Spondylolisthesis Degenerative

Definition

Spondylolithesis L4/5

Spondylolithesis caused by

- facet joint degeneration

- no pars or dysplastic pathology

- disc space usually preserved

 

Most common at L4/5 level

 

Epidemiology

 

More common in elderly females

- F: M = 5:1

 

Diabetics

 

Pathogenesis

 

1.  Facet degeneration

- body weight displaces lumbar vertebrae ventrally 

- resisted by facet joints

 

2.  Sagittal orientation of facet joints obviates restraining effect 

 

Boden JBJS 1996

- facet joint angle L4 or L5 >45° to coronal plane

- 25x more likely to have degenerate spondylolisthesis

 

3.  Segmental Instability

 

Pathology

 

Slip usually mild / rarely past Meyerding Grade II

- average 15% 

- maximum 30% 

- facet involvement may be asymmetrical & this causes rotatory component 

 

Symptoms

 

1.  Low Back Pain 80%

 

2.  Radiculopathy

- sciatica 50% 

- usually L5 in lateral recess

- can be L4 via narrowing foramen

 

3.  Neurogenic Claudication 50% 

- worse with standing, relieved by flexion

- claudication distance is variable

- sensory changes

- normal pulses

 

4.  Cauda Equina 5%

 

Signs

 

ROM

- normal lumbar forward flexion

- pain on extension

 

Minimal tenderness & spasm 

 

Neurological deficit 50%

- sensory alteration 30%

- weakness 20%

 

Xray

 

AP

- facet hypertrophy / osteophyte formation 

 

Lateral

- mild forward slip 

 

Dynamic Views

- >10° or 4mm = objective instability

 

CT 

 

Degeneration of facet 

 

Degenerative Spondylolithesis CT 2Degenerative Spondylolithesis CT 1

 

MRI

 

Demonstrate stenosis with spondylolithesis

 

L45 Spondylolithesis MRI

 

NHx

 

Don't tend to progress past Grade II

 

Do well if have no neurological symptoms

 

Often need surgery for neurological claudication / stenosis

 

Management

 

Non-operative

 

Indications

 

Mild symptoms / short duration / unfit for surgery

 

Technique

 

Activity modification / analgesics / physio

 

Results

 

Weinstein et al N Eng J Med 2007

- RCT of operative v non operative, multicentred

- operative group had substantial improvement in pain and function at 2 years

 

Pearson et al Spine 2009

- SPORT

- RCT of operative v non operative

- operative group had significantly better outcomes

- grade 1 better outcome than grade 2 with surgery

- dynamic instability better outcome than static

 

Operative

 

Indications

- failure of non operative treatment 

- radiculopathy / neurogenic claudication

- progressive neurological defect

- bladder or bowel symptoms

 

Principles / Issues

 

1.  Decompress + fusion

- demonstrated superior results in degenerative spondylolithesis

 

Herkowitz et al Spine 1991

- fusion & decompression alone had better results at 3 years than decompression alone 

- slip increased 95% vs 30%

 

2.  Instrumentation

- instrumentation increases fusion rate

- ? solid fusion improves outcome

 

Fischgrund et al 1997

- RCT of PLF with and without instrumentation

- increased fusion rates with pedicle screws (82% v 45%)

- no evidence of superior outcome

 

Martin et al Spine 2007

- systematic review

- fusion leads to better outcome than decompression alone

- evidence that instrumentation increases fusion rate

- no evidence that instrumentation improves outcome

 

3.  Interbody cages

- increase foraminal height / important if radiculopathy

- improve fusion rates

 

Options

 

Decompression + PLF without instrumentation

Decompression + instrumented PLF

Decompression + PLF + interbody cage / PLIF / 360o fusion

 

Results

 

Abdu et al Spine 2009

- SPORT

- 360 patients comparing PLF / instrumented PLF / PLIF (360o fusion)

- no difference at 4 years in outcome

 

Decompression + Instrumented Posterolateral Fusion 

 

Degenerative Spondylolithesis PLF

 

Technique

 

Midline incision

- elevate para-spinal muscles

- expose L4/5 facets and TP's

- laminectomy +/- foraminotomy

- pedicle screws + rods

- decorticate lamina, transverse processes, facet joints

- posterolateral fusion with BMP collagen and synthetic BG sushi rolls

 

Results

 

Decompression and PLIF / 360o fusion

 

Adult Spondylithesis PLIF