Jwalant S. MehtaMS(Orth), D (Orth), MCh (Orth), FRCS (Tr &

Orth)

Consultant Spine Surgeon, ABMU Health Board

SPONDYLOLISTHESIS

OUTLINE OF THE TALK

¤ Classification

¤ Natural history

¤ Patho-physiology

¤ Treatment rationale

¤ Cases

SPONDYL OLISTHESIS

1741 Nicholas Andry: hollow back

1782 Herbiniaux Belgian obstetrician

1854 Kilian slow displacement ‘Spondylolisthesis’

1855 Roberts: No slip if arch intact

CLASSIFICATIONS

Newman & Stone JBJS Br 1963; 45: 39 - 59

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

MEYERDINGS GRADES

Low Grade

High GradeIII

IIIIVV

SLIP ANGLE

Important in grades III – V

SPINO-PELVIC MEASURES

PELVIC INCIDENCE

Pelvic tilt Sacral slope

PI = PT + SS

High PT Low SSLow PT High SS

RELEVANCE OF PELVIC MEASURES

¤ PI quantifies the pelvic shape

¤ Pelvic morphology and spino-pelvic balance are abnormal in spondylolisthesis

PATHO-PHYSIOLOGY

HOOK AND CATCH

Hook:¤ Pedicle

¤ Pars inter-articularis

¤ Inferior process of the cephalad level

Catch:¤ Superior process of the caudal

level

PATHOPHYSIOLOGY

¤ Dysplastic pathway

¤ Traumatic pathway

Dysplastic pathway Traumatic pathway

Weakness in the hook & catch mechanism

Body weight transmitted through weak zone

Soft tissue restraints: plastic deformation

Growth plate overloaded

Repetitive cyclic loads (sports)

Stress fracture of a Normal pars

Hard cortical pars pre-disposes to fatigue

fracture and non-union

Predisposes to a vertical subluxation

DYSPLASTIC CHANGES¤ Proximal sacral rounding

¤ Trapezoidal L5

¤ Vertical sacrum

¤ Junctional kyphosis

¤ Compensatory hyper-lordosis

Contributes to the mechanics of progression, but not causation

PROXIMAL SACRAL ROUNDING

Yue Spine 2005

PROXIMAL SACRAL ROUNDING

DISCAL OVER-LOADING

¤ Both the pathways lead to ↑ shear loads, axial loads remaining constant

¤ Premature disc degeneration

Alternative loading pathwayHaher Spine 1994

¤ Chronic muscle spasm (protective): ‘painful’ pars Annular tears Root compression / traction

Leg pain is the most common symptomMoller Spine 2000

The pain generators: Back pain

THE PAIN GENERATORS: LEG PAIN

¤ L5 compression / traction

¤ Abnormal motion

¤ Facet joint arthrosis

¤ Pars scar

¤ The disc above far-lateral

CLINICAL EVALUATION: HISTORY

¤ Symptoms: Back painLeg painNeurology

¤ Severity

¤ Activities of daily living

CLINICAL EVALUATION: EXAMINATION

¤ Range and rhythm of trunk motion

¤ Neurology

¤ Sagittal alignment & gait

SAGITTAL ALIGNMENT

¤ Stance

¤ Gait

¤ Head over pelvis

¤ Hips and knees

IMAGING

¤ Erect radiographs:APLateral (to include the hips)

¤ MRI; CT

¤ Occasionally:

SPECT; Dynamic radiographs; Discography

PURPOSE OF IMAGING

¤ Disc degeneration (MRI / CT)

¤ Facet joint orientation, tropism, degeneration (MRI / CT)

¤ Pelvic and spinal measures (Erect xrays)

DISC DEGENERATION

DISC DEGENERATION: MRI

Pfirrmann et al Spine 2001

Grade I Grade II Grade III Grade IV Grade V

FACET JOINTS

FACET JOINTS: ORIENTATION & TROPISM

¤ Mean facet joint angle:

Sagittal: anterior forces

¤ Tropism

R –L: asymmetric loads

Mild < 5°Moderate 7° – 15°Severe > 15°

Vanharanta Spine 1993

Don JSDT 2008 Wang Spine 2009Boden JBJS Am 1996

FACET DEGENERATION: CARTILAGE

1. Uniformly thick layer

2. Focal erosions

3. Areas of deficiency with exposed bone

4. Cartilage absent except traces

Grogan et al AJNR 1997

FACET DEGENERATION: SUB-CHONDRAL SCLEROSIS

1. Thin layer of cortical bone

2. Focal thickening

3. Thick < ½ of the surface

4. Dense cortical bone > ½ of the surface

Grogan et al AJNR 1997

FACET DEGENERATION: OSTEOPHYTES

1. No osteophyte

2. Small

3. Moderate

4. Large

Grogan et al AJNR 1997

Severe Spinal Stenosis

Centre for Spinal Studies and Surgery NottinghamCentre for Spinal Studies and Surgery Nottingham

WILTSE CLASSIFICATION:III. DEGENERATIVE

Instability phase: Kirkaldy Willis

Posterior elements are intact

L45; F >M

Disc:

¤ degeneration,

¤ ↓ height

Facets:

¤ Tropism

¤ Abnormal sagittal orientation

¤ Facetal arthritis; subluxation

NATURAL HISTORY

NATURAL HISTORY: GENETICS

¤ 15 – 70% 1st degree relatives

¤ Lysis commoner in boys

¤ Slips commoner in girls

¤ Eskimos 25% (arch defects)

Albanese JPO 1982Wynne-Davies JBJS Br 1979

Roche JBJS Am 1952

Stewart JBJS Am 1953

NATURAL HISTORY: ‘THE SLIP’

¤ 15% of persons with a pars lesion

¤ During the growth spurt

¤ Minimal change after 16 y

¤ No pain during progression

Bentley Spine 2003

EXTENT OF THE PROBLEM

¤ Most are asymptomatic

¤ 90% slips at initial presentation do not progress

Seitsalo JBJS Br 1990Danielson Spine 1991Frennerd JPO 1991

Seitsalo Spine 1991

PROGRESSION

PROGRESSION RISK

¤ > 20 y: more stable, less symptomatic, less likely to progress

¤ High level of athletic activity, no effect on progression

¤ Association with back pain ‘weak’

Ohmori JBJS Br 1995

Muschik JPO 1996

RISK OF PROGRESSION: HIGHER LEVELS

THE RISK OF PROGRESSION IN THE YOUNG ADULT: DISC DEGENERATION

RISK FACTORS FOR SLIP PROGRESSION IN SPONDYOLISTHESIS(HENSINGER 1989)

Clinical

¤ Growth yrs (9 – 15)

¤ Girls > Boys

¤ Back pain

¤ Postural or gait abn

Radiographic

¤ Type 1 (dysplastic)

¤ Vertical sacrum

¤ >50 % slip

¤ Increasing slip angle

¤ Instability on flex/ext views

RISK OF PROGRESSION: PROXIMAL SACRAL ROUNDING

TREATMENT RATIONALE

NATURAL HISTORY OF PROGRESSION

¤ Adolescents III+: likely to progress

¤ I, II after mid-adolescence: unlikely to progress

NON-OPERATIVE TREATMENT

¤ Always consider first……………….everytime!

¤ Improvement likely if back > leg pain

¤ Isthmic / degnerative with leg pain: improvement less likely

¤ Investigate / treat osteopaenia

NON-OPERATIVE TREATMENT: PAEDIATRIC

¤ Stop aggravating activities

¤ Gradual mobilisation

¤ Trunk strengthening

¤ Period of bracing

NON-OPERATIVE TREATMENT: ADULTS

¤ Exercises

¤ Aerobics

¤ NSAID’S

¤ Epidural steroids

MANAGEMENT DECISION

¤ Individualized for each patient

¤ Think of the natural history

¤ Severity and duration of symptoms

¤ Co-morbidities

SURGICAL INDICATIONS

¤ Severe back and leg pain

¤ Failed conservative trial

¤ Abnormal neurology

¤ +ve diagnostic injections

SURGICAL GOALS

¤ Address the pars defect & the rattler

¤ Decompress the foraminal stenosis

¤ Address the degenerate disc/s

¤ Address the dynamic instability

SURGICAL OPTIONS

1. In-situ postero-lateral fusion

2. Decompression + In-situ postero-lateral fusion

3. Additional inter-body fusion options

DECOMPRESSION: ABSOLUTE INDICATIONS

¤ Neurology

¤ Leg pain

¤ Sphincter dysfunction

¤ Claudication

DECOMPRESSION: EXTENT¤ The Gill procedure: Removal of the loose

laminar arch

¤ Foraminotomy + facetectomy

¤ Never in isolation

¤ Associated with ↑ pseudarthrosis rateCarragee JBJS Am 1997

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

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

¤ Indirect reduction

INTER-BODY FUSIONS ( …… IF)

P LIF T LIF

A LIF

INDICATIONS FOR SURGERY:CHILDREN

¤ Low grade slip / ‘lysis…..non op measures effective

¤ Progression beyond Gr II

¤ At presentation, > Gr III

¤ Persisting pain; neurologic deficit

¤ Progressive postural deformity / gait abnoralities

SURGERY:PAEDIATRIC / ADOLESCENT

¤ ‘ Lysis Intact disc on MR (Gr I slip)

Direct repair of defect

¤ Grade I Asymptomatic….no surgery

¤ Grade II, III 1 level bilateral lateral fusion

Rarely decompression

Documented progression; back pain

SURGERY:PAEDIATRIC / ADOLESCENT

¤ Grade III+ Asymptomatic: 2 level in situ….L4 – S1

Slip angle < 55° good fusion rate

Post op: Hyper-extension cast + thigh extension

Slip angle > 55° add anterior fusion

Post-op: recumbent during healing

¤ Severe slips Excise body ( Gaines procedure) L4 – S1 fusion

INDICATIONS FOR SURGERY:ADULTS

¤ Non responsive to conservative measures

¤ Results better for leg than for back pain

¤ Isthmic / degenerative………persistent neurology; radicular symptoms

¤ Back pain alone…….decompress & stabilise (↓ symptoms)

DEGENERATIVE SLIP

¤ Caudal + facet injections

¤ Decompress stenosis

¤ Non-instrumented or instrumented fusion

¤ Think of the natural history

¤ Look at each patient and analyse the problems

¤ Individualize the treatment plan

¤ If surgery is the last resort ………….

RECOMMENDATIONS

RECOMMENDATIONS

¤ Choose surgical targets carefully

¤ Ensure patient expectations match with your goals

¤ In-situ PL fusion + decompression

¤ Add inter-body in ‘high risk’ situations

CASES

PROGRESSION ON WAITING LIST

FLEXION EXTENSION X RAYS

R L

POST OP

CASE

CASE

CASE

RADIOLOGICAL RESULT

Centre for Spinal Studies and Surgery NottinghamCentre for Spinal Studies and Surgery Nottingham

CLINICAL RESULT

Centre for Spinal Studies and Surgery NottinghamCentre for Spinal Studies and Surgery Nottingham

CASE

Centre for Spinal Studies and Surgery NottinghamCentre for Spinal Studies and Surgery Nottingham

RADIOLOGICAL RESULT

Centre for Spinal Studies and Surgery NottinghamCentre for Spinal Studies and Surgery Nottingham

CLINICAL RESULT