failures lumbar instability

Lumbar Instability Lumbar Instability

Causes - Diagnosis - ManagementCauses - Diagnosis - Management

George SapkasGeorge Sapkas

Asc. ProfessorAsc. Professor

11stst Orthopaedic Department Orthopaedic Department

Athens Medical SchoolAthens Medical School

Lumbar Instability

• Clinical

• Radiological

Clinical Lumbar Instability

• Not any specific definition• … the condition that the

patient feels that his back is unstable

White A. & Panjabi M.Clinical Biomechanics of the Spine 1980

Radiological Instability

• Spondylolysis• Spondylolisthesis• Adult Degenerative

Scoliosis• Post-Laminectomy

Lumbar Instability

The main cause of lumbar instability in adults is the instability of the spine that follows the operative treatment of lumbar stenosis

ETIOLOGY OF THE LUMBAR STENOSIS

Lumbar Stenosis-

Developmental

LumbarStenosis

-

DegenerativeSpondylolisthesis

Lumbar Stenosis-

Isthmic Spondylolisthesis

Lumbar Stenosis-

Congenital

Lumbar Stenosis-

Degenerative Adult Scoliosis

Etiology of Lumbar StenosisAdultAdult

scoliosisscoliosis

Congenital

Congenital

DevelopmentalDevelopmental

Isthmic Isthmic SpondyloSpondylolisthesislisthesis

DegenerativeDegenerative

SpondylolisthesisSpondylolisthesis

Foramen

Interverterbral Disc Space - Foramen

LUMBAR STENOSIS TREATMENT

•CONSERVATIVE

•OPERATIVE

Conservative treatment

• NSAIDS• Injections - Facet’s Block• Epidural - Caudal injection• Brace• Psychological support• Social support

Operative treatment

Laminectomy without stabilization

Laminectomy associated with

Transpedicular Stabilization

Laminectomy associated with PLIF

Laminectomy associated with

PLIF and Transpedicular stabilization

Causes of Failure

•Pre-operative •Intra-operative•Post-operative

Preoperative causes of failure

•Wrong diagnosis•Pre-existing conditions associated with increased operative risk or difficulties

Wrong diagnosis

• Infection• Tumor• Other causes of pain• Psychological –

social problems

Infection Tumor

Other causes of pain

Psychological – Social problems

Pre-existing conditions associated with increased operative risk or difficulties

I. Deformities e.g. scoliosis,

spondylolysis, spondylisthesis

II. Infections or tumorsIII. Previous discectomiesIV. Previous laminectomiesV. Previous lumbar fusions VI. Previous operated spinal

deformities VII. Pre existing instabilitiesVIII. Inadequate investigation

• Clinical • Radiological

Intra-operative causes of failure

• Hemorrhage • Facets’ – pedicles’

destruction• Screws misplacement• Battered nerve roots• Osteoporosis• Graft’s quality and

quantity• Inadequate

decompression

Post-operative causes of failure

Early post-operative causes of failure (0 – 3 wks)

•Haematoma•Infection•Implants’

failure

Late post-operative causes of failure(a. 3wks – 3mths)

• Implants‘ failure– Screws

• loosening • Broken • Dislodged

– Rods • Broken

• Destabilization • Infection

Late post-operative causes of failure(b. > 3mths)

• Implants failure• Destabilization

– at the level(s) of the operation– at the level above -//-– at the level below -//-

• Pseudarthrosis • Recurrence of stenosis • Late infection

Consequences

Intra-operative

• Removal of the ligamentous and bony structures destabilizes the lumbar spine

• Instability discovered intra-operatively extends the operative time.

• In case of pre-existed pathology e.g.

osteoporosis,tumor, infection

• The fixation of the implants is not safe

• The dissemination (malignant tumor) is very likely

Post-operative

•Immediate•Early•Late

Immediate / early post operative

• Unchanged symptoms• Recurrence of -//-• Deterioration of -//-

Late post-operative

a. Instability

b. Recurrence of stenosis

± neurologic deficit

c. PainPost-operative failures due to:–Buttered nerve roots–Muscles destruction–Implants failure–Instability

cause a. considerable

back and leg pain b. disability

Neurologic compromise:•Recurrence of stenosis•Instability

– May lead to anterioposterior or lateral subluxation – displacement.

The abnormal spatial relationship is achieved at the cost of spaces through which the nerve roots of the cauda equina travel in their course from the spinal cord to and through the neural foramen:

injury to the nerve root(s) may result.

Management

Investigations

•Clinical •Radiological•Psychological - Social

Clinical examination

• Medical evaluation• Neurological

investigation

Radiological investigation

• Plain x-rays• Dynamic x-rays• CT- scan• M.R.I.• Discograms• Scanning • Local injections

Conservative treatment

• NSAIDS• Brace• Injections – Facets’ Blocks• Epidural – Caudal injections• Epidural endoscopy

(pain management) • Back schools• Psychological – Social support

Local injections

• Epidural• Caudal• Facet’s block

Unpredictable results

Temporary improvement

and

Limited satisfaction

Operative treatment

Intra-operative:

• When the spinal instability is recognized intra-operatively consideration should be given to perform spondylodesia with or without instrumentation

Post Laminectomy Instability

Revision surgery for

post-laminectomy instability

Revision surgery for

post-operative instability

(above or below the operated level)

Cases

1st caseDegenerative Spondylolisthesis – Lumbar Stenosis

Instability at the level above the spondylodesia

Extension of the spondylodesia

2nd caseLumbar Fracture Laminectomy & Plif without

internal fixation

Facetectomies - Lumbar Instability

Facetectomies

Lumbar Instability

Lumbar Instability

Treatment: Transpedicular Internal Fixation

3rd casePost Facetectomies – Laminectomies

Instability

Extensive Facetectomies

Post Laminectomy Lumbar Instability

Treatment: Transpedicular Internal Fixation

4th casePost Laminectomies - Facetectomies

Instability

Facetectomies

Lumbar Instability

Treatment: Transpedicular Stabilization

Conclusions

I. Careful pre-operative evaluation is mandatory to realize the underlying

pathology

II. The frequency of

instability complicating lumbar laminectomy is higher in patients with:

• pre-existing pars defect (spondylolysis - sthesis)

• Spondylolisthesis• Congenital or

developmental lumbar stenosis

III. Removal of the least

possible of the bone (facets) and soft tissues (ligaments & facets capsule) is essential in the prevention of instability following lumbar laminectomy

IV. Instability complicating lumbar laminectomy can be avoided if the surgeon proceeds in spondylodesia of the affected levels with or without instrumentation in case that instability is encountered intra-operatively

V.V. PLIF + Internal Stabilization provides PLIF + Internal Stabilization provides stable Post Laminectomy spinal levelsstable Post Laminectomy spinal levels

VI.VI. Stability of the spinal level above the Stability of the spinal level above the rigid transpendicular stabilization can rigid transpendicular stabilization can be provided by the interspinous be provided by the interspinous implantsimplants

VII.The stabilization of the affected level is associated with better results in the following conditions:

A. Lumbar stenosis associated with degenerative spondylolisthesis

B. Lumbar stenosis associated B. Lumbar stenosis associated with adult scoliosiswith adult scoliosis

C. Revision surgeryC. Revision surgery