FLAT BACK SYNDROME

GEORGE SAPKASGEORGE SAPKAS

1st Orthopaedic Department1st Orthopaedic DepartmentMedical School-Athens UniversityMedical School-Athens University

Introduction

Reduction Reduction

of normal lumbar of normal lumbar lordosis can lordosis can produce fixed produce fixed sagittal sagittal imbalance imbalance resulting in resulting in flatback flatback deformity.deformity.

Clinically, the Clinically, the deformity appears deformity appears as : as :

1.1.fixed lumbar flexion fixed lumbar flexion

2.2. inability to stand inability to stand

3.3. erect without erect without compensatory compensatory hip extension hip extension and and knee flexion. knee flexion.

This results in This results in muscle fatigue muscle fatigue and activity-and activity-related pain. related pain.

As the patient ages: As the patient ages: 1.1. reduced muscle reduced muscle

strength, strength, 2.2. adjacent disc adjacent disc

degeneration, degeneration, and and

3.3. hip and pelvic hip and pelvic disease disease

may combine to may combine to decrease the decrease the patient’s ability to patient’s ability to compensate compensate and and may result in may result in increased disability.increased disability.

Kostuik JP, et al, Spine 1988;

There are multiple There are multiple causes of the causes of the

flat back syndrome.flat back syndrome.

Many reports Many reports describe the results describe the results of placing of placing Harrington Harrington distraction distraction instrumentationinstrumentation to to the sacrum. the sacrum. This is of This is of contemporary contemporary concern, because concern, because many patients many patients treated for scoliosis treated for scoliosis 20 or 30 years ago 20 or 30 years ago are becoming are becoming symptomatic. symptomatic.

Bradford DS, et al Clin Orthop 1994;

Denis F, et al Inc., 1994;

Farcy J-PC, et al Spine 1997

LaGrone MO, et al J bone Joint Sur {Am} 1988;

Other described Other described causes include :causes include :anterior anterior compressioncompression instrumentationinstrumentation (Dwyer or Zielke) (Dwyer or Zielke)

without the use of without the use of structural interbody structural interbody grafts grafts

DeWald RL, et al 1993

or or the settling of a the settling of a long posterior long posterior lumbar fusionlumbar fusion performed without performed without structural grafting.structural grafting.

DeWald RL, et al 1993

E.P.F 7709.02.042½ yrs pop

Fixed sagittal Fixed sagittal imbalance may also imbalance may also be the result of :be the result of :

traumatrauma

Bradford DS, et al Spine 1987

or or systemic illness systemic illness such as such as

ankylosing ankylosing spondylitisspondylitis

Bradford DS, et al Spine 1987

The treatment of The treatment of a fixed sagittal a fixed sagittal deformitydeformity requires rebalancing of requires rebalancing of the spine with one or the spine with one or several osteotomies. several osteotomies.

There are inherent There are inherent dangers with dangers with reconstructive reconstructive procedures needed to procedures needed to restore sagittal restore sagittal balance.balance.

Goals of surgical treatment

Restoration of sagittal and Restoration of sagittal and coronal balance in a patient with coronal balance in a patient with fixed spinal deformityfixed spinal deformity

Achievement of solid arthrodesisAchievement of solid arthrodesis Rigid internal fixation to permit a Rigid internal fixation to permit a

brace-free mobilizationbrace-free mobilization Relief of axial and radicular painRelief of axial and radicular pain

Devlin J.V., Surg. Techn. Odf the spine Devlin J.V., Surg. Techn. Odf the spine 20032003

Diagnosis

Back painBack pain Spinal fatigueSpinal fatigue Progressive spinal Progressive spinal

deformitydeformity Inability to stand Inability to stand

erect with the knees erect with the knees full extendedfull extended

A comprehensive A comprehensive musculoskeletal musculoskeletal examination examination includes includes consideration of the consideration of the following questions:following questions:

1.1. Is the most severe Is the most severe spinal deformity located spinal deformity located in the sagittal plane or in the sagittal plane or coronal plane ? coronal plane ? Is a complex deformity Is a complex deformity involving multiple involving multiple planes present ?planes present ?

2.2. Is the spinal Is the spinal

deformity deformity balanced or balanced or unbalanced ? unbalanced ? This is This is assessed by assessed by the relationship the relationship of the C7 of the C7 plump line to plump line to the sacrum in the sacrum in the coronal and the coronal and sagittal planessagittal planes

3.3. Is the spinal Is the spinal

deformity flexible deformity flexible or rigid ? or rigid ? Are flexible Are flexible nonfused spinal nonfused spinal segments present segments present above or below a above or below a previously fused previously fused spinal region ?spinal region ?

4.4. What is the What is the relationship of the relationship of the shoulders and pelvis to shoulders and pelvis to the spinal deformity ?the spinal deformity ?Factors such as Factors such as shoulder imbalance, shoulder imbalance, pelvic obliquity, and pelvic obliquity, and hip flexion hip flexion contractures require contractures require consideration when consideration when planning osteotomy planning osteotomy proceduresprocedures

Radiographic assessment

GlobalGlobal1.1. In the coronal planeIn the coronal plane

2.2. In the sagittal planeIn the sagittal plane RegionalRegional SegmentalSegmental

Pre-op evaluation

Operative techniques

S.S.E.P. – M.E.P.

Smith - Peterson Type Osteotomy Smith - Peterson Type Osteotomy

Smith Peterson et al J.B.J.S 27, 1:11, 1945

Indications for surgery Ankylosing spondylitisAnkylosing spondylitis Post surgical flat back Post surgical flat back

syndromesyndrome Iatrogenic spinal Iatrogenic spinal

deformities arising after deformities arising after scoliosis fusion scoliosis fusion

Post-traumatic kyphotic Post-traumatic kyphotic deformitydeformity

Transition syndromes Transition syndromes (proximal or distal) (proximal or distal) following degenerative following degenerative lumbar spinal procedureslumbar spinal procedures

Contra- Indications

Spinal deformities that can be treated by Spinal deformities that can be treated by combined procedures such as:combined procedures such as:– multiple anterior discectomies and fusion multiple anterior discectomies and fusion

followed by followed by – posterior segmental instrumentation and posterior segmental instrumentation and

fusionfusion Patients with severe degree of fixed Patients with severe degree of fixed

decompensated spinal deformities in decompensated spinal deformities in whom spinal balance would not be whom spinal balance would not be achieved despite multiple S-P osteotomiesachieved despite multiple S-P osteotomies

Advantages

May be used to treat coexistent May be used to treat coexistent sagittal and coronal spinal deformitiessagittal and coronal spinal deformities

May result in long harmonious sagittal May result in long harmonious sagittal curves if multiple osteotomies are curves if multiple osteotomies are performed over adjacent levelsperformed over adjacent levels

Disadvantages Requires the Requires the anterior anterior

structures of the spine structures of the spine to be flexibleto be flexible enough to enough to allow the osteotomy gap allow the osteotomy gap to completely close to completely close posteriorly.posteriorly.

S-P type osteotomies S-P type osteotomies performed at spinal performed at spinal segments with existing segments with existing foraminal stenosis foraminal stenosis may may worsen foraminal worsen foraminal stenosisstenosis as the posterior as the posterior wedge is closed wedge is closed

Cont..ed

When multiple S-P type When multiple S-P type osteotomies are osteotomies are performed performed correction correction may occur preferentially may occur preferentially at aat a single levelsingle level resulting in less than resulting in less than complete correction, complete correction, nonharmonious nonharmonious correction, or a correction, or a neurologic complicationneurologic complication

If a large degree of If a large degree of correction is obtained at correction is obtained at a single spinal level an a single spinal level an anterior column defectanterior column defect may be created because may be created because the axis of closure of the the axis of closure of the osteotomy is located at osteotomy is located at the posterior disc the posterior disc marginmargin

Procedure

Planning Planning

1.1. Location of osteotomiesLocation of osteotomies

2.2. Size and number of osteotomiesSize and number of osteotomies

3.3. Distal extent of fusion and Distal extent of fusion and instrumentationinstrumentation

4.4. Proximal extent of posterior fusion and Proximal extent of posterior fusion and instrumentationinstrumentation

5.5. Posterior vs. anterior and posterior Posterior vs. anterior and posterior surgerysurgery

Technique of osteotomy

Position of patient prior to Position of patient prior to surgerysurgery

The osteotomies are V- The osteotomies are V- shaped with their base shaped with their base located inferiorly in the located inferiorly in the midline at the original midline at the original interlaminar spaceinterlaminar space

The lateral extensions The lateral extensions of the osteotomy pass of the osteotomy pass proximally across the proximally across the original facet joints original facet joints and exit through the and exit through the neural foramen just neural foramen just proximal to the proximal to the pediclespedicles

Elevation of kidney rest assists Elevation of kidney rest assists in closing the osteotomyin closing the osteotomy

Closure of the Closure of the posterior osteotomy posterior osteotomy is accompanied by is accompanied by opening of the opening of the anterior and middle anterior and middle spinal columnsspinal columns

Osteotomy

for Ankylosing Spondylitis

Osteotomy

for Ankylosing Spondylitis

Goals of surgical treatments

Osteotomy of the spine in Osteotomy of the spine in akylosing spondylitis is done to akylosing spondylitis is done to correct fixed rigid deformities of correct fixed rigid deformities of the: the: – cervical, cervical, – thoracic, thoracic, – lumbar spine lumbar spine

that are impairing functional status that are impairing functional status and quality of lifeand quality of life

Indications for surgery

In the cervical spine the flexion In the cervical spine the flexion deformity is often a result of a deformity is often a result of a misdiagnosed fracture that went on misdiagnosed fracture that went on to heal in a forward flexed positionto heal in a forward flexed position

Osteotomy of the lumbar spine is Osteotomy of the lumbar spine is commonly done for lumbar commonly done for lumbar hypolordosis or actual kyphosis hypolordosis or actual kyphosis giving rise to a fixed flexion giving rise to a fixed flexion deformitydeformity

Contra - Indications

Include patients who are not Include patients who are not suitable candidates for medical suitable candidates for medical reasons and where the severity of reasons and where the severity of the deformity does not warrant the deformity does not warrant the procedure. the procedure.

Severe osteopenia Severe osteopenia

Advantages

The osteotomy may de done from a The osteotomy may de done from a single – stage posterior approachsingle – stage posterior approach in in the lumbar and cervical spines and the lumbar and cervical spines and allows for a allows for a high degree of correctionhigh degree of correction to be obtained in a safe manner with to be obtained in a safe manner with the least morbidity to the patientthe least morbidity to the patient

The results can be very gratifying in The results can be very gratifying in terms of overall improvement in terms of overall improvement in functional status and quality of lifefunctional status and quality of life

Disadvantages

The disadvantages of the procedure The disadvantages of the procedure predominantly are those related to predominantly are those related to potential complicationspotential complications or morbidity or morbidity from the procedurefrom the procedure

Many of these patients have Many of these patients have concomitant medical illnesses and concomitant medical illnesses and cardiac problems and must be carefully cardiac problems and must be carefully evaluated preoperatively from a evaluated preoperatively from a medical standpointmedical standpoint

Major neurologic problems are Major neurologic problems are relatively infrequent; however they can relatively infrequent; however they can be a major problem when they occurbe a major problem when they occur

Lumbar spine

osteotomy Selected Selected

levels of levels of

osteotomy osteotomy

L2

L3

L4

Position of patient prior to Position of patient prior to surgerysurgery

Exposure secrets

Be certain of Be certain of the level that the level that you are you are preparing to do preparing to do osteotomy at as osteotomy at as the landmarks the landmarks are obscured. are obscured.

Radiographic Radiographic confirmation is confirmation is often necessaryoften necessary

Elevation of kidney rest assists Elevation of kidney rest assists in closing the osteotomyin closing the osteotomy

lumbar kyphotic lumbar kyphotic deformity due to deformity due to ankylosing ankylosing spondylitisspondylitis

Postoperative Postoperative radiograph following radiograph following lumbar extension lumbar extension osteotomy and osteotomy and realignment of the realignment of the spinespine

Pedicle subtraction and

lumbar extensionosteotomy

Pedicle subtraction and

lumbar extensionosteotomy

Indications for Surgery

Loss of lumbar Loss of lumbar lordosis (flat back) lordosis (flat back) with associated with associated complaints and complaints and physical findings physical findings as mentioned as mentioned above.above.

Contraindications

1.1. History of ongoing History of ongoing infection from infection from previous surgeryprevious surgery

2.2. Severe osteoporosis, Severe osteoporosis, which could lead to which could lead to implant looseningimplant loosening

3.3. Severe comorbiditiesSevere comorbidities

Advantages

1.1. Elimination of the need for multiple Elimination of the need for multiple posterior osteotomies.posterior osteotomies.

2.2. Anterior disc space is not opened as Anterior disc space is not opened as a result of the posterior closure of the a result of the posterior closure of the posterior elements.posterior elements.

3.3. Elimination of an anterior procedure.Elimination of an anterior procedure.

4.4. Biplanar osteotomy may be Biplanar osteotomy may be performed if coronal decompensation performed if coronal decompensation exists.exists.

Disadvantages

1.1. Coronal decompensation may Coronal decompensation may occur if the osteotomy cuts are occur if the osteotomy cuts are not parallel. not parallel.

2.2. Blood loss, dural rents, and Blood loss, dural rents, and neurologic compromise. neurologic compromise.

Position of patient prior to surgeryPosition of patient prior to surgery

35 degrees wedge to be resected

Type A

Elevation of kidney rest assists Elevation of kidney rest assists in closing the osteotomyin closing the osteotomy

Type B

•Vertebrae are exposed at appropiate levels to allow osteotomy as indicated by dotted lines and shaded portion

•Complete laminectomy and pedicle subtraction are performed

•Wedge osteotomy of the entire L4 verterbral body is completed

•Wedge removal from right side L4 body. Note that anterior longitudinal ligament is intact

•Precontoured posterior instrumentation is applied

•Compression of the osteotomy

Posterior Lumbar decancellation

osteotomy (eggshell decancellation)

Posterior Lumbar decancellation

osteotomy (eggshell decancellation)

Michelle A., Krudger F.J J.B.J.S. 1949Thomasen E. Cliin. Orthop. 1996Heinig C.F. et al The Spine 1997

Indications The eggeshell procedure or The eggeshell procedure or

transpedicular transpedicular vertebrectomy may be vertebrectomy may be used for variety of used for variety of indications.indications.

The transpedicular The transpedicular approach can be used approach can be used open or percutaneously open or percutaneously under computed under computed tomography (CT) control tomography (CT) control biopsies or damagebiopsies or damage

The same approach can be The same approach can be used for total or partial used for total or partial cancellous bone removal cancellous bone removal and decompression of the and decompression of the anterior portion of the anterior portion of the spinal canal in cases of spinal canal in cases of tumor or fracturetumor or fracture

A posterior vertebrectomy A posterior vertebrectomy and /or osteotomy for and /or osteotomy for correction of a fixed correction of a fixed sagittal deformity is the sagittal deformity is the most complex indication most complex indication for this approachfor this approach

Operative technique The term The term

eggshell eggshell describes the describes the appearance of appearance of the vertebral the vertebral body after the body after the cancellous part cancellous part of the vertebral of the vertebral body has been body has been removed leaving removed leaving only a cortical only a cortical shell similar to an shell similar to an empty eggshell.empty eggshell.

Operative technique This operation consists of This operation consists of

removal of cancellous removal of cancellous bone of the selected bone of the selected vertebra body through vertebra body through both pedicle to weaken both pedicle to weaken the vertebral body and the vertebral body and create a posterior create a posterior compression of the compression of the vertebral body with vertebral body with minimal force while the minimal force while the posterior arches of the posterior arches of the adjacent vertebrae are adjacent vertebrae are approximated under approximated under direct vision by direct vision by manipulating the manipulating the operating table or spinal operating table or spinal column and securing with column and securing with internal fixation.internal fixation.

Anterior Osteotomy(ies) and Posterior Corrective

osteotomy(ies) and

stabilization

Anterior Osteotomy(ies) and Posterior Corrective

osteotomy(ies) and

stabilization

Indications Spinal deformities Spinal deformities

that can be treated that can be treated by multiple by multiple anterior anterior discectomies – discectomies – osteotomies and osteotomies and fusion followed by fusion followed by posterior posterior segmental segmental instrumentation instrumentation and fusionand fusion

Indications

Patients with severe degrees Patients with severe degrees of fixed decompensated of fixed decompensated spinal deformities in whom spinal deformities in whom spinal balance would not be spinal balance would not be achieved despite various achieved despite various types of posterior types of posterior osteotomies e.g.: osteotomies e.g.: – Smith-Peterson type Smith-Peterson type

osteotomy, osteotomy, – Pedicle Subtraction osteotomy, Pedicle Subtraction osteotomy, – Posterior Lumbar Posterior Lumbar

Decancellation osteotomyDecancellation osteotomy

Preoperative standing anteroposterior Preoperative standing anteroposterior (AP) (A) and lateral (B) radiographs of (AP) (A) and lateral (B) radiographs of a patient with a sagittal imbalance a patient with a sagittal imbalance following scoliosis surgeryfollowing scoliosis surgery

Postoperative standing Postoperative standing (AP) (A) and lateral (B) (AP) (A) and lateral (B) radiographs following radiographs following revision surgery. revision surgery.

Multilevel anterior Multilevel anterior discectomy and fusiondiscectomy and fusion with non structural with non structural grafting was followed grafting was followed by multiple level by multiple level Smith Smith Peterson type Peterson type osteotomiesosteotomies with with restoration of sagittal restoration of sagittal and coronal plane and coronal plane alignment and alignment and achievement of achievement of successful arthrodesissuccessful arthrodesis

Anterior intervertebral Anterior intervertebral graftgraftand and

posterior extension posterior extension osteotomy osteotomy

and and stabilizationstabilization

University Hospital “ATTIKON”