Spondylolisthesis

SPONDYLOLISTHESIS

By Dr Gajendra Mani Shah

Orthopedics Department

NAMS, Bir Hospital

Introduction Herbiniaux, a Belgian obstetrician, noted a bone prominence in front of the sacrum that caused problems in delivery. Credited with having first described spondylolisthesis.

The term spondylolisthesis was used by Kilian in 1854 and is derived from the Greek spondylos, meaning “vertebra,” and olisthenein, meaning “to slip.”

Spondylolisthesis is defined as anterior or posterior slipping of one segment of the spine on the next lower segment.

ANATOMY OF LUMBAR VERTEBRA

SPONDYLOLYSIS

SPODYLOLISTHESIS

SPONDYLOPTOSIS

Classification

Wiltse, Newman, and Macnab's classification

Marchetti and Bartolozzi


Based on a mixture of etiological and topographical criteria.

Type I, Dysplastic (20%)

Congenital abnormalities of the upper sacral facets or inferior facets of the fifth lumbar vertebra that allow slipping of L5 on S1. No pars interarticularis defect


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

Three Types:

1. Lytic:- stress # of pars interarticularis

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

3. Acute # of pars interarticularis due high energy injury.


Type III: Degenerative(25%):-

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


Type IV :- Traumatic # in the area of the bony hook other than pars, ie pedicle, laminas or facets.


Type V :- Pathological :-

D/t generalized or localized bone disease, osteogenic imperfecta, multiple myeloma, TB.


Type VI Post surgical :- Due to loss of posterior elements secondary to surgery.


Two drawbacks of Wiltse et al classification: Difficult to predict the progression or response to surgery.Difficult to identify the type precisely.


Marchetti – Bartolozzi classificationDevelopmental Acquired

High dysplastic Traumatic With lysis Acute fracture With elongation Stress fractureLow dysplastic Postsurgery With lysis Direct surgery With elongation Indirect surgery

Pathological Local pathology Systemic pathologyDegenerative Primary /Secondary

ETIOLOGY

Prevalance: -5%, M= F; However-in Eskimos- 50%; White males- 6-7%; Black females 1.1% ; indicates definite genetic predisposition.

Spondylolysis:- in 15-70% of the 1st degree relatives. - 2-3 times more common in boys than girls but Slippage 2-3 times more common in girls.

ETIOLOGY CONTD…

DEVELOPMENTAL SPONDYLOLISTHESIS with lysis:- due to stress # in children with genetic predisposition for the defect.

Wiltse et al:- normal flexon contracture of the hip in childhoods- increased lumbar lordosis:– 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.

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 CONTD…

DEGENARATIVE 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- overloading of facets .Accelerated arthritic changes

.Secondary remodelling .Anterolisthesis

ETIOLOGY CONTD…

TRAUMATIC: Acute fracture other than Pars

POST SURGICAL : Laminectomy, Intervertebral fusion.

ETIOLOGY CONTD…

PATHOPHYSIOLOGY

TRAUMATIC PATHWAY

DYSPLASTIC PATHWAY

DEGENERATIVE PATHWAY

TRAUMATIC PATHWAYErect posture-CG anterior to LS jointLumbar spine-forward force and rotate Anteriorly into flexion about

the sacral dome. Initiated by the repetitive cyclic loading

Supr and infr articular process impingement creates a bending moment that is resisted by the Pars.

Repetitive impingement- fatigue

TRAUMATIC PATHWAY

Stress # of Pars and post. neural arc separates from body Gap occupied by the fibrous tissueNon union

Increased shear load to disc though Vertebral axial load remains unchanged Subluxation

Premature disc degeneration

DYSPLASTIC PATHWAY

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

-supr articular facet -infr articular facet

Repeated loading unopposed by bony constraints Plastic deformation of soft tissue restrains: IV Disc

Antr and postr Long. L

Postr Ligament complex

Subluxation of vertebra

DYSPLASTIC PATHWAY

With continuous growth

Slippage and abnormal growth in the involved vertebral bodies or sacrum

eg -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 Disc degeneration

No resistance for anterior Disc narrows translation force Subsequent overloading of facets

Predilection for slippage .Accelerated arthritic changes .Secondary remodelling .Anterolisthesis

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

•Whatever the inciting event - Facet arthritis - Disc degeneration and - Ligamentous hypertrophy All contribute to produce the symptoms.

•True deformity of degn spondylolisthesis – Rotatory deformity – not pure translation

Distort dura and its contents

Exaggerate the appearance of spinal stenosis

DEGENERATIVE SPONDYLOLISTHESIS

PATHOLOGICAL SPONDYLOLISTHESIS

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

Vertebral Subluxation

TRAUMATIC SPONDYLOLISTHESIS

High 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 : Fusion of segments

Removal of > ½ or entire Resection of capsular, Supraspinousarticular process and Interspinous ligaments

Destabilize the spineTranslational deformity Increasing motion demand the next

SUBLUXATION

Compression of nerve roots

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 pedical , 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 complicationsHigher risk of slip progression-cauda equina syndrome as the neural arc is intact.

2)Isthmic spondylolisthesis : No progression of slip Progression of slip < 10% displacement .Asymptomatic >25% slip .No progression after .Risk of slip progression adulthood .No backache later in life .Backache in later life

3)Degenerative Spondylolisthesis : .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 S/S deteriorated

NATURAL HISTORY

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.

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

CLINICAL EVALUATION

In patients > 50 yrs: •Backache – episodes of back “giving out”• 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 EXAMINATION: LOOK:• 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

CLINICAL EVALUATION

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 wt with hands on knee.In spondyloptosis- shortening of lumbar spine

CLINICAL EVALUATION

CLINICAL EVALUATION

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

Radiographic Findings

Anteroposterior views, standing lateral views, and a Ferguson coronal view.Flexion-extension lateral views :- may reveal instability,

The Ferguson coronal view is obtained by angling the x-ray beam parallel to the L5-S1 disc. With this view, the profile of the L5 pedicles, transverse processes, and sacral ala is more easily seen.

Radiographic Findings

Lowe et al. found a 26% increase in slipping on standing films compared with recumbent films.

Oblique views of the lumbar spine can put the pars area in relief apart from the underlying bony elements, making viewing of the defect easier.

Lateral bending films should be obtained for coronal deformities .

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.

SPECT And CT Scan

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.

A CT scan with arrow pointing to the pars fracture.

Radiographic Grading

Meyerding system of grading , the slip grade is calculated by determining the ratio between the anteroposterior diameter of the top of the first sacral vertebra and the distance the L5 vertebra has slipped anteriorly

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.

Meyerding System

Grade I spondylolisthesis is 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.



Modified Newman Spondylolisthesis GradingSystem.

Better define the amount of anterior roll of L5.

The scoring is based on the position of the posterior inferior corner of the body of the fifth lumbar vertebra 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.

Boxall Et Al., The Angular Relationships

Are the best predictors of instability or progression of the spondylolisthesis deformity.


These relationships are expressed as the slip angle, which is formed by the intersection of a line drawn parallel to the inferior or superior aspect of the L5 vertebra and a line drawn perpendicular to the posterior aspect of the body of the S1 vertebra .



. A, Standard method of measurement. B, Method used when inferior L5 end plate is irregularly shaped

The normal slip angle in a patient without spondylolisthesis should be lordotic. With a high-grade spondylolisthesis, the angle is commonly kyphotic.

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



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

Management

Goal

Pain relief,

Core muscle strengthening, and

Restoration of full lumbar range of motion.

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.


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.


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.


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.

Broadly divided into two categories:

Direct repair of the pars defects

Arthrodesis of the involved segments

OPERATIVE TREATMENT OF PARS INTARARTICULARIS

Operative Treatment

Procedures :- Buck technique, Scott wiring, and repair with an ipsilateral pedicle screw and hook.

Principles:- • Débridement, • Grafting of the site with autogenous bone graft, and • Compression across the fracture.

BUCK TECHNIQUE

Open technique

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.

Is a demanding procedure.

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.

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.

Salib And Pettine 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%.

A, Posterior view of lumbar spine model showing 6.5 × 25-mm cancellous screw placed approximately two thirds into ipsilateral pedicle; 18-gauge wire has been looped around screw head and passed through hole in base of spinous process. B, Oblique view of lumbar model with wire ends passed through metal button and twisted tightly against metal button.

Kakiuchi Technique

With this technique, hooks are fixed at the lamina and connected with a rod to an ipsilateral pedicle screw after compression

Pseudarthrosis Repair /Direct Repair

Area of soft-tissueremoval withoutdecortication

Area ofdecortication

Locationof pedicle

Spondylolyticdefect

Recipient bed prepared for autogenous cancellous bone graft


Area of excision ofPosterior elements

Ligamentumflavum not tobe excised

Nerve root beforedecompression

Posterior elements overlying affected nerve root are excised.


Head of variableanglescrew

Area ofbone graft

Starting point ofscrew insertion

Variable-angle pedicle screw and bone graft inserted


Rod

Laminarhook

Rod attached to head of screw with variable angle eyebolt. Laminar hook attached to rod.

For a pediatric patient with grade I or II spondylolisthesis, dysplastic spondylolisthesis at the lumbosacral junction, or a slip secondary to a defect of the L5 pars who has failed conservative treatment, posterior in situ fusion is recommended from L5 to S1.Most authors agree that slippage of more than 50% requires fusion.

OPERATIVE TREATMENT

Operative optionsPosterior in situ fusion, adding instrumentation to a posterior in situ fusion;

Posterior decompression, partial reduction, instrumentation, and fusion;

Posterior decompression, complete reduction, instrumentation, and posterior fusion;

Posterior fusion with postoperative cast reduction;

Posterior instrumentation and fusion combined with posterior Lumbar interbody fusion;

Anterior release;

Intradiscal Graft or structural cage combined with posterior instrumentation And fusion; and reduction and circumferential fusion With or without instrumentation.

Reduction And Fusion In High Dysplastic Spondylolisthesis With Internal Fixation

The method of immobilization after an in situ posterior fusion ranges from bed rest to bilateral pantaloon spica casts for 6 months.

TREATMENT OF SPONDYLOPTOSIS

L5 VERTEBRECTOMY

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

THANK YOU

References

1) Campbells operative orthopedics 2) Chapmans orthopedic surgery 4) Rothman spine 3) Apleys System of orthopedics

and fracture. 4) Millers review of orthopedics.

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