach
Tumor lesions that do not exceed to adjacent structures can
be resected by a posterior approach with costotransversectomy [6]. This technique provides an adequate exposure of
all three columns through a single posterior approach. It
allows for en bloc corpectomy and sufcient stabilization
with anterior support. The spinal cord can be observed during the whole resection maneuver. A clear disadvantage of
the procedure is the limited visualization and control of the
great vessels especially when the tumor exceeds the border
of the vertebral body.
• Patient in prone position on radiolucent table under general anesthesia.
• Midline skin incision and subperiostal dissection of muscles far lateral to expose the proximal ribs. In case of
tumor expansion to the posterior muscles, dissection
leaves the muscles at the resectate.
• Placement of pedicle screws typically two levels below
and above affected vertebra/vertebrae.
Fig. 51.2 Tomita’s surgical
classication of spinal tumors
[4]
Type 1
vertebral body
Type 2
pedicle
extension
Type 3
body-lamina
ext.
Intra-
Compartmental
Type 4
epidural ext.
Type 5
paravertebral
ext.
Type 6
2-3
vertebrae
Extra-
Compartmental
Multiple
Type 7
51 Thoracic Vertebrectomy andSpinal Reconstruction Via Posterior orCombined Approaches
https://t.me/medicina_free
363
Minimum requirement :
Prognostic Scoring System
Factor
Point
Fig. 51.3 Surgical strategy for spinal metastasis [4]
1
2
3
Primary
tumor
slow
growth
moderate
growth
rapid
growth
Mets. to vital
organ
no met : 0
controllable
uncontrollable
Bone
mets.
isolated
multiple
ECOG Performance Status
Karnofsky Performance Scale:
Total
P. Score
2
3
4
5
6
7
8
9
10
or
LifeTreatment
ExpentacyAim
2y <
1−2y
6−12m
< 3m
0
0
Long-term
local control
Middle-term
local control
Short-term
palliation
Terminal
care
3
30
5
0%
Surgery
En bloc exc.
Debulking
Palliative
decomposition
No surgical
treatment
Fig. 51.4 Artist`s view for blunt dissection around the vertebral body
• The ribs on the affected level are transected lateral to the
costotransverse joints with sufcient distance to an eventual tumor inltration.
• The pleura is bluntly separated from the ribs and the vertebra. The aorta is carefully dissected from the anterior
aspect of the vertebral body (Fig.51.4). The segmental
vessels are ligated if necessary.
• Blunt spatulae are inserted to protect the anterior lying
vessels (Fig.51.5).
• The lamina, facet joints, and pedicle are now cut and
removed according to the preoperative planning
(Fig. 51.1). The spinal cord and the nerve roots are
visualized.
Fig. 51.5 Artist`s view of how the spatula protects the anterior
structures
• The nerve roots at the affected level(s) are ligated and cut.
• The disks above and below the tumor-inltrated vertebra/
ae are incised and removed from both sides including the
posterior longitudinal ligament. A temporary rod is inserted
for stabilization alternatingly at the contralateral side.
• The spinal cord is carefully dissected from the posterior
wall.
• When the resection of the vertebral body is intended by
the posterior approach, it is now carefully rotated around
the dural sac and removed en bloc (Fig.51.6).
Соседние файлы в папке Библиотека им академика М.И. Перельмана