The midline and lateral parascapular extrapleural exposures

The midline and lateral parascapular The midline and lateral parascapular extrapleural exposures. extrapleural exposures.

Advantages, disadvantages and stabilization techniquesAdvantages, disadvantages and stabilization techniques

GEORGE SAPKASASC. PROFESSOR

1st Orthopaedic DepartmentMedical School-Athens University

Attikon Hospital

Metropolitan Hospital

Athens Greece

The cervicothoracic junction (CTJ) is a unique region in the spine.

Biomechanically, it has unique mechanical properties because of the transition between the cervical and the thoracic spine.

The CTJ represents a region that transitions from the fairly mobile cervical spine to the fairly rigid thoracic spine

An HS, et al. Spine 1994

The thoracic spine is immobile because of the rib cage, which limits the mobility significantly.

In addition, it represents a transition from the lordotic cervical spine to the kyphotic thoracic spine

An HS, et al. Spine 1994

Radiographically, it is a region that is difficult to image, particularly in traumatic injury.

Surgically, it may be difficult to access this region because of the manubrium, sternum, and neurovascular structures in the region.

Anatomically, the CTJ posterior has characteristics that pose special considerations to spinal instrumentation.

Strictly speaking, the CTJ should involve the C7 vertebra, the T1 vertebra, the disc between these two vertebrae, and their associated ligaments.

C7

T1

Other investigators include the T2 and sometimes the T3-T4 vertebrae when discussing the CTJ.

C7

T2T3

C6

T1

Le Hoang et al, Neursurg 2003Frank L Acosta et al, Spine, 2007

T4

Lesions involving the T2 and T3 vertebrae often face similar difficulties for getting access to them through an anterior approach.

C7T1T2T3

C6

In addition, many of the spinal fusion constructs of the CTJ often involve the T2 or T3 vertebra, and for these reasons, the CTJ can be defined as the region involving the C7 to T3 vertebrae.

As a result, this puts significant stress on the CTJ in the static and dynamic states. Disruptions to the structures in this region can thus lead to instability.

An HS, et al. Spine

Common causes of instability include:

An HS, et al. Spine 1994Yasuoka S, et al. J Neurosurg 1982Steinmetz MP, et al. J Neurosurg Spine 2006.Schlenk RP, et al Neurosurg Focus 2003.

Trauma Trauma

TumorTumor

Pneumon’s metastasisPneumon’s metastasis

Post-laminectomy instabilityswan-neck deformity

Iatrogenic causesIatrogenic causes

Trauma Trauma to the to the

cervicothoracic junctioncervicothoracic junction

Trauma to the CTJ ranges from 2% to 9% of all cervical spine trauma

Nichols CG, et al Ann Emerg Med 1987.Evans DK. J Bone Joint Surg Br 1983.Amin A, et al J Spinal Disord Tech 2005

C7

T1

Especially important is that a significant number of CTJ injuries are missed during the initial evaluation Injuries to the CTJ usually involve fractures or dislocations Ligamentous injuries, burst fractures, and facet fractures are common causes of fractures and dislocations.

An HS, et al. Spine 1994Amin A, et al J Spinal Disord Tech 2005.Chapman JR, et al J Neurosurg 1996Sapkas G, et al Eur Spine J 1999

Posterior fixation is performed in almost all cases, and this may be supplemented with anterior fixation

An HS, et al. Spine 1994Chapman JR, et al J Neurosurg 1996Sapkas G, et al Eur Spine J 1999

Tumors Tumors of the of the


Tumors of the CTJ are a common cause of instability in the region.

Metastatic lesions are much more common than primary tumors in this region.

M. Riz.

F 41

15-6-1997

Chondrosarcoma

Primary tumors of the CTJ may include:

angiosarcoma chordoma LymphomaplasmacytomaSchwannomaOsteosarcomagiant cell tumor

An HS, et al. Spine 1994Le Hoang, et al Neurosurg Focus 2003

Cavernous hemagiosarcomaCavernous hemagiosarcoma

Metastatic lesions include: distant metastases (eg, prostate, breast) and

local extension of tumor

Le Hoang, et al Neurosurg Focus 2003Mazel C, et al. Spine 2004

Pneumon’s metastasis

A pancoast tumor often extends into the junction between the rib and the vertebral body, but the vertebra is not always involved.

Pancoast Pancoast

Other local tumors include:

thyroid and

esophageal tumors that erode into the vertebrae of the CTJ

Mazel C, et al. Spine 2004Ulmar B, et al Acta Orthop Belg 2005

Pneumon’s metastasisPneumon’s metastasis

Surgical treatment depends on :

the tumor type

life expectancy of the patient,

elements that are involved.

Factors for evaluationFactors for evaluation::

The biology of the tumorThe biology of the tumor

The locationThe location

The painThe pain

The neurologic deficitThe neurologic deficit

The spinal instabilityThe spinal instability

Life expectancy Life expectancy

Overall condition of the patientOverall condition of the patient

Aboulafia A. Levine A., OKU Spine 2, 2004

Weinstein Boriani Biagnini Weinstein Boriani Biagnini Surgical classification systemSurgical classification system

Weinstein et al, 21st ISSSL annual meeting 1994

The two strategies are :

palliativecord decompression and spine stabilization versus

curative with en bloc radical resection of the tumor and stabilization

Mazel C, et al. Spine 2004

An HS, et al. Spine 1994Mazel C, et al. Spine 2004

A decompression strategy usually involves :

laminectomy supplemented by posterior fusion

A posterior procedure may also be used for:

resection of tumors involving the anterior elements, such as through a transpedicular approach or costotransversectomy, thus avoiding the more morbid anterior approaches

Le Hoang, et al Neurosurg Focus 2003

En bloc resection of local extension from tumors like a pancoast tumor often involves vertebrectomy, and may include an anterior approach



Other conditions Other conditions that affect the that affect the


OsteomyelitisTBC

TBC has a predilection to the upper lobe of the lung; therefore, spread to the CTJ is not uncommon.Instability occurs when there is destruction of the anterior column. Progressive kyphosis occurs as the mobile cervical spine topples over the thoracic spine

Mihir B, et al Spine 2006TBCTBC

Ankylosing spondylitisIt predisposes the spine to traumatic fractures and dislocation as well as to several deformities

Fox MW, et al. J Neurosurg 1993

Iatrogenic instabilitymultilevel laminectomy in the cervical spine in children predisposes the CTJ to instability

laminectomy across the CTJ without instrumentation tends to introduce instability to the CTJ

Yasuoka S, et al J Neurosurg An HS, et al Spine

Posterior approach Posterior approach to the to the


Midline procedureMidline procedure

Standard midline posterior approachis useful for :

A laminectomy for decompression or for

Tumors located in the posterior column.

Decompressive laminectomy

POSTERIOR CERVICO-POSTERIOR CERVICO-THORACIC FIXATIONTHORACIC FIXATION

Screw positioningScrew positioning CC44--55--6 6 screws screws are are into the lateral massinto the lateral mass

CC7 7

Lateral mass implantation Lateral mass implantation

or or

Pedicle implantationPedicle implantation

TT11-T-T22-T-T33-T-T44-T-T55 are are into the pedicleinto the pedicle

LATERAL MASS SCREW LATERAL MASS SCREW FIXATION TECHNIQUESFIXATION TECHNIQUES

Roy Roy CamilleCamille

MagërlMagërl

AndersonAnderson

AnAn

AbumiAbumi

Rongming Xu Spine vol 24 numb 19 pp 2057-201

TWO POSSIBLE SCREW TWO POSSIBLE SCREW IMPLANTATION IN C-7IMPLANTATION IN C-7

Lateral mass Lateral mass implantationimplantation

Pedicle implantationPedicle implantation

C7

C6

T1

T2

THORACIC PEDICLE SCREW THORACIC PEDICLE SCREW IMPLANTATION TECHNIQUEIMPLANTATION TECHNIQUE

Takes advantage of the oblique medial Takes advantage of the oblique medial pedicle orientation giving to the screw a pedicle orientation giving to the screw a better pull out resistancebetter pull out resistance

Original Roy CamilleScrew position


POSTERIOR INSTRUMENTATION POSTERIOR INSTRUMENTATION CHARACTERISTICSCHARACTERISTICS

Most instrumentations are Most instrumentations are devoted to cervical or devoted to cervical or thoracic fixationsthoracic fixations

Rods size are usually Rods size are usually different 3.5/6mmdifferent 3.5/6mm

Some systems have double Some systems have double diameter rods enabling diameter rods enabling connection between both connection between both

Transpedicular approach may also be used for limited access to the anterior column.

Cervicothoracic JunctionCervicothoracic Junction

If more lateral access is needed:

a costotransversectomy or

lateral extracavitary approach can be used

An HS, et al Spine 1994Kaya RA, et al. Surg Neurol 2006

Cervicothoracic JunctionCervicothoracic Junctionposterolateral approachposterolateral approach

CostotransversectomyCostotransversectomy Menard V. 1894Menard V. 1894

Lateral rachotomyLateral rachotomy Capener N. 1954Capener N. 1954

Lateral extracavitary approachLateral extracavitary approachLarson SJ et al 1976Larson SJ et al 1976

Lateral parascapular extrapleural approachLateral parascapular extrapleural approachFessler RG et al 1991Fessler RG et al 1991

In a costotransversectomy, a midline or paramedian incision is used and the rib head and costotransverse joint are resectedSometimes, the superior or inferior pedicles may be removed

Vaccaro et al Principles and practice of spine surgery. 2003

The lateral extracavitary approach is used for limited access to the anterior column and if the patient cannot tolerate a thoracotomy or anterior approaches


In this case, a short incision is made over the rib at the desired level, and the rib head is removed, along with the pedicle and the posterior-lateral vertebral body


Posterior - anterior proceduresPosterior - anterior procedures

Thyroid metastasisThyroid metastasis

C6

T1

MRI Axial MRI Coronal

1st operation

Anterior procedureAnterior procedureCorpectomy Corpectomy

Vertebral body Vertebral body replacement by replacement by expandable cage - expandable cage - Peek E.C.S. (Zimmer)Peek E.C.S. (Zimmer)

Stabilization with plate Stabilization with plate and screws and screws Zephyr (Medtronic)Zephyr (Medtronic)

2nd operationPosterior procedurePosterior procedure

Cervico thoracic level Cervico thoracic level

Stabilization by Stabilization by Vertex system Vertex system (Medtronic)(Medtronic)

1st post-op. 1st post-op CT

1st post-op CT

Biomechanical analysis of instrumentation of Biomechanical analysis of instrumentation of Cervicothoracic JunctionCervicothoracic Junction

The experience with lateral mass and pedicle screw fixation across the CTJ has been fairly positive.

Heller G et al JBJS (am), 1996Kotani Y, et al, Spine, 1994

New constructs using a screw-rod system have been developed in the past 10 years.

Kreshak JL, et al. Spine 2002Mazel C, et al. Spine 2004Rhee JM, et al Spine 2005Jeanneret B. Eur Spine J 1996

Biomechanically, these constructs provide significant stabilization to the CTJ in cadaver studies

Ulrich C et al, Eur. Spine, 2001Kreshak JL, et al. Spine 2002

The pedicle screw fixation is superior compared with lateral mass fixation at C7 in all biomechanical tests Biomechanical studies have yielded important information about the number of levels that should be included and also the relative strength of anterior and posterior fixation.This can be partially corrected by adding another level of fixation with lateral mass screws at C6

Ulrich C, eta, Spine (sup), 1991Mazel C, et al. Spine 2004Le Hoang, et al Neurosurg Focus 2003Chapman JR, et al. J Neurosurg 1996

Compared with the intact spine, posterior instrumentation with a screw-rod system can restore almost 100% of the strength in a two column but not a three-column injury

Kreshak JL, et al. Spine 2002

Although some authors have used only posterior fixation in trauma that included the anterior column, such as burst fracture, biomechanical studies have shown that in a three-column injury, posterior fixation is not sufficient to restore the stiffness to the level of intact spine It is therefore believed that a three-column injury is probably better treated with anterior and posterior fixation.

Chapman JR, et al J Neurosurg 1996Sapkas G, et al Eur Spine J 1999Kreshak JL, et al. Spine 2002

In tumor cases, is recommend that the fusion be extended three levels above and three levels below if a vertebrectomy is performed.


The use of pedicle screws and lateral mass fixation at the CTJ is safe.

In one study, breaching of the pedicle was found on postoperative CT scans in 9% of the screws when inserted without any guidance, but the incidence was reduced to 3% when a navigation system was used

Richter M. Orthop Traumatol 2005

The incidence of vascular injury is extremely rare, and radiculopathy is estimated to be in the range of 1% to 2%

Deen HG, et al Spine J 2003Mazel C, et al. Spine 2004

Cervicothoracic level is Cervicothoracic level is difficult to deal withdifficult to deal with

Cord compression can Cord compression can occur at the early stage of occur at the early stage of the diseasethe disease

Difficult surgery can be Difficult surgery can be highly rewardinghighly rewarding

CONCLUSIONSCONCLUSIONS

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The midline and lateral parascapular extrapleural exposures