Presented by : Dr. N Benthungo Tungoe

Post Graduate, M.S (Orthopedics)

Moderator:

Director. (Prof). Dr. Ramesh Kumar

Director,

Central Institute of Orthopedics

VMMC & Safdarjung Hospital, New Delhi

SPONDYLOLISTHESIS

HISTORICAL ASPECTS

In 1782, Herbiniaux, a Belgian obstetrician, noted a bone prominence in front of the sacrum that caused problems in delivery.

In 1854, Kilian coined the term spondylolisthesis, derived from the Greek spondylos, meaning “vertebra,” and olisthenein, meaning “to slip.”

DEFINITION

• Spondylolisthesis is defined as the forward slippage of one vertebra on its adjacent caudal segment.

• Spondylolysis is a defect in pars interarticularis (the part of neural arch just caudal to the confluence of the pedicle, the superior articular process and the most cephalad part of the lamina)

• Spondyloptosis: used to describe as fall of L5 vertebra into the pelvis and lie anterior to sacrum.

RELEVANT ANATOMICAL STRUCTURES

GLOSSARY: BASIC THINGS FIRST!

• Pars interarticularis: portion of bone between superior and inferior articulating processes and the thinnest part of the neural arch

• Neural arch: bridge of bone formed by the posterior elements of a vertebra that surrounds the spinal cord

• Facet joint: the contact junction between the inferior articular process of one vertebra and the superior articulating process of the vertebra below it

• Motion segment: functional unit of the spine, consisting of two adjacent vertebrae and the intervening disc along with, facet joints, capsule and ligaments.

• Pedicles: thick bony struts that connect the vertebral body with the posterior elements

• Lamina: the portion of the neural arch between the articular processes and the spinous process

• Spondylosis: degenerative changes of the spine(vertebral joints and disc)

Hook:• Pedicle• Pars inter-articularis• Inferior process of the cephalad level

Catch:• Superior process of the caudal level

HOOK AND CATCH CONCEPT

CLASSIFICATION

• Wiltse, Newman and Macnab (Based on a mixture of etiological and topographical criteria)

• Meyerding Classification( based on percentage of slip in lateral radiograph)

• Marchetti and Bartolozzi ( emphasizes the developmental and dysplastic aspects)

• Spinal Deformity Study Group/SDSG classification

Type Name Description

I Congenital Dysplastic abnormalities

II Isthmic

A Lytic (stress fracture)B Healed fracture (elongated, intact)

C Acute high energy fracture

III Degenerative Segmental instability

IV Traumatic Fracture of hook other than pars

V Pathologic Underlying pathology

VI Iatrogenic Surgical excision of posterior elements

Wiltse, Newmann, MacNab Clin Orthop 1976

WILTSE, NEWMAN, AND MACNAB'S CLASSIFICATION

Type I, Dysplastic (20%)• Occurs only at L5-S1 level• Primary congenital dysplasia of L5-S1

facet joints.• Typically the inferior facet of L5 is

dysplastic and the sacral facet absent.• No pars interarticularis defect• Frequent assosciation with spina bifida

occulta of L5 and sacrum.• More common in females.• Increased incidence in first degree relatives

of patients: genetic

WILTSE, NEWMAN, AND MACNAB'S CLASSIFICATION

• Type II: Isthmic(50%) Defect in pars interarticularis that allows forward slippage of L5 over S1

• Three Types:

A. Lytic:- stress fracture of pars interarticularis

B. Healed version of Lytic- pars interarticularis intact but elongated

C. Acute fracture of pars interarticularis due high energy injury.

Spondylosis most common at L5(87%), L4(10%), L3(3%)

The incidence tends to stabilize in adulthood.

WILTSE, NEWMAN, AND MACNAB'S CLASSIFICATION• Type III: Degenerative(25%):

• Due to intersegmental instability of long duration and subsequent remodelling of the articilar process.

• Often accompanied by spinal stenosis,

• older than 40 years

• Most common at L4-5 (six times more)

• Women ( four to six times )

• 2 theories: sagittal facet theory & disc degeneration theory

• Studies shows progressive spondylolisthesis occurred in 34%, and further disc space narrowing continued in the patients without further slip.

• Low back pain improved in patients with continued disc space narrowing: autostabilization.

• Type IV :- Traumatic • fracture in the area of the bony hook other than pars, ie

pedicle, laminas or facets.

• Type V :- Pathological :• Due to generalized or localized bone disease,

osteogenic imperfecta, multiple myeloma, infection.

• Type VI Post surgical :

Due to loss of posterior elements secondary to surgery.

Wiltse, Newman, and Macnab's classification

MEYERDING CLASSIFICATION

• Based on the ratio of [overhanging part of the superior vertebral body] to [anteroposterior length of the adjacent inferior vertebral body]: 

• grade I: 0-25%

• grade II: 26-50% 

• grade III: 51-75% 

• grade IV: 76-100%  

• grade V (spondyloptosis): >100%

SPINAL DEFORMITY STUDY GROUP(SDSG) CLASSIFICATION

EPIDEMIOLOGY• Incidence: 6% in general population• Male:female ratio: 2:1, slippage more in females.• Incidence in children <6years: 2.6%• Ethnicity: more common in Caucasians than Blacks;

eskimos of Alaska reported incidence upto 50%.• Exact etiology: obscure• Degenerative spondylolisthesis(>40years) more

common in females.• Genetic and familial assosciation: 26% of patients

with isthmic spondylolisthesis had first degree relatives with same disease.

ETIOLOGY: DEVELOPMENTAL SPONDYLOLISTHESIS WITH LYSIS

It is due to stress fracture in children with genetic predisposition for the defect.

• Wiltse et al: normal flexon contracture of the hip in childhood causes increased lumbar lordosis leading to increased force at Pars interarticularis.

• Lett et al: shear stress greater at pars when lumbar spine is extended.

• Cryon and Hutton: Pars is thinner and vertebral disc is less resistant to shear in children and adolescents than in adults

Etiology: isthmic spondylolisthesis :Due to upright walking and wt . bearing.

M=F: 2:1

Risk factors: Gymnastics / Football/wt. lifting, dancing and others with excessive lordosis or hyperflexion of the lumbar spine.

Etiology of degenerative spondylolisthesis:• TWO THEORIES

a)Sagital facet theory: Facet oriented in such a way that it doesn’t resist Intratranslation forces over time leading to degenaration and Spondylolisthesis

b) Disc degeneration theory: Disc narrows first leading to overloading of facets, Accelerated arthritic changes , Secondary remodelling ,Anterolisthesis

ETIOLOGY:

• TRAUMATIC: Acute fracture other than Pars

• POST SURGICAL : Laminectomy, Intervertebral fusion.

PATHOPHYSIOLOGY

• TRAUMATIC PATHWAY • DYSPLASTIC PATHWAY• DEGENERATIVE PATHWAY

TRAUMATIC PATHWAYIn Erect posture-Center of Gravity is anterior to LS joint

Lumbar spine-forward force and rotate anteriorly into flexion about the sacral dome. Initiated by the repetitive cyclic loading

Sup. and inf. articular process impingement creates a bending moment that is resisted by the Pars.

Repetitive impingement- fatigue

Stress fracture of Pars and post. neural arc separates from body

Gap occupied by the fibrous tissue

Non union

Increased shear load to disc though axial load remains unchanged

Premature disc degeneration

Vertebral subluxation

DYSPLASTIC PATHWAY

Initiated by the cong. defect (dysplasia) in the bony hook or its catch.

Repeated loading unopposed by bony constraints

Plastic deformation of soft tissue restrains: IV Disc, Antr and Postr Ligament complex

Subluxation of vertebra

DYSPLASTIC PATHWAY

With continuous growth

Slippage and abnormal growth in the involved vertebral bodies or sacrum

Changes seen:

-Trapezoid shape of L5 - Rounding of supero anterior aspect of sacrum - Vertical orientation of the sacrum - Junctional kyphosis at involved segments - Compensatory hyperlordosis at the adjacent levels

DEGENERATIVE SPONDYLOLISTHESIS

Sagital facets degeneration

No resistance for anterior translation force

Predilection for slippage

Anterolisthesis

• Boden et al - sagital facet angles of > 45 degree at L4-L5 - 25 times greater likelihood of degenerative spondylolisthesis.

DEGENERATIVE SPONDYLOLISTHESIS

• Disc degeneration

• Disc narrowing and subsequent overloading of facets

Accelerated arthritic changesSecondary remodelling

Anterolisthesis

PATHOLOGICAL SPONDYLOLISTHESIS

Due to local or systemic pathological process causing a defect in the neural arch

Vertebral Subluxation

TRAUMATIC SPONDYLOLISTHESISHigh energy trauma

Translational deformity

Fracture of bony hook other than Pars ie: Pedicle, Superior and Inferior articular facets Associated multiple bony and STI

Subluxation

POST SURGICAL

• Laminectomy

• Removal of >1/2 or entire articular process

• Destabilize the spine

• subluxation

POST SURGICAL

Fusion of segments

Resection of capsular, Supraspinous and Interspinous ligaments

• Increasing motion demand

• subluxation

NATURAL HISTORY

• Risk factors for the progression :

1)Young age at presentation

2)Female gender

3)A slip angle of > 10 degree.

4)A high grade slip

5)Dome shaped or significantly inclined sacrum

NATURAL HISTORY IS PREDOMINANTLY DETERMINED BY

• Developmental or acquired spondylolisthesis• Low or high dysplasia• Quality of pedicle , pars and facets• Age when diagnosis is made• Degree of lordosis and position of gravity line• Degree of secondary or remodeled deformity• Competency, hydration and height of the disc

NATURAL HISTORY

1)Dysplastic spondylolisthesis :

Early age; usually asymptomatic

Severe slip(9-15,seldom after 20)

Risk of neurological complications

Higher risk of slip progression-cauda equina syndrome as the neural arc is intact.

NATURAL HISTORY OF ISHTHMIC SPONDYLOLISTHESIS

:

• No progression of slip Progression of slip

• < 10% displacement >25% slip

• Asymptomatic symptomatic

• No progression after Risk of slip progression

• adulthood

• No backache later in life .Backache in later life

-Rare before 50.

-Matsunaga et al 10 yrs prospective study--34% showed progression of the slippage-though no significant effect in the clinical outcome

-further disc space narrowing continued in those without slip -However back pain improved (Autostabilisation)

-83% of the pts with neurological signs and symptoms deteriorated

Natural history of Degenerative Spondylolisthesis :

CLINICAL EVALUATION

-Usually asymptomatic – Incidental finding in X ray.

-Symptoms depend on the severity of slip and is caused by :

1)Chronic muscle spasm : Body limits motion around a painful pseudo-arthrosis of facet and its Pars .

2) Tears in the Annulus Fibrosus of the degenerated discs.

3) Compression of the nerve roots.

CLINICAL EVALUATION

When symptomatic :

In Children and Young adults :

• Back fatigue and back pain-on movement (Hyperextension) due to instability of the affected segment.

• Hamstring fatigue and pain due to irritation of L5 nerve root.

• Sciatica – may occur in one or both legs

In patients > 50 yrs:

•Backache

•Sciatica

•Pseudoclaudication d/t spinal stenosis when subluxation is severe. • •Other signs of nerve root compression- motor weakness, reflex

changes and sensory deficits.

CLINICAL EVALUATION

Compression of central canal : Features:

1. Bladder and bowel dysfunction

2. Bilateral leg symptoms

3. +ve SLRT B/L

4. +ve crossed SLRT

CLINICAL EVALUATION

ON INSPECTION:

• Buttocks – Flat - Heart shaped in high grade slip d/t sacral prominence.• Sacrum – more vertical - appears to extend to the waist • Lumbar hyperlordosis above the level of the slip to compensate for the displacement.

• Transverse loin crease• With severity- absence of waist line• Peculiar spastic gait -due to hamstring tightness and lumbosacral kyphosis.

CLINICAL EVALUATION

INSPECTION FINDINGS

absence of waist lineTransverse loin creaseLumbar hyperlordosis

Scoliosis – esp in children – 3 types: a) Sciatic : Lumbar curve caused by the muscle spasm .resolve with symptoms b) Olisthetic : Due to asymmetrical slipping of vertebra c) Idiopathic :In Olisthetic crisis with total canal occlusion- typical posture– decrease nerve root tension by supporting trunk with hands on knee.In spondyloptosis- shortening of lumbar spine

CLINICAL EVALUATION

CLINICAL EVALUATION

PALPATION : Palpable step Tenderness over Pars defect Hamstring tightness on leg raising.

MOVEMENTS : Usually normal in young pts. May be – Hamstring + Paraspinal muscle tightness-

limiting forward bending and hip flexon. Degenerative type: spine-often stiff. Positive nerve root tests if root compression.

CLINICAL EVALUATION

• L5 compression / traction

• Abnormal motion

• Facet joint arthrosis

• Pars scar

• The disc above far-lateral

THE PAIN GENERATORS: LEG PAIN

IMAGING

Radiographs:

• AP view

• Standing Lateral view including the hips.(15% of deformities spontaneously reduce on supine imaging.)

• Oblique view: help in viewing pars interarticularis defect( decapitated scotty dog)

• Lateral flexion and extension views: determination of translational instability.

• Flexion-extension lateral views may reveal instability, which is considered to be present when 4 mm of translation or 10 degrees of sagittal rotation greater than the adjacent level is identified

• Fegurson view depicts the L5 pedicles, transverse processes and sacral ala more clearly

FEGURSON VIEW(20 DEGREES CAUDO CEPHALIC AP VIEW)

RADIOGRAPHS

FLEXION EXTENSION X RAYS

Demonstratesa bilateral break in the pars interarticularis or spondylolysis (lucency shown by black arrow) that allows the L5 vertebral body (red arrow) to slip orward on the S1 vertebral body (blue arrow).

The normal pars interarticularis is shown by the white arrow.

INVERTED NAPOLEON’S HAT SIGN

indicates the presence of bilateral spondylosis and significant spondylolisthesis. The dome of the hat is formed by the overlying body of L5 vertebra and the brim is formed by downward rotation of the transverse processes.

SCOTTY DOG SIGN ON OBLIQUE VIEWS

OTHER INVESTIGATIONS

CT myelography and MRI are used as indicated for the evaluation of spinal stenosis and may show facet overgrowth, hypertrophy of the ligamentum flavum, and, rarely, disc herniation, tumors, etc.

SPECT: most senstive for impending spondylolysis., Can determine the chronicity of lytic defect.

NCV, EMG: to rule out peripheral neuropathy

Arterial doppler/ CT angiography: to rule out vascular causes of claudication

ROLE OF SPECT

• A Single-photon Emission Computed Tomography bone scan is necessary to show whether uptake is increased in the pars. A SPECT scan is helpful in determining whether the process is acute or chronic.

• If increased uptake is confirmed, a CT scan can be obtained to evaluate whether there are thickened cortices consistent with a stress reaction or whether there is an acute stress fracture.

MAGNETIC RESONANCE IMAGING

• Allows for additional visualization of soft tissue and neural structures and is recommended in all cases associated with neurologic findings.

• In the early course of the disease, MRI helps in identifying the stress reaction at the pars interarticularis before the end-stage bony defect.

• MRI may show the degree of impingement of neural elements by fibrous scar tissue at the spondylolytic defect.

• Status of disc

DISC DEGENERATION: MRI

Pfirrmann et al Spine 2001

Grade I Grade II Grade III Grade IV Grade V

IMPORTANT RADIOLOGICAL PARAMETERS

• SLIP ANGLE(by Boxall et.al):

• The slip angle is measured from the superior border of L5 and a perpendicular line from the posterior edge of the sacrum

• Angle greater than 45 to 50 degrees associated with greater risk of slip progression, instability, and development of postoperative pseudarthrosis.

• It is the best predictor of progression os slip.

• A slip angle greater than 55 degrees is associated with a high probability and increased rate of progression

PELVIC INCIDENCE (PI)• Pelvic incidence: A line

perpendicular to the midpoint of the sacral end plate is drawn. A second line connecting the same sacral midpoint and the center of the femoral heads is drawn. The angle subtended by these lines is the pelvic incidence

• Pelvic incidence: Pelvic tilt + sacral slope

• normal, ≈50 degrees)

• Unaffected by posture

• Increased PI may predispose to spondylolisthesis.

PELVIC TILT (PT)

• Pelvic tilt:. A line from the midpoint of the sacral end plate is drawn to the center of the femoral heads. The angle subtended between this line and the vertical reference line is the pelvic tilt.

• Higher pelvic tilt predisposes to spondylolisthesis.

SACRAL SLOPE(SS)

• Sacral slope: A line parallel to the sacral end plate is drawn. The angle subtended between this line and the horizontal reference line is the sacral slope.

• Vertical sacrum (SS<100 degrees) is causes progression in slippage.

ALPHA ANGLE L5 INCIDENCE

• Alpha angle L5 incidence: A line from the midpoint of the upper end plate of L5 is connected to the center of the femoral heads. A second line perpendicular to the upper L5 end plate is drawn from the midpoint of the end plate. The angle subtended by these two lines (α) is the L5 incidence.

• Higher values are associated with spondylolisthesis/unbalanced pelvis

CONCEPT OF BALANCED VS UNBALANCED PELVIS• The balanced pelvis is one in which compensatory

increased lumbar lordosis and decreased thoracic kyphosis of the spine are adequate to maintain an adequate C7 plumbline or normal sagittal balance.

• In the unbalanced, or retroverted, pelvis, there is high PI because of increased pelvic tilt (visualized as an anterior position of the femoral heads relative to the sacrum) that the spine cannot accommodate the associated high L5 incidence angle, leading to positive forward balance.

• unbalanced spine, occurs when the C7 plumbline falls anterior to the femoral heads on the standing lateral radiograph.

• The spine is balanced when the plumbline falls on or posterior to the femoral heads.

BALANCED VS UNBALANCED PELVIS

MEYERDING XRAY GRADING OF SPONDYLOLISTHESIS

• Percentage of slipping calculated by measurement of distance from line parallel to posterior portion of first sacral vertebral body to line parallel to posterior portion of body of L5; anteroposterior dimension of L5 inferiorly is used to calculate percentage of slipping.

• Grade I: displacement of 25% or less;

• Grade II: between 25% and 50%;

• Grade III: between 50% and 75%; and

• Grade IV: more than 75%. A

• Grade V represents the position of L5 completely below the top of the sacrum -SPONDYLOPTOSIS.

DE WALD MODIFIED NEWMAN SPONDYLOLISTHESIS GRADING SYSTEM

• Better define the amount of anterior roll of L5.

• The dome and the anterior surface of the sacrum is divided into 10 equal parts.

• The scoring is based on the position of the posterior inferior corner of the body of the L5 with respect to the dome of the sacrum.

• The second number indicates the position of the anterior inferior corner of the body of the L5 vertebra with respect to the anterior surface of the first sacral segment.

Modified Newman spondylolisthesis grading system. Degree of slip is measured by two numbers—one along sacral endplate and second along anterior portion of sacrum:A = 3 + 0; B = 8 + 6; and C = 10 + 10.

Modified Newman Spondylolisthesis GradingSystem.

Clinical • Growth yrs (9 – 15)• Girls > Boys• symptomatic• Postural or gait

abnormality

Radiographic• Type 1 (dysplastic)• Vertical sacrum• >50 % slip• Increasing slip angle• Instability on flex/ext

views

RISK FACTORS FOR SLIP PROGRESSION IN SPONDYOLISTHESIS(HENSINGER 1989)

MANAGEMENT

• Nonoperative Treatment

• Operative Treatment

• Includes complete cessation of activity, rehabilitation with strengthening of the abdominal and paraspinal musculature, minimization of pelvic tilt, and antilordotic bracing.

• The brace is worn for 23 hours/day for minimum of 3 to 6 months. If clinical symptoms improve, the brace can be gradually weaned through a period of part-time wear.

Conservative Management

• Vigorous activities are restricted and back, abdominal and core strengthening exercises are prescribed.

• If the symptoms are more severe, a brief period of bed rest or brace immobilization may be required. Once the pain has improved and the hamstring tightness has lessened, the child is allowed progressive activities.

• Yearly examinations with standing spot lateral radiographs of the lumbosacral spine are advised to rule out the development of spondylolisthesis.

• If the patient remains asymptomatic, limitation of activities or contact sports is not necessary.

Conservative Management

• If the SPECT scan reveals metabolic activity and a CT scan shows thickening of the pars, avoidance of aggravating activity and core strengthening exercises are recommended.

• If the SPECT scan is metabolically active and CT indicates an acute stress fracture, a 3-month trial of orthotic treatment is warranted.

• If the defect has not healed in 3 months, continued orthotic wear is not indicated. The CT scan is the most helpful radiographic technique to determine the presence or absence of healing.

Conservative Management

• Have excellent relief of symptoms or only minimal discomfort at long-term follow-up.

• If a child does not respond to conservative measures, other causes of back pain should be ruled out.

• Special attention should be paid to children whose symptoms do not respond to bed rest or who have objective neurological findings.

• A very small percentage of children with spondylolysis who do not respond to conservative measures and in whom the other possible causes of back pain have been eliminated may require OPERATIVE TREATMENT.

Conservative Management.

OPERATIVE TREATMENT: INDICATIONS:

• Persistent symptoms despite 9 months to 1 year of conservative treatment,

• Persistent tight hamstrings, abnormal gait, and pelvic-trunk deformity.

• Development of a neurological deficit .

• In a skeletally immature patient with slippage greater than 50% or a mature adolescent with a slip greater than 75%, even if the patient is asymptomatic.

SURGICAL GOALS

• Address the pars defect & the rattler

• Decompress the foraminal stenosis

• Address the degenerate disc/s

• Address the dynamic instability

OPERATIVE OPTIONS

• Direct repair of pars defect• Decompression and fusion without fixation• Decompression and fusion with pedicle screw fixation• Posterolateral insitu fixation• Partial reduction and fixation• Complete reduction, fusion and fixation• Posterolateral interbody fusion and fixation/PLIF• Trans foraminal interbody fusion/TLIF• Anterior interbody fusion/ALIF• Note:

• repair preserves motion segment• Fusion removes motion segment

DECOMPRESSION: ABSOLUTE INDICATIONS

• Neurological deficit

• Non relieving Leg pain

• Sphincter dysfunction

• Claudication

DECOMPRESSION:

• The Gill procedure: Removal of the loose laminar arch

• Foraminotomy + facetectomy

• Never in isolation

• Associated with ↑ pseudarthrosis rate

Carragee JBJS Am 1997

DECOMPRESSION AND INTERBODY FIBULAR GRAFT FIXATION

IN-SITU POSTERO-LATERAL FUSION

• L5 S1 only adequate

• Improvement in leg pain even when not decompressed

Burkus JBJS Am 1992Frennerd Spine 1991Ishikawa Spine 1994

deLobrresse Clin Orthop 1996

POSTERIOR INSTRUMENTATION

• Better fusion rate, better clinical outcomes

• Un-instrumented better for osteoporortic bones

Moller Spine 2000

Zdeblick Spine 1993Yuan Spine 1994Bjarke Spine 2002Deguchi J Spinal Dis 1998Ricciardi Spine 1995

LEVELS TO INSTRUMENT

• Look at the changes at the levels above

• Higher slip angle: retro-listhesis above the slip

REPAIR OF SPONDYLOLYTIC DEFECT• Principles:

• Debridement, • Grafting of the site with autogenous bone graft, and • Compression across the fracture.

• If a direct repair of the spondylolysis is considered, the disc status should be evaluated with MRI. If disc degeneration is significant, an arthrodesis at that level may be a better choice

• Procedures :• Buck technique, • Scott wiring and Modified Scott Technique• Kakiuchi procedure (repair with an ipsilateral pedicle screw and hook).

BUCK TECHNIQUE : DIRECT REPAIR OF PARS INTERARTICULARIS

• Fibrous tissue at the pars defect is identified, thoroughly débrided, and stabilized with a 4.5-mm stainless steel cortical screw in compression.

• This technique was indicated only in cases in which the gap was smaller than 3 to 4 mm.

• The narrowness of the lamina, a minimal displacement or malposition of the screw can lead to implant failure or complications Such as nerve root irritation, injury to the posterior arch Or dura, or pseudarthrosis.

• Better clinical results have been obtained in patients younger than age 30 years, possibly because chronic instability leads to degenerative disc disease in older patients, which causes continued symptoms despite fusion of the defect

• (a) Preoperative lateral radiograph

• (b) axial CT scan showing unilateral defect of the pars interarticularis of the L4 vertebra.

• (c) Sagittal T2 weighted MRI demonstrating the normal L4-L5 disc without any degeneration.

• Follow-up lateral dynamic radiographs in (d) flexion and (e) extension, showing complete healing of the defect without signs of instability

• . (f) Postoperative axial CT scan demonstrating complete healing of the spondylolytic defect

SCOTT TECHNIQUE

• A stainless steel wire is looped from the transverse processes to the spinous process of the level involved and tightened, in conjunction with local iliac crest bone graft.

• This wire creates a tension band construct, placing the pars defect under compression, and holds the bone graft in place.

• Bradford and Iza reported 80% good to excellent results and 90% radiographic healing of the defects.

• This technique requires greater surgical exposure, with extensive stripping of the muscles to expose the transverse process.

• Complications such as wire breakage are common with this technique.

SCOTT WIRING TECHNIQUE

MODIFIED SCOTT TECHNIQUE

• Modified SCOTT TECHNIQUE in which a wire is passed around the cortical screws introduced into both pedicles and tightening it beneath the spinous process.

• Biomechanical tests show that fixation of the wire to the pedicle screw does not increase the stiffness of the system.

• This techniques have defect healing rates of 86% to 100%.

MODIFIED SCOTT TECHNIQUE

KAKIUCHI TECHNIQUE

• Kakiuchi reported successful union of pars defects with the use of a pedicle screw, laminar hook, and rod system.

• A pedicle screw is placed in the pedicle above the pars defect.

• The pars defect is bone grafted.

• A rod is placed in the pedicle screw and then into the caudal laminar hook, and compression is applied.

• This gives a more stable construct than that afforded by wire techniques

COMPARATIVE STUDIES

IN-SITU PEDICLE SCREW FIXATION

GROB’S TECHNIQUE: DIRECT PEDICULO-BODY FIXATION

GROB TECHNIQUE

• In situ fusion is a relatively safe and reliable procedure associated with a high rate of arthrodesis and at lower risk of neurologic injury .

• Fixation of the segment is achieved by two cancellous bone screws inserted bilaterally through the pedicles of the lower vertebra into the body of the upper slipped, vertebra

• In advanced intervertebral disc degeneration

INTER-BODY FUSIONS: THEORETICAL CONSIDERATIONS

• Anterior column support

• Bio-mecahnically superior:• Large area for fusion• Grafts under compressive loads

• Degenerate disc removed• consider disc height• Build in the lordosis

INTER-BODY FUSIONS

P LIF T LIF

A LIF

PLIF WITH TITANIUM MESH CAGE AND PEDICLE FIXATION

RADIOLOGICAL RESULT

RADIOLOGICAL RESULT

ALIF WITH TITANIUM CAGE AND PEDICLE SCREW FIXATION

KELLOG SPEED ANTERIOR FUSION USING FIBULAR GRAFT

TREATMENT OF SEVERE (HIGHDYSPLASTIC) SPONDYLOLISTHESIS

• Most authors agree that slippage of more than 50% requires fusion.

• the reduction of spondylolisthesis with instrumentation improves the chance of fusion, but these procedures have many risks and potential complications/neurological injury

• fusion in situ should be considered a method of choice in severe L5 isthmic spondylolisthesis.

• Remember: in severe spondylolisthesis, the sacral roots are stretched over the back of the body of S1 and are sensitive to any movement of L5 on S1

INSTRUMENTED REDUCTION AND FIXATION

Reduction And Fusion In High Dysplastic Spondylolisthesis With Internal Fixation

TREATMENT OF SPONDYLOPTOSIS

• L5 VERTEBRECTOMY

Resection of the L5 vertebra with reduction of L4 onto S1 described by Gaines and Nichols in 1985

SATISFIED WITH THE PRESENTATION? YES NO

THANKS FOR YOUR KIND ATTENTION