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U. Vieweg and R. Morrison
important to realize that it is not a question of error, for an
error is not caused intentionally, but is an expression of various latent problems contained in the system. But only if the
employees are also ready to participate in a certain “error
culture”, it will be possible to successfully establish a CIRS
in the hospital. No industrial sector that strives for high operational safety relinquishes the advantages of an incident
reporting system. The most important criteria for a functioning operation are the following:
– Fullest support from the management and the will to
implement
– Anonymity and guaranteed freedom from sanctions
– Notications as free text
– Interdisciplinary analysis and processing of cases
– Prompt feedback to employees
A CIRS is conducted as follows:
– Identifying (anomic reporting of “near-miss events”)
– Analysing (what causes?)
– Evaluating
– Managing (corrective and preventive actions)
– Reporting (evaluating and deriving strategies)
A CIRS is part of an IRM, which also includes the com-
plaints management.
19.6 Improvement ofNon-technical Skills
factors”. The crew (cockpit) resource management (CRM)
refer to NASA’s workshop in 1979 after the catastrophic
crash of Tenerife (1977) with a crash of Boeing 737-40 British
Midland and the fall of the Boing 737-40 of the British
Midland (1969). CRM training courses have been a prerequisite for FAA (USA) and JAA (Europe) pilots since these accidents. These courses address these ndings with a view to
increasing the awareness of the staff, with the following
focus: increasing the professionalism of the individual by
training the non-technical skills and improving the corporate
and security culture. Since the situation in the team with
regard to the workload and with regard to routine and habit as
well as other organizational structures and as new employees
are added to the team, this team training becomes necessary
at regular intervals. An introduction of checklists and reliable
work without an employee motivation and training makes no
sense or can only be realized with an enormous organizational effort or with punished reprisals. Routine and increasing workload means updating the team training. The
implementation is carried out in a one to three active team
resource management courses that include all those involved
in the process (surgeons, anaesthesiologists, surgical nurses),
based on the aviation courses. Teamwork and leadership are
an important part of team training. Now these courses are
being offered by different providers in different formats.
Table 4 presents three different courses (see Table4).
Many airlines are interested in the personnel selection for the
personality prole of their future personnel in the cockpit. In
addition to cognitive and psychological criteria, complex
requirements on personality are important. Personalityoriented behavioural analysis was developed in order to identify these characteristics. It is obvious that these selection
criteria are also applicable in medicine. Unfortunately, however, some of the social skills are still not chosen as a selection criterion for medical studies. In the “Medical Studies
(2020)” Master Plan, a project of the Union and the German
political party SPD, these selection criteria had already been
agreed upon in the 2013 Coalition Treaty. While the admission to universities is still dependent on the grade secured in
the Abitur, or the school leaving examination, and is thus an
important selection criterion, universities must, however, add
on at least two new criteria (from such options as social and
communicative skills, willingness to perform, previous work
in a medical profession and voluntary commitment). In the
aviation sector, there has been a long- standing demand that
executives and ying and highly qualied technical personnel
receive further and advanced training in the eld of “human
References
1. Badke-Schaub P, Honger G, Lauche K. Human Factors.
Psychologie sicheren Handelns in Risikobranchen. 2nd ed.
Heidelberg: Springer; 2012.
2. Holzner E, Thomeczek C.Patienntensicherheit. Wien: Facultas AG;
2005.
3. Kohn L, Corrigan JM, Donaldson MS; Committee on Quality of
Health Care in America. Institute of Medicine. To err is human,
building a safer health system. Washington DC: National Academy
Press; 2001.
4. Leape LL.Error in medicine. JAMA. 1994;272:1851–7.
5. Reason J.Human error. Cambridge: Cambridge University Press;
1990.
6. Bogner MS. Human error in medicine. Hillsdale, NJ: Lawrence
Erlbaum Associates; 1994. 411pp.
7. Rall M, Dieckmann P, Stricker E; The Working Group Incident
Reporting of the German Anesthesia Society DGAI and BDA.Das
Patientensicherheits-Optimierungs-System PaSOS [Patient safety
optimizing system PaSOS]. Anaesthesiol Intensivmed. 2006,
47:S20–S24.
8. Schmitt T.The better the team, the safer the world. Ladenburg:
Gottlieb Daimler und Karl-Benz-Stiftung; 2007.
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9. Pierre St M, Honger G, Buerschaper C. Notfallmanagement.
Human Factors in der Akutmedizin. 2nd ed. Heidelberg: Springer;
2011.
10. Flanagan JC. The critical incident technique. Psychol Bull.
1954;51:327–58.
11. Cooper JB, etal. Preventable anesthesia mishaps. A study of human
factors. Anesthesiology. 1978;49:399–406.
12. Möllemann A, etal. Clinical risk management. Implementation of
an anonymous error registration system in the anesthesia department of a university hospital. Der Anaesthesist. 2005;54:377–84.
13. Rall M, Martin J, Geldner G, et al. Charakteristika effektiver
Incident- Reporting-Systeme zur Erhöhung der Patientensicherheit
[Characteristics of effective incident-reporting-systems for the
increase of patient safety]. Anaesthesiol Intensivmed. 2006;47:S9–19.
Sagittal Balance Concept: Radiological
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Measurement Parameters
TheophiloAsforaLins, GuilhermeAugustoFoizer,
andWilsonT.Asfora
20
20.1 Introduction and Core Messages
Over the last decades, there has been an increase in
concern over quality of life issues, especially in the
elderly patient. Spinal diseases are among the main
factors that cause loss in quality of life in the elderly
population because these diseases not only restrict
independent mobility but also contribute to other
mechanical, neurological, or chronic pain limitations
[1]. In the large group of spinal diseases, deformities
and degeneration with loss of sagittal balance are very
prevalent, and the impact on daily activities is tremendous [2, 3]. In addition, studies have shown that the
postoperative incidence of sagittal spinal imbalance,
also known as at back deformity, has increased [4–7],
thus bringing greater signicance to a fuller understanding of this theme in an attempt to mitigate or
avoid unfavorable postoperative outcomes. To study
conditions which involve deformities of the spine, it is
necessary to establish what is considered “standard”
for sagittal balance. Many authors have dened the
ranges of spinopelvic parameters for specic populations. However, they stressed the fact that these anthropometrical parameters were very scattered as a result
of human diversity, and therefore, it seemed difcult to
T. A. Lins (*)
Clínica Phitris, São Paulo, Brazil
Departamento de Ortopedia e Traumatologia, Escola Paulista de
Medicina - UNIFESP, São Paulo, Brazil
e-mail: theoasfora@gmail.com
G. A. Foizer
Department of Orthopedic Surgery, Unicamp, Campinas, Brazil
Spine Surgery at Hospital Adventista de São Paulo, São Paulo, Brazil
W. T. Asfora
Department of Neurosurgery, Sanford School of Medicine, Sanford
Neurosurgery and Spine, University of South Dakota,
Sioux Falls, SD, USA
dene what is normal in the upright posture for a specic subject [1, 8]. Thus, it is believed that analyzing
multiple parameters may lead to more consistently
interpretable data. Many factors such as age, gender,
weight, and morphology of the pelvis can cause variation of spinal and pelvic parameters, which in turn
inuences the ability to more accurately dene what is
an acceptable normal biometric standard for the aging
spine.
20.2 Sagittal Balance
The spinal column consists of four main curves: cervical lordosis (CL), thoracic kyphosis (TK), lumbar lordosis (LL),
and sacral kyphosis (SK). Between these curves, there are
transition areas that may present some characteristics of both
curves. These curvatures have mechanical functions to
absorb loads applied to the spine in addition to allowing better utilization of muscle function, enhancing the movement
through lever arms, and seeking a better erect posture [8],
while always protecting the neurological structures.
Moreover, due to an intimate relationship between the spine
and the pelvis, upright posture also depends on spinopelvic
relations and features that play a key role in this context. For
a thorough evaluation of the spine, a lateral panoramic radiograph must be done using a vertical 30×90-cm lm, maintaining a distance between the subject and the radiographic
source, usually 250cm. The subject should stand in a comfortable position with knees fully extended and arms, resting
on supports, exed forward to 45°. The radiograph is centered on the 12th thoracic vertebra and imaging taken during
inhalation [8–14]. The most important sagittal spinal radiographic parameters for clinical and surgical practices are
illustrated in Fig.20.1.
Thoracic kyphosis (TK): This is an angle measured
between the upper endplate of T4 and lower endplate of T12.
© Springer-Verlag GmbH Germany 2023
U. Vieweg, F. Grochulla (eds.), Manual of Spine Surgery, https://doi.org/10.1007/978-3-662-64062-3_20
143
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C7
SVA
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T12
L1
T4
LLA
TK
SS
PT
T. A. Lins et al.
C7
C7 Tilt
PI
SSA
Fig. 20.1 Sagittal spinal radiologic parameters (original gure from
Todd etal. [15]. Image reproduced with permission of the publisher)
Although there is great variation, normal values usually
range between 20° and 50° [10, 13, 16, 17].
Lumbar lordosis (LL): This angle is formed between the
upper endplate of L1 and the upper endplate of S1. It presents a wide variation, with values ranging from 30° to 79° in
normal individuals. The lumbar lordosis is greatly inuenced
by the pelvic incidence (PI). Any increase in the pelvic incidence leads to increase of lumbar lordosis [3, 11, 13]. An
adequate LL for the sagittal balance presents an estimated
value of 80% of the sacral slope [17].
Sagittal vertical axis (SVA): This is used to document
the location of the head with respect to the normal center of
gravity (offset of the head from the sacral promontory). This
is identied by a plumb line dropped from the center of the
body of C7 to the sacral endplate. According to the Scoliosis
Research Society guidance, sagittal balance occurs when the
SVA lies within ±2 cm of the sacral promontory. There is
controversy regarding the accuracy of the SVA as a measure
of sagittal spine balance due to small changes in the position
of lower extremity joints and segmental spine movement
during radiographic imaging [18]. The C7 plumb line and
center of gravity are not identical. Usually the center of gravity is located in front of the C7 plumb line and slightly behind
the hip joints [19].
Spino-sacral angle (SSA): This is an angle formed
between a line from the center of the C7 vertebra to the center of the vertebra of S1 and a horizontal line crossing the
upper endplate of S1. It represents the overall orientation of
the spine in the sagittal plane and the evaluation of how the
Fig. 20.2 Positioning angles of C7; in case of severe kyphosis (right),
SSA decreases strongly (original gure from Roussouly et al. [29].
Image reproduced with permission of the publisher)
spinopelvic compensation is to keep C7 centered over the
sacrum [13, 17, 20]. This is an angle that quanties the global
kyphosis of the whole spine. In a well-balanced spine, SSA
remains proportional to sacral slope. In case of kyphosis, or
loss of lumbar lordosis, SSA decreases. In severe kyphosis,
SSA decreases strongly. These relations may provide a guide
to evaluate the need of correction for the kyphosis. This
parameter carries the advantage of being an angular measurement which avoids the error inherent in measuring offsets in noncalibrated radiographs (Fig.20.2)
20.3 Anteroposterior Listhesis
It measures the linear displacement of one vertebra relative
to another [17]. This is the distance in millimeters between
the vertical line of the posterior wall of the upper vertebral
body and the vertical line of the posterior wall of the inferior
vertebral body.
20.4 Pelvic Parameters
Pelvic tilt (PT): The angle between the vertical and the line
through the midpoint of the upper sacral endplate to the femoral head axis demonstrates the spatial orientation of the pelvis. Higher values represent retroversion of the pelvis or
lower values of anteversion.
TK
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Sacral slope (SS): This is dened as the angle between
the horizontal and the upper sacral endplates. A vertical
sacrum is described by a low value and a horizontal sacrum
by a high value.
Pelvic incidence (PI): This is dened as the angle
between the perpendicular to the upper sacral endplates at its
midpoint and the line connecting this point to the femoral
head axis [11].
20.5 Interpretation oftheSpinopelvic
Parameters
145
SS
SS
PT
PT
It has recently been shown by different authors that the pelvic morphology can signicantly inuence the spinopelvic
balance in normal and pathological conditions [21–23]. The
ultimate goal of the spinopelvic balance is to maintain the
head centered to the pelvis or, more precisely, to the center of
gravity of the human body. To understand how this mechanism occurs, it is important to consider that the ideal spinal
alignment allows an individual to assume standing posture
with minimal muscular energy expenditure. This concept is
reected in the “cone of economy” or “cone of balance”
principle conceptualized by Dubousset [24]. Within the center of the cone, the individual may remain in an ergonomically favorable erect position. However, larger deviations in
the anterior-posterior or lateral plane will require greater
energy use to maintain a standing position. Finally, progression outside of the “stable cone” results in a loss of postural
control and the need for external supports. All adaptations of
the spinopelvic parameters, therefore, aim to reestablish the
sagittal balance. Many conditions may lead to sagittal imbalance. The most common are degenerative changes, such as
hypertrophic facet joint arthritis, degenerative disc disease
(DDD), bone remodeling, and atrophy of extensor muscles,
resulting in a progressive kyphosis of the lumbar spine.
There are other presentations such as individuals who had a
long fusion for adolescent idiopathic scoliosis with subsequent degeneration distally, individuals with degenerative
sagittal imbalance in whom fusions have initially been performed in the distal lumbar spine in a somewhat hypolordotic or kyphotic position with subsequent degeneration of
segments above the fusion, and posttraumatic kyphosis and
ankylosing spondylitis [25]. When the trunk is tilted anteriorly, the individual uses compensatory mechanisms in order
to maintain the spinopelvic balance. The main compensatory
mechanism are, from cranial to caudal, cervical hyperlordosis, reduction of thoracic kyphosis, increase of lordosis in the
upper lumbar spine, retrolisthesis, retroversion of the pelvis,
decrease of sacral slope, extension of the hips and exion of
the knees and ankle extension, as illustrated in Figs.20.3,
20.4, 20.5. These mechanisms are rarely seen all together,
but they are present in different degrees according to indi-
Fig. 20.3 Pelvis back tilt mechanism. Increase of pelvis tilt results in
posterior placement of the sacrum related to the coxofemoral heads thus
increasing the sacrofemoral distance (red line) (original gure from
Barrey etal. [26]. Image reproduced with permission of the publisher)
Hyperlordosis
SPINE
PELVIS
LOWER LIMBS
Fig. 20.4 Sagittal imbalance and the different compensatory mecha-
nisms in the spine, pelvis, and lower limb areas (original gure from
Barrey etal. [26]. Image reproduced with permission of the publisher)
Reduction of
Retrolisthesis
Hyperextension
Pelvis backtilt
Knee flessum
Ankle extension
vidual conditions: musculature status, arthrosis, stiffness of
the spine, pain, and severity of the sagittal unbalance. Their
basic concept is to extend adjacent segments of the kyphotic
spine allowing for compensation of the elevated SVA but
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Fig. 20.5 For a given structural deformity, how pelvic retroversion
compensates for spinal deformity. Left, no pelvic retroversion and high
SVA; middle, moderate pelvic retroversion and SVA; right, high pelvic
retroversion and no SVA [11]
may potentially result in adverse effects. It is believed that
these compensatory mechanisms predispose patients to
accelerate DDD, thus leading to an increase in preexisting
sagittal imbalance [25]. In clinical practice, the angular values obtained in the radiograph help to identify regional angular alterations that may indicate imbalance. However, there is
a certain difculty in evaluating the absolute values of these
angles, since the normal range for each of these parameters
is wide [10]. For this reason, it is important to consider the
harmony of the spinopelvic balance as a whole [27], and not
just one of the parameters. In a simplied way, the harmonic
balance consists of LL proportional to the PI, while the TK is
proportional to the LL.Schwab etal. [11] suggested to maintain values of SVA <50mm, PT <25°, and correction of LL
such that LL=PI±9° in order to achieve good postoperative
result. These parameters are of utmost importance to reestablish or maintain sagittal balance in spine surgery.
Understanding the relationships between spinopelvic parameters allows the calculation of predicted lordosis for those
who have altered parameters secondary to disease, which can
then inuence surgical planning for correction to prepathological lordosis:
PI=PT+SS
Rose etal. [30] also developed a formula for predicting
the amount of lordosis needed to restore sagittal balance in
preoperative planning, which takes into account PI and TK:
LL=PI+TK−45
It is interesting to note that according to Lafage etal. [16],
no parameters in the coronal plane seem to be related to pain
and quality of life in the postoperative period. Sagittal balance, however, plays a vital role to achieve the best possible
surgical outcome.
T. A. Lins et al.
References
1. Garbossa D, etal. Pelvic parameters and global spine balance for
spine degenerative disease: the importance of containing for the
well being of content. Eur Spine J. 2014;23(Suppl 6):616–27.
2. Ismail AA, etal. Number and type of vertebral deformities: epidemiological characteristics and relation to back pain and height
loss. European Vertebral Osteoporosis Study Group. Osteoporos
Int. 1999;9(3):206–13.
3. DeWald CJ, Stanley T. Instrumentation-related complications of
multilevel fusions for adult spinal deformity patients over age 65:
surgical considerations and treatment options in patients with poor
bone quality. Spine. 2006;31(19 Suppl):S144–51.
4. Krismer M.Comment to "Sagittal morphology and equilibrium of
pelvis and spine" by G.Vaz etal. Eur Spine J. 2002;11(1):88.
5. Kumar MN, Baklanov A, Chopin D.Correlation between sagittal
plane changes and adjacent segment degeneration following lumbar
spine fusion. Eur Spine J. 2001;10(4):314–9.
6. Duval-Beaupère G, Robain G.Visualization on full spine radiographs of the anatomical connections of the centres of the segmental body mass supported by each vertebra and measured invivo. Int
Orthop. 1987;11(3):261–9.
7. Stagnara P, etal. Reciprocal angulation of vertebral bodies in a sagittal plane: approach to references for the evaluation of kyphosis
and lordosis. Spine. 1982;7(4):335–42.
8. Vialle R, Levassor N, Rillardon L, Templier A, Skalli W, Guigui
P. Radiographic analysis of the sagittal alignment and balance
of the spine in asymptomatic subjects. J Bone Joint Surg Am.
2005;87(2):260–7.
9. Legaye J, Duval-Beaupère G, Hecquet J, Marty C.Pelvic incidence:
a fundamental pelvic parameter for three-dimensional regulation of
spinal sagittal curves. Eur Spine J. 1998;7(2):99–103.
10. Schwab F, Lafage V, Patel A, Farcy JP.Sagittal plane considerations
and the pelvis in the adult patient. Spine. 2009;34:1828–33.
11. Schwab F, Patel A, Ungar B, Farcy JP, Lafage V. Adult spinal
deformity- postoperative standing imbalance: how much can you
tolerate? An overview of key parameters in assessing alignment and
planning corrective surgery. Spine. 2010;35(25):2224–31.
12. Roussouly P, Gollogly S, Berthonnaud E, Dimnet J.Classication of
the normal variation in the sagittal alignment of the human lumbar
spine and pelvis in the standing position. Spine. 2005;30(3):346–53.
13. Kobayashi T, Atsuta Y, Matsuno T, Takeda N.A longitudinal study
of congruent sagittal spinal alignment in an adult cohort. Spine.
2004;29(6):671–6.
14. Cavali PTM, et al. Correlation between symptoms and sagittal
alignment parameters in patients with lumbar canal stenosis: a casecontrol study. Columna. 2012;11(4):302–9.
15. Todd C, Kovac P, Swärd A, etal. Comparison of radiological spinopelvic sagittal parameters in skiers and non-athletes. J Orthop Surg
Res. 2015;10:162.
16. Lafage V, Schwab F, Patel A, Hawkinson N, Farcy JP.Pelvic tilt and
truncal inclination: two key radiographic parameters in the setting
of adults with spinal deformity. Spine. 2009;34(17):E599–606.
17. Pudles E, Deno HLA.A coluna vertebral: conceitos básicos. Porto
Alegre: Artmed; 2014. p.66–73.
18. Van Royen BJ, etal. Accuracy of the sagittal vertical axis in a standing lateral radiograph as a measurement of balance in spinal deformities. Eur Spine J. 1998;7(5):408–12.
19. Bridwell KH.Causes of sagittal spinal imbalance and assessment of
the extent of needed correction. Instr Course Lect. 2006;55:567–75.
20. Berthonnaud E, Dimnet J, Roussouly P, Labelle H.Analysis of the
sagittal balance of the spine and pelvis using shape and orientation
parameters. J Spinal Disord Tech. 2005;18(1):40–7.
21. Jackson RP, Kanemura T, Kawakami N, Hales C.Lumbopelvic lordosis and pelvic balance on repeated standing lateral radiographs of
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adult volunteers and untreated patients with constant low back pain.
Spine. 2000;25:575–86.
22. Boulay C, Tardieu C, Hecquet J, etal. Sagittal alignment of spine
and pelvis regulated by pelvic incidence: standard values and prediction of lordosis. Eur Spine J. 2006;15:415–22.
23. Roussouly P, Gollogly S, Noseda O, etal. The vertical projection of
the sum of the ground reactive forces of a standing patient is not the
same as the C7 plumb line: a radiographic study of the sagittal alignment of 153 asymptomatic volunteers. Spine. 2006;31:E320–5.
24. Dubousset J.Three-dimensional analysis of the scoliotic deformity.
In: Weinstein SL, editor. Pediatric spine: principles and practice.
NewYork: Raven Press; 1994.
25. Schwab F, Lafage V, Boyce R, etal. Gravity line analysis in adult
volunteers: age-related correlation with spinal parameters, pelvic
parameters, and foot position. Spine. 2006;31:E959–67.
26. Barrey C, Roussouly P, Le Huec JC, D'Acunzi G, Perrin
G.Compensatory mechanisms contributing to keep the sagittal balance of the spine. Eur Spine J. 2013;22(Suppl 6):S834–41.
27. Barrey C, Roussouly P, Perrin G, Le Huec J-C.Sagittal balance
disorders in severe degenerative spine. Can we identify the compensatory mechanisms? Eur Spine J. 2011;20(Suppl 5):626–33.
28. Merrill RK, etal. Incidence-lumbar lordosis mismatch: the importance of assessing the entire spine to achieve global sagittal alignment. Global Spine J. 2017;7(6):536–42.
29. Roussouly P, Pinheiro-Franco JL. Biomechanical analysis of the
spino-pelvic organization and adaptation in pathology. Eur Spine J.
2011;20:609.
30. Rose PS, Bridwell KH, Lenke LG, Cronen GA, Mulconrey
DS, Buchowski JM, Kim YJ. Role of pelvic incidence, thoracic
kyphosis, and patient factors on sagittal plane correction following pedicle subtraction osteotomy. Spine (Phila Pa 1976).
2009;34(8):785–91.
Patient Positioning Techniques inSpinal
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Surgery
SvenY.Vetter andUweVieweg
21
21.1 Introduction and Core Messages
The objectives of correct patient positioning are to:
• Ensure access to patient´s airway, intravenous lines
and monitor devices
• Prevent injury of anatomical structures
• Provide optimal surgical exposure
• Achieve stable positioning of the patient
The centrepiece of an operating theatre is the oper-
ating table. An operating table has the purpose to
ensure a safe and stable positioning of the patient
during surgery. Adjacent to the operating table are
ceiling mounts for the anaesthetic and surgical equipment, as well as surgical room lights. In addition a
C-arm image intensier, a microscope or an endoscope tower system may be present in the operating
theatre.
An operating table (Fig.21.1a–f) should be mobile,
radiolucent and adjustable in height, inclination and
tilt. Special operating tables with different surgical
frames and kneeling attachments have been designed
over the years to realise adequate patient positioning
and decrease intra-abdominal pressure to reduce perioperative bleeding.
21.2 Factors Inuencing Blood Loss During
Positioning
The Batson venous plexus plays an important role with
regard to blood loss during spinal surgery. The Batson plexus
consists of three parts:
– An internal venous system
– An external venous system
– A complex network of connecting or anastomotic veins
[1, 2]
The internal venous system (anterior internal veins, posterior internal veins, anastomotic veins) represents a continuous
venous pathway from the sacrococcygeal region to the base
of the skull [3]. The longitudinally travelling veins lie anterior
to the vertebral bodies, on the outer aspect of the lamina and
on the outer aspect of the transverse process. There is an
extensive anastomotic system of veins connecting the internal
and the external vertebral system and connecting both parts of
the vertebral venous system to the systematic vena cava circulation. These anatomical features need to be taken into
account when positioning patients undergoing spinal procedures. For example, placing obese patients in a prone position
can result in an increase in intra- abdominal pressure, and thus
increased intraoperative haemorrhage.
S. Y. Vetter
Division of Spinal Surgery at BG Trauma Center Ludwigshafen at
Heidelberg University Hospital, Ludwigshafen, Germany
e-mail: sven.vetter@bgu-ludwigshafen.de
U. Vieweg (*)
Department of Conservative and Surgical Spine Therapy with
Interdisciplinary Spinal Deformities Centre and Rummelsberg
Sectional Center, Hospital Rummelsberg, Schwarzenbruck,
Germany
e-mail: uwe.vieweg@sana.de
© Springer-Verlag GmbH Germany 2023
U. Vieweg, F. Grochulla (eds.), Manual of Spine Surgery, https://doi.org/10.1007/978-3-662-64062-3_21
21.3 Methods ofReducing Blood Loss
Without theUse ofFrames
This can be achieved by means of various positioning
techniques.
These include:
– The kneeling position
– The Mohammedan praying position
– The knee-chest position
– The Wayne tuck position [4–6]
149
150
c
a
b
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de
S. Y. Vetter and U. Vieweg
f
Fig. 21.1 (a–f) Operating table adjustment (height and longitudinal
adjustment, inclination—Trendelenburg, reversed Trendelenburg—tilt
right/left, ex position with key operation, beach chair position with
key operation, adjustment range under back plate and leg plate, range
for manual adjustment of upper plate)
cab
Fig. 21.2 (a–c) Operating table with back plate and head plate, various cushions and Wiltse frame© for surgery of the lumbar and thoracic spine
in the prone position
Considerable exion of the spine, hips and knees occur
during such extreme tucked positions, and this may produce
vascular and nerve compression in the popliteal compartment. An extreme exed position may also tighten the posterior paraspinal muscle. Prolonged joint exion is potentially
harmful for patients with hip or knee disorders, joint degeneration or total joint replacement [7].
On the Andrews frame, patients are positioned in a modied knee-chest position with a chest pad and adjustable tibial
support lowered to obtain 90° hip exion. The tibial support
may be adjusted to produce 60° hip exion for spinal surgery.
The frame allows the integration of the C-arm for intraoperative imaging. The usage of a Wilson frame (see Fig.21.2a–c)
is a convenient and stable method of maintaining patients in a
exed position for spinal surgery. It has two full- length curved
pads, which provide continuous support for chest and pelvis.
21.4 Methods ofReducing Blood Loss
Using Frames
An alternative option is the Jackson surgical table. It can be
rotated in an angle of 360°, allowing combined approaches.
Positioning devices can be used to offset the abdominal
decompression and preserve lordosis [8]. Many such devises
are available (see Fig.21.2a–c), including:
– The Relton-Hall frame
– The Canadian frame (Hastings)
– The Andrews frame
– The Wilson frame [8–10]
21.5 The History oftheOperating Table
The earliest operating furniture took into account the anatomical exion points of the human body—in the hip and
knee regions. The rst operating tables were wooden and in
some cases were particularly elaborately designed.
21 Patient Positioning Techniques inSpinal Surgery
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Subsequently developed operating tables were made out of
metal and with mobile castors. Important features of these
tables were that they allowed a Trendelenburg and reversed
Trendelenburg positioning of patients. This was particularly
important in the early days of surgery as there were very few
other intensive care techniques that could be used to control
circulation in the intraoperative situation. The so-called
“large Heidelberg” operating table was the rst that actually
met all requirements for a system that could be used for general surgery. Contemporary mobile operating tables consist
of a basis, an operating table column and the table top. Due
to the provision of upper and lower backplates, seat plate,
separate leg plates and hydraulic height adjustment systems,
the ideal positioning of patients can be achieved for all sorts
of surgical interventions. There were two versions of such
operating tables that competed against each other: the
Maquet 1120 system (originally designed in 1964) and the
battery-powered hydraulic Heidelberger 1130 (1984–2003).
The top was divided into eight segments and was radiolucent; the upper back section was motor-operated.
21.6 Positioning Equipment andAids
• Humerus support plates
• Different clamps
• Head rest for neurosurgery
• Carbon bre plate
• Thoracic supports
• Fixtures and head supports
• Ankle and knee cushion, tube pillow, wedge pillow
• Chest roll
• Closed and open head ring, gel-foam
• Operating table sections and different mattresses.
21.8 Special Equipment
For certain spinal surgical procedures, special equipment is
required. This can include:
• Motor-operated headrest adjustors
• Spinal support systems/head extenders for intraoperative
repositioning and xation during surgery to the dorsal
ventral spine in patients with a halo ring
21.9 Patient Warming Systems [11, 12]
There are various items of positioning equipment and aids
available for supporting the positioning of patients for spinal
surgical procedures (Fig.21.2a–c):
• Pads with viscoelastic foam cores (such as head cushions,
head rings, special cushions, wedge cushions, rolls and
half-rolls, double-wedge cushions, knee positioning cushions, heel positioning cushions, etc.)
• Gel-lled pads
• Operating table overlays
• Universal positioning aids
• Universal frame system
21.7 Operating Table Accessories
The following accessories can be attached to an operating
table:
• Head xation piece
• Headrests
• Arm positioning devices
• Arm protectors
• Lateral support and multi-lateral support
• Anaesthesia screens
• Arm straps for anaesthesia screens
• Leg and body strap
• Armboards with clamps
• Radial setting clamps
There is the risk of the development of hypothermia in
patients under anaesthesia, particularly during prolonged surgical procedures, which can have negative consequences for
the cardiovascular system, wound healing and blood coagulation. The onset of hypothermia can occur within 60min of the
induction of anaesthesia. During this period, the body temperature of the patient is prone to decrease. If hypothermia is
not prevented, the relative risk of serious complications
increases by a factor of 3.25 for wound healing impairments,
4.49 for cardiac problems and 1.33 for increased haemorrhaging requiring blood transfusion in comparison to a situation in
normothermia [11]. Modern body temperature management
systems consist of a heat generator, warming blankets and
warming underlays. These allow the body temperature of
patients to be maintained in the normothermic range. In addition, there are various patient warming systems available
from a range of manufacturers that include systems for warming blood and uids for infusion.
21.10 Complications ofPositioning inSpinal
Surgery
The potential complications that can arise in connection with
patient positioning for spinal surgery can be as follows:
• Injury to the lateral femoral cutaneous nerve
• Direct pressure on the eye
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