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Failed Back Surgery Syndrome

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Failed Back Surgery Syndrome

Comprehensive Orthopaedic exam guide to failed back surgery syndrome (FBSS) - definition, etiology including wrong level surgery and inadequate decompression, evaluation algorithm, scar tissue vs recurrent disc herniation, pain management, spinal cord stimulation, revision surgery indications, and prevention strategies.

complete
Updated: 2025-12-25

Failed Back Surgery Syndrome

High Yield Overview

FAILED BACK SURGERY SYNDROME (FBSS)

Persistent or recurrent pain following anatomically successful lumbar spine surgery

10-40%Incidence post-surgery
50%Pain reduction with SCS
15-20%Wrong level surgery rate
30%Recurrent disc herniation rate

FBSS Classification

Early
PatternUnder 3 months post-op
TreatmentConservative, assess for technical failure
Intermediate
Pattern3-12 months
TreatmentImaging with gadolinium MRI
Late
PatternOver 12 months
TreatmentMultidisciplinary approach

Critical Must-Knows

  • FBSS is a diagnosis of exclusion - must rule out infection, instability, recurrence
  • Most common causes: Wrong diagnosis, inadequate decompression, recurrent pathology
  • MRI with gadolinium: Scar (peripheral enhancement) vs recurrent disc (central mass)
  • Multidisciplinary approach: Pain management, physical therapy, psychological support
  • Spinal cord stimulation provides 50% pain reduction in selected patients

Examiner's Pearls

  • "
    FBSS is NOT a specific diagnosis - it's a syndrome requiring systematic evaluation
  • "
    Prevention is key: Correct diagnosis, appropriate surgery, proper level verification
  • "
    Psychosocial factors strongly predict FBSS - screen preoperatively
  • "
    Multiple surgeries worsen outcomes - avoid 'the next operation syndrome'

Clinical Imaging

Imaging Gallery

Lateral radiographs of the internal fixator and spine. (A) An immediate postoperative lateral radiograph. (B) Radiograph at 3 mo after postoperative, showing areas of osteolysis and malposition of the
Click to expand
Lateral radiographs of the internal fixator and spine. (A) An immediate postoperative lateral radiograph. (B) Radiograph at 3 mo after postoperative, Credit: Shang X et al. via BMC Musculoskelet Disord via Open-i (NIH) (Open Access (CC BY))
Sagital, 3.0 T, T1-weighted magnetic resonance image(MRI) demonstrate the swelling adjacent soft tissue (A) and “cloud sign” in the adipose layer (B).
Click to expand
Sagital, 3.0 T, T1-weighted magnetic resonance image(MRI) demonstrate the swelling adjacent soft tissue (A) and “cloud sign” in the adipose layer (B).Credit: Shang X et al. via BMC Musculoskelet Disord via Open-i (NIH) (Open Access (CC BY))
Osteolysis between L4 to S1. Sagital, Computed tomography (CT) revealing osteolysis between L4 to S1 (A, B). Note the gap around the pedicle screws in the vertebrae body(especially in C and E), and at
Click to expand
Osteolysis between L4 to S1. Sagital, Computed tomography (CT) revealing osteolysis between L4 to S1 (A, B). Note the gap around the pedicle screws inCredit: Shang X et al. via BMC Musculoskelet Disord via Open-i (NIH) (Open Access (CC BY))
Musculoskeletal and fixator changes. Coronal, Computed tomography (CT) showing loosening of the pedicle screws and the osteolysis (A, B). Axial view indicating metallosis in the intervertebral space,
Click to expand
Musculoskeletal and fixator changes. Coronal, Computed tomography (CT) showing loosening of the pedicle screws and the osteolysis (A, B). Axial view iCredit: Shang X et al. via BMC Musculoskelet Disord via Open-i (NIH) (Open Access (CC BY))

High-Yield Exam Points

Critical Distinction

FBSS vs Surgical Failure: FBSS occurs despite anatomically successful surgery. True surgical failure (wrong level, incomplete decompression, instrument failure) requires different management. Always verify surgical success first!

MRI Enhancement Pattern

Scar vs Recurrence: Epidural scar enhances on EARLY post-gadolinium images (under 5 minutes) with PERIPHERAL pattern. Recurrent disc shows DELAYED central enhancement or NO enhancement. This is the gold standard imaging distinction!

Prevention Strategies

Best Treatment is Prevention: Correct preoperative diagnosis, verify surgical level intraoperatively, avoid over-fusion, preserve posterior structures when possible, manage patient expectations, screen for psychosocial risk factors.

Revision Surgery Indications

Very Selective: Only consider revision if clear structural pathology (recurrent disc, inadequate decompression, instability), failed conservative care 6-12 months, and favorable psychosocial profile. Outcomes worsen with each reoperation!


At a Glance

Failed back surgery syndrome (FBSS) is persistent or recurrent pain following anatomically successful lumbar spine surgery, affecting 10-40% of patients. It is a diagnosis of exclusion—common causes include epidural fibrosis (scar tissue tethering nerve roots), wrong level surgery (15-20%), inadequate decompression, and recurrent disc herniation. MRI with gadolinium distinguishes scar (peripheral enhancement under 5 min) from recurrent disc (delayed/central enhancement). Management is multidisciplinary: conservative rehabilitation, interventional pain procedures, and spinal cord stimulation (50% pain reduction in selected patients). Revision surgery has diminishing returns with each operation and is reserved for clear structural pathology with favourable psychosocial profile.

Mnemonic

FAILEDFBSS Common Causes

F
Fibrosis (epidural)
Scar tissue tethering nerve roots - most common
A
Adjacent segment disease
Degeneration at levels above/below fusion
I
Inadequate decompression
Incomplete removal of compressive pathology
L
Level wrong
Surgery at incorrect level (15-20% incidence)
E
Epidural hematoma or infection
Postoperative complications causing symptoms
D
Disc recurrent herniation
Same level recurrence (5-15% rate)

Memory Hook:Why the back surgery FAILED!

Mnemonic

SCARSFBSS Evaluation Algorithm

S
Structural pathology
Recurrent disc, stenosis, instability on imaging
C
Central sensitization
Chronic pain syndrome with altered pain processing
A
Arachnoiditis
Inflammatory changes on MRI, clumped nerve roots
R
Recurrence vs residual
New herniation vs incomplete initial decompression
S
Scar tissue (fibrosis)
Epidural fibrosis causing nerve tethering

Memory Hook:Look for SCARS as causes of persistent pain!

Mnemonic

PREVENTPrevention Strategies

P
Psychosocial screening
Identify high-risk patients preoperatively
R
Right diagnosis
Confirm pathology matches symptoms
E
Expectations managed
Realistic goals and outcomes discussion
V
Verify level intraoperatively
Count levels, use imaging confirmation
E
Early mobilization
Prevent deconditioning and chronic pain
N
Nerve protection
Minimize retraction, preserve vascularity
T
Tissue preservation
Limit dissection, preserve facets and muscles

Memory Hook:How to PREVENT FBSS in the first place!


Overview and Definition

Failed back surgery syndrome (FBSS) represents one of the most challenging complications in spine surgery. The term encompasses a heterogeneous group of patients with persistent or recurrent pain following technically successful lumbar spine operations.

Definition and Terminology

Failed Back Surgery Syndrome (FBSS)

  • Persistent or recurrent low back and/or leg pain following lumbar spine surgery
  • Occurs despite anatomically successful surgical procedure
  • Symptoms present beyond expected recovery period (typically 3-6 months)
  • Also termed "post-laminectomy syndrome" or "persistent spinal pain syndrome type 2"

Key Distinction

  • FBSS: Anatomically successful surgery with persistent symptoms
  • Surgical Failure: Technical failure (wrong level, incomplete decompression, hardware failure)

Epidemiology

Incidence and Prevalence

ParameterValueNotes
Overall incidence10-40% post-lumbar surgeryVaries by indication and technique
Post-discectomy5-15%Lower rate with minimally invasive techniques
Post-laminectomy10-30%Higher with extensive decompressions
Post-fusion15-40%Highest rates with multi-level fusion
Prevalence in pain clinics20-25% of referralsMajor burden on healthcare system

Risk Factors for FBSS

CategoryRisk Factors
Patient factorsSmoking, obesity, poor conditioning, workers' compensation, litigation
PsychologicalDepression, anxiety, catastrophizing, poor coping strategies
SurgicalWrong level, inadequate decompression, excessive tissue damage
Disease-relatedMulti-level disease, severe degeneration, instability
PostoperativeDelayed mobilization, inadequate rehabilitation, poor compliance

Exam Pearl

Psychosocial factors are the strongest predictors of FBSS development. Depression, catastrophizing, and poor coping predict outcomes more strongly than surgical technique. Preoperative psychological screening is essential!

Pathophysiology

Understanding the causes of FBSS is critical for both prevention and management. Causes can be broadly categorized into technical, biological, and psychological factors.

Etiology

Technical Causes

Wrong Level Surgery

Epidemiology

  • Incidence: 5-15% of primary operations
  • More common in obesity, anatomical variants
  • Preventable with proper technique

Contributing Factors

FactorImpact
Anatomical variantsTransitional vertebrae, six lumbar vertebrae
Counting errorStarting from wrong reference point
Imaging correlationFailure to verify level intraoperatively
ObesityDifficulty palpating landmarks

Prevention

  • Count from sacrum upward (most reliable)
  • Obtain intraoperative imaging before incision
  • Use radiopaque marker on skin over planned level
  • Verify with AP and lateral fluoroscopy
  • Document level verification in operative note

Wrong-site surgery is a never event! Always verify level with imaging before incision. Mark the skin with a radiopaque marker, obtain AP and lateral films, and document verification before proceeding.

This completes the wrong level surgery discussion.

Inadequate Decompression

Types of Inadequate Decompression

TypeDescriptionManagement
Residual disc fragmentIncomplete discectomy, retained fragmentRevision discectomy if symptomatic
Lateral recess stenosisUnaddressed lateral stenosisUndercutting facetectomy
Foraminal stenosisUndecompressed foramenForaminal decompression, consider fusion
Contralateral pathologyBilateral symptoms, unilateral decompressionContralateral decompression
Multi-level diseaseAdjacent level stenosis not addressedConsider additional level decompression

Recognition

  • Symptoms never improve postoperatively
  • Same dermatomal pattern persists
  • Imaging shows residual compression
  • Early recognition allows early revision

This represents a true surgical failure requiring revision surgery.

Iatrogenic Instability

Causes of Postoperative Instability

  • Excessive facetectomy (over 50% facet removal)
  • Bilateral facet disruption
  • Pars fracture during decompression
  • Unrecognized preoperative instability
  • Adjacent segment disease following fusion

Clinical Features

FeatureDescription
Pain patternMechanical back pain, worse with activity
PositionalBetter lying down, worse standing/walking
Instability symptomsCatching, giving way sensation
RadiographicOver 3-4mm translation or over 10-15 degrees angulation on flexion-extension films

Management

  • Consider fusion if symptomatic instability confirmed
  • Must correlate imaging with symptoms
  • Assess adjacent segments for concurrent pathology

Proper surgical technique and preoperative planning prevent most iatrogenic instability.

Biological Causes

Epidural Fibrosis (Scar Tissue)

The most common cause of FBSS, occurring in 5-60% of postoperative patients.

AspectDetails
PathophysiologyExcessive scar formation tethering nerve roots
TimelineDevelops 3-6 months postoperatively
SymptomsRadicular pain, worse with activity, burning quality
MRI appearancePeripheral enhancement on early gadolinium images
TreatmentConservative management, epidural injections, consider adhesiolysis

Recurrent Disc Herniation

ParameterDetails
Incidence5-15% following discectomy
TimelineCan occur early (under 3 months) or late (over 2 years)
Risk factorsLarge annular defect, smoking, young age, heavy labor
SymptomsRadicular pain, often sudden onset with activity
DifferentiationMRI with gadolinium (no enhancement or delayed central)

Scar Tissue vs Recurrent Disc Herniation

FeatureEpidural Fibrosis (Scar)Recurrent Disc Herniation
Timeline3-6 months post-opVariable, often sudden
Pain onsetGradualOften acute with activity
Pain characterBurning, achingSharp, radiating
MRI T1 pre-contrastIntermediate signalHypointense
MRI T2Variable signalHyperintense
Gadolinium enhancementEARLY peripheral enhancementNO enhancement or DELAYED central
Mass effectMinimalModerate to severe
Surgical treatmentGenerally ineffectiveMay benefit from revision

Adjacent Segment Disease

Degeneration at levels adjacent to fusion, occurring in 5-25% by 10 years.

FeatureDescription
MechanismIncreased stress on adjacent mobile segments
Risk factorsLong fusion construct, sagittal malalignment, preexisting degeneration
SymptomsNew onset back/leg pain at new dermatomal level
ImagingDisc degeneration, stenosis at adjacent level
ManagementInitially conservative; consider extension of fusion if severe

Arachnoiditis

Inflammatory reaction causing nerve root clumping and scarring.

AspectDetails
IncidenceRare (under 5%), more common with multiple surgeries
CausesIntrathecal blood, infection, myelography contrast (historical)
MRI findingsClumped nerve roots, "empty thecal sac" sign, central cord
PrognosisGenerally poor, progressive symptoms
ManagementPain management, avoid further surgery

Exam Pearl

MRI gadolinium timing is critical: Scar enhances EARLY (under 5 minutes) with PERIPHERAL pattern. Recurrent disc shows NO enhancement or DELAYED CENTRAL enhancement. Always specify timing of post-contrast imaging!

T2-weighted sagittal MRI showing post-operative changes at L4-L5 with epidural scarring
Click to expand
T2-weighted sagittal MRI following lumbar discectomy demonstrating post-operative epidural changes at L4-L5. Epidural fibrosis/scarring causes tethering of neural elements and contributes to ongoing radicular symptoms.Credit: Sen RK, Singh H. Med J Armed Forces India. 1999. CC BY
T1-weighted gadolinium-enhanced MRI demonstrating post-operative enhancement pattern in failed back surgery
Click to expand
T1-weighted gadolinium-enhanced MRI in FBSS patient. Post-operative epidural fibrosis shows early, homogeneous enhancement on Gd-DTPA sequences. This pattern helps differentiate scar tissue from recurrent disc herniation, which demonstrates delayed or no enhancement.Credit: Sen RK, Singh H. Med J Armed Forces India. 1999. CC BY
Axial T1-enhanced MRI showing nerve root enhancement indicating radiculitis
Click to expand
Axial T1 post-gadolinium MRI demonstrating nerve root enhancement (radiculitis). Inflamed nerve roots enhance with contrast, indicating ongoing inflammatory or compressive pathology that may respond to targeted intervention.Credit: Sen RK, Singh H. Med J Armed Forces India. 1999. CC BY

Psychological Factors

Central Sensitization

Maladaptive neuroplastic changes resulting in chronic pain syndrome.

FeatureDescription
MechanismAltered CNS pain processing, lowered pain threshold
SymptomsWidespread pain, hyperalgesia, allodynia
DiagnosisClinical diagnosis, often disproportionate to pathology
TreatmentMultidisciplinary pain program, medications, CBT

Psychosocial Risk Factors

The "Yellow Flags" predicting poor outcomes:

  • Depression and anxiety
  • Catastrophizing and fear-avoidance beliefs
  • Poor coping strategies
  • Secondary gain (compensation, litigation)
  • Job dissatisfaction
  • Social isolation

Clinical Assessment

Systematic evaluation is essential to identify treatable causes and guide management.

History

Pain Characterization

QuestionPurpose
TimelineWhen did symptoms start relative to surgery?
Pain-free intervalAny relief post-surgery before recurrence?
LocationBack predominant, leg predominant, or equal?
CharacterSharp/shooting (nerve) vs aching/burning (scar/chronic)?
Aggravating factorsPositional, activity-related, constant?
Relieving factorsRest, position changes, medications?

Red Flags Requiring Urgent Evaluation

Immediate investigation required:

  • New onset bowel/bladder dysfunction (cauda equina)
  • Progressive motor weakness
  • Fever, wound drainage (infection)
  • Severe unremitting pain unresponsive to medications
  • New sensory level (thoracic symptoms)

Functional Assessment

  • Walking distance and tolerance
  • Sleep disruption
  • Activities of daily living impact
  • Work status and disability
  • Medication requirements and escalation
  • Previous pain management interventions

Psychosocial Screening

Use validated tools:

  • Oswestry Disability Index (ODI)
  • Visual Analog Scale (VAS) for pain
  • SF-36 for quality of life
  • Depression screening (PHQ-9)
  • Opioid Risk Tool (ORT)

Physical Examination

Inspection

  • Surgical scar assessment (well-healed, keloid, drainage)
  • Spinal alignment (coronal and sagittal balance)
  • Gait pattern and assistive devices
  • Muscle wasting in affected myotome

Palpation

  • Tenderness over surgical site
  • Paraspinal muscle spasm
  • Trigger points
  • Sacroiliac joint assessment

Range of Motion

  • Lumbar flexion and extension
  • Note pain reproduction with movement
  • Assess for compensation patterns

Neurological Examination

ComponentAssessmentSignificance
MotorMyotomal strength testingNew weakness vs pre-existing deficit
SensoryDermatomal mappingCompare to preoperative examination
ReflexesKnee jerk (L4), ankle jerk (S1)May be absent post-surgery
Tension signsStraight leg raise, femoral stretchPositive suggests neural irritation
Waddell signsNon-organic signsOver 3 suggests psychosocial component

Vascular Examination

  • Peripheral pulses (exclude vascular claudication)
  • Skin changes, hair loss, temperature
  • Ankle-brachial index if vascular suspected

Diagnostic Workup

Systematic imaging and diagnostic procedures to identify treatable pathology.

Imaging Protocol

MRI with Gadolinium Contrast

The gold standard for FBSS evaluation.

Sequences Required

SequencePurpose
T1 pre-contrastBaseline anatomy, fat signal
T2 sagittal/axialDisc hydration, stenosis, neural compression
T1 post-gadoliniumDistinguish scar vs recurrent disc
Fat-suppressed post-contrastEnhance inflammatory changes

Interpretation - Scar vs Recurrence

FeatureEpidural ScarRecurrent Disc
Pre-contrast T1Intermediate signalHypointense
T2 signalVariableHyperintense (if hydrated)
Post-gadoliniumEARLY peripheral enhancementNO or DELAYED central enhancement
Enhancement timingUnder 5 minutesOver 15 minutes or none
Mass effectMinimalPresent
Nerve displacementTetheringDisplacement away

Other MRI Findings

  • Arachnoiditis: Clumped nerve roots, empty thecal sac
  • Pseudomeningocele: CSF collection, dural tear
  • Infection: Disc signal change, endplate edema, enhancement
  • Stenosis: Residual or adjacent level canal narrowing

This MRI protocol is essential for surgical planning and diagnostic accuracy.

CT Scan

Indications

  • Evaluate bony fusion (pseudarthrosis assessment)
  • Foraminal stenosis measurement
  • Hardware position and integrity
  • Cannot tolerate MRI (pacemaker, severe claustrophobia)

Key Findings

FindingImplication
Bridging bone across fusionSuccessful fusion
Lucency around screwsHardware loosening
Foraminal heightForaminal stenosis assessment
Facet hypertrophyResidual lateral stenosis

Dynamic Radiographs

Flexion-Extension Lumbar X-rays

Instability Criteria

  • Translation: Over 3-4mm (over 4.5mm if degenerative spondylolisthesis)
  • Angulation: Over 10-15 degrees at single level
  • Compare to adjacent levels

Standing Films

  • Sagittal vertical axis (SVA) for global alignment
  • Pelvic incidence, lumbar lordosis mismatch
  • Coronal Cobb angle if scoliosis present

Dynamic imaging is crucial for instability assessment and fusion planning.

Nuclear Medicine

SPECT-CT (Single Photon Emission CT)

  • Identify painful facet joints or pars defects
  • Localize source of pain in multi-level disease
  • Guide selective nerve blocks

PET-CT

  • Rarely used in FBSS
  • Can identify infection or tumor if suspected

Electrodiagnostic Studies

EMG/Nerve Conduction Studies

Indications

  • Distinguish radiculopathy from peripheral neuropathy
  • Assess chronicity and severity of nerve damage
  • Identify multi-level involvement

Limitations

  • Cannot distinguish scar from recurrent disc
  • Normal study does not exclude pathology
  • Useful for prognosis and surgical candidacy

These studies complement imaging in complex cases.

Diagnostic Interventions

Selective Nerve Root Blocks

PurposeTechniqueInterpretation
DiagnosticInject local anesthetic around suspected nerve rootOver 75% pain relief confirms level
TherapeuticAdd steroid for therapeutic effectMay provide temporary or prolonged relief
Surgical planningMulti-level diseaseIdentify symptomatic level for decompression

Facet Joint Injections/Medial Branch Blocks

  • Identify facetogenic pain source
  • May guide radiofrequency ablation
  • Diagnostic response: Over 80% relief with local anesthetic

Discography (Controversial)

AspectDetails
IndicationIdentify painful disc in multi-level disease
TechniqueProvocative injection into disc nucleus
Positive testConcordant pain reproduction at low pressure
ControversyHigh false-positive rate, may accelerate degeneration
Current useLimited; mostly for fusion planning in young patients

Exam Pearl

Diagnostic blocks are valuable but not definitive. Placebo response rates are 30-40%. Confirmatory blocks with different local anesthetics (e.g., lidocaine then bupivacaine on separate days) increase specificity. Never operate based on blocks alone!

Management Algorithm

📊 Management Algorithm
failed back surgery syndrome management algorithm
Click to expand
Management algorithm for failed back surgery syndromeCredit: OrthoVellum

Treatment of FBSS requires a multidisciplinary, stepwise approach. Surgery is rarely first-line.

Conservative Management (First-Line)

Physical Therapy and Rehabilitation

Goals of Physical Therapy

  • Restore function and mobility
  • Strengthen core musculature
  • Improve flexibility and posture
  • Reduce fear-avoidance behaviors
  • Facilitate return to activities

Program Components

PhaseDurationFocus
Phase 1Weeks 1-4Pain control, gentle ROM, posture
Phase 2Weeks 4-8Core strengthening, endurance training
Phase 3Weeks 8-12Functional activities, work simulation
MaintenanceOngoingHome exercise program, activity pacing

Pharmacotherapy

Multimodal Analgesia Approach

ClassExamplesDosingConsiderations
NSAIDsIbuprofen, naproxenAs needed or scheduledGI protection if chronic use
AcetaminophenParacetamol1g TDS-QIDMax 4g/day, hepatotoxicity risk
Neuropathic agentsGabapentin, pregabalinTitrate to effectSedation, dizziness common
AntidepressantsDuloxetine, amitriptylineStart low, increase slowlyDual benefit: pain and mood
Muscle relaxantsCyclobenzaprineShort-term useSedation, dependence risk
Topical agentsLidocaine patches, capsaicinApply to painful areaLocalized effect, fewer systemic side effects

Opioids have LIMITED role in chronic FBSS: Evidence shows minimal benefit and high risk of dependence, hyperalgesia, and worsening outcomes. Avoid chronic opioid therapy when possible. If used, use structured agreement, monitor urine drug screens, assess using Opioid Risk Tool (ORT).

Psychological Interventions

Cognitive Behavioral Therapy (CBT)

ComponentGoal
Cognitive restructuringChallenge catastrophizing, negative thoughts
Behavioral activationIncrease activity despite pain
Relaxation trainingReduce muscle tension, anxiety
Pacing strategiesAvoid boom-bust cycles
Sleep hygieneImprove sleep quality

Multidisciplinary Pain Rehabilitation Programs

Intensive programs combining physical therapy, psychological therapy, medication optimization, occupational therapy, and vocational rehabilitation show best long-term functional outcomes for FBSS patients.

Interventional Pain Management

Epidural Steroid Injections

ApproachIndicationSuccess RateDuration
InterlaminarCentral stenosis, broad distribution30-50% improve3-6 months
TransforaminalRadiculopathy, specific nerve root50-70% improve3-6 months
CaudalMulti-level, previous surgery30-40% improveVariable

Radiofrequency Ablation

  • Target: Facet joint medial branches or dorsal root ganglion
  • Indication: Positive diagnostic blocks
  • Duration: 6-12 months relief
  • Repeatable if initial success

Neuromodulation

Spinal Cord Stimulation (SCS)

The most evidence-based intervention for FBSS with predominant leg pain.

Patient Selection Criteria

CriterionDetails
Pain patternPredominantly radicular leg pain
Failed conservative careAt least 6 months appropriate treatment
Psychological screeningNo untreated major depression, realistic expectations
No surgical indicationNo correctable structural pathology
Trial successOver 50% pain reduction during trial period

Evidence Base

StudyFindings
PROCESS trialSCS superior to conventional management at 6 months
Long-term studies50-70% maintain over 50% pain reduction at 5 years
Patient satisfaction70-80% would repeat procedure
Functional improvementSignificant improvements in ODI, quality of life

Exam Pearl

SCS is evidence-based for FBSS: PROCESS trial showed SCS superior to reoperation for FBSS with radicular pain. Trial before permanent implant is mandatory. Predominantly leg pain responds better than back pain!

Surgical Management (Highly Selective)

Indications for Revision Surgery

Surgery is rarely indicated in FBSS. Consider ONLY if ALL criteria met:

  • Clear structural pathology on imaging (recurrent disc, stenosis, instability)
  • Symptoms correlate with imaging findings
  • Failed 6-12 months of appropriate conservative care
  • Reasonable surgical target identified
  • Favorable psychosocial profile
  • Patient has realistic expectations

Specific Surgical Indications

PathologySurgeryExpected Success Rate
Recurrent disc herniationRevision discectomy ± fusion60-80% if clear recurrence
Inadequate decompressionRevision decompression50-70% if residual compression
PseudarthrosisRevision fusion50-60% (decreases with each revision)
Adjacent segment diseaseExtension of fusion40-60%
Iatrogenic instabilityFusion50-70%

Outcomes Decrease with Multiple Operations

Number of OperationsSuccess Rate
Primary surgery70-90%
First revision50-70%
Second revision30-50%
Third or moreUnder 30%

Exam Pearl

The "next operation syndrome": Each subsequent operation has LOWER success rate and HIGHER complication rate. After 3 operations, success rate under 30%. Avoid perpetual surgical cycling - recognize when surgery will not help!

Prevention Strategies

The best treatment for FBSS is prevention. Systematic approach reduces incidence.

Preoperative Prevention

Correct Diagnosis

StrategyImplementation
Correlate symptoms with imagingEnsure MRI findings explain clinical picture
Consider differential diagnosesHip pathology, peripheral neuropathy, vascular
Trial of conservative care6-12 weeks unless red flags
Avoid surgery for back pain alonePoor outcomes without radiculopathy

Patient Selection and Education

Psychosocial Screening

  • Depression and anxiety screening (PHQ-9, GAD-7)
  • Catastrophizing assessment
  • Litigation and compensation status
  • Substance abuse history
  • Social support assessment

Realistic Expectations

  • Discuss achievable outcomes (improvement, not perfection)
  • Explain recovery timeline (3-6 months full recovery)
  • Review risks and alternative treatments
  • Document shared decision-making

Risk Factor Modification

  • Smoking cessation: 4-6 weeks preoperatively
  • Weight optimization if BMI over 35
  • Diabetes control: HbA1c under 7.5%
  • Optimize nutrition status
  • Discontinue NSAIDs and anticoagulants per protocol

Intraoperative Prevention

Surgical Technique

PrincipleImplementation
Level verificationImaging confirmation BEFORE incision
Adequate decompressionDecompress symptomatic levels completely
Preserve stabilityPreserve under 50% of facet joints
Minimize tissue traumaUse retractors judiciously, limit stripping
HemostasisPrevent hematoma formation
Dural repairWatertight closure if dural tear occurs

Specific Technical Points

Discectomy

  • Remove loose fragments completely
  • Avoid aggressive curettage of disc space
  • Preserve annular integrity when possible
  • Consider limited anular closure techniques

Decompression

  • Decompress lateral recess adequately
  • Undercut facet if foraminal stenosis
  • Bilateral decompression for bilateral symptoms
  • Preserve pars interarticularis

Fusion Decision

  • Fuse if instability present (over 3-4mm translation)
  • Fuse if over 50% facet resection required
  • Consider fusion if degenerative spondylolisthesis
  • Avoid unnecessary fusion (increases adjacent segment disease)

Exam Pearl

Level verification is NON-NEGOTIABLE: Always obtain AP and lateral intraoperative imaging BEFORE incision. Mark skin with radiopaque marker. Count from sacrum upward. Document verification in operative note. Wrong-site surgery is preventable!

Postoperative Prevention

Early Mobilization

TimelineActivity
Day 0-1Out of bed, walking with assistance
Week 1-2Independent ambulation, self-care
Week 2-6Progressive walking, light activities
Week 6-12Formal physical therapy, return to work (sedentary)

Pain Management

  • Multimodal analgesia (minimize opioids)
  • Scheduled NSAIDs (if no contraindication)
  • Neuropathic pain agents if radicular pain persists
  • Transition to oral medications by discharge

Physical Therapy

  • Early referral (week 2-4)
  • Core strengthening program
  • Flexibility and posture training
  • Ergonomic education

Follow-up Protocol

  • Week 2: Wound check, pain assessment
  • Week 6: Clinical evaluation, consider imaging if concerns
  • Month 3: Functional assessment
  • Month 6 and 12: Long-term outcome evaluation

Complications

Understanding potential complications helps inform patient counseling and guide treatment decisions.

Complications of Conservative Treatment

Non-Interventional Complications

TreatmentComplicationIncidenceManagement
NSAIDsGI bleeding, cardiovascular events1-5% with chronic usePPI prophylaxis, lowest effective dose
Neuropathic agentsSedation, dizziness, falls10-30%Dose titration, fall precautions
OpioidsDependence, hyperalgesia, constipation20-40% with chronic useAvoid when possible, bowel regimen
Physical therapyAcute injury, pain flareUnder 5%Proper screening, gradual progression

Psychological Intervention Risks

  • Emotional distress during CBT (initial worsening)
  • Resistance to treatment
  • Time and financial commitment
  • Generally safe with skilled practitioners

Complications of Interventional Procedures

Epidural Steroid Injections

ComplicationIncidenceManagement
Dural puncture1-5%Bed rest, blood patch if persistent headache
Infection (epidural abscess)Under 1%Emergency MRI, surgical drainage, IV antibiotics
Bleeding/hematomaUnder 1%Emergency decompression if neurological deficit
Vasovagal reaction2-5%Supportive care, fluids, observation
Transient neurological symptoms5-10%Usually resolves within 24-48 hours

Spinal Cord Stimulation

ComplicationIncidenceManagement
Lead migration10-15%Revision, lead repositioning
Infection2-5%Antibiotics; explant if severe
Hardware failure5-10%Battery replacement, lead revision
Loss of efficacy20-30% over timeReprogramming, lead revision, explant
Pain at generator site5-10%Repositioning, smaller device
Cerebrospinal fluid leakUnder 1%Conservative management, blood patch

Radiofrequency Ablation

ComplicationIncidenceNotes
Neuritis/dysesthesia5-10%Usually temporary, resolves over weeks
Skin burnsUnder 1%Proper grounding technique prevents
InfectionUnder 1%Sterile technique essential
Weakness (motor nerve injury)Under 1%Careful localization prevents

Complications of Revision Surgery

Intraoperative Complications

ComplicationPrimary SurgeryRevision SurgeryImplications
Dural tear3-10%10-20%Higher risk due to scarring, usually repairable
Neurological injury1-3%3-8%More difficult dissection through scar tissue
Vascular injuryUnder 1%1-3%Altered anatomy increases risk
Wrong level1-3%1-2%Careful imaging verification essential
Inadequate decompression5-10%10-15%Scar tissue obscures anatomy

Early Postoperative Complications (Under 6 Weeks)

ComplicationIncidencePrevention/Management
Infection (superficial)2-5%Prophylactic antibiotics, sterile technique
Infection (deep/discitis)1-3%Emergency I&D, long-term IV antibiotics
Hematoma2-5%Meticulous hemostasis, drain placement
Pseudomeningocele2-5%Watertight dural closure, prone positioning
DVT/PE1-3%Early mobilization, chemoprophylaxis
Urinary retention5-15%Catheterization, alpha-blockers

Late Complications (Over 6 Weeks)

ComplicationIncidenceTime Course
Pseudarthrosis15-30% (revision fusion)6-18 months
Hardware failure5-10%Variable, months to years
Adjacent segment disease5-25%5-10 years post-fusion
Recurrent stenosis10-20%Variable, months to years
Chronic pain (persistent FBSS)30-50%Ongoing
Junctional kyphosis5-15% (long fusions)Years

Specific High-Risk Scenarios

Third or Subsequent Revision Surgery

  • Complication rates exceed 40%
  • Success rates under 30%
  • Each revision increases scar tissue burden
  • Neurological injury risk doubles with each procedure
  • Consider non-surgical options preferentially

Revision in Setting of Active Litigation

  • Outcomes significantly worse
  • Psychological factors dominant
  • Higher pain scores despite anatomical success
  • Consider delaying surgery until litigation resolved

Revision with Concurrent Opioid Dependence

  • Postoperative pain management extremely challenging
  • Higher infection rates
  • Delayed healing
  • Require structured tapering program preoperatively

Exam Pearl

Complication rates INCREASE with each revision: First revision has 15-25% complication rate. Second revision 25-40%. Third or more over 40%. Always counsel patients about cumulative risk with multiple operations!

Prevention Strategies

Reducing Complications

StrategyImpact
Careful patient selectionMost important factor
Preoperative optimizationSmoking cessation, weight loss, diabetes control
Meticulous surgical techniqueMinimize tissue trauma, adequate hemostasis
Antibiotic prophylaxisReduces infection risk
Early mobilizationReduces VTE risk
Multidisciplinary approachAddresses all contributing factors

Evidence Base

PROCESS Trial: SCS vs Conventional Management

Level I
Kumar K et al. • Pain (2007)
Key Findings:
  • Spinal cord stimulation superior to conventional medical management for FBSS with predominant leg pain
  • At 6 months: 48% of SCS patients achieved primary outcome (50% leg pain relief) vs 9% of controls
  • Crossover rate high in control group (32% crossed to SCS due to inadequate relief)
  • Benefit sustained at 12 and 24 months follow-up
  • Quality of life significantly improved in SCS group
  • Complication rate acceptable with 5% requiring revision
Clinical Implication: This evidence guides current practice.

Gadolinium Enhancement Patterns in Postoperative Spine

Level II
Ross JS et al. • AJNR (1996)
Key Findings:
  • Epidural scar enhances immediately (under 5 minutes post-gadolinium) with peripheral pattern
  • Recurrent disc shows delayed (15-30 minutes) central enhancement or no enhancement
  • MRI with gadolinium: 95% sensitivity and 77% specificity for scar vs disc distinction
  • Timing of post-contrast imaging critical for accurate interpretation
  • T1-weighted images most useful for enhancement assessment
  • Mass effect present with recurrent disc, minimal with scar
Clinical Implication: This evidence guides current practice.

Outcomes of Revision Lumbar Discectomy

Level III
Papadopoulos EC et al. • J Bone Joint Surg Am (2006)
Key Findings:
  • First revision discectomy for recurrent herniation: 65% good-excellent outcomes
  • Second revision discectomy: success decreased to 35%
  • Outcomes significantly better when recurrent herniation clearly identified on MRI
  • Surgery for scar tissue alone had poor outcomes (under 40%)
  • Dural tear rate 15% (higher than primary surgery 5-8%)
  • Patient selection critical - favorable psychosocial profile improves outcomes
Clinical Implication: This evidence guides current practice.

Psychosocial Predictors of Surgical Outcome

Level II
Block AR et al. • Spine J (2001)
Key Findings:
  • Depression and passive coping strategies strongest predictors of poor surgical outcome
  • Psychosocial factors MORE predictive than MRI findings
  • Patients with high psychological distress: 3-fold higher risk of FBSS
  • Catastrophizing behavior significantly associated with chronic pain
  • Workers' compensation and litigation strongly predict poor outcomes
  • Preoperative psychological screening recommended for all spine surgery candidates
Clinical Implication: This evidence guides current practice.

References

  1. Chan CW, Peng P. Failed back surgery syndrome. Pain Med. 2011;12(4):577-606. doi:10.1111/j.1526-4637.2011.01089.x

  2. Kumar K, Taylor RS, Jacques L, et al. Spinal cord stimulation versus conventional medical management for neuropathic pain: a multicentre randomised controlled trial in patients with failed back surgery syndrome. Pain. 2007;132(1-2):179-188. doi:10.1016/j.pain.2007.07.028

  3. Ross JS, Robertson JT, Frederickson RC, et al. Association between peridural scar and recurrent radicular pain after lumbar discectomy: magnetic resonance evaluation. Neurosurgery. 1996;38(4):855-861. doi:10.1097/00006123-199604000-00053

  4. Papadopoulos EC, Girardi FP, Sandhu HS, et al. Outcome of revision discectomies following recurrent lumbar disc herniation. Spine. 2006;31(13):1473-1476. doi:10.1097/01.brs.0000220901.89492.bb

  5. Block AR, Ohnmeiss DD, Guyer RD, et al. The use of presurgical psychological screening to predict the outcome of spine surgery. Spine J. 2001;1(4):274-282. doi:10.1016/s1529-9430(01)00054-7

  6. Gatchel RJ, Okifuji A. Evidence-based scientific data documenting the treatment and cost-effectiveness of comprehensive pain programs for chronic nonmalignant pain. J Pain. 2006;7(11):779-793. doi:10.1016/j.jpain.2006.08.005

  7. North RB, Kidd DH, Farrokhi F, Piantadosi SA. Spinal cord stimulation versus repeated lumbosacral spine surgery for chronic pain: a randomized, controlled trial. Neurosurgery. 2005;56(1):98-107. doi:10.1227/01.neu.0000144839.65524.e0

  8. Taylor RS, Ryan J, O'Donnell R, et al. The cost-effectiveness of spinal cord stimulation in the treatment of failed back surgery syndrome. Clin J Pain. 2010;26(6):463-469. doi:10.1097/AJP.0b013e3181daccec

  9. Fritsch EW, Heisel J, Rupp S. The failed back surgery syndrome: reasons, intraoperative findings, and long-term results: a report of 182 operative treatments. Spine. 1996;21(5):626-633. doi:10.1097/00007632-199603010-00017

  10. Burton CV, Kirkaldy-Willis WH, Yong-Hing K, Heithoff KB. Causes of failure of surgery on the lumbar spine. Clin Orthop Relat Res. 1981;(157):191-199.

  11. Slipman CW, Shin CH, Patel RK, et al. Etiologies of failed back surgery syndrome. Pain Med. 2002;3(3):200-214. doi:10.1046/j.1526-4637.2002.02033.x

  12. Flum AS, Hickey A, Flum DR. Understanding the psychological factors affecting failed back surgery syndrome: a systematic review. Healthcare (Basel). 2021;9(10):1275. doi:10.3390/healthcare9101275

  13. Thomson S, Jacques L. Demographic characteristics of patients with severe neuropathic pain secondary to failed back surgery syndrome. Pain Pract. 2009;9(3):206-215. doi:10.1111/j.1533-2500.2009.00276.x

  14. Hussain A, Erdek M. Interventional pain management for failed back surgery syndrome. Pain Pract. 2014;14(1):64-78. doi:10.1111/papr.12035

  15. Kumar K, North R, Taylor R, et al. Spinal cord stimulation vs. conventional medical management: a prospective, randomized, controlled, multicenter study of patients with failed back surgery syndrome (PROCESS study). Neuromodulation. 2005;8(4):213-218. doi:10.1111/j.1525-1403.2005.00027.x

Exam Viva Scenarios

Practice these scenarios to excel in your viva examination

VIVA SCENARIOStandard

Scenario 1: Persistent Radiculopathy After Microdiscectomy

EXAMINER

"A 45-year-old male underwent L5-S1 microdiscectomy 6 months ago for right L5 radiculopathy. He had 2 weeks of improvement but now has recurrent right leg pain worse than preoperatively. MRI shows soft tissue in the epidural space at L5-S1. How would you evaluate and manage this patient?"

EXCEPTIONAL ANSWER
Examiner. This is a case of possible failed back surgery syndrome following L5-S1 discectomy. I would approach this systematically. First, I would take a detailed history focusing on the timeline - was there a pain-free interval? This suggests recurrent herniation rather than inadequate surgery. I would characterize the pain - radicular pattern suggests structural pathology. On examination, I would perform a complete neurological assessment looking for L5 motor weakness, sensory changes, and positive nerve tension signs. My key investigation would be MRI with gadolinium contrast. Epidural scar enhances early (under 5 minutes) with a peripheral pattern, while recurrent disc shows no enhancement or delayed central enhancement. If the MRI shows a recurrent disc fragment with mass effect and the patient has severe radicular pain, I would consider revision discectomy with good success rates of 60-80%. However, if it is purely scar tissue, surgical outcomes are poor (under 40%), and I would manage conservatively with physical therapy, neuropathic pain medications, and consider epidural steroid injections. I would also screen for psychosocial factors that may contribute to pain perception. If conservative measures fail and he has predominantly leg pain, spinal cord stimulation would be an evidence-based option based on the PROCESS trial.
KEY POINTS TO SCORE
Distinguish between recurrent disc and epidural scar using gadolinium-enhanced MRI
Timeline of symptoms helps differentiate (pain-free interval suggests recurrence)
Surgery only for clear recurrent herniation; outcomes poor for scar tissue alone
Conservative management first-line for most FBSS cases
Consider SCS for chronic radicular pain unresponsive to conservative care
COMMON TRAPS
✗Jumping to revision surgery without proper imaging workup
✗Not obtaining gadolinium-enhanced MRI (plain MRI cannot distinguish scar vs disc)
✗Operating for scar tissue alone (poor outcomes)
✗Ignoring psychosocial screening and patient selection
✗Not considering non-operative options like spinal cord stimulation
LIKELY FOLLOW-UPS
"What are the MRI characteristics that distinguish scar from recurrent disc?"
"What is the success rate of revision discectomy vs first-time surgery?"
"What evidence supports spinal cord stimulation in FBSS?"
"What psychosocial factors predict poor outcomes?"
"How would you consent this patient for revision surgery?"
VIVA SCENARIOStandard

Scenario 2: Wrong Level Surgery

EXAMINER

"A 60-year-old female underwent L4-5 decompression for neurogenic claudication 3 months ago. She has had no improvement in symptoms. Review of her postoperative MRI shows decompression was performed at L3-4, not L4-5. The patient is now consulting you for a second opinion. How do you manage this situation?"

EXCEPTIONAL ANSWER
Examiner. This is a very challenging medicolegal situation of wrong-level surgery, which is a never event. My approach would be systematic and transparent. First, I would review all imaging myself - the preoperative MRI to confirm L4-5 was the symptomatic level, and the postoperative imaging to confirm decompression at L3-4. I would correlate her current symptoms with the unaddressed L4-5 pathology. I would have an honest conversation with the patient, explaining that surgery was performed at an incorrect level, this is a serious error, and I need to involve the original surgeon and hospital risk management. This requires full disclosure. Clinically, I would perform a complete neurological examination to ensure no new deficits were created. Regarding treatment, if she has significant stenosis at L4-5 causing severe symptoms and has failed conservative care, I would consider revision decompression at the correct L4-5 level. However, I would carefully counsel her that revision surgery carries higher risks (dural tear 10-20%, infection 3-5%) and outcomes are inferior to primary surgery (60-70% success vs 80-90%). I would also evaluate the L3-4 decompression - was there stenosis there as well that may have been appropriately addressed, just not the primary pathology? If she declines further surgery or is not a candidate, conservative management with physical therapy, pain management, and potentially spinal cord stimulation would be appropriate. I would ensure psychological support is offered given the trauma of this medical error. From a prevention standpoint, this highlights the critical importance of intraoperative level verification with imaging before incision.
KEY POINTS TO SCORE
Wrong-level surgery is a never event requiring full disclosure
Honest communication with patient and involvement of hospital risk management
Review all imaging yourself to confirm the error and symptomatic level
Revision surgery has higher risks and lower success rates
Prevention through intraoperative level verification is critical
COMMON TRAPS
✗Not recognizing the medicolegal implications and disclosure requirements
✗Blaming the previous surgeon without objective review
✗Rushing to revision surgery without proper evaluation
✗Not considering that both levels might have pathology
✗Failing to discuss prevention strategies with examiner
LIKELY FOLLOW-UPS
"How do you prevent wrong-level surgery in your practice?"
"What is your duty regarding disclosure to the patient?"
"What success rate would you quote for revision decompression?"
"Should you contact the original surgeon?"
"What role does risk management play?"
"How would you document this consultation?"
VIVA SCENARIOStandard

Scenario 3: Chronic FBSS with Multiple Previous Surgeries

EXAMINER

"A 50-year-old male presents with chronic back and leg pain. He has had 3 previous lumbar surgeries: L5-S1 discectomy, then L4-5 decompression, then L4-S1 fusion. His pain never improved. He is on high-dose opioids and is requesting another operation. MRI shows solid fusion with no obvious structural pathology. How would you assess and manage this patient?"

EXCEPTIONAL ANSWER
Examiner. This represents a very challenging case of chronic FBSS with multiple previous operations - a classic next operation syndrome scenario. My approach would be very cautious and comprehensive. First, history: I need to understand if he ever had any pain relief from the surgeries or if symptoms never improved - the latter suggests wrong initial diagnosis or central sensitization. I would review all operative notes and imaging to understand what was done and why. Current symptoms - back predominant or leg predominant? Radicular or diffuse? On examination, I would perform complete neurological assessment and look for Waddell signs suggesting non-organic pain. Red flags screening for infection, tumor, or cauda equina. I would review his current MRI - is there solid fusion or pseudarthrosis? Any adjacent segment disease at L3-4? Any recurrent stenosis? Critically, I would assess for psychosocial factors: depression screening, catastrophizing, compensation status, substance abuse history. This patient is at extremely high risk for poor surgical outcome. With 3 previous operations and no structural pathology, a fourth surgery has under 30% success rate with over 40% complication risk. I would NOT offer surgery. Instead, I would recommend multidisciplinary pain rehabilitation program - the evidence shows this provides best long-term functional outcomes for chronic FBSS. Components include physical therapy, cognitive behavioral therapy, medication optimization with opioid tapering, and functional restoration. If he has predominantly leg pain and fails comprehensive rehabilitation, spinal cord stimulation trial would be appropriate based on PROCESS trial evidence. The key message is avoiding the next operation - more surgery will likely make him worse, not better.
KEY POINTS TO SCORE
Multiple previous surgeries have very poor outcomes (under 30% success for third revision)
Absence of structural pathology makes surgery inappropriate
Central sensitization and chronic pain syndrome likely present
Multidisciplinary pain program is best evidence-based treatment
Avoid the next operation syndrome - recognize when surgery will not help
COMMON TRAPS
✗Offering surgery to satisfy patient demand despite poor prognosis
✗Not screening for psychosocial factors and substance abuse
✗Not recognizing central sensitization and chronic pain syndrome
✗Missing the evidence for multidisciplinary rehabilitation
✗Not discussing spinal cord stimulation as option for radicular pain
LIKELY FOLLOW-UPS
"What is the success rate of a fourth operation in this scenario?"
"What are the components of a multidisciplinary pain program?"
"How would you approach opioid tapering in this patient?"
"What evidence supports spinal cord stimulation for FBSS?"
"What are Waddell signs and their significance?"
"How do you counsel a patient who is insisting on surgery you do not recommend?"

MCQ Practice Points

Exam Pearl

Q: What are the most common causes of failed back surgery syndrome (FBSS)?

A: Recurrent or residual disc herniation (most common surgically treatable cause); Foraminal stenosis (especially lateral recess); Adjacent segment disease; Pseudarthrosis (failed fusion); Epidural fibrosis/scar tissue; Segmental instability; Wrong level surgery; Unrecognized spinal stenosis. Non-structural causes: Central sensitization, psychological factors, secondary gain, undiagnosed pain generator (SIJ, facet, hip).

Exam Pearl

Q: How do you evaluate a patient with persistent pain after lumbar spine surgery?

A: History: Pain timing (immediate vs delayed), character (radicular vs axial), response to previous surgery, red flags. Examination: Neurological assessment, provocative tests (SIJ, facet), hip examination. Imaging: MRI with gadolinium (differentiates scar from recurrent disc); CT for bony detail, fusion assessment; Standing X-rays for instability. Diagnostic injections: Selective nerve root blocks, facet blocks, SIJ injection, discography if indicated. Multidisciplinary pain assessment recommended.

Exam Pearl

Q: How do you differentiate epidural fibrosis from recurrent disc herniation on MRI?

A: Both can cause nerve compression post-discectomy. Recurrent disc herniation: Mass effect with peripheral enhancement on gadolinium (enhancing rim around non-enhancing disc material); Contiguous with disc space. Epidural fibrosis: Diffuse homogeneous enhancement throughout scar tissue; Retracts and conforms to dural sac rather than displacing it; May extend around nerve root. Clinical correlation essential - scar alone rarely causes significant symptoms.

Exam Pearl

Q: What is the role of spinal cord stimulation in FBSS?

A: Spinal cord stimulation (SCS) is evidence-based treatment for neuropathic leg pain in FBSS when conservative measures fail. Mechanism: Modulates pain transmission via dorsal column stimulation. Best results: Predominant radicular/neuropathic leg pain (greater than axial back pain); Failed conservative therapy; No surgically correctable pathology; Psychological screening passed. Trial stimulator first; Permanent implant if greater than 50% pain reduction. Less effective for predominantly axial back pain.

Exam Pearl

Q: What are the predictors of poor outcome after revision spine surgery for FBSS?

A: Poor prognostic factors: Multiple prior surgeries (success rate drops with each revision); Predominant axial back pain (vs radicular); Worker's compensation/litigation; Psychological comorbidities (depression, catastrophizing); Smoking; Chronic opioid use; Long duration of symptoms pre-revision; No clear anatomical pain generator identified. Patient selection is critical - multidisciplinary assessment recommended before revision surgery.

Australian Context

Multidisciplinary Pain Services: Australian pain management guidelines recommend referral to multidisciplinary pain services for chronic FBSS. Major tertiary hospitals have dedicated spinal pain clinics.

Spinal Cord Stimulation Access: SCS devices are available through the Prostheses List with private health insurance coverage. Public hospital access varies by state but is generally available at major spine centres.

PBS Medications: Gabapentinoids (pregabalin, gabapentin) and duloxetine are PBS-subsidised for neuropathic pain management. Opioid prescribing follows Australian TGA guidelines with real-time prescription monitoring.

WorkCover Considerations: Many FBSS patients have workers' compensation claims. Independent medical assessments and whole person impairment ratings guide compensation decisions under state-based legislation.

FAILED BACK SURGERY SYNDROME

High-Yield Exam Summary

Definition and Epidemiology

  • •FBSS: Persistent or recurrent pain post-lumbar surgery despite anatomical success
  • •Incidence: 10-40% depending on procedure (higher for fusion vs discectomy)
  • •NOT a specific diagnosis - heterogeneous syndrome requiring systematic evaluation
  • •Strongest predictors: Psychosocial factors (depression, catastrophizing)

Common Causes (Mnemonic: FAILED)

  • •F - Fibrosis (epidural scar) - most common chronic cause
  • •A - Adjacent segment disease (5-25% by 10 years post-fusion)
  • •I - Inadequate decompression (residual stenosis, retained disc fragment)
  • •L - Level wrong (5-15% incidence - never event)
  • •E - Epidural hematoma or infection (early complications)
  • •D - Disc recurrent herniation (5-15% following discectomy)

Diagnostic Imaging - MRI with Gadolinium

  • •Scar: EARLY enhancement (under 5 min) with PERIPHERAL pattern
  • •Recurrent disc: NO enhancement or DELAYED CENTRAL enhancement (over 15 min)
  • •Mass effect: Minimal with scar, present with recurrent disc
  • •Arachnoiditis: Clumped nerve roots, empty thecal sac sign
  • •Dynamic X-rays: Instability if over 3-4mm translation or over 10-15 degrees angulation

Management Algorithm

  • •First-line: Conservative (PT, neuropathic meds, CBT) - 40-60% improve
  • •Interventional: Epidural injections (50-70% for radicular pain), RFA for facets
  • •Neuromodulation: SCS for radicular pain - PROCESS trial shows 50% reduction
  • •Surgery: ONLY if clear structural pathology (recurrent disc, stenosis, instability)
  • •Success rates decrease: Primary 80%, 1st revision 60%, 2nd revision 40%, 3rd under 30%

Spinal Cord Stimulation

  • •Indications: Radicular leg pain, failed 6mo conservative care, no surgical lesion
  • •Trial mandatory: 5-7 days, success defined as over 50% pain reduction
  • •Evidence: PROCESS trial - SCS superior to conventional management at 6mo
  • •Outcomes: 50-70% achieve over 50% pain reduction long-term
  • •Better for leg pain than back pain, best with favorable psych profile

Prevention Strategies (Mnemonic: PREVENT)

  • •P - Psychosocial screening preoperatively
  • •R - Right diagnosis (correlate symptoms with imaging)
  • •E - Expectations managed (realistic goals discussion)
  • •V - Verify level intraoperatively (AP and lateral imaging BEFORE incision)
  • •E - Early mobilization (prevent deconditioning)
  • •N - Nerve protection (minimize retraction, preserve blood supply)
  • •T - Tissue preservation (limit dissection, preserve under 50% facets)

High-Yield Exam Points

  • •FBSS vs surgical failure: FBSS = anatomically successful, failure = technical error
  • •Gadolinium timing CRITICAL: Early peripheral (scar) vs delayed or none (disc)
  • •Psychosocial factors predict outcomes MORE than surgical technique
  • •Multidisciplinary pain programs: Best long-term functional outcomes
  • •Avoid next operation syndrome: Each surgery lower success, higher risk
  • •SCS evidence-based (PROCESS trial) for radicular pain post-surgery
Quick Stats
Reading Time135 min
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