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terval. Mobilize the psoas muscle off the vertebral bodies using the Cobb
elevators, and isolate and ligate the segmental vessels that cross the surgical field. This approach is preferred for levels T11-L1.
Vertebral Corpectomy
The vertebral corpectomy is indicated to relieve anterior compression of
spinal cord by tumor or infection, or to remove incompetent or fractured
bone in preparation for reconstruction. Corpectomy may be en bloc or intralesional (piecemeal), depending on the goal of surgery. If local control is
not an issue, as in disseminated metastasis or in radiosensitive tumors
where the aim is to debulk the tumor prior to radiation therapy, then intralesional corpectomy is often sufficient. Here, following an exposure appropriate to the zonal location of the tumor, a piecemeal resection is car-
ried out to achieve decompression of the cord and debulking of the tumor
mass. This is followed by appropriate instrumented stabilization of the
spine (Fig. 20–3).
If a curative resection is being attempted, an en-bloc excision should be
carried out. The first step to achieve this is a posterior approach to expose
the spinous processes, laminae, facets, and transverse processes of the
level affected, as well as the levels above and below that are to be included
in the instrumentation. Both superior and inferior articular facets of the affected vertebra are exposed with a curet, as well as by piecemeal bites off
adjacent overlying facets and laminae using Kerrison and Lexel rongeurs.
A careful flavectomy is carried out using a combination of blunt dissection
with a Penfield or curet and bites with a Kerrison rongeur. The spinal
canal, cord, and nerve roots must be carefully defined before attempting
corpectomy. Laminectomy and facetectomy of the affected level are then
performed, and the pedicles and transverse processes are excised flush
with the posterior vertebral body, taking care not to breach the tumor
tissue. The cord and nerve roots are then protected with a nerve root retractor or Penfield as the posterior annulus is sharply incised above and below
the affected level. After ensuring adequate decompression of the cord posteriorly, the appropriate posterior instrumentation is applied, graft placed,
and the wound closed. The patient is flipped into a decubitus position
after closure of the wound.
After the appropriate anterolateral approach to the affected vertebrae,
the segmental vessels are ligated and the vertebral body exposed by a com-
bination of blunt and sharp dissection. The healthy discs above and below
the lesion are excised, using a scalpel for initial incision, followed by pituitary rongeurs, cobs, and curets to expose the end plates of the healthy
vertebrae above and below. The affected vertebra is now sufficiently free to
be delivered en bloc into the wound, without breaching the tumor surface.
When the tumor predominantly affects one side of the vertebral body and
pedicle, it may be possible to resect extensively along the uninvolved side
and deliver the vertebra by rotating it around the cord without breaching
the tumor surface. Note, however, that the bony “ring” has to be broken
somewhere for the vertebra to be delivered from around the thecal sac, and
in some cases the tumor surface may be exposed at that point.
After corpectomy, reconstruction options to fill the ensuing space include tricortical iliac crest autograft, femoral shaft allograft, cage devices,
and ceramic or metal prosthesis with or without methylmethacrylate
augmentation. This is supplemented by anterior or posterior instrumentation as appropriate. Our preference is to use tricortical iliac crest autograft
with anterior and posterior instrumentation or a titanium mesh cage with
posterior instrumentation.
Closure
A 28- to 32-French chest tube is placed so the tip is at the apex of the lung.
If excessive bleeding is expected from raw surfaces, a second chest tube
may be placed. This is tunneled through subcutaneous tissue. The lung is
reinflated and the ribs approximated with No. 1 absorbable suture. If the
diaphragm has been incised, it is carefully repaired using the silk tags for
guidance. The intercostals, serratus anterior, latissimus dorsi, trapezius,
and, if the abdomen has been opened, the transversalis fascia and the obliques are closed in layers with No. 1 suture. Subcutaneous 4–0 absorbable
suture is used for skin. The chest drain is secured to skin and connected to
water sealed drainage.
Pitfalls
1. Do not initiate definitive care without a diagnosis.
2. Do not attempt to resect a highly vascular lesion, (renal cell,
melanoma, etc.) without prior angiography and embolization.
3. Provide sound fixation for every patient who warrants surgery. Avoid
inadequate treatment of any patient who may outlive the predicted
survival and the spinal construct.
4. Adhesions to great vessels by neoplastic or infected tissue make dissection difficult, and predispose to vessel injury and catastrophic
hemorrhage. Preoperative angiography may clarify issues brought up
on MRI.
Complications
1. Wound infection, particularly of dorsal incisions and in irradiated tissues
2. Pneumothorax, hemothorax
3. Atelectasis, pneumonia
4. Loss of fixation, pullout, and instability
5. Dural tear and/or neurologic injury
6. Hemorrhage, disseminated intravascular coagulopathy
Postoperative Care
1. Chest x-ray in the postanesthesia care unit (PACU) and every other day
thereafter to rule out pneumothorax.
2. Intravenous antibiotics until all indwelling catheters and drains have
been removed.
3. Remove chest tube when drainage is less than 100 mL over 24 hours.
4. Encourage ambulation as tolerated from the first postoperative day.
5. Bracing (molded TLSO) is used routinely for 3 to 6 months after
surgery.
6. Mechanical means of thromboprophylaxis such as thromboembolic
disease (TED) stockings, pneumatic antiembolic (PAS) stockings, and
early mobilization.
Suggested Readings
McLain RF. Endoscopic assisted decompression for metastatic thoracic
neoplasms. Spine 1998;23:1130–1135.
McLain RF, Weinstein JN. Tumors of the spine. Semin Spine Surg
1990;2:157–180.
McLain RF, Weinstein JN. Tumors of the spine. In: Herkowitz H, Garfin S,
Balderston R, Eismont F, Bell G, Wiesel S, eds. Rothman-Simeone The
Spine. 4th ed. Philadelphia: WB Saunders; 1999:1171–1206.
Webb JK. The spine. In: Colton CL, Hall AJ, eds. Atlas of Orthopaedic Sur-
gical Approaches. Butterworth Heinemann; 1994:97–119.
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21
Posterior Techniques for Thoracic Disc Disorders
Raj Murali
Goals of Surgical Treatment
The goals of the transpedicular microsurgical approach are to remove a soft
or a hard herniated thoracic disc and decompress the spinal cord and/or
the nerve root.
Diagnosis
About 35 % of patients present with complaints of a radiating pain along
the chest wall in the distribution of an intercostal nerve. In acute thoracic
disc herniations, spinal pain may be experienced at the appropriate level.
Central and paramedian disc herniations cause spinal cord compression.
This may present as different types of myelopathy. Spastic paraparesis or
Brown-Séquard syndrome may occur. Chronic thoracic disc herniations
may not cause any pain at all and may occur only with neurologic deficits.
The best diagnostic tests to confirm the diagnosis are magnetic resonance
imaging (MRI) and computed axial tomography (CAT) scan. Sagittal views
of an MRI scan can serve as a screening test for viewing the entire thoracic
spine and correctly localize the site of a herniated disc. Select axial views
are then obtained at the suspected site. An MRI scan is also very useful in
giving information regarding spinal cord compromise, such as edema, displacement, myelomalacia, and syrinx formation. The scan is usually done
with and without contrast and with all the usual sequences.
High-resolution computed tomography (CT) scans are also recommended once the site of thoracic disc herniation has been revealed by the
MRI scan. CT scan will reveal information, such as calcification in the
herniated disc and the relationship of the disc herniation to bony anatomic
structures, such as the pedicle, which has important surgical implications
(Figs. 21–1 and 21–2).
Axial images of CT and MRI scans are carefully reviewed to assess the
mediolateral extent of disc herniation. Large calcific and centrally situated
herniations are best managed by anterior transthoracic approaches. Paramedian and lateral herniations can be managed by the posterolateral transpedicular approach. Occasionally, in difficult cases, CT myelogram is also
of value.
Indications for Surgery
1. Neurologic deficits, such as paraparesis.
2. Pain, especially radiating radicular pain.
3. Small herniated discs seen on a routine MRI scan of the thoracic spine
do not require surgery.
4. Severe neurologic deficits seen in the presence of a small thoracic disc
herniation need a full neurologic workup to exclude entities such as
multiple sclerosis, motor neuron disease, and spinal cord arteriovenous malformation.
Contraindications
A large centrally located calcified disc with significant spinal cord compression and serious neurologic deficits, such as paraparesis (Fig. 21–3).
Advantages
1. The transpedicular approach is a direct x-ray-controlled approach,
which can be performed by most spinal surgeons.
2. Does not require a thoracotomy or the need for a thoracic surgeon.
3. No spine stabilization is required.
Disadvantages
1. The angle of approach is such that this procedure is unsuitable for
large centrally located and especially calcified herniated discs.
2. Some modifications of the transpedicular approach are required, espe-
cially in obese patients, to improve visualization. This usually involves adding a costotransversectomy to improve visualization.
3. Intraoperative radiographs or fluoroscopy is necessary for correct lo-
calization of level and appropriate pedicle.
Procedure
Preoperative Preparation
1. Corticosteroids are given, especially for patients presenting with my-
elopathy. Dexamethasone, 10 mg, is used. Solumedrol protocol, such
as in spinal cord injury, is used in patients with severe myelopathy.
This usually consists of administering methylprednisolone 2.5 g intravenously as a bolus before the commencement of the procedure followed by an infusion of methylprednisolone 10 g over a period of 23
hours given through an infusion pump.
2. Prophylactic antibiotics are used.
3. Somatosensory evoked potential monitoring is utilized and baseline
parameters are established at the commencement of the case.
4. The patient is positioned prone on a laminectomy frame. Endotracheal
anesthesia is used. The x-ray machine or C-arm fluoroscope is positioned and adjusted to clearly view the affected vertebral level in the
anteroposterior view. One should make sure that the metal bars from
the table or laminectomy frame does not obscure viewing the desired
area. The pedicle below the affected disc should be visualized. Skin is
then marked to make a 10-cm incision centered at the affected disc.
5. The paraspinous muscles on the side of herniation are mobilized with
cautery. Complete muscle relaxation is provided by the anesthesiologist. The paraspinous muscles are dissected as far laterally as possible
to expose the facet joints and the transverse processes. The paraspinous muscles are then retracted by a self-retaining retractor.
Bone Removal
1. X-rays are used to again correctly localize the level and locate the
pedicle below the affected disc. For example, if there is a T7-T8
herniated disc in the right lateral location, the right T8 pedicle is the
one to be drilled. It should be noted that in the thoracic vertebrae, the
pedicle is located in the superior part of the vertebra. Therefore, in a
T7-T8 herniated disc the T8 pedicle is the one that is located closest to
the disc. This is the pedicle to be drilled.
2. First curet the lateral part of the ligamentum flavum from the lamina
above and below. Then remove the adjacent halves of the lamina above
and below in its lateral part only. Do not disturb the medial part of the
lamina or midline spinous processes and ligamentous structures. The
laminae can be removed with the help of a drill.
3. Remove the facet joint capsule and expose the entire facet joint. A 5mm steel bur is used to drill the facet joint and enter the appropriate
pedicle. If in doubt, the patient is x-rayed again to correctly identify
the pedicle. The center of the pedicle is cored out with the drill, and
the thin shell is then removed with small rongeurs (Fig. 21–4).
4. At this point, the lateral dura will be in view. As the pedicle is drilled
flush with the body of the vertebra, epidural veins will be encountered
and require coagulation with bipolar cautery and division.
5. Superiorly, the axilla of the nerve root will come into view, and the
facet should be removed to completely uncover the axilla and the proximal part of the nerve root. The herniated disc above the pedicle will
start to appear at this time (Fig. 21–5). Venous bleeding could be troublesome, but is usually controlled with bipolar cautery or Gelfoam.
6. The microscope is now swung into position. A combination of angling
the microscope and tilting the operating table side to side will give optimal view into the ventral epidural space. A smaller drill bit is used
now to further remove the pedicle to enhance the view. More drilling
may be needed later. A diamond bur may be required if the dura is adherent to the herniated disc.
Removal of the Disc
Through the microscope, one should clearly visualize the lateral dura on
the medial aspect, the axilla of the nerve root on the superior aspect, the
vertebral body, and the ventral epidural space on the anterior aspect
(Fig. 21–6). The herniated disc will be seen as a pearly white structure superiorly or superomedially. Fragmented, soft extruded disc material can be
delivered with a nerve hook and removed. Microcurets, angled up and
down, are invaluable tools for the discectomy. These angled microcurets
can be inserted through the annulus into the disc space, and the disc material can be mobilized and delivered for removal (Fig. 21–7). The annular
opening can be enlarged with a No. 11 knife. Angled down-pointing microcurets are the instrument of choice for delivering disc fragments from the
paramedian location by pushing them away from the dura. The intercostal
nerve can be gently manipulated to remove disc fragments from underneath.
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21 POSTERIOR TECHNIQUES FOR THORACIC DISC DISORDERS
101
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Figure 21–1
Axial view of computed axial tomography (CAT) scan showing a laterally placed
calcified thoracic disc herniation (arrow).
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102
SECTION II THE THORACIC SPINE
Eurostile
A
Figure 21–2
(A) Sagittal view of magnetic resonance imaging (MRI) scan showing a large midline thoracic disc herniation with severe spinal cord compression. (B) Axial view of MRI
scan of the same patient showing the disc herniation to be large and occupying the entire width of the spinal canal with severe cord compression (arrows). This is an example of contraindication for transpedicular approach. Instead, the anterior transthoracic approach should be used.
B
Eurostile
21 POSTERIOR TECHNIQUES FOR THORACIC DISC DISORDERS
103
■
Area of
bone removal
A
Figures 21–3
(A,B) Transpedicular approach. Shaded area shows area of bone removed.
Transpedicular approach
T7
T8
B
Exposure of
herniated disc
Center of pedicle
cored with
drill
Area of
drilling
and bone
removal
Cord
T7
T8
Figure 21–4
Exposure of herniated disc, nerve root, and dura after bone removal.
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104
SECTION II THE THORACIC SPINE
Eurostile
Figure 21–5
Shaded area shows the area of drilling and bone removal.
Thin
pedicle
and remove
Smaller drill bit now used
to further remove the pedicle
Annulus
incised
T7
T8
Figure 21–6
After completion of transpedicular approach, the relationship of the dura
and nerve root to the disc can be appreciated.
Microcurets
deliver
disc
fragments
Eurostile
Figure 21–7
Discectomy is accomplished.
21 POSTERIOR TECHNIQUES FOR THORACIC DISC DISORDERS
105
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Additional Bone Removal
1. At this juncture, a decision is made whether to extend the pedicular
drilling into the body itself and create a trough in the lateral part of the
vertebral body into which the disc fragments can be pushed down for
removal. This maneuver is recommended for calcified discs, especially closer to the midline. This additional bone removal is not necessary for laterally placed soft disc herniations. The discectomy is
completed by irrigating out the disc space of any loose fragments. The
evoked potential tracings are periodically checked to recognize any
spinal cord compromise. At the end of the procedure, the nerve root
and the dura should be well decompressed.
2. Any damage to arteries accompanying the nerve roots should be
Closure
1. Hemostasis is obtained with bipolar cautery and Gelfoam.
2. Paraspinous muscles and fascia are reapproximated, and the skin is
closed in routine fashion. No drain is required. Prior to closure, evidence of a cerebrospinal fluid (CSF) leak is sought, especially at the
nerve root axilla.
3. Small leaks of CSF are closed with a muscle plug and Gelfoam. Larger
leaks may require suturing of dura and fibrin glue sealant.
4. Blood loss is usually minimal.
Modifications
1. In very obese patients, the exposure can be significantly enhanced by
cutting across the paraspinous muscles with cautery at the level of the
discectomy. The cut muscle can be resutured at the end.
2. In obese patients, the exposure can also be improved by removing the
transverse process with the drill up to the rib. This will give a wider
angle of exposure into the ventral epidural space, allowing a better
view toward the midline.
Tips and Pitfalls
1. Obtain good preoperative imaging studies to clearly see the thoracic
disc herniation, its location, and whether it is calcified.
2. Good intraoperative x-rays or fluoroscopy is essential; check the
equipment before draping the patient. Clearly visualize and locate the
level of disc herniation and the pedicle below the affected disc that is
to be drilled.
3. Microscope, fine drills, and microcurets are invaluable tools.
4. Never retract the spinal cord. Remove bone as required to improve exposure.
5. Changing the angle of the microscope and tilting the operating table
from side to side greatly enhances the exposure.
6. Exposure is more difficult in obese, stocky, or muscular patients.
7. While excising the disc, all the movements must be away from the spinal cord.
8. If the disc herniation is calcified, adherent to dura, or midline in location, the transpedicular approach may not be suitable. Be prepared to
change to a transthoracic anterior approach.
9. Be gentle. Do not apply the techniques of lumbar disc surgery for
herniated thoracic discs.
bone causing neural compression. If such is found, the patient should be
returned to the operating room for removal of such fragments either by the
transpedicular or transthoracic route. Evoked potential tracing from the
procedure should also be checked for changes. If no compressive
pathology is found, the patient should be continued on corticosteroids and
observed for improvement, which may occur slowly.
The factors usually associated with postoperative neurologic worsen-
ing are as follows:
1. Old age.
2. Severe preoperative myelopathy.
3. Abnormal signal from the spinal cord in the preoperative MRI scan at
the level of compression from the disc. This usually indicates spinal
cord edema or myelomalacia.
4. Diabetes mellitus.
5. Severe hypertension and other vascular diseases causing compromise
to spinal cord blood supply.
6. Intraoperative hypoxia and hypotension.
The thoracic spinal cord blood supply is reinforced segmentally by
arterial branches accompanying nerve roots. The artery of Adamkiewicz is
one such important radicular artery usually supplying the spinal cord at
T9 level on the left side. However, the vessel is variable in location. As a
general rule, while performing transpedicular approach, especially in the
lower thoracic spine, damage to these radicular arteries should be avoided
to prevent spinal cord infarction.
CSF Leak
CSF leakage through the wound is best treated by inserting a lumbar spinal
CSF drain and diverting the fluid for a few days. If the CSF leak persists,
direct reexploration and repair is required.
Wound Infection
Any evidence of wound infection should be treated aggressively with reopening, debridement, drainage, and appropriate antibiotics. Early recognition and aggressive treatment of wound infection is necessary to prevent
more serious complications, such as osteomyelitis, discitis, and epidural
abscess.
Postoperative Care
As the transpedicular approach requires only removal of bone at one segment on one side, no postoperative bracing is required. Postoperative pain
is managed with appropriate analgesics. Routine daily activities are permitted immediately, but vigorous activities and exercises should wait for 6
weeks until the wound heals securely. No postoperative antibiotics are
used. The sutures are removed in 1 week. A postoperative MRI is obtained
in 6 weeks to check the discectomy site for residual fragments or any evidence of spinal cord compression.
Suggested Readings
Bauer R, Kerschbanner F, Poisel S. Atlas of Spinal Operations. New York:
Thieme; 1999:317, 324.
Patterson RH Jr, Arbit E. A surgical approach through the pedicle to pro-
truded thoracic discs. J Neurosurg 1978;48:768–772.
Complications
Neurologic Worsening
If the patient is neurologically worse after surgery, immediately administer
methylprednisolone as mentioned earlier. Immediate MRI scanning
should then be done to rule out residual or recurrent disc fragments or
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SECTION II THE THORACIC SPINE
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22
Posterior Column Shortening for
Scheuermann’s Kyphosis
An Innovative One-Stage Technique
Alberto Ponte
Goals of Treatment
1. Correct structural thoracic or thoracolumbar hyperkyphosis:
a. By a single-stage procedure.
b. By substantial shortening of the posterior spine.
2. Restore a normal sagittal profile and balance:
a. By correcting to optimal physiologic ranges of 30 to 40 degrees
(without inducing junctional kyphosis).
b. By a harmonious distribution of correction over the entire curve.
3. Provide immediate and long-term stability of correction:
a. By avoiding anterior column disruption, thus preserving the im-
mediate load sharing capacity.
b. By fusion and a fully segmental anchorage of instrumentation.
Diagnosis
The diagnosis of typical Scheuermann’s kyphosis is based on radiographic
changes of irregular vertebral end plates, narrowing of intervertebral disc
spaces, wedging of at least 5 degrees of three contiguous vertebrae, and
Schmorl’s nodules. In more recent years the wedging of 5 degrees or more
of only one vertebra has been considered sufficient for the diagnosis. A disease affecting a short segment of the spine induces a long segment deformity. In atypical forms there is an absence of end plate irregularities and/or
vertebral wedging.
On clinical examination both forms present with a rigid thoracic or
thoracolumbar kyphosis greater than 45 degrees, which appears in adolescence and resists forced extension. This differentiates these patients from
flexible postural roundbacks. A lateral radiograph in hyperextension over
a plastic wedge, placed just below the apex of the curvature, confirms a
fixed deformity. There is a compensatory, nonstructural increase in lumbar
lordosis, whereas cervical lordosis is usually decreased.
Mechanics of Kyphosis Correction
Surgical correction is obtained by combining anterior lengthening and
posterior shortening of the spine. Each technique, however, either primarily lengthens the anterior spine or primarily shortens the posterior
spine. The innovative posterior technique, developed in 1987 and described here, is the only one correcting almost entirely by shortening the
posterior spine. This procedure also produces the longest moment arm
for posterior corrective forces among all techniques. Much lesser forces
are therefore needed to obtain the same bending moment, with consequently much smaller loads on the bone/metal interface. Anterior
column integrity, with the anterior longitudinal ligament and anterior
discs acting as a tension band, is essential for producing the mechanical
advantage.
Essential Principles of the Innovative Posterior Technique
1. A substantial shortening of the posterior spine through the closure of
wide intersegmental resections (osteotomies) at every level within the
deformity.
2. A construct with bilateral, fully segmental (not multilevel) anchorage,
capable of achieving a harmonious correction by proportionally modulated compression forces (no excessive stress concentrations).
3. An intact anterior column (see above).
Indications
1. Scheuermann’s kyphosis: Surgical treatment should be performed
only in patients who have reached complete skeletal maturity. Before
that a nonoperative treatment can provide satisfactory results, with
severe deformities being corrected by plaster casts. Indications for
surgery are more restrictive than in scoliosis and should be based on an
individualized evaluation of the patient, and not on a numerical threshold of x-ray degrees. Indications include significant pain, adult progression, severity, prevention of further increase in deformity, and unacceptable appearance problems with psychological distress. There
are no limits of severity for the innovative technique.
2. Kyphosis from severe osteopenia: Long segment kyphosis from postmenopausal osteoporosis, of a severity interfering with function (100
degrees or more) and with pain unresponsive to conservative treatment, has been successfully treated with the innovative technique (see
Fig. 22−8). In this pathology, a second-stage augmentation fusion after
4 months was thought to be indicated to create a thicker fusion mass
and secure stability of correction. Implanting an osteoinductive
growth factor (e.g., rhBMP-2) at the initial surgery, and in addition to
the autogenous bone graft, may produce the same result.
3. Kyphosis from ankylosing spondylitis: Selected cases lacking
complete obliteration of disc spaces and a fully developed bamboo
spine. The distinctive biomechanical properties of this technique
made it possible to achieve significant corrections, directly at the site
of deformity.
Contraindications
1. Poor general health conditions.
2. Skeletally immature spines (nonoperative treatment is preferred).
3. Presence or history of neurologic symptoms or an increased interpedicular distance on radiographs: more in-depth investigations are
required [e.g., magnetic resonance imaging (MRI), myelogram, selective arteriography].
4. Anterior discectomies: they alter the mechanics of correction (see
above).
Advantages
1. A single-stage, posterior-only procedure.
2. A significant biomechanical advantage (see above) resulting in:
a. Increased capability to overcome stiffness (superior corrections in
very rigid deformities).
b. Reduced risk of bone/metal interface and implant failures.
c. Successful use in osteopenic spines.
d. Successful use in deformities of greatest magnitude.
3. Increased safety: shortening the posterior spine is safer than lengthening the anterior spine.
4. A gradual correction (no sudden cantilever reduction), taking full
advantage of viscoelasticity.
5. A segmentally controlled, harmonious correction.
6. A correction to optimal physiologic ranges of 30 to 40 degrees.
The advantages of this technique as opposed to the combined anterior/
posterior technique are:
1. Less invasive, less complex, more cost-effective.
2. A lower failure rate (junctional kyphosis, implant failures, pseudoarthrosis).
3. No complications due to thoracotomy or thoracoscopy.
4. No surgical interference with anterior blood supply to spinal cord.
5. No need for anterior column reconstruction.
6. No need to limit the amount of correction.
7. More patient and surgeon friendly.
Disadvantages
More sites of vertebral canal invasion by sublaminar hooks.
Procedure
1. Fusion/instrumentation levels: The cranial limit of the construct for
thoracic as well as thoracolumbar kyphosis should always include T1.
Even by stopping at T2, there is the risk of cranial junctional kyphosis.
The caudal limit is determined by the first lordotic disc (open anteriorly) on lateral standing films, which must always be included. In
thoracic kyphosis the area extends from T1 to L1 or L2, in thoracolumbar kyphosis from T1 to usually L3. The presence of a structural scoliosis may require a further caudal extension.
2. Approach: A posterior midline incision is made, encompassing the deformity. The subperiosteal exposure should include one vertebra
above and one below the fusion levels previously determined.
Eurostile
22 POSTERIOR COLUMN SHORTENING FOR SCHEUERMANN’S KYPHOSIS
107
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Pedicle
T9
Spinal
cord
Resections for
caudal-most
hooks
T10
Area of bone
resection
T11
T12
L1
Pedicle
T10
T11
Sites after
complete
resection
T12
L2
Figure 22–1
Broad posterior resections of bone (shaded parts) are performed at every inter-
segmental level of the entire area of fusion/instrumentation.
L1
Figure 22–2
Posterior view showing three levels of completed resections (osteotomies), consisting in removal of spinous processes, wide facetectomies, and partial resection
of inferior and superior borders of laminae. The ligamentum flavum is entirely removed at all levels.
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Figure 22–3
Lateral view showing the gaps resulting from the osteotomies. Correction is achieved by closing these gaps
through segmentally applied compression forces.
SECTION II THE THORACIC SPINE
Eurostile
T7
Figure 22–4
Oblique view showing the three apical vertebrae after the completion of bony resections (osteotomies). Apically oriented supra- and infralaminar hooks are
shown on one side. The apical vertebra is the only one that is left uninstrumented.
Spinous
processes
partially
removed
T8
T9
AB C D
Figure 22–5
Schematic representation of reduction of kyphosis. (A) Thoracic hyperkyphosis (T2-T12) after the completion of osteotomies at every intersegmental level. (B) The fully
segmental, semirigid rod/hook compression system has been anchored to the kyphotic spine from T1 to L1. Corrective compression forces have not yet been applied. (C)
Sequential, convergent compression forces are applied to the hooks on both rods, beginning at the apex and continuing to both ends of the construct. As the compression
system shortens, the semirigid rods and the kyphotic spine straighten out. (D) Posterior view showing the fully segmental hook pattern of the construct and two transverse
connectors.
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22 POSTERIOR COLUMN SHORTENING FOR SCHEUERMANN’S KYPHOSIS
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