Spondylolisthesis

Summary

Describe:
– relative displacement of vertebrae
Types: Wiltse classification
– Dysplastic (congenital)
– Isthmic
– Lytic – fatigue fracture of pars
– Degenerative
– Traumatic (fracture other than pars)
– Pathologic
– Iatrogenic

Diagnosis:
– History: trauma, chronicity, surgical history, age of presentation, concurrent medical problems
– Imaging: spinal XR (AP and lateral)
Management:
– Non-operative
– operative indication

Wiltse Types

Dysplastic (congenital)
- sacrum/ nerual arch, normal pars
Isthmic
- Lytic – fatigue fracture of pars
- Elongated but intact pars
- Acute pars fracture
Degenerative
Traumatic (fracture other than pars)
Pathologic
Iatrogenic

Meyerding Grade

1 – 25%
2 – 50%
3 – 75%
4 – 100%
5 – >100%
>50% considered high grade

Degenerative Spondylolisthesis

Background
- L45
- Pathophys – facet arthrosis
- Demographics
  - Females
  - >40
  - Blacks
  - Diabetics
Presenttation
- Mechanical back pain relieved with rest
- Neurogenic claudication and leg pain
Risk factors
- Sagittally oriented facets
- Transitional lumbosacral L5
Stenosis
- Central and lateral recess
  - Slippage, flavum hypertrophy, facet arthrosis
  - Descending L5 nerve root
- Foraminal
  - Vertical stenosis
  - A to P stenosis (facet arthosis)
  - Exiting L4 nerve root
Management
- Non op
- Decompression
- Decompression + fusion
  - Sagittal facets
  - Dynamical instability: Flex-ex view >4mm
  - Intact disc height
  - Facet gapping >1
  - Fluid in facet capsule
- Interbody Fusion
  - Increase costs
  - No fusion rate increase
Complications
- ASD of 20-30% requiring surgery within 10 years

Isthmic Spondylolisthesis

Background
- Overall incidence of 5%
  - 7% of adolescent athletes
  - Adults
    - Throwing 27%
    - Gymnastics 17%
    - Rrowing 17%
    - Weight lifting 13%
    - Swimming 10%
- 47% of low back complaints in adolescents
- Common in Native (20-60% in Inuit)
- L5 most common
- M>F
  - But females more likely to slip
Natural Hx
- Repetitive loading Hx
  - Childrern and adults
- Heals with immobilization
- Dysplastic
  - 32% progression
- Isthmmimc
  - 4% progression
- RF for slipping
  - Dx before growth spurt
  - F
  - >50% slip
  - >50 degree slip
- Slip progression and back pain not correlated
- At presentation
  - No slip
    - Half no futherr flip
    - 50% slip a mean of 24%
  - Slippage present
    - Additional slippage of 7-20%
- Slip progression
  - 20% of symptomatic get it
  - Disk degen and slip go hand in hand
  - Progression worse in adults
  - Wose in L4 lysis

Presentation
- LBP (lumbar extension)
- L5 radiculopathy
  - Posterior elements stay behind
  - Degen and Congenital, the posterior element go forward which causes central stenosis
- Hamstring spasm most common neurologic abnormality
- Gait
  - Shorten stride, flex knee and hips
Imaging
- Meyer Ding
- Slip Angle
  - Superior endplate L5
  - Superior endplate S1
Classification
- Type 1
  - Low grade
  - Low PI <45
- Type 2
  - Low grade
  - Med PI 45-60
- Type 3
  - Low grrade
  - High PI >60
- Typee 4
  - High grade
  - Balanced Pelvis (SS 2/3 of PI)
- Type 5
  - High grade
  - Retro pelvis (SS <2/3 of PI)
  - Normal SVA
- Type 6
  - High grade
  - Retro pelvis (SS <2/3 of PI)
  - Positive SVA

Pathophysiology
- Pars defect (spectrum)
- Pars tress reaction
- Spondylolysis
  - Complete fracture of parrs
  - Not present at bith
  - 5% of population
  - Activity related – repetitive hyperextension
- Spondylolisthesis
  - 15% with pars lesion progress to spondylolisthesis (is that in peds, adult number is 5%)
Risk factors for development of spondylolisthesis
- Increase PI (increase SS) so increase LL requires to maintain balance
- Hyperextension activities
- Inuit
Risk factors for slip progression
- <15
- Disc degen
- L45 Level (Iliolumbar ligament stabilized L5
Risk factors for spondylolisthesis progression
- Adolescent growth spurt
- LS kyphosis (Slip angle >40)
- Younger age
- female
- Dysplastic posterior elements
- Dome shaped sacrum
- Trapezoidal L5
- High grade slip
- Hypoplastic facets
Imaging
- SPECT replaced by MRI
- CT best for anatomy
Management
- Non op
  - Observationo
  - PT and activity resitrcion 6 months
    - Hamstring stretch, pelvic tilt, abdominal
  - Bracing (6-12) – for acute pars reaction TLSO
- Surgery
  - Low grade with persistent symptoms despite >6 months non surgical
  - High grade
  - L1-L4 isthmic defect – Pars repair Indications for Surgery Significant or progressive neuro impairment Functional impairment despite non-op treatment High risk of progression (to spondyloptosis) >50% if young, >40% if young and dysplastic >75% in mature patient
Considerations
- Low grade
  - In Situ fusion
    - Decompression PRN
    - L5-S1 PSIF with TLIF
      - TLIF reduces pseudoarthrosis
      - c/i: disc degen
- High grade
  - Balanced pelvis
    - L4-S1 PSIF with TLIF in situ
  - Unbalances pelvis retroverted (compensated Type 5 or uncompensated Type 6)
    - L4-S1 PSIF with TLIF correct LS kyphosis (slip angle) – will decrease pelvic till
    - Decompression L5 and visualize before reduction
    - Sacral dome osteotomy PRN
    - Max 50% reduction
      - The final 50% puts +++ traction on neve (non linear relationship)
    - IONM
      - Baselines
        2mA for normal neve
        8mA for damaged nerve
  - Spondyloptosis
    - Consider L5 vertebrectomy

Degen vs Isthmic

L45
Central stenosis – L5
Can have foraminal stenosis (vertical height loss, facet arthrosis) – L4
Isthmic
- L5S1
- No central stenosis
- Foraminal aka far lateral L5 compression

“Balanced Pelvis”

SS is 2/3 and PT is 1/3 of PI

“Balanced Spinopelvic”

C7 within 2cm of PS corner S1

PI corelates with grade of spondylolisthesis

Inherent to the patient
No change with reduction

PI and age

Same during childhood
Inc during adolescence
Static in adulthood

ASD and revisions (in the SPORT Trial)

18% of patients need addition surgey for ASD within 10 years. Most recentt data says 20-29%

All of the following are associated with isthmic spondylolisthesis, except?

Inuit heritage

Elongation of the pars

Back pain

Spina bifida occulta