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
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
Insert a balloon first and inflate
- bilaterally into each pedicle
- will restore some anatomy
- then inject PMMA
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
Degenerative Scoliosis
Definition
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
MRI
Myelopathy
Decreased height of nerve foramina
Management
Non Operative
Epidural Steroids
Operative
Technique
Multilevel decompression and posterior instrumented fusion
- laminectomy / foraminotomy
- +/- interbody cages to increase foraminal size
Deformity correction rare
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
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
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
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
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
3. Extrusion
- under PLL
- mass of discal tissue of greater diameter than the aperature through which it has passed
4. Sequestration
- free disc in canal
- fragment with no continuity with tissue in disc of origin
Anatomical Classification
1. Central
2. Lateral Recess / Posterolateral
- between dura and foramina
- anterior: disc (annulus) and vertebral body
- posterior: facet joint, lamina, ligamentum flava
- lateral: foramen, L5 pedicle
3. Foraminal
- anterior: body of L5, L5/S1 disc
- posterior: pars, apex of superior facet of S1
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
T1 Axial - see nerve root against white fat
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
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
Definition
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
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
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
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
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
Definition
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
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"
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
B. Axial slices
Findings
- no fat about dura
- trefoil shape canal
- lateral recess or foramina compression
- nerve root compression
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)
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 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
MRI
Demonstrate stenosis with spondylolithesis
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
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
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
3 types
A Stress fracture
B Elongated type
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
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
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
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)
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%
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
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
Technique
- lesion identified / debrided / iliac crest bone graft
Options ORIF
1. Screw across lytic defect
- unilateral defect
2. Pedicle screw + laminar hook
- bilateral defect
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
2. PLIF / interbody cage
3. Bohlman procedure
- interbody fusion with fibula strut
- augmented with decompression and PLF
4. Transfixing L5 / sacral screw
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
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
MRI
Very sensitive
- 40% incidence asymptomatic thoracic disc protrusion
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
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
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
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
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%
CT
Look for canal compromise
- cord signal change
- kyphotic deformity
Retropulsed fragments
- always between pedicles
- typically one or two main fragments (saloon door)
- assess canal compromise
MRI
- HNP
- cord signal change
- assess posterior ligament integrity
- assess level of conus medullaris
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
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
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
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
Neurology / deformity
- reduction and posterior stabilisation
- add decompression if required
4. Translational - Fracture / Dislocation
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
