ThoracoLumbar

Approaches

Options

 

Anterior

- thoracotomy

- thoracoabdominal

- abdominal

 

Posterior

 

Anterior Approaches

 

C2 - T2

- anterior cervical approach

- may have to split manubrium / sternotomy for lowest levels

 

T3 - T7

- thoracotomy

- patient on side left side up to avoid veins

- always easier to mobilise aorta

- scapular in the way of the ribs

- release scapula and lift away from ribs

- go through bed of appropriate rib

- usually rib 2 above vertebra

- have to deflate lung with double lumen ETT

- divide segmental artery away from foramen

- identify discs (hills) and vertebral bodies (valleys)

 

T7 - T12

- thoracotomy

- patient on side

- bed of rib 2 above vertebra

- can usually push lung out of way without deflation

 

T12 - L1

- thoracoabdominal

- patient on side

- through bed of 10th rib

- diaphragm attaches at T12/L1 and 12th rib

- must take down diaphragm if need to instrument or cross T12/L1

 

L2 - L5

- anterolateral flank / retroperitoneal approach

- incision below 12th rib

- patient on side

 

L5/S1

- anterior / transabdominal approach

- pelvis blocks flank approach

 

Retroperitoneal Approach L2 - L4

 

Position

- patient left side up 45o

- surgeon stands on right

 

Technique

 

Incision

- in line with 12th rib and towards pubic symphysis

 

Approach

- split musculature / external and internal oblique / transversalis

- identify and preserve peritoneum / stay retroperitoneal

- dissection done with peanuts

- ureter and genitofemoral nerve on psoas / reflect medially

- stay anterior to psoas to preserve nerve roots

- symphathetic chain medial to psoas

- aorta and IVC on vertebral bodies

- tie off segmental arteries

- gently reflect vessels

 

Transabdominal Approach L4 - S1

 

Position

- patient supine

 

Technique

 

Paramedian incision

- stand on right / approach from left

- midway between umbilicus and symphysis

- through skin and subcutaneous fat

- divide anterior rectus sheath (external and internal oblique)

- separate left rectus muscle from posterior rectus sheath

- posterior rectus sheath is deficient by L4/5, ending in semilunar membrane

- divide posterior rectus sheath (transversalis / internal oblique), staying outside peritoneum

- divide peritoneum

- mobilise bowel

 

Aorta bifurcates at L4/5

- common iliac artery and vein on medial psoas

- identify sacral promontory between

- divide posterior peritoneum in midline distal to bifurcation

- superior hypogastric plexus on common iliac vein / sympathetic

- injury causes retrograde ejaculation

 

L4/5

- reflect artery and vein medially

- have to divide and ligate iliolumbar vein

 

L5/S1

 

Access between common iliac vessels

- must divide median sacral vein

 

 

 

Crush Fractures

Definition

 

Minimal trauma fracture

- secondary to osteoporosis

- wedge fractures

 

Epidemiology

 

F > M

More common in elderly patients

 

Uncommon in men < 75

- look for alternative diagnosis

 

DDx

 

Renal failure

Malignancy - metastasis

Infection

 

Clinically

 

Can present with pain

Can be asymptomatic

 

Issues

 

1.  Pain

 

2.  Deformity / kyphosis

 

Management

 

Non operative Management

 

Algorithm

 

1.  Exclude other diagnosis

- metastasis

- primary malignancy

- infection

- CRF

 

2.  Pain relief

- analgesics as required

 

3.  Manage osteoporosis

- DEXA scan

- bisphosphonates

- vitamin D + calcium

 

4.  Bracing

- indicated if kyphotic deformity > 20o

 

5.  Early mobilisation

 

Operative Management

 

Options

 

Vertebroplasty

Kyphoplasty

Fusion

 

Vertebroplasty

 

Indications

 

Pain

- non responsive to non operative treatment

 

Technique

 

Percutaneous

- trochar into pedicle under fluoroscopy

- injection PMMA

 

KyphoplastyKyphoplasty Lateral

 

Results

 

Klazen et al Lancet 2010

- RCT of vertebroplasty v non operative treatment

- 431 patients over 50, all T5 or lower

- no complications

- immediate pain relief which was maintained at 1 year follow up

 

Kyphoplasty

 

Indication

- pain relief

- restoration of deformity

 

Technique

 

Kyphoplasty InsertionKyphoplasty Insertion LateralKyphoplasty Balloons APKyphoplasty Balloons Lateral

 

Insert a balloon first and inflate

- bilaterally into each pedicle

- will restore some anatomy

- then inject PMMA

 

Kyphoplasty cement APKyphoplasty cement Lateral

 

Results

 

Liu et al Osteoporosis Int 2010

- RCT of vertebroplasty v kyphoplasty

- improved vertebral height with increased injected PMMA in kyphoplasty

- no difference in outcome regards to pain relief

- 2/50 adjacent segment fractures in kyphoplasty group

- recommended vertebroplasty

 

Fusion

 

Crush Fracture CompressionCrush Fracture Fusion 2

 

Degenerative Scoliosis

Definition

Lumbar Degenerative Scoliosis

 

Lateral deviation of the spine that develops after the age of 50

- minimal structural vertebral deformity

 

Lower lumbar

- convex left

 

Aetiology

 

Unknown

- only very weak links to osteoporosis and degenerative disc disease

 

NHx

 

Progression

- larger curves > 30o

- increased rotation

- lateral lithesis > 6mm

- inter-crest line through or below L4/5 space

 

Larger curves more likely to have pain

 

Symptoms

 

LBP

 

Neurogenic claudication

 

Radiculopathy

- nerve roots compressed in concavity

 

X-ray

 

Degenerative Scoliosis APDegenerative Scoliosis Lateral

 

MRI

 

Myelopathy

 

Decreased height of nerve foramina

 

Degenerative Scoliosis MRI

 

Management

 

Non Operative

 

Epidural Steroids

 

Operative 

 

Technique

 

Multilevel decompression and posterior instrumented fusion

- laminectomy / foraminotomy

- +/- interbody cages to increase foraminal size

 

Deformity correction rare

 

Fusion Degenerative Scoliosis

 

 

 

Lumbar Discectomy Techniques

Disectomy Technique for Posterolateral L4/5 disc 

 

Anatomy

 

L4/5 disc at level of facet joints

 

Interlaminar space is below disc

- have to take inferior aspect of superior lamina

 

Pedicle and transverse process at same level

 

Disc usually on one side

- hemilaminotomy

- no need to remove spinous process

- this preserves stability

 

Position

 

4 poster support

- abdomen free (decrease venous drainage) / Jackson Table

- knees below hips

- pillows under legs and feet

- pressure care knees

- arms forward on supports

- back level & slightly head down

- protect eyes / CPN at knees / ulna nerve at elbows

 

Pre-Operative antibiotics

 

Often dressing + betadine in natal cleft

 

Levels

 

Careful correlation of clinical and MRI

- level of disc

- side of disc

 

Iliac Crests L4/5

- mark

- prep with antimicrobial solution

- insert 18G needle into L4/5 interspinous space

- obtain cross table xray to confirm level

- this centres incision

 

Incision

 

Square drape

LA with adrenalin

Incise skin L4 spinous process to S1 spinous process

 

Superficial Dissection

 

Divide thoracolumbar fascia

- in midline down to spinous processes

- subperiosteal dissection down side of spinous process

- with cobb / diathermy

- preserve suprasinous ligament

 

Subperiosteal dissection to lamina on lesion side

- expose but don't disturb facet joint capsule

- self retractor inserted

- don't go between transverse processes

 

Lamina spreader between spinous processes

- under supraspinous ligament

- opens up interlaminar space

 

Recheck level at L4/5 interspinous

 

Disc Localisation

 

5 ways to identify L5/S1

 

Sacrum

- hollow sound 

- non mobile

- midline crest with no ligamentum flavum / interlaminar space

- anterior slope L5 lamina

- large L5 S1 interlaminar space

 

Lumbosacral Junction

 

Deep Dissection

 

Expose Ligament Flavum 

- attaches on top of inferior lamina to superior lamina

- find midline raphae

- incise flavum with scalpel over inferior laminae

- create flap of flavum

- use Watson Cheyne Dissector to gently dissect off dural adhesions

- remove flavum laterally 

- 1, 2 or 3 mm 40° Kerrison Rongeur

- see fat overlying blue dura

 

Remove inferior aspect of superior lamina

- will take up to L4/5 disc 

- resect medial two thirds of superior facet /  lower one third inferior facet

 

Lumbar Spine PosteriorLumbar Spine HemilaminotomyLumbar Intervertebral Foramen

 

Exiting L4 nerve root

- above L5 pedicle

 

L5 nerve root

- below L5 pedicle

- remove inferior lamina and pars

 

Discectomy

 

Retract dura gently

- dural retactor

- remove sequestered disc with pituitary rongeur

- cruciate incision in PLL to remove protruding / extruding disc

 

L5 nerve root

- exit under pedicle L5 inferiorly

- medial facetectomy

- follow root out laterally around pedicle

- ensure free passage through foramina 

- should be able to pass Watson Cheyne easily

 

L4 nerve root

- L3/4 interlaminar space

- remove inferior lamina and pars

- will pass under pedicle of L4 inferiorly

- medial facetectomy of L3/4 facet joint

- access L4 pass under pedicle of L4 superiorly

 

Wiltse Approach to Extra-Foraminal Disc

 

Incision

 

Paramedian incision

- 2 fingerbreadths / 5cm lateral to midline

 

Superficial Dissection

 

Muscles split to intertransverse ligament

- between Longissimus & Multifidus

- always a bleeder on the way down

- clear transverse processes

- preserve posterior ramus by hooking finger around & then follow ramus to nerve

 

Deep Dissection 

 

Removed intertransverse ligaments and fascia between TP

- nerve root anterior to fascia and just below TP

- runs at a 45o angle

- follow nerve medially and identify disc

- retract nerve laterally & remove disk

- may have to incise annulus to remove bulge

- if intra-foraminal element, remove lateral facet

 

Post operatively

 

Symptoms should be immediately relieved

 

Analgesia

Watch retention

No anticoagulation

Mobilize ASAP

No heavy lifting 6/52

 

 

Lumbar Fusion Techniques

PLIF / Posterior Lumbar Interbody Fusion

 

PLIF APPLIF Lateral

 

Technique

 

1.  Wide laminotomy 

- resection flavum, significant cranial lamina

- preserve if possible the posterior elements

- spinous processes, supra and interspinous ligaments

- these provide tension stability

- resect medial two thirds of superior facet /  lower one third inferior facet

 

2.  Resect disc

- retract dura and traversing nerve root medially

- distract disc space with lamina spreader

- disc space retractors (insert wedge, then turn on side) 

- remove end plates

 

3.  Insert interbody device 

- carbon or titanium cages

- wedge shaped

- allows correction of sagittal deformity

- allows restoration of disc height

- immediate stability

- facilitates fusion

- usually contain morcellised allograft / BMP

- check under II that interbody device not too posterior

 

4.  Stabilise with pedicle screws

 

Complications

- dural tears

- nerve palsy

- hard ware failure

- psedoarthrosis

 

ALIF / Anterior Lumbar Interbody Fusion

 

Surgical Technique L2 - L5

 

Patient supine, stand on right

- find level with II

- make incision through skin and subcutaneous fat

- divide external and intenal obliques and transversus

- mobilise peritoneum around, until see psoas

 

All dissection with swabs on sticks or peanuts

- ureter lifted up with peritoneum

- diva retractors for bowel, as per general surgery

- self retainers attached to side of bed

 

Common iliac artery and vein on medial psoas

- mobilise vessels medially, psoas laterally

- will see large sympathetic trunk, mobilise either way (don't damage to avoid retrograde ejaculation)

- may need to divide iliolumbar vein

 

Identify disc

- check level again with needle

 

Steinman type pins in vertebral body to keep back bowel

 

Divide ALL (can keep as layer, especially in Disc replacement)

- remove entire disc

- knife, rongeurs, normal and ring curettes 

 

Distract disc space

- special lamina spreaders

- disc distractors (wedges inserted then turn on side i.e. 10 - 14 mm)

- pins in bodies above and below and add distracting device as per cervical fusion

 

Remove end plate to bleeding bone

 

Interbody cage

- trial for height, depth and angle

- i.e. 6o 10 mm

- check II to make sure not too far back

- insert real prosthesis

- augment with plate

 

Surgical Technique L5/S1 Fusion

 

Access between vessels

- much easier than going to the lateral side of one and mobilising it medially

- identify sacral promontory, big angle as sacrum dives away

- use pins and retractors as before

 

Resect disc and minimal end plate

- just to bleeding bone for fusion

- not too much so bone is soft and cage or disc subsides

 

Trial for height & angle, II for depth

- insert cage

- these made of plastic with same modulus as bone

- doesn't compress but at same time doesn't subside into bone

- cage is radiolucent except for small opacities to see on x-ray

- cage has cental hole

- fill with synthetic bone graft, mixed with patient's blood and rolled as sushi in BMP membrane

- insert cage, can put more synthetic BG/BMP around it

- check II, ensure not too posterior

- application of anterior plate and screws

 

Pedicle Screws

 

Concepts

 

Advantage

- superior to sublaminar wires or hooks

- purchase in all 3 columns

- cross-linkage and converging screws enhances pullout strength

 

Considerations

- essential to have fit & fill of pedicle

- bone mineral density of vital importance with pedicle screws

- minor osteoporosis OK

- marked osteoporosis hooks as good as screws

- bicortical fixation improves strength but only safe in S1

- pedicle screws not safe in S2 at all

- if fracture pedicle greatly reduces strength of construct

 

Objective

 

To place screw through centre of pedicles 

- parallel to upper end plate or slightly angled downward

- screws also converge towards midline

- up to 20% depending on spinal level

- this is to ensure do not penetrate lateral wall of vertebral body

 

Radiation

- II facilitates insertion

- can use computer navigation

 

Entry Points

 

1.  Thoracic spine

- entry just below rim of upper facet near base of TP

- angle 7-10o towards midline & 10-20o caudally

 

2.  Lumbar Spine

- entry at junction TP & superior facet

- angle: screws converge 5o at TLJ and increase 10-15o as one progresses from L2-L5

 

3.  Sacrum

- S1 only safe level

- line tangential to lateral border superior articular facet &

- line along inferior border of superior articular facet

- angle: screws converge towards midline / aim at anterior corner of promontorium

 

Technique

 

Osteotome away facet joint

- reveal cancellous bone

- entry with curved awl

- ball tip guide, bone on all 4 sides, check II

- pass tap

- insert screw (6.5, 5.5, 4.5, 30 - 40 mm long)

- usually poly-axial heads

 

Complications

 

Union rate >90%

 

Screw misplacement 4%

 

Nerve and spinal injury 1-20%

- most misplaced screws don't cause neural injury

- higher risks with power over hand preparation

 

Infection 1.1-4.2%

- usually can leave metal in situ with early washout & debridement

 

Screw breakage 2-60%

 

 

 

 

Lumbar Herniated Discs

Epidemiology

 

Sciatica > 2/52 1.6%

 

M:F = 1:1

 

Most common L4/5 

L5/S1 inherently stable 

 

Risk factors

 

Sedentary lifestyle

Smokers

Frequent driving

Heavy lifting 

 

Anatomy

 

Annulus Fibrosis

- circumferential, multilayered rim

- type 1 collagen fibres at 30o to horizontal

- peripheral nerve endings

- high resistance to torsional and axial loads

 

Nucleus pulposis

- hydrophilic PG + 70% water

- type 2 collagen

- resist axial compression

 

Avascular

- nutrients diffuse from the end plate

 

Wiltse Classification

 

1.  Bulge 

- annulus diffusely extends beyond the plane of the disc space

- annulus intact / nil focal protrusion

 

2.  Protrusion

- focal bulging within margin of annulus

- diameter of base is greater than diameter of tissue displaced beyond disc space

 

Lumbar Disc Protrusion

 

3.  Extrusion

- under PLL

- mass of discal tissue of greater diameter than the aperature through which it has passed

 

Lumbar Disc ExtrusionL5 S1 Extruded Disc

 

4.  Sequestration

- free disc in canal

- fragment with no continuity with tissue in disc of origin

 

Sequestered Disc MRI 3Sequestered Disc MRI 2Sequestered Disc MRI 4Sequestered Disc MRI 1

 

Anatomical Classification

 

1. Central

 

Lumbar Central Disc Herniation MRICentral Lumbar Disc Herniation

 

2. Lateral Recess / Posterolateral

- between dura and foramina

- anterior: disc (annulus) and vertebral body

- posterior: facet joint, lamina, ligamentum flava

- lateral: foramen, L5 pedicle

 

Herniated disc lateral Recess S1 nerve root compressionL45 Posterolateral Disc

 

3. Foraminal

- anterior: body of L5, L5/S1 disc

- posterior: pars, apex of superior facet of S1

 

Foraminal Disc MRIForaminal Disc 2 MRI

 

4. Extra- Foraminal / Far Lateral

 

Pathophysiology Nerve Root

 

Compression

 

Poorly resistant to compression

- dural sheath instead of perineurium

- tethered between dura and foramen

- compression impairs blood flow to nerve

 

Problem

- asymptomatic nerve compressions

- studies suggest that normal nerve roots do not generate pain when compressed

 

Biochemical

 

Chemical factors

- make nerve root more susceptible to effects of compression

 

Anatomy

 

L4/5

- traversing nerve root is L5

- exiting nerve root is L4

 

Posterolateral disc

- compresses traversing nerve i.e. L4/5 disc hits L5 nerve root

- this is most common situation

 

Foraminal disc

- compresses exiting nerve root i.e. L4/5 disc hits L4 nerve root

- require partial medial facetectomy / stand on opposite side of table

 

Far Lateral / Extra-foraminal disc

- compresses nerve root already exited i.e. L4/5 disk hits L4 nerve root

- Wiltse approach or complete facetectomy / follow nerve out

 

Symptoms

 

Typical patient 20-45 year old male

 

Pain

- leg in dermatomal distribution

 

Neurology

- numbness / parasthesia / weakness

 

Cauda Equina Syndrome

- saddle anaesthesia / urinary incontinence / weak EHL

 

Signs

 

Tension signs

 

1.  SLR / Straight leg raise / Lasegue's Sign

- elevate leg from hip with knee straight

- reproduce pain below knee

- L5 / S1 nerve roots

 

Deville et al Spine 2000

- meta-analysis

- SLR very sensitive 90% but lower specificity 26%

- crossed SLR low sensitivity 29% but more specific 88%

 

2.  Femoral nerve stretch test

- patient prone, knee flexed, extend hip

- reproduces pain

- L4 nerve root

 

Neurology

  Pain Sensation Weakness Reflex Test
L2 Lateral thigh Lateral thigh HF    
L3 Medial knee Medial knee Quads    
L4 Anteromedial knee Medial Malleolus T Ant Knee Jerk Femoral Stretch
L5 Dorsum foot First webspace EHL   SLR
S1 Sole / lateral foot Sole / lateral foot FHL Ankle Jerk SLR

DDx L4 nerve root

- CPN / DPN palsy

- test peroneals, tibialis posterior

 

DDx L5 nerve root

- CPN / DPN / Sciatic palsy

- test peroneals / abductors

 

DDx S1 nerve root

- tibial nerve

- test tibialis posterior

 

MRI

 

T2 Sagittal - myelogram

 

Lumbar MRI T1 Herniated DiscHerniated disc lateral Recess S1 nerve root compressionCauda Equina MRI

 

T1 Axial - see nerve root against white fat

 

Lumbar HNP T1 Axial

 

DDx

 

Infection / Tumour / Fracture

 

Management

 

Non-operative Management

 

NHx

 

Recovery  

- 80% improve after 6/52

- 90% improve after 3/12

- 95% improve after 6/12

 

Weakness just as likely to resolve as pain

 

Results Operative v Nonoperative

 

Peul et al BMJ 2008

- RCT of conservative treatment v microdiscectomy

- symptoms 6 - 12 weeks

- earlier symptomatic relief in surgical group

- no difference at one or two years

 

Options

 

Medications

- NSAIDs / opiates / steroids / tricyclic antidepressants

 

Physiotherapy / lumbar stabilisation exercises

 

Traction

 

Chiropractic manipulation

 

Epidural steroids

 

Price Health Technol Assess 2005

- multicentred RCT placebo control

- 220 patients with unilateral sciatica

- minimal and transient value over placebo at 3 weeks

- no difference after 6 weeks

- not cost effective / drain on resources

 

Arden et al Rheumatology 2005

- WEST study

- exactly the same findings

 

Transforaminal CS / Nerve Root Injections

 

Nerve Root Injection

 

Riew et al JBJS Am 2000

- RCT of patients with unilateral nerve root compression

- all considered suitable for operative intervention

- effectively prevented need for surgery in more than half of the patients

- LA + steroid more effective than LA alone

 

Operative Management

 

Absolute Indications

 

Cauda Equina Syndrome

 

Relative Indications

 

Failure of non operative treatment

Severe debilitating anatomical leg pain

Progression neurological deficit

 

Prediction of good operative outcome

 

6/6 Nachemson

 

1. Leg > back pain

2. Symptoms consistent with root irritation

3. Signs consistent with root irritation

4. Tension signs / positive SLR

5. Imaging consistent with Symptoms & Signs

6. Pain > 6 weeks

 

Options

 

Chemonucleolysis

Standard Discectomy

- open

- microdiscecotmy

Percutaneous / Endoscopic Discectomy

 

Chemonucleolysis

 

Mechanism

- chymopapain dissolves nucleosus pulposis

- older technique largely out of favour

 

Results

 

Muralikuttan et al Spine 1992

- RCT of discectomy v chemonucleolysis

- inferior short term results with chemonucleolysis

- no difference at one year

 

Discectomy

 

Advantage

- suitable for noncontained disc

 

Results

 

Dewing et al Spine 2007

- prospective followup of 183 single level lumbar discectomies

- average age 27

- 85% satisfied with surgery

- recurrent disc herniation in 3%

- better outcomes in L4/5 than L5/S1

- better outcomes in sequestered / extruded discs than contained discs

- poorer outcomes in smokers and patients with predominance of back pain

 

Righesso et al Neurosurgery 2007

- RCT of open v microdiscectomy

- no difference in outcome

- longer scar and inpatient stay in open group

- longer surgical times in microdiscectomy

 

Percutaneous Discectomy

 

Indications

- contained disc

 

Technique

- image guidance / endoscopic techniques

- interlaminar or transforaminal

- discectomy with cutting / suction probe

 

Advantage

- minimal scar

- rapid recovery

 

Results

 

Ruetten et al Spine 2008

- RCT of endoscopic interlaminar and transforaminal v microdiscectomy

- 82% relief of leg pain, no difference in each group

- 6% recurrence, no difference in each group

- reduced back pain and complications with improved rehab in endoscopic group

 

Complications Discectomy

 

Wrong level surgery

 

Neural injury

- paraplegia 1: 25 000

- nerve root injury

- cauda equina 0.2%

 

Dural tears

 

A.  Intraoperative Management

- head down

- stop ventilating / hand ventilate / anaesthetic valsalva

- ensure free abdomen

- CSF can make nerve root in danger / protect with patty

- attempt primary repair with 6.0 prolene non cutting needle

- supplement with Tisseel glue

- +/- fat graft / thoracolumbar graft

- subfascial drain

- bed rest 2 days

 

B.  Postoperative CSF leak

- ensure no meningitis symptoms

- glucose / microscopy test to confirm

- adequate fluids / head down / quiet room / bed rest

- antibiotics controversial

- MRI: small leak or large leak

 

Non operative Management

- insert drain below conus

- decreases CSF pressure

- bed rest / leave drain for 5 - 7 days

 

Operative Management

- failure nonoperative / large leak

- thoracolumbar fascia / synthetic graft repair

 

Incomplete decompression / failure to relieve symptoms

 

Infection 2%

 

Thromboembolism 1%

 

Arachnoiditis / Intradural fibrosis

 

Incidence 5%

 

MRI changes

1.  Central root clumping

2.  Empty sac appearance

3.  Soft tissue mass in subarachnoid space

 

HNP recurrence

 

Incidence

- life long 6 - 7%

- second time 50%

- third time 90%

 

Investigation

- gadolinium MRI

- scar enhances but recurrent HNP does not

 

Management

- disc resection +/- fusion

Lumbar Spine Degeneration

DefinitionLumbar Disc Degeneration Xray

 

Lumbar spondylosis

- disc degeneration causing arthritis / lower back pain

 

Discogenic lower back pain

 

Anatomy

 

Annulus fibrosis

- outer aspect of disc

- type I collagen

- fibres continuous with endplate & ALL/PLL

- provides tensile strength to contain NP

 

Nucleus Pulposus

- water + type II collagen + PG

- semifluid gel

- turns solid as ages and becomes brown

- Keratan : Chondroitin ratio increases as age

 

Epidemiology

 

100% at autopsy > 90 years

- males > females and earlier

 

Aetiology

 

Unknown in 90%

 

Associations

- heavy labour

- obese & tall

- driving / vibration

- smoking

- previous back injury

 

Pathogenesis

 

1.  Dysfunction (15 - 45 years)

 

Disc degenerates with age / dessication

- concentration of PG declines

- decrease number of chondrocytes

- decrease water content

- collagen fibres thicker in cross section

 

Lose ability to resist torsional loads

- circumferential & radial tears in disc

- localised synovitis of facets

 

2.  Instability (35 - 70 years)

- disc herniation

- resorption of disc

- degeneration of facet joint with capsular laxity / subluxation & erosion / osteophytes

 

3.  Stabilisation (>60 years)

- ankylosis of discs & facets

 

Symptoms

 

Lower back pain

- usually worse with activity

- especially bending & lifting

 

Maybe referred to 

- buttocks / posterior thigh / groin

 

Signs

 

General

- loss of lordosis

- decreased ROM, especially flexion

 

X-ray

 

Unexpected finding in 1:2500

- infection, fracture, tumour

 

Disc degeneration

- disc space narrowing

- vertebral sclerosis

- osteophytes

 

MRI 

 

Disc

 

Spine MRI Normal and Degenerative Discs

 

Normal disc / bright T2 signal

Degenerative disc / dark T2  

 

Very sensitive

- 30% of asymptomatic patients < 60 years have abnormality

- 60% > 60 years have abnormality

 

Modic End Plate Changes

 

Lumbar Disc Degeneration Modic Changes

 

Classification of bone marrow changes in bone marrow adjacent to vertebral end plates

 

Type 1:  High on T2 / Low on T1

Type 2:  High on T2 / High on T1 (lipid changes)

Type 3:  Low on T2 and T1 (sclerotic)

 

Discography

 

Aim

- confirm isolated disc degeneration responsible for pain

- must check disc below and disc above

 

Technique

- inject contrast under pressure / LA and II guidance

- look for dye leak

- look for reproduction of symptoms

 

Alternative / Discoblock

- inject LA

- positive test if relieves pain

 

Results

 

Ohtori et al Spine 2009

- only operative on patients with positive discogram or discoblock

- 15 patients in each group

- treated with anterior discectomy and interbody fusion

- significantly improved results in discoblock group

 

Natural History

 

90% lower back pain resolves < 2/12

- 10% chronic

- prognosis poor if pain > 6/12

 

DDx

 

Traumatic

- crush fracture / isthmic spondylolisthesis

 

Infective

- vertebral osteomyelitis / discitis / epidural abscess

 

Tumour

- Benign (Haemangioma / OO / OB / EG / Giant Cell / ABC)

- Malignant (Chordoma / Myeloma / Metastasis)

 

Inflammatory

- AS / Reiter's / Psoriatic arthritis / Enteropathic disease

 

Neurogenic

- primary pathology of nerve roots (Neurilemmoma, neurofibromata, ependymoma)

 

Viscera / Vascular

- Pelvic viscera / retroperitoneal cancer

- AAA / Superior gluteal artery claudication / Claudication 2° PVD 

 

Management

 

Non-operative Management

 

Acute LBP

 

Initial

- rest 2 days

- local measures - massage / local NSAIDs

- pain relief - acetominophen / NSAIDS

 

Once pain settles

- exercise

- general fitness important

- core strengthening

- brace no benefit

 

Chronic LBP

 

Back School / Structured rehab programme / Lifestyle modification

Relaxation \ Exercise

Avoid narcotics

 

Epidural Steroids

 

Indication

- lumbar pain without HNP / radiculopathy

 

Manchikanti et al Pain Physician 2010

- HCLA epidural injections

- 86% significant pain relief at 12 months

 

Operative Management

 

Indications

 

Unremitting pain & disability > 1 year

MRI single level disc degeneration

 

Isolated L5 S1 Disc Degeneration

 

Options

 

1.  PLF / Posterolateral Fusion +/- instrumentation

 

2.  Instrumented PLIF / Posterolateral Interbody Fusion

 

3.  ALIF / Anterior Lumbar Interbody Fusion

 

4.  Disc Replacement

 

PFL

 

Concept

- decortication of pedicles / lamina / transverse process

- bone graft applied

- instrumentation added to improve fusion rate

 

Advantage

- high fusion rate

- no risk of interbody graft / cage migration

- low risk neural injury

 

Results

 

Fritzell et al Spine 2001

- RCT of surgical treatment v non surgical with 2 year follow up

- back pain reduced 33% to 7%

- return to work 36% v 13%

 

Fritzell et al Spine 2002

- RCT of PLF v instrumented PLF v PLIF

- no significant difference in reduction in pain and disability

- complications 6% v 16% v 30%

- fusion rate 72% v 87% v 91%

 

Instrumented PLIF

 

PLIF L5 S1 LateralPLIF L5 S1 AP

 

Principles

- wide post decompression and removal of entire disc

- graft / fusion cage placed between vertebral bodies

- 360o fusion (PLF + interbody)

 

Advantages over PLF

- excise disc & decompress nerve roots

- disc height restored with graft decompressing foramina vertically

- fusion of anterior column / increased fusion surface / site of arthrodesis compressed

 

Disadvantages

- wide post decompression needed / newer minimally invasive techniques

- risk of canal compromise by graft

 

Results

 

Leufven et al Spine

- 29 patients treated with PLIF

- fusion in 27/29

- excellent results in 31% and good in 21%

- fair in 21% and poor in 27%

 

ALIF

 

Concept

- anterior approach + complete discectomy and graft

 

Results

 

Penta et al Spine

- 108 patients with ALIF at 10 years

- only 34% good or excellent

- not related to fusion rates

- psychological rating intially and at review correlated with outcome

 

Disc Replacement

 

Concept

- maintain small degree of motion

- prevents adjacent level degeneration

 

Results

 

Herkowitz et al JBJS Am 2006

- RCT of disc replacement v ALIF

- 304 patients with single level disease L5S1 or L45

- 2 year follow up

- clinical success 64% in disc replacement v 56% ALIF
- better ROM and restoration disc height in disc replacement

 

Harrop et al Spine 2008

- systemic review looking at adjacent level degeneration in lumbar fusion v disc

- radiographic degeneration 34% in fusion v 9% in disc replacement

- symptomatic degeneration 14% in fusion v 1% in disc replacement

 

Complications

 

Mortality 0.2%  

Infection 1.5%

DVT 4%

PE 2%

Neural injury 3%

Instrument failure 7%

Failed back surgery syndrome

Lumbar Stenosis

DefinitionLumbar Stenosis

 

Reduction of space available for neural elements in spinal canal or intervertebral foramina

- due to degenerative changes, congenital abnormalities or both

- involves compression of the thecal sac or nerve roots

 

Epidemiology

 

Onset 50 - 60's

- M = F

- associated with onset OA spine

 

L3/4 & L4/5 most common

 

Aetiological Classification

 

1. Congenital

 

Achondroplastic

- short thick pedicles and narrowed interpedicular distance

 

SED

 

Idiopathic ~ Polynesians

- trefoil-shaped canal

 

Congenital narrow spinal canal

- most syptomatic patients have canals at lower end of spectrum

 

Prematurity

- narrow L3

 

Ostepetrosis

 

2. Acquired

 

Degenerative

- most common aetiology

- disc desiccation / loss of height / bulging of annulus

- facet subluxation / capsular hypertrophy / osteophytes

- overall shortening of lumbar spine / decreased volume

- ligamentum flavum hypertrophy

 

Spondylolisthesis

 

Kyphosis

 

Iatrogenic

- post-laminectomy

- post-fusion

 

Miscellaneous

- Paget's disease

- Fluorosis

- DISH

- Ankylsing spondylitis

- Tumour

- Infection - TB

 

Traumatic / Post fracture

 

Anatomical Classification

 

1.  Central Canal Stenosis

 

2.  Lateral Recess Stenosis

 

3.  Foraminal

 

Anatomy

 

1.  Central canal

 

Posterior wall - ligamentum flavum & laminae

Lateral wall - medial facet joints & intervertebral foramina

Anterior wall - annulus fibrosis & posterior vertebral body

 

2.  Lateral recess

 

Extends from where nerve root leaves dural sac to where nerve root enters foramen

 

Posterior wall - ligamentum flavum & superior part of lamina

Anterior wall - posterior vertebral body & annulus fibrosis

Lateral wall - medial & inferior pedicle

 

3.  Intervertebral foramen

 

Extends from inner to outer foramen

 

Superior wall - inferior part of pedicle above

Inferior wall - superior part of pedicle below

Anterior wall - above is body, below is disc

Posterior wall - pars interarticularis, ligamentum flavum & apex of superior facet of vertebrae below

 

Pathology

 

Stenosis typically at disc level either due to disc or facets

 

1.  Central Canal

- bulging of annulus posterior

- facet osteophytes posterolateral

- hypertrophied ligamentum flavum posterolateral

 

Lumbar MRI Stenosis Trefoil Canal

 

2.  Lateral Recess

- facet subluxation & osteophytes + hypertrophied ligamentum flavum

 

3.  Intervertebral Foramen

- loss of disc height with approximation of pedicles

- inferior annular bulge

- medial facet hypertrophy

 

Effects

 

Mechanical

- increased canal narrowing with extension

- also get posterior disc protrusion and redundancy of ligamentum flavum

- root lacks perineurium & hence more susceptible to compression

 

Ischaemia

- interference with metabolic demands of nerve root

- exercise increased nutritional requirements & waste production

- canal constriction limits response = relative ischaemia

 

Symptoms

 

Back Pain

 

Sciatica

- L5 most common, then S1

 

Neuropathic claudication

- insidious onset

- usually bilateral

- diffuse / no dermatomal pattern

- buttocks / thighs / calves

- heaviness / weakness / burning / cramping / tingling / numbness

 

Worse with walking, standing & lumbar extension

 

Relieved by sitting, flexion, walking upstairs, squatting

 

Signs

 

Often none, but can overlap with HNP

 

DDx

 

Vascular claudication

- calf pain with exercise

- rapid relief with cessation walking

- no back pain / no numbness

- abnormal pulses

 

Hip Disease

Diabetic neuropathy

Retroperitoneal pathology

 

X-ray

 

Rule out 

- infection / tumour / fracture

 

Confirm degenerative changes

- facet hypertrophy / disc narrowing

- decreased AP diameter of canal

- identify associated pathology i.e. spondylolisthesis / scoliosis

 

MRI

 

T2 Sagittal "MRI Myelogram"

 

Lumbar MRI Stenosis Sagittal T2Lumbar Stenosis MRI SagittalLumbar Stenosis MRI

 

Stenotic Measurement

 

A.  Volume

- more accurate

- critical area is 100 mm2

 

B.  AP diameter less accurate

- normal if > 12mm

- absolute stenosis if < 10mm

 

Intervertebral foramina

- no fat about nerve root

- reduced height

 

Lumbar Foraminal Stenosis L45 MRILumbar MRI Tight Intervertebral Foramina L3

 

B.  Axial slices

 

Findings

- no fat about dura

- trefoil shape canal

- lateral recess or foramina compression

- nerve root compression

 

Lumbar MRI Stenosis Trefoil CanalLumbar stenosis axial MRILumbar MRI Axial Stenosis

 

NHx

 

Not clear not all patients progress

 

Johnsson 1993 Clin Orthop

- 32 patients followed 4 years

- 70% unchanged

- remainder: half worse, half better

 

Management

 

Non-Operative Management

 

Options

 

Rest / Avoid aggravating activities

 

Analgesics

- simple analgesia

- short course NSAIDS

 

Back support

- prevent extension

 

Physio

- back strength in flexion

- stabilise abdominal muscles

- aerobic fitness on exercise bike 

 

Epidural steroids

 

Koc et al Spine 2009

- RCT of exercise v epidural steroids v control in spinal stenosis

- exercise and epidural steroids both efficious up to 6 months

 

Calcitonin

 

Podichetty et al Spine 2004

- RCT of calcitonin v placebo

- no difference in two treatment groups

 

Operative Management

 

Indications

 

Absolute 

 

Cauda equina syndrome

 

Relative

 

Failure to respond to non operative treatment

Disabling neurogenic claudication

Progressive neurological deficit

 

Back pain is not an indication

 

Options

 

Decompression +/- fusion

 

Interspinous devices

- limit extension

 

Indications for fusion

 

1.  Degenerative Spondylolisthesis

 

2.  Radiological instability

- > 3mm or > 11o

 

3.  Intra-operative destabilisation

- removal of > 1 facet joint or pars

- i.e. radical decompression required laterally

 

4.  Degenerative scoliosis

 

5.  Significant low back pain / disc degeneration

 

Decompression

 

Define site of compression

- central / lateral recess / foramina

 

Define levels

- single / multilevel

 

Fusion

- must be prepared to fuse if cause instability

- consent

 

Results

 

Operative v Non Operative

 

Weinstein et al Spine 2010

- SPORT trial

- RCT of operative v non operative treatment lumbar stenosis

- 289 patients with 4 year follow up

- substantially improved pain and function in operative group

 

Interspinous Devices

 

Hsu et al J Neurosurg Spine 2006

- RCT of non operative v X Stop interspinous device

- significant improvement in QOL, with results similar to surgical decompression

 

Decompression v Fusion

 

Niggemeyer et al Eur Spine J 1997

- meta-analysis

- if symptoms < 8 years, decompression without fusion yields best results

- if symptoms 15 years or more, decompression with instrumented fusion best results

- decompression and fusion without instrumentation had worst results

 

Complications

 

Epidural haematoma

Instability

Infection

Nerve root injury

Dural Tears

 

Technique L4/5 Decompression

 

Position

- abdomen free to limit venous pressure and bleeding

- 4 poster / knee below hips / arms on bolster

- feet / knees / elbows / face / eyes cushioned

- SCUDS, TEDS

- betadine packs in buttocks

- +/- Jackson table (enables more lordotic position if instrumentation planned)

 

Landmarks / Check level

- iliac crest L4/5 interspinous space

- prep area aseptically, spinal needle

- check with lateral x-ray

- square drape

 

Incision

- inject LA with A

- midline

- meticulous haemostasis

- divide thoracolumbar fascia

 

Superficial Dissection

- subperiosteal elevate of supraspinous muscles (Cobb's and diathermy)

- sequentially pack with rolled swabs / sausages to control bleeding

- out to lateral extent of pars

- expose facet joints, but preserve capsule if not fusing

- beware parafacetal arteries

- don't extend between transverse processes as nerve root at risk

 

Deep dissection (L4/5)

 

L4 5 DecompressionL4 5 Decompression Laminectomy

 

Recheck level

- L4/5 interspinous gap

 

Resect L4 spinous process

- remove ligamentum flavum above and below

- Kerrison Rongeur / knife

- remove all of L4 lamina

- expose L4/5 disc space

- L5 nerve root exits inferior

- L5 nerve root will pass below L5 pedicle

 

Remove L4/5 disc fragments if needed

- nerve root retractor

- gently retract dura to each side

- take out with pituitary rongeur

 

L4/5 medial facetectomy

- above L5 pedicle

- L5 nerve root exits inferior to it

- decompress, pass Watson Chaney

 

Preserve pars & half of facet

- may have to remove entire facet joint & pars

- preserve one facet joint at each level

- can be 1/2 on each side

 

 

 

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

Spondylolisthesis Dyplastic Isthmic

Definition 

 

Forward slip of one vertebra relative to inferior one

 

Classification

 

Wiltse  "DID TIP"

 

Dysplastic

Isthmic

 

Degenerate

Traumatic

Iatrogenic

Pathological

 

1. Dysplastic 20 %

 

Congenital Dysplasia of Upper Sacrum 

- occurs at L5-S1

- hypoplasia of superior facets of S1

- dysplastic L5/S1 facet joints

 

Usually around 6 years old

 

Spina bifida ccculta common

- more unstable

 

Prone to more severe slips

 

Most high grade slips are dysplastic

 

2. Isthmic 50 %

 

Pars Discontinuity / Defect

- L5 /S1 80%

- unilateral or bilateral

- can have a pars defect at L4/5

- typically adolescent

- due to repetitive stress with fracture

- increased in competitive sports eg gymnastics, football

- is a genetic predisposition due to increased pelvic incidence

- tend to be mild and non progressive

 

Tend to present in 2 groups

- some present in young patient

- some present in adulthood when the disc degenerates and foramina compressed

 

Isthmic SponydlolithesisL4 Pars Defect

 

3 types

 

A Stress fracture

 

B Elongated type

 

Spondylithesis Elongated

 

C Acute fracture

 

3. Degenerative

 

2° to Facet OA

- L4/L5

- > 40 years old

- associated with DM

- F>M

- compared with lytic the disc tends to be preserved

 

Degenerative Spondylolithesis L45

 

4. Traumatic

 

Bilateral acute fracture through neural arch outside pars

- i.e. hangman's fracture

 

5. Iatrogenic

 

Post surgical

 

6. Pathological

 

Pathological weakening of neural arch or pedicle 

- OI / Larsen / Marfan's / tumour

 

Epidemiology

 

Occurs after walking

- never present at birth 

 

Spondylolysis seen in 5% causcasion population

- 15% develop spondylolithesis

 

Gender

- more common in boys 

- girls more severe slips

 

NHx Lytic

 

Early NHx

- by early adulthood L5-S1 disc narrowed

- anterior sacrum develops sclerotic lip

- further slip unlikely in adulthood

- will only progress whilst skeletally immature

 

Late NHx

- increased incidence of L5-S1 disc degeneration

- significant increase in LBP > 50% slip

- may develop nerve root pain when foramina compressed due to disc degeneration

 

Aetiology Isthmic

 

Fracture of pars  

 

Lumbar extension concentrates shear stresses on thin pars 

- inferior articular process of cranial vertebrae continuously impacts on pars

- nutcracker mechanism

 

Most common

- soldiers /weight lifters / footballer's

- female gymnasts 10%

 

FHx

- positive FHx in 15%

 

Pelvic Incidence

 

Isthmic associated with increased pelvic incidence > 50o

- patients have increase lumbar lordosis with increased shear stress

- predisposed to pars fracture if engage in certain sports with hyperextension

 

Measurement

- line superior border sacrum / sacral slope

- drop perpendicular line from centre of sacral slope line

- line to centre femoral head

- pelvic incidence is line between the two

 

Pelvic IncidencePelvic Incidence > 50 degrees

 

Aetiology Dysplastic 

 

Secondary to posterior element abnormality

- increased incidence of sacral spina bifida

 

FHx

- positive FHx in 33%

 

Pathology

 

1.  Isthmic

 

Usually lower grades

- posterior elements left behind

- canal diameter increased

 

L5 nerve root compression

- fibrocartilage mass at pars defect 

- stretched over posterior sacrum

 

2.  Dysplastic

 

Higher grades

- severe lumbosacral kyphosis

- canal diameter decreased

 

L5 nerve root + cauda equina pressure

- intact neural arch of L5 pulled forward

 

Symptoms

 

Usually asymptomatic in children

- only 10% are painful

- pain usually in growth spurt adolescents 

 

Back pain

- low back / buttocks & thighs 

- initiated by strenuous activity 

- repetitive flexion extension

- relieved by rest

 

Can often recall a specific inciting event

 

Neurology

- radicular pain 

- exiting nerve root / usually L5 in both dysplastic and isthmic

 

Signs

 

Lumbar hyperlordosis

 

Lumbosacral step off with severe slips

 

Numbness in L5 area

 

Scoliosis

- increased incidence in symptomatic slip 

- 25-50% 

- more common with dysplastic

 

Spondylo-crisis

- acute presentation with severe back pain

- hands on knees, hips and knees flexed

- bladder and bowel dysfunction

 

Standing AP and Lateral X-ray

 

Findings

 

May miss subtle listhesis on supine XR

- spondylosis

- Meyerding classification

- slip angle

- sacral inclination

 

Spondylolysis

 

Pars Defect Lateral Xray

 

Definition

- radiolucent defect of pars 

 

Types

- acute - narrow gap & irregular edges 

- pars elongated & thinned

- chronic - wide gap with smooth sclerotic edges

 

Scotty Dog / Oblique Xray

- Ear (superior articular facet) / Nose (TP) / Eye (pedicle)

- Front leg (inferior articular facet) /  Body (lamina and body with superimposed SP)

- Tail (superior articular facet of other side) /  Back leg (inferior articular facet of other side)

- Neck (Pars and if Collar then has defect)

 

Scotty dog NormalPars Defect Oblique Xray

 

Meyerding Classification

 

Degree of slip compared with width of S1

- Grade I 0-25%

- Grade II  25-50%

- Grade III  50-75%

- Grade IV 75-100%

- Grade V  > 100% / Spondyloptosis

 

Stability

- stable / slip < 50%

- unstable / slip > 50%

 

Spondylolithesis Meyerding Classification

 

Slip Angle / kyphotic angle

 

Measurement

- line along inferior border L5

- line along superior border S1

 

Normally L5/S1 disc is in 20-30° lordosis 

- angle is negative

 

As L5 slips forward it slips into kyphosis

- angle becomes positive

- sacrum becomes more vertical with high grade slips 

- this worsens the kyphosis further

 

Dangers

- typically > 10° with dysplastic

-  > 30° high risk progression progression

 

Sacral inclination

 

Angle between posterior border of sacrum and vertical

- > 60o associated with progression

 

Chronic Changes

 

Seen in older presentation

- anterior sacral erosion

- domed sacrum

- L5 Trapezoidal 

- L5/S1 disc degeneration

 

Bone Scan

 

1.  Diagnosis

 

SPECT 

 

2.  Prognosis

 

Hot lesion

- will heal

 

Cold lesion

- not healing

 

CT scan

 

Technique

- reverse gantry

 

Indication

- perform instead of obliques

- oblique x-rays have high radiation dose with little extra information compared with CT 

 

Spondylithesis L5 S1 with disc degenerationPars Defect Bilateral CT

 

MRI

 

Indication

- neurological signs

- rule out other diagnosis

 

DDx

 

Infection - vertebral OM / discitis 

Tumour - osteoid osteoma / cord tumour

Herniated disc 

Inflammatory - Scheuermann's / Ankylosing Spondylitis

 

Management

 

High Risks Progression

 

1. Clinical

- skeletally immature

- female 

 

2.  X-ray

- dysplastic slip 

- grade III or IV (> 50%)

- slip angle  / kyphosis > 30° (normal is -20° i.e. lordosis)

 

Non Operative

 

Indication

 

Minimal symptoms

Low risk progression

- isthmic

- mild slip (Meyerding I / II, slip angle < 30o)

 

Protocol

 

Observation until mature

- review annually to ensure no progression of slip

 

Consists of

- activity modification 

- cease aggravating symptoms

- NSAIDS

- hamstring stretches

- brace

 

Brace 

 

Indication

- spondylosis / grade 1 spondylolithesis

- acute / hot on bone scan

 

Theory

- attempt to heal pars fracture

- healing is not required for symptoms to settle

 

Type

- anti-lordotic

- 3/12 full time, no sport

- 3/12 full time with sport

 

Results

 

Debnath et al Spine 2007

- 42 patients with unilateral spondylysis hot on SPECT

- 6/12 non operative treatment including bracing

- 81% avoided surgery / complete resolution of symptoms

- remainder had CT confirmed non union and underwent unilateral pars fixation

 

Operative Management

 

Indications

 

1.  High risk slip

- slip degree > 50%

- slip angle > 30o

- dysplastic

- skeletally immature

 

2.  Progression of slip

 

3.  Neurological symptoms

- L5 Radiculopathy / Stenotic symptoms / cauda equina

 

4.  Debilitating pain

- spondylysis

- spondylolithesis

 

Options

 

1.  Pars fusion

- painful spondylysis

- minimal spondylolithesis

 

2.  Fusion

 

A.  In situ v reduction

- not required for grade 1 - 2

- consider if sagittal malalignment

- associated with risk neurology especially L5

- controversial if should be performed in high grade slips

 

B.  Instrumented / non instrumented

 

C.  Levels

- L5/S1 if grade I or II / 50% or less

- L4/S1 if 50% for more

 

D.  Interbody cages

- useful in long standing spondylolithesis presenting in adulthood

- degenerative disc disease

- nerve root pain from interforaminal compression

- improves nerve root space

- improves healing rate

 

E.  Posterior v circumferential

- circumferential approaches may improve fusion rates and outcome in high grade slips

 

Fusion of Pars

 

Indication

- normal discs and facets

- pain relieved by pars injection

- failure brace / non operative treatment

- minimal slip

 

Pars Defect LA Injection

 

Technique

- lesion identified / debrided / iliac crest bone graft

 

Options ORIF

 

1.  Screw across lytic defect

- unilateral defect

 

Lytic Pars Grade 1 SpondylolithesisLytic Spondylithesis CT Unilateral Pars Defect

 

Lytic Pars Defect Unilateral Pars Screw0001Lytic Pars Defect Unilateral Pars Screw0002Pars Defect Screw CT

 

2.  Pedicle screw + laminar hook

- bilateral defect

 

Pars Defect Bilateral CTPars Defect Hook and Screw L50001Pars Defect Hook and Screw Lateral

 

Bilateral Pars Defect Union

 

3.  TBW spinous process and transverse process

 

Results

 

Kakluchi et al JBJS Am 1997

- 16 patients with failure non operative treatment bilateral pars defect

- pain relieved by pars injection with LA

- pedicle screw + lamina hook

- nerve root decompression where required

- union in all 16

- 3 patients only had occasional back pain

 

Fusion in Situ

 

A.  Wiltse Lateral Mass Fusion in situ

 

Concept

- in situ fusion via a paraspinal muscle splitting approach

- no reduction or instrumentation

 

Indication

- for L5/S1 with minor slip in young patient

- rarely done these days

- most surgeons perform instrumented fusion

 

Technique

- midline incision

- two paramedian incisions in lumbodorsal fascia 4.5cm lateral to midline

- paraspinous muscle splitting approach 2 fingerbreadths lateral to midline

- split sacrospinalis using finger to dissect through muscle

- don't go anterior to TP or risk damage to nerve root

- decorticate TP / Sacral ala / facet / famina and add crest graft / allograft / BMP

 

Post-op

- spica 3/12 with 1 leg incorporated   

- activity modification for 6/12

 

Instrumented fusion in situ without reduction

 

Indications

- slip grade 1 or II

- grade III or IV with no sagittal malalignment

 

Levels instrumentation

- L5 / S1 grade I or II

- L4 / S1 grade III or IV

 

Options

1.  Pedicle screw instrumentation

 

Spondylolithesis PLF

 

2.  PLIF / interbody cage

 

Isthmic Spondylolithesis PLIFSpondylolithesis PLIF

 

3.  Bohlman procedure

- interbody fusion with fibula strut

- augmented with decompression and PLF

 

Dysplastic Spondylolithesis Bohlman Procedure

 

4.  Transfixing L5 / sacral screw

 

Spondylolithesis Transfixing Screw LateralSpondylolithesis Transfixing Screw Lateral

 

Reduction + Instrumented fusion

 

Indications

- sagittal malignment

 

Disadvantage

- risk of neurology (L5)

- up to 25%, usually transient

 

Advantage

- cosmesis

- less pain from correction of alignment

- more likely fusion, less pseuodoarthrosis

- improved neurological decompression

 

Technique

 

A.  Posterior approach

- wide foraminatomy bilateral to protect L5 nerve root

- disc removed

- screws used to correct angulation +/- some translation

- interbody fusion device to restore height

 

B.  Anterior approach

 

Spondyloptosis 

 

Option

 

A.  L5 vertebrectomy / Gaines procedure

 

B.  Reduction and fusion as above

Thoracic Disc Disease

Epidemiology

 

0.05% incidence

- rare due to stabilising effect of rib cage

- even more rare to have symptoms

 

Reasoning

1.  Discs are narrower

2.  Foramina larger

3.  Thoracic spine

- facet joints orientated for rotation

- lumbar spine for flexion extension

- flexion is typically the motion which ruptures annulus

 

Anatomy

 

Increase in size from T1 to T12

- small pedicles

- long spinous processes

- relatively large intervertebral foramina

- facets nearly vertical

- TP come off the pedicle

- costal articulation TP and vertebral body

 

Thoracic Vertebrae

 

Clinical

 

Present with intercostal radiculopathy or myelopathy

 

Xray

 

Disc space narrowing / degenerative changes

 

> 50% thoracic discs associated with calcified disc material in canal

- probably indicates chronicity

 

Thoracic Disc Calcified CT 1Thoracic Disc Calcified CT 2

 

MRI 

 

Very sensitive 

- 40% incidence asymptomatic thoracic disc protrusion

 

Thoracic Herniate Disc SagittalThoracic Herniate Disc Axial

 

Thoracic Disc MRIThoracic Disc MRI Axial

 

Management

 

Non Operative

 

Indication

- single level disease

- no myelopathy

- operation rarely indicated

- usually settles with physiotherapy / analgesia

 

Operative

 

Indications

- myelopathy 

- unrelieved radiculopathy

 

Options

 

Posterior approach / discectomy via laminectomy

- contraindicated

- spinal cord does not tolerate retraction 

 

Anterior Approach

- costotransversectomy

- corpectomy (2 level disc)

 

A.  Thoracotomy and Costotransversectomy

 

Definition

- resection of rib + transverse process

 

Indication

- single level disc resection

- unilateral disc

 

Technique

- posterior approach

- remove of rib and transverse process

- ipsilateral pedicle removal

- removal disc protrusion

 

B.  Thoracotomy and Corpectomy

 

Indication

- 2 level disc protrusion

 

Thoracic disc 2 Level Precorpectomy

 

Technique

 

Thoractomy Approach

- loin incision

- removal of rib 2 levels above

- through bed of rib

- extrapleural approach

- from left to avoid IVC

 

Tie off segmental artery on one side

- disc convex, body concave

- allows access to disc protrusion

- discectomy + / - corpectomy as required for exposure / 2 level disc

- anterior +/- posterior stabilisation if corpectomy

- if simply remove disc may not need stabilisation especially in elderly

- will autofuse

 

Thoracic Corpectomy HNP

 

Complications

 

Cord injury

 

Cord infarct 

- ligation segmental artery

- exceedingly rare with unilateral approach

- much higher risk with bilateral approaches

- CTA to look for artery adamkiewicz

 

Intercostal neuritis 

- not uncommon

- treat with repeated intercostal nerve blocks

 

Bleeding

- usually from segmental artery

- patient presents difficulty breathing / hemothorax

- may have high output from drain

- > 200mls / hour clamp drain and urgent return to OT with vascular surgeon

 

 

 

Thoraco Lumbar Fracture

Xray Assessment

 

A:  Alignment

B:  Bony

C:  Canal

D:  Disc

S:  Soft tissues

 

Goals of surgery

 

1.  Correct deformity

2.  Restore stability

3.  Decompress neural elements if required

 

MRI

 

Advantage

- defines level of conus

- may need anterior rather than posterior surgery if lesion above conus

 

Denis's 3 column Classification 1982

 

> 3 columns injured with translation

- unstable

 

Posterior column 

- supraspinous / infraspinous ligament / ligamentum flavum

- neural arch (lamina / pedicle / facet joints / spinous process)

 

Middle column 

- PLL, posterior disc & annulus

- posterior half vertebral body

- most important

 

Anterior column 

- ALL, anterior disc & annulus

- anterior half vertebral body

 

Denis Classification

 

1.  Compression fracture

- anterior column only

 

L1 anterior compression fracture MRI

 

2.  Burst fracture

- anterior and middle column disrupted

- widening of pedicles on AP

- decreased posterior body height compared to anterior

- may have retropulsed fragment

- this occurs at top of vertebral body between pedicles

- obscured by pedicles on lateral xray

 

Burst Fracture CT

 

3.  Flexion-distraction

- distraction of posterior structures

- disruption of middle column

- splaying of spinous processes on AP and lateral

- bony or ligamentous

- chance injury (pure bony)

- anterior column intact / no translation

 

4.  Fracture-dislocation

- all three columns disrupted

- characterised by translation

 

Surgical Indications

 

1.  Neurology 

- decompress 

- complete v incomplete

 

2.  Deformity

- correct deformity

 

Gertzbein SRS 1992

- 1109 patients

- kyphosis >30° associated with increased back pain

 

3.  Stability

- prevent neurology

- prevent deformity / late pain

 

4.  Multi-trauma patient

 

TLISS (Thoracolumbar Injury Severity Score)

 

Spine Trauma Study Group 

- 3 issues

- calculate a score

- gives an indication if patient needs surgery

 

1.  Injury Mechanism

 

Compression 1

Burst 2

Rotation 3

Distraction 4

 

2.  Posterior Ligament Complex

 

Intact 0

Suspected 2

Definite 3

 

3.  Neurology

 

Nil 0

Nerve root 1

Complete cord 2

Incomplete cord 3

Cauda equina 3

 

10 is maximum score

- < 4 no treatment

- 5 or more - surgery

- 4 - either way

 

Burst fracture

- 2 points for burst

- 2 for indeterminate posterior injury

- usually no neurology

- 4 in total

 

Timing

 

Incomplete neurology

- emergency

- especially if neurology worsening

- have more time if neurology stable

- i.e. time to get MRI

 

Complete neurology

- not an emergency

- surgery still indicated

- gain 1 or 2 neurological levels (crucial in C spine)

- prevent syrinx

- prevent development of neuropathic pain

- aid nursing / rehabilitation

 

Bohlman 1985 JBJS

 

184 thoracic spine fractures with complete cord injury

- no recovery with or without OT

- posterior fusion only to speed recovery

 

17 incomplete cord injuries treated with laminectomy

- 7 became worse

- hence contra-indicated

 

8 incomplete cord injuries treated with anterior decompress+ fusion

- all improved  

- decreased rehabilication time by 50% in operative group

 

Approach

 

Posterior

 

Indications

- flexion distraction

- fracture dislocation

- compression fractures

- +/- burst

 

Requires integrity of posterior column

- Gaines score

 

Issue

- disruption of posterior column

- higher risk of dural tears

 

Anterior

 

Indication

- decompression required

- i.e. burst with retropulsed fragment

- perform corpectomy via anterior approach

 

Anterior & Posterior

 

Gaines / Load sharing Classification

 

Enables decision be made

- short segment posterior stabilisation v

- anterior decompression and stabilisation

 

Gaines Class >/=7 = failure with pedicle screw construct alone

 

A. Comminution vertebral body on lateral X-ray

1. <30%

2. 30-60%

3. >60%

 

B. Apposition of Fragments

1. Minimal displacement

2. 2mm or <50% of body

3. > 2mm or >50% body

 

C. Deformity Correction

1. Kyphosis 3o or less

2. 4-9o

3. >10o needed

 

Score of 3-9

 

1.  Compression Fractures

 

DDx

- burst

- pathological

 

CT scan

- xray only 25% accurate distinguishing compression from burst

- indicated if anterior body height < half posterior body height

- i.e. > 50% anterior wedging

- assess integrity of middle column / look for retropulsed fragments

 

Operative Indications

- kyphosis > 30o

 

Non Operative Management

- elderly - mobilise

- young - extension orthosis / TLSO

- check standing X-ray 2/52

- ensure kyphosis < 20 - 30o

 

Surgery

- posterior approach

- instrumentation

 

2.  Burst Fracture

 

Characteristics

- axial load

- most common thoracolumbar junction

- retropulsed fragment here causes conus

 

Definition

- anterior & middle column disrupted

- posterior column injured but no displacement / translation

 

X-ray

- pedicle widening on AP

- posterior body height decreased on lateral < 50%

 

Thoracic Burst Xrays LateralThoracic Burst Xrays AP Widened Pedicles

 

CT

 

Look for canal compromise

- cord signal change

- kyphotic deformity

 

Burst Fracture CT No Canal CompromiseBurst Fracture Coronal

 

Retropulsed fragments

- always between pedicles

- typically one or two main fragments (saloon door)

- assess canal compromise

 

Thoracic Burst CT Canal Fragment SagittalThoracic Burst CT Canal Fragment Axial

 

Burst Fracture Axial CT

 

MRI

- HNP

- cord signal change

- assess posterior ligament integrity

- assess level of conus medullaris

 

Thoracic Burst MRI Sagittal Kyphosis and Cord SignalThoracic Burst MRI Canal Compromise

 

Clinically

 

1.  High association abdominal trauma

- duodenum, aorta, spleen

 

2.  Neurology

- complete v incomplete

- from retropulsed fragments

 

Non-Operative management

 

Indications

- no neurology 

- no deformity / < 30o kyphosis

- stable

 

TLSO

 

Surgical Indications

 

TLISS > 4

- usually means neurology

 

Kyphotic deformity

 

Failure non operative

 

Anterior corpectomy and strut graft

 

Indication

- decompression of retropulsed fragments in patient with neurology

 

Lumbar Burst Fracture0001Lumbar Burst Fracture0002Lumbar Burst Fracture0003Lumbar Burst Fracture0004

 

Technique

- approach as per level

- thoracoabdominal for T11 - L1

- thoracotomy for T2 - T10

- remove disc above and below and remove vertebral body

- remove fragments / need to know if 1 or 2

- screws in vertebral body above and below

- 2 screws in a lateral plane

- insert fibular strut allograft / titanium cage

- augment with cage

 

Posterior instrumentation 

 

Indication

- < 7 gaines criteria

- no neurology

 

Technique

- ligamentotaxis clears canal / PLL acts as bowstring

- pedicle screws lumbar, avoided in thoracic

- use transverse process and pedicle hooks in thoracic

- bone graft inserted via pedicles

- need to do before 5 days post injury

 

Burst Fracture Posterior stabilisation 3Burst Fracture Posterior stabilisation

 

Thoracic Burst Posterior Stabilisation APThoracic Burst Posterior Stabilisation Lateral

 

3.  Flexion Distraction

 

Definition

 

Seat belt injuries

- injury all 3 columns

- posterior fails in tension

- anterior and middle in distraction

- anterior undisplaced with no translation

 

Associated injuries

 

1.  Hollow viscus

 

Anderson et al J Orthop Trauma 1991

- 2/3 have injury to hollow viscus

- duodenum very common as second part fixed

- 1/4 have hemoperitoneum from mesenteric laceration

 

2.  Ileus

- very common

- manage NBM / NGT

 

Types

 

1.  Pure bony

- through vertebral body

- Chance fracture

 

2.  Ligamentous

- through disc space and facet joints

 

Thoracolumbar Chance Fracture CT CoronalThoracolumbar Chance Fracture CT Sagittal

 

3.  Combined

- rare injury

 

Management

 

Bony chance

- can heal in hyperextension orthosis

- assess reduction in brace / < 15o kyphosis

- otherwise can fix with pedicle screws and TP hooks of same vertebrae

 

Ligamentous

- treat surgically as unstable and ligament heals poorly

- respond well to short segment posterior instrumentation

- above and below disc space injured

- i.e. T12 and L1 instrumented

 

TL Chance Fracture Stabilisation LateralChance Fracture Stabilisation APTL Chance Fracture

 

Neurology / deformity

- reduction and posterior stabilisation

- add decompression if required

 

4.  Translational - Fracture / Dislocation

 

T12 L1 Soft Tissue Chance CT 2T12 L1 Soft Tissue Chance CTT12 L1 Soft Tissue Chance MRI

 

Background

 

3 Column injury

- high energy

- unstable by definition

- required operative stabilisation

- profound neurological deficit common

 

Types

1.  Shear

2.  Flexion-distraction with translation

3.  Flexion-rotation

- unilateral facet dislocation

- < 25% translated

 

Management

 

Incomplete or no neurology

- rare

- great care must be taken to not worsen patient

- MRI to exclude disc / determine level of conus

 

Options

- posterior approach / decompression / reduction / stabilisation

- consider anterior approach if HNP / above level conus

 

Levels

- 1 up and 1 down sufficient unless

- osteoporosis

- thoracolumbar junction

 

T12 L1 Soft Tissue Chance OTT12 L1 Soft Tissue Chance Posterior StabilisationT12 L1 Soft Tissue Chance Posterior Decompression