Cervical

Cervical Degeneration

Cervical Myelopathy

DefinitionCervical Myelopathy MRI

 

Spinal cord dysfunction
- extrinsic compression of the cord or its vascular supply
- caused by degenerative disease of spine

 

Epidemiology

 

Most common spinal cord dysfunction in patients > 55 years old
 

C5/6 commonest level


Pathophysiology

 

Congenital

- congenital / developmental stenosis
- decreased space available for cord
- average mid cervical spine is 17 – 18 mm

 

Acquired

1. HNP

2. Osteophytes from facet and uncovertebral joints
3. Ligamentum Flavum

4. Instability

5. Kyphosis
- stretches spinal cord over posterior vertebral bodies and discs
- dictates an anterior approach

6. Ossification of PLL
- more common in certain Asian populations i.e. Japanese

 

DDx
 

Need to exclude other causes of spinal cord dysfunction

 

Supratentorial
- CVA / AVM / Tumour / Hydrocephalus

- Metabolic or alcoholic encephalopathy

 

Spinal
- demyelinating disease / MS / MND
- syringomyelia / Tabes dorsalis

- myopathy / peripheral neuropathy

 

History

 

Neck pain

 

Parasthesia
- global, non dermatomal distribution over upper extremities

 

Difficulty walking / unsteadiness on feet

 

UL > LL

- have central cord like presentation
- distal worst than central

 

UL
- pain , numbness and weakness
- clumsiness of hands common
- difficulty with fine motor function
- may also have radicular symptoms

 

Bladder dysfunction uncommonly occurs

 

May present acutely with central cord syndrome

 

Examination

 

UMN in extremities below lesion

LMN signs at level of lesion

 

Ataxia

 

Wide based gait

Unable to heel toe

 

Poor proprioception
 

1.  Finger escape sign
- deficient adduction or extension of ulnar digits of affected hand

 

2.  Romberg Positive

 

Hyper-reflexia

 

1.  Hoffman Reflex
- flexion of ipsilateral IPJ of index and thumb when long finger DIPJ flexed

- extension of neck increases sensitivity

 

2.  Inverted Brachioradial Reflex

- spontaneous flexion of digits when BR reflex elicited
- indicates cord compression at C5 and C6 / commonest levels

 

3.  Babinski Reflex


X-ray

 

Narrowed joint space
- C5/6 commonest level followed by C6/7

 

Osteophytic lipping
- foraminal and uncovertebral osteophytes seen

 

Alignment
- lordosis v kyphosis
 

Cervical Stenosis Kyphotic AlignmentLordotic Cervical SpineCervical Spinal Kyphosis Flexion View

 

Ossification PLL

 

Cervical Spine OPLL

 

Flexion / Extension views show instability
- > 3 o
- > 11 mm

 

Pavlovs Ratio
- AP diameter of spinal canal divided by the AP diameter of body at same level
- indicator of developmental stenosis
- should be 1.0

- < 0.8 is narrowed and stenotic

 

AP diameter / SAC
- normal (17mm)
- relative (13mm)
- absolute stenosis (10mm)

 

NB: X-ray estimates of space available for cord

- do not take into account ST i.e. discs and ligamentum flavum

 

CT

 

Helps distinguish disc from osteophytes

- soft v hard disc

 

OPLL

 

OPLL Cervical Spine

 

MRI

 

Disc herniation

- high incidence of asymptomatic findings
- 19% of asymptomatic patients have abnormality on MRI

 

Cervical Myelopathy Herniated Discs

 

Cord changes
- cord oedema with signal change seen

 

Cervical Myelopathy Cord Changes

 

AP diameter thecal sac < 10 mm

 

Compression Ratio
- banana cord
- divide the smallest AP diameter by largest transverse diameter at same level of spinal cord
- ratio of < 0.4 after decompression particularly with myelopathy > 6 months has poor prognosis

 

Cervical Myelopathy Compression Cord Ratio

 

Cross sectional area of spinal cord
- < 30 mm2 poor prognosis

 

NHx

 

Natural history suggests that > 50% of patients become worse if not treated
- some stable
- most slowly progressive
- < 5% acute deterioration

 

Management

 

Non operative

 

Cervical collar
NSAIDS
Physiotherapy with isometric strengthening
Ice , heat and massage

Follow up every 6-12 weeks initially followed by yearly if no progression

Traction and manipulation contraindicated

Must counsel them to the risks of trauma

 

Operative

 

Absolute Indications

 

1. Progressive neurological deficit
2. Failure of symptoms to improve with 6 months of non operative treatment
- base on severity of clinical neurological fingings

 

Relative indications

 

1. Compression ratio < 0.4
2. Transverse spinal cord diameter of < 40 mm2
3. Increased signal intensity of cord on T2 of MRI
4. Acute central cord syndrome
- initially collar and methylprednisolone
- no operation if near full recovery
- decompress if residual neurological deficit

 

Order

 

The patient with cervical and lumbar stenosis

- should have the cervical spine decompressed first

- risk of intubation damage to cervical spine
- reduces need for lumbar surgery
- leg symptoms may improve after the cervical decompression

 

Prognosis

 

Surgery can be expected to halt progression

- may improve motor, sensory and gait disturbance

 

The best spinal cord recovery seen in those treated
- decompression within 6 - 12 months
- early, mild myelopathic signs
- transverse area of cord greater than 40 mm2 postoperatively
- age < 60

 

Preoperative Considerations

 

NSAIDS ceased 2 weeks prior to surgery

 

Positioning should avoid hyperextension of the cervical spine

- may need awake fibreoptic intubation

 

Options

 

1.  Laminectomy & fusion

2.  Laminoplasty

2.  ACDF

3.  Corpectomy

 

1. Laminectomy & Fusion

 

Cervical Myelopathy Posterior Decompression InstrumentedCervical Myelopathy Posterior Decompression Instrumentation

 

Concept

 

Any posterior decompression procedure is an indirect technique

- requires posterior shifting of the cord in the thecal sac

- to diminish the effect of the anterior compression

 

Indications


Lordotic cervical spine / no kyphotic deformity


Ossification of PLL

- dura may be adhered

- high risk of irreparable dural tears with anterior approach

 

Indications for fusion
 

Instability

 

Technique

 

Positioning for the posterior approach
- prone
- Mayfield head tongs in neutral

- protect eyes / elbows (ulna nerve) / knees (CPN)
- pneumatic compression stockings
- IDC
- infiltration of skin with adrenaline solution

 

Decompression

- wide laminectomy +/- foraminotomy

 

Instrumentation
- avoids progressive kyphotic deformity
- lateral mass screws

 

Cervical Myelopathy Posterior Decompression

 

Complications

 

Postoperative instability / kyphosis
- > 50% facet resection = instability
- avoid by fusion or laminoplasty

 

2.  Laminoplasty

 

Concept

- divide lamina unilaterally

- elevate to decompress

- insert device to keep lamina elevated

 

Advantage

- maintains stability

- no need to insert pedicle screws

 

Indication

- no kyphotic deformity

 

3. ACDF / Corpectomy and Arthrodesis

 

2 Level ACDFACDF

 

Indication

- anterior cord compression

- pathology primarily at disc level

- kyphotic deformity

 

Advantages
-
removes entire disc

- can maintain / restore lordosis

- restores foramina / decompresses nerve root

 

Disadvantages
- difficulty decompressing the nerve roots in foramen from front
- difficult access to the posterior osteophytes

 

Technique

 

Smith - Robinson approach

 

Positioning
- supine with interscapular roll
- head turned slightly to right for left sided approach

 

Disc removal in full
- MRI reviewed carefully to exclude free disc lying behind the PLL
- resect the disc until the longitudinal fibres of PLL seen

- inspect carefully for defect
- if no defect on MRI findings then should not routinely remove the PLL

 

Insertion cage 

- contains autograft / allograft / BMP & collagen
- sized first, check on x-ray
- insert cage, ensuring not too posterior
- aiming to decompress foramina

 

Anterior plate for stability

 

4.  Corpectomy and strut Graft

 

 

 

Indication

- multilevel disease

- soft and hard disc causing compression

- kyphotic deformity

 

Technique

 

Anterior approach
- decompression of disc above and below

- resection of vertebral body with burr
- leave lateral walls to protect vertebral artery
- typical midline channel is 16 – 18 mm

 

Bone Grafting Technique
- single level, iliac crest
- multiple level, fibular strut
- autograft superior to allograft

 

Instrumentation
- maintains alignment / improves graft stability
 

Post op
- usually require HTB

 

Complications

 

1. Transient sore throat or difficulty swallowing

- most common complication

- superior laryngeal nerve

 

2. Recurrent Laryngeal Nerve paralysis
- more common in right sided approach
- post operative hoarseness

 

3. Respiratory compromise
- drains
- strict monitoring

- emergency release of wound stitches if haematoma

 

4. Neurological injury 1 – 2%

 

5. Injury vertebral artery

 

6. Dural tears
- more common if OPLL
- fibrin glue, fascial patch

 

7. Graft related
- dislodgement
- fracture
- severe settling
- pseudoarthrosis

Cervical Radiculopathy

Definition

 

Clinical diagnosis

- based on a sclerotomal distribution of motor &/or sensory symptoms or signs

 

Caused by impingement of exiting nerve roots

- HNP

- zygo-apophyseal / facet joint hypertrophy

- neuro-central joint hypertrophy

 

May be acute or chronic

 

Epidemiology

 

M>F

 

Peak age 50-54

 

C7 > C6

 

Natural History

 

Mayo Clinic Natural History Radiculopathy

- 50% of population at some stage

- ~50% recurrent

- 90% asymptomatic at 5 years

 

Anatomy

 

Each subaxial C-spine motion segment has 5 articulations

 

A. Intervertebral disc

 

B.  2 neurocentral / uncovertebral joints

- along posterolateral vertebral body / Joint of Luschka

- lie between disc & nerve root

- each body has upturned postero-lateral uncinate process

- pedicle is attached below uncinate process

 

C.  2 facet joints

- angulated 30-50° to transverse plane

 

Intervertebral foramina boundaries

 

A. Anterior

- both vertebral bodies, uncinate process & disc

 

B.  Posterior

- facet joints

 

C.  Above & below

- pedicles

 

Foramina are 45° to sagittal plane

 

Transverse process

 

3 elements

1. Embryological TP to posterior tubercle

2. Embryological rib to anterior tubercle

3. Tubercles joined by intertubercular lamella

 

Foramen transversarium in middle with vertebral artery

Dorsal root ganglion and ventral ramus spinal nerve on intertubercular lamella

 

Tubercles

 

Posterior tubercle

- Scalenus medius

 

Anterior tubercle

- Scalenus anterior, longus coli & capitus

- progressively enlarge from C3 down to C6

- C6 Chassaignacs tubercle

 

Cervical Nerve Roots

 

Each cervical root exits above the pedicle for which it is named except C8

- C5/6 – C6

- C6/7 – C7

- C7/T1 – C8

 

Pathophysiology Nerve root compression

 

1.  HNP

- in contrast to lumbar spine

- both posterolateral and central HNP compress exiting nerve root

- inflammatory and ischaemic components

 

A. Central - myelopathy

B. Posterolateral - mainly motor weakness

C. Intraforaminal - most common / often dermatomal distribution

 

Cervical Spine Central Disc HerniationCervical MRI Posterolateral Disc

 

2.  Spondylosis / Disc degeneration

- loss of height / annular bulging

- foraminal compression

 

3.  Bony 

 

A.  Uncovertebral osteophytes / hard discs

- compress nerve root anteriorly

 

B.  Superior articular facet osteophyte

- extend from ventral surface to compress the neural foramen

- are less common

 

Clinical

 

Pain / parasthesia

- often don’t follow dermatomal distribution

 

Weakness

- 60-70% motor deficiency

 

Spurling maneuver

- hyperextension with tilt toward affected side 

- stimulates radiculopathy symptoms

 

Nerve root signs (C6 and C7 most common)

 

C2 Posterior occipital headaches

C3 Occipital headache

C4 Neck and trapezial pain +/- shoulder / scapula pain

C5 Pain lateral upper arm (epaulet) / deltoid weakness / biceps jerk decreased

C6 Radial forearm and hand pain / weak biceps and wrist extension / BR reflex decreased

C7 MF pain / weak triceps / absent triceps jerk

C8 Pain ring and little fingers / weak finger flexors

T1 Ulna forearm pain / weak hand intrinsics

 

DDx Myopathy

 

Entrapment syndromes (ulna / median nerves)

Thoracic outlet syndrome

RC disease

 

X-ray

 

Demonstrate loss of disc height and degeneration

 

MRI

 

Note

- 19% of asymptomatic patients will have evidence of nerve root compression

- difficult to distinguish between hard and soft discs

 

CT

 

Adds complementary information to MRI in C spine

 

Demonstrates the posterolateral impingement is from “hard” disc

- i.e. uncovertebral spur 

 

Cervical nerve root injections

 

Confirm diagnosis

- should get some temporary symptomatic relief

 

EMG / NCS

 

Indication

- concern re peripheral nerve entrapment

 

SNAP

- are usually normal because lesion proximal to DRG

 

CMAP

- amplitude decreased proportional to muscle atrophy

 

Nerve conduction velocity

- not abnormal unless severe demyelination of axons

 

EMG

- best for differentiating peripheral nerve root compression from central

- fibrillations

 

Management

 

Non operative

 

Options

 

Rest

Pharmaceutical / NSAIDS

Physio

- hot / cold

- electrical stimulation

- ROM / stretching

- isometric strengthening exercises 

Cervical traction

Collar

HCLA / nerve root injections

 

Results

 

Lellad et al Ann Phys Rehabil Med 2009

- RCT demonstrating benefit of reducing symptoms with cervical traction

 

Cervical Traction

 

Kuijper et al BMJ 2009

- RCT demonstrating benefit of wearing semi-hard collar for 3 weeks 

 

Operative

 

Indications

- severe pain

- severe neurological impairment

- failure non operative treatment

 

Options

 

ACDF

Disc replacement

Corpectomy

Laminoforaminotomy

 

1. ACDF

 

ACDF 2ACDF C34

 

Definition

 

Anterior Cervical Discectomy and Fusion

 

Concept

- anterior approach

- interbody fusion

- iliac crest bone graft / synthetic bone graft / allograft / cage

- anterior plate / eliminates need for brace

 

Advantage

- deal with HNP and uncovertebral osteophytes

- opens up the neuroforamina and decompresses the nerve

- fusion relieves pain of spondylosis

- anterior approach dissects little muscle and has little pain

- scar very cosmetically acceptable

 

Technique

 

Smith & Robinson / anterior approach

- divide platysma and deep cervical fascia

- SCM laterally

- divide pretracheal fascia / carotid sheath laterally

- divide prevertebral fascia in midline, separate longus colli

 

Discectomy

- decorticate end plates

- excision of osteophytes controversial

- generally only if causing compression

- otherwise will absorb with stability

 

Complications

- pseudarthrosis

- graft / cage displacement posteriorly

- wrong level

- insufficient decompression

- neurological injury (quadriplegia /  nerve root / RLN / Superior Laryngeal Nerve)

- injury to other structures (carotid artery / oesophagus)

- degeneration at second level

 

Cervical Disc Degeneration Above Fusion

 

 

 

2. Disc replacement

 

Technique

- as above

- insert disc replacement

- no anterior plate

 

Advantage

- maintain some motion

- preserve other disc segments

 

Results

 

Murrey et al Spine 2009

- RCT of ACDF v disc replacement

- disc replacement maintained 4o of motion

- significant reduced reoperation rate in disc replacement (1 v 8%)

 

3. Corpectomy

 

Indication

- multilevel hard and soft compression

- can remove body with disc above and below

- decompress 2 levels

 

Cervical HNP 2 Levels

 

Cervical Corpectomy APCervical Corpectomy

 

4. Laminoforaminotomy

 

Technique

- posterior approach

- deroofing of foramina

 

Results

 

Herkowitz et al Spine 1990

- compared ACDF with posterior laminotomy / foraminotomy

- patients with both central and posterolateral discs

- combination of radiculopathy and myelopathy symptoms

- 4 year followup

- 95% vs 75% G/E

 

Johnson et al Spine 2000

- prospective study of patients with posterolateral disc and radiculopathy

- patients had no neck pain

- removal of HNP + uncovertebral osteophytes

- 91% improved or resolved

- 9% revision (ACDF / repeat posterior foraminotomy)

 

 

 

 

Cervical Spondylosis

Definitions

 

Cervical spondylosis

- chronic disc degeneration & associated facet arthropathy

 

Cervical myelopathy

- spinal cord dysfunction

- secondary to extrinsic compression of cord or its vascular supply

 

Cervical radiculopathy

- sclerotomal distribution of motor &/or sensory symptoms or signs

- due to compression of nerve root

 

Epidemiology

 

Usually begins at age 40-50

 

M>F

 

Most common at C5/6 > C6/7 > C4/5

 

Pathology

 

Spondylosis

 

Degenerative changes at disc / facet joints / uncovertebral joints

 

Clinical Features

 

Neck pain / headaches / local tenderness

 

Reduced ROM

 

X-ray

 

Typical changes of spondylosis

- disc space narrowing

- osteophyte formation

- degenerative facet & uncovertebral joints

 

May be present in asymptomatic individuals

 

Cervical Spine Degeneration

 

CT scan

 

Degenerative changes

 

Cervical Spondylosis CT

 

MRI

 

Degenerative disc changes

- dessicated (loss of fluid), narrowed, end plate changes

 

Space available for cord

 

Neural compression

- intrinsic cord changes

- cord compression / ratio / cross sectional area

 

Cervical Spine Degeneration MRI

 

Management

 

Non-operative

 

Education & Reassurance

- analgesics

- local modalities

- exercise programme

- traction

 

Operative

 

Indications

 

Spondylosis

- failure non operative treatment

- disease isolated to 1 or 2 levels

 

Options

 

Posterior Instrumented Fusion

 

Cervical Pedicle Screws LateralCervical Pedicle Screws AP

 

ACDF

 

ACDF

 

Advantage

- restores disc height and aligment

- decompresses foramina

 

Options

- autograft

- allograft

- cage

 

Jacobs et al Cochrane Database Review 2011

- autograft superior to discectomy alone

- autograft superior to cage in fusion rate but with higher complications

 

Disc Replacement

 

Advantage

- elevate / decompress foramin

- maintain motion / decrease degeneration at subsequent levels

 

Burkus et al J Neurosurg Spine 2010

- prospective multicentred RCT 541 patients with single level disc degeneration

- disc replacement v ACDF

- improved outcome scores and neurological outcome in disc replacement

- no difference in rates of subsequent level surgery

 

PLOS One March 2015

- meta-analysis of 19 RCT of ACDF v disc replacement

- disc replacement had better scores, better pt outcome, better ROM, and decreased secondary degeneration

 

 

Technique ACDF

Anterior Cervical Discectomy and Fusion

 

ACDF C5 6

 

Position

 

Place the patient in the supine position

- small roll placed under the shoulder blades to drop the shoulders from the field

- exposes the anterior neck

- strap the shoulders at the side with minimal traction 

- allows visualization of the lower cervical spine on lateral radiographs

- apply skull traction with Gardner-Wells tongs

- keep head rotation to a minimum because deep dissection will depend on identifying the vertebrae midline

- prevents inadvertent injury to adjacent structures

- reverse Trendelenburg position facilitates venous drainage and results in less bleeding during surgery

 

Dissection

 

Anatomic landmarks for incision 

- hyoid bone overlying C3

- thyroid cartilage overlying the C4/5 interspace

- cricoid cartilage overlying the C6 level

 

Use transverse incision for exposure in most cases

- more cosmetic

- from the midline to the anterior border of SCM in Langer's lines

- divide the deep cervical fascia and platysma muscle exposing the middle layer of the cervical fascia

- bluntly dissect the pretracheal fascia and palpate the carotid pulse

 

When three or more levels are approached, use a longitudinal incision

 

Dissection through the pretracheal fascia places several structures at risk

- superior and inferior thyroid arteries extend through the pretracheal fascia from the carotid artery to the midline

- travel at the C3/4 and C6/7 levels, respectively

- intervening area provides a relatively avascular plane for dissection

 

Recurrent laryngeal nerves

- right recurrent laryngeal nerve ascends in the neck after passing around the subclavian vessels

- courses medially and cranially at the C6–C7 level, often along with the inferior thyroid artery

- left recurrent laryngeal nerve ascends after curving around the aortic arch along the tracheoesophageal groove

- more midline and protected position

- left-sided procedure may be safer, especially when lower cervical segments are approached

- the thoracic duct is often visible on the left at the C7–T1 level and must be protected

 

Retract the sternocleidomastoid muscle and the carotid sheath medially

- contents (common carotid artery, internal jugular vein, and vagus nerve)

 

Retract the midline structures, including the trachea, esophagus, and thyroid gland medially

- complete blunt dissection through the deeper levels to the prevertebral fascia and vertebral bodies

 

Once the midline is identified, incise the prevertebral fascia

- elevate the medial edges of the longus colli muscles

- place blunt self-retaining retractors under the leading edges of the muscle

- Tramline retractor is used (Medial Lateral)

- take care to avoid dissecting along the longus colli muscle because of injury to the cervical sympathetic plexus

- screws in vertebral bodies for vertebral distraction

 

Discectomy

 

Identify

- vertebral bodies by their concave appearance 

- the discs by their more convex contour

 

Localize the disc space with a radiopaque marker and lateral radiograph

 

Remove disc

- incise the disc with an annulotomy blade

- cut lateral to medial away from the vertebral artery

- remove the disc contents and endplate cartilage to the PLL

- use thorough evaluative preoperative imaging to determine the presence of a sequestered disc behind the PLL

- palpate the PLL for the presence of a rent that may also indicate a sequestered fragment

- in the event that a rent is noted, or if an expected disc fragment is not identified, remove the PLL with Kerrison rongeurs

- beware of routine removal of the PLL, because reports of postoperative epidural hematoma have been associated with this technique

 

Removal of endplate and uncovertebral osteophytes is controversial

- disc space distraction reduces ligamentum flavum buckling and increases neuroforaminal area

- it is believed that fusion will arrest spur progression, and stability may allow for resorption over time

- however, this is not a consistent phenomenon

- the location and size of the offending spur must be carefully considered when performing decompression

- exposure of the uncinate processes is critical to safely remove osteophytes

- utilize a high-speed burr to excise the spur from medial to lateral

 

Foraminotomy

- judge the adequacy of foraminotomy

- ability to place the tip of a curret anterior to the exiting nerve root without significant resistance

 

 

Fractures

Atlantoaxial Instability

Definition

 

Loss of ligamentous stability between atlas and axis

 

Spectrum of conditions

1.  Subluxation AP / insufficiency transverse ligament

2.  Rotatory / insufficiency apical ligament

 

Epidemiology

 

Most common older children and adolescents

 

Aetiology

 

Primary

 

Secondary to laxity of transverse ligament

- DIAL HOME CS

- Larsen's / Marfans

 

Secondary

 

1. Infection

- retropharyngeal abscess / Grisel's syndrome

 

2. Trauma

 

3. Hypoplasia

- Down's Syndrome (15%)

- SED

- Achondroplasia

- Morquio

 

4. Inflammatory

- Rheumatoid arthritis

 

5. Developmental

- Os Odontoideum

- Klippel Feil

 

Anatomy

 

Cruciform ligament

A. Transverse ligament

- tubercles medial aspect lateral mass C1

B. Longitudinal bands from transverse ligament

- up to occiput

- down to C2

 

Alar ligament

- side of the dens up to the lateral margins foramen magnum

- prevent excessive lateral rotation

 

Apical ligament

- dens to occiput

 

Tectorial membrane

- extension of PLL

- behind transverse and alar ligaments

 

Symptoms

 

Neck pain

Occipital neuralgia

Rarely vertebro-basilar insufficiency

 

Examination

 

Atlanto-Axial Rotatory Subluxation (AARS)

- Cock Robin Tilt

- Torticollis

- facial asymmetry in children

 

DDx

 

Torticollis

- fibrosis SCM

 

Ondontoid fracture

 

Os ondontoid

 

Xray

 

Flexion / Extension views

 

ADI < 3.5 mm in flexion – transverse ligament intact

ADI 3-5 mm – transverse ligament insufficient / type II injury

ADI > 5mm – failure alar ligaments / type III rotatory subluxation

 

Open mouth xray

 

Lateral mass C1 rotated & asymmetric

Wink Sign - C1 facet locked over C2

 

CT Scan

 

Confirms above diagnosis

 

MRI

 

Assess transverse ligament

 

Classification Fielding & Hawkins

 

Type I

 

Definition

- rotary subluxation with no anterior displacement (ADI < 3mm)

- transverse ligament intact

 

Treatment

- often resolves spontaneously

- soft collar and analgesics

- may need correction with halter traction with application HTB

 

Type II

 

Definition

- rotation about one intact facet with increase ADI 3-5 mm

- transverse ligament insufficient & unilateral capsular tear

- alar ligs intact

- one lateral mass displaced

- other lateral mass acts as pivot

 

Treatment

- holter traction till reduced + application HTB

 

Type III

 

Definition

- bilateral anterior subluxation with ADI > 5mm

- failure of the alar ligament

- Wink sign positive / C1 facet locks over C2

 

Treatment

- traction till reduced

- C1/2 fusion

 

Type IV

 

Definition

- complete posterior displacement of the atlas

- really a posteriorly displaced type II dens fracture

- rare 

 

Management

 

Specific Conditions

 

Children

- often no history of trauma

- reasonable to observe for 1-2/52 as often corrects spontaneously

 

Down's Syndrome

- may have peg hypoplasia

- increased ADI secondary to transverse ligamentous laxity more common

- ADI > 5mm & asymptomatic = avoid contact sports

- ADI > 5mm & symptomatic = fusion

 

JRA

- transverse ligament incompetent

- often zygapophyseal fusion has occurred

- rarely peg base can be eroded

 

Operative Management

 

Indications

- neglected fixed deformity

- failure to correct with nonoperative management

- type III & IV

- instability

- neurological problems

- ADI > 10 mm

 

Surgery

 

Posterior C1-C2 arthrodesis

- Gallie / Brooks

- Magerl's screws / transarticular

- Harms

 

 

Lower Cervical Spine Fractures

Background

Anatomy Lower Cervical Spine

 

Movement

- 50% of cervical rotation

- 60% of cervical flexion / extension

 

Uncovertebral joint

- lateral projections of body 

- medial to vertebral artery

 

Facet joints

- sagittal orientation 30 – 45o

 

Spinous processes

- bifid C3-5

- prominent C7

 

ATLS

 

Awake, alert, neurologically normal & no neck pain very unlikely to have C-spine injury

 

Lateral C-Spine C1-T1

- will detect 85% of fractures

- need swimmers view if cannot visualise T1

 

Swimmers View

 

AP + Lateral + Peg view

- 92% of fractures

 

C-spine fracture

- 10% risk another cervical spine fracture

- 30% risk fracture other level in spine (may be masked by neurological injury)

 

Stability

 

The ability of the spine under physiological loads to maintain the relationship between vertebrae

- without neurological compromise

 

Instability  / Panjabi & White Spine 1976

 

Scoring

- Anterior elements destroyed    2

- Posterior elements destroyed   2

- Sagittal translation >3.5 mm   2

- Sagittal rotation >11°             2

- Positive Stretch Test > 1.7mm 2

- Medullary cord damage           2

- Root damage                          1

- Abnormal disc narrowing         1

- Dangerous loading anticipated  1

 

Total of 5 or more = Unstable

 

Stretch Test

- medical supervision / tongs + roll under head

- add 3lb / wait 5 min / add 2lb to max 40lb / xray

- repeat until weight a third body weight / neurological changes / abnormal separation occurs >1.7mm

 

Mechanism of Injury / Allen & Ferguson Classification

 

Determined by

1. Position of the neck at the time of injury - flexion / extension / neutral

2. Direction of the force - compression / distraction / lateral bending

 

6 Types

- flexion compression / wedge

- vertical compression / burst

- flexion distraction / facet dislocation

- extension compression

- extension distraction 

- lateral flexion

 

Subaxial Injury Classification Scoring System / SLIC

 

Dvorak et al Spine vol 32 no 23

 

1. Injury Morphology / Pattern injury

No abnormality                        0       

Compression                            1 

Burst                                       2          

Distraction / facet perch            3         

Rotation / translation                 4

 

2. Discoligamentous complex

Intact                                        0                     

Indeterminate (MRI change only) 1   

Disrupted                                   2

 

3. Neurological status

Intact                                        0                     

Root Injury                                1                                   

Complete cord injury                  2            

Incomplete cord injury               3    

Continuous cord compression    +1

 

5 or more - surgery                   3 or less - non operative                4 - equivocal

 

Problem

- burst + disrupted ligaments + intact nerves = 4 / equivocal

 

 

 

Burst Fractures

 

Definition

 

Burst fractures

- injury to anterior and middle columns +/- posterior column

 

Mechanism

 

Vertical compression

 

Epidemiology

 

10% cervical fractures

Most commonly C5/6

 

Pathology

 

Anterior & middle columns fail

- if severe, posterior ligament complex fails

 

Canal compromise / neurological injury

- retropulsed fragments

- typically one or two main retropulsed fragments

 

Clinical

 

Neck pain

 

Complete / incomplete cord lesion

 

X-ray

 

AP

- widening between pedicles is hallmark on AP

 

Lateral

- > 50% anterior column loss of height very suspicious

- loss of posterior vertebral height

 

CT

 

Assess retropulsion / canal compromise

 

MRI

 

Assess integrity of posterior column

 

Non operative Management

 

Indications

 

< 50% height loss

Minimal kyphosis 

Nil neurology

Posterior column intact / nil instability

 

SLIC score 4+

 

Treatment

 

Collar for 6 weeks

 

Operative Management

 

Indications

 

Instability

Neurology

 

Neurology

 

Incomplete cord lesion (urgent / good prognosis)

Complete cord lesion (may gain 1 or 2 levels recovery which is very significant)

 

Aim

 

Decompression of retropulsed fragments and stabilisation

 

Technique

 

Tongs + Traction

- incomplete neurology / will decompress canal

 

Anterior corpectomy / discectomy and fusion

- tricortical graft + anterior plate

- may sometimes need supplemental posterior fixation / cervical lateral mass screws

 

Results

 

Complete v Incomplete lesion is best prognostic predictor

 

 

 

Facet Joint Dislocation

Definition

 

Facet joint dislocations secondary flexion distraction injury

 

Epidemiology

 

10%

 

Stages

 

1. Unifacet subluxation - interspinous process widening

2. Unifacet dislocation - 25% anterolisthesis

3. Bifacet dislocation - 50% anterolisthesis

4. Complete vertebral translation - 100% anterolisthesis

 

Unilateral Facet Joint Dislocation

 

Epidemiology

 

C5/6 or C6/7

 

Mechanism

 

Flexion / Distraction / Rotation about contralateral intact facet

 

X-ray

 

Unilateral facet subluxation

- widening of interlaminar or interspinous spaces

 

Unilateral facet dislocation

- 25% subluxation on lateral X-ray (<50%)

 

C56 Unilateral Facet Dislocation

 

CT

 

Unilateral Facet Joint Dislocation CT

 

Management Principles

 

1.  Exclude Herniated Nucleated Pulposis

 

Issue

- large disc could worsen neurology with tong traction

- indication for anterior approach / discetomy / fusion

 

Problem

- disc always looks injured on MRI

- look for herniation

 

2.  Reduce and fuse

 

Will improve partial neurology

May gain 1 or 2 levels of recovery in complete

Unreduced unifacet dislocations painful

Facet joint dislocation is a ligamentous injury / poor healing potential

 

Treatment Algorithm

 

1.  No neurology

- MRI to exclude HNP

- awake tong traction reduction if conscious and non obtunded

 

2.  Stable Neurology

- complete or non progressive incomplete neurology

- MRI to exclude HNP

- awake tong traction reduction if conscious and non obtunded

- if successful reduction / collar / fusion when able

- unsuccessful /  reduce in OT and fuse

 

3. Progressive Neurology

- MRI to exclude HNP

- emergent open reduction and fusion

 

4.  HNP

- anterior approach / discectomy / fusion

 

Reduction

 

Options

- tong traction

- MUA

- open reduction

 

MUA v tong traction

 

Lee 1994 JBJS

- 210 patients MUA vs traction

- traction more success 88%vs 73%

- traction safer as patient awake & can monitor neurology

 

Tong traction

 

Indication

- no HNP on MRI

- patient awake and able to communicate if neurology worsening

 

Contra-indication

- obtunded patient

 

Technique

- Gardener Wells tongs 1" above  and behind pinna

- below equator / maximum diameter of skull to prevent slippage

- place towels under head to recreate flexion deformity

- best performed in OT, can use cross table II

- start 10 lb for head, then 5 lb for each cervical level every 10 min

- repeat X-ray after each weight increase

- monitor neurological status

- if neurology worsens, release all traction

- maximum 40% body weight

- once facet unlocked, removed towels to extend head

 

Successful reduction

- place in HTB

- fusion when able

 

MUA

 

Indication

- experienced surgeon

- failure closed reduction

- intention to proceed to open reduction + fusion if required

 

Open reduction

 

Indication

- failure closed reduction

- herniated disc

- reduction + fusion

 

Technique

- GA + II + Tongs

- head flexed 45° & rotated 45° away from side of facet dislocation

- traction in above position, then rotate to side of facet dislocation

- should hear click on reduction

- gently extend to stabilize

- similar method if bilateral, but no rotation (flexion / traction / extension)

 

MRI Post Closed Reduction

 

MRI Post C5 Unilateral Facet Dislocation

 

ORIF

 

Options

 

1.  ACDF

- remove herniated disc / anterior plate

ACDF post C56 Unilateral Facet Dislocation

 

2.  Posterior stabilisation

Unilateral Facet Dislocation Posterior Stabilisation

 

Bilateral Facet Joint Dislocation

 

X-ray

 

>50% forward subluxation

 

Cervical Bilateral Facet Joint Dislocation Xray

 

CT

 

Evidence of bilateral facet joint dislocation

 

Cervical Bilateral Facet Dislocation CTCervical Bilateral Facet Dislocation CT 2

 

Pathology

 

Cervical Cord Injury Post Unilateral Facet Dislocation

 

Cord injury common

 

HNP 47%

 

Unstable - posterior & middle ligament failure

 

Management

 

As for unilateral facet joint dislocation

- MRI first to exclude HNP

- closed reduction with traction if safe with elective anterior / post fusion

- open reduction if HNP / failure closed reduction

 

Other fractures

Extension distraction

 

Epidemiology

- 20%

- common with ankylosing spondylitis / DISH

 

Stages

 

1. Anterior ligament failure

– disc space widening (or transverse fracture of vertebral body)

 

2. Posterior ligament failure with retrolisthesis of superior vertebral body

 

Articular process fracture

 

Superior process fracture

 

Cervical Spine Facet FractureCervical Superior Articular Facet Fracture0001Cervical Superior Articular Facet Fracture0002

 

Can allow superior vertebrae to dislocate anteriorly

- incidence of spinal injury

 

Management

- undisplaced - hard collar

- displaced - anterior fusion

 

Superior Articular Process Fracture

 

Inferior process fracture

- don’t allow significant displacement

- Stable ->Orthosis

 

Clay Shoveller's

 

Spinous process avulsion C7 secondary to Ligamentum Nuchae

- sudden single overload 

- treat symptomatically

Teardrop Fracture

Mechanism

 

Hyperflexion

- diving into swimming pool type injury

- 3 column injury

- high incidence of spinal cord injury

 

Xray / CT

 

Large antero-inferior body fragment

- > 20 %

- stays attached to  ALL

 

Posterior superior fragment retropulsed into canal

 

Sagittal fracture on CT

 

DDx

 

Extension tear drop injury

- fragment much smaller

- stable injury

 

Management

 

Reduction with tong traction

- improves canal / aids neurology 

 

Anterior corpectomy + plate

- may need posterior stabilisation as well

 

 

 

 

Wedge Fracture

 

Definition

 

Anterior compression / wedge fractures

- injury to anterior column

 

Mechanism

 

Flexion compression

 

Epidemiology

 

20% 

Most common at C4/5/6

 

Management

 

Usually stable

- rule out burst fracture

- suspicious if > 50% anterior height loss

- CT scan

 

Collar

ORIF Cervical Spine Fractures

C1/2 fusion

 

Options

 

1. Sublaminar wiring

- Gallie / Brooks

2.  Transarticular / Magerl screws

3.  Harms technique

- C1 lateral mas screws

- C2 pedicle screws

 

Gallie Fusion

 

Gallie Fusion C12

 

Indication

- C1/2 instability

- peg fracture with anterior displacement

- rupture of transverse ligament

 

Advantages

- relatively easy technique

- graft firmly fixed between two arches of C1 and C2

- aids in reduction of the anterior subluxation

 

Disadvantages

- sublaminal wiring technique

- can't use with C1 arch fracture

- not suitable for posterior peg displacement

 

Technique

 

Prone position

- head in line traction with tongs

- midline incision occiput to C4

- soft tissue dissection from midline

- no further than 1.5cm from midline to avoid vertebral artery and venous plexus

- clear soft tissues of posterior arch C1 circumferentially to allow passage of wire

- 1.2mm wire is fashioned as loop with a hook

- loop is passed deep to C1 arch from inferior to superior

- then passed over arch superficially so loop ends up around C2 spinous process

- unless C1 and 2 are reduced significant risk of injury to cord at this point

- decorticate arch of C1 and C2

- corticocancellous rectangular graft 3x4cm removed from post iliac crest

- fashioned into a "H" to fit snugly around SP's

- fashion cancellous surface to fit snugly on post arches

- notch graft laterally to fit wire 

- tie wire over graft to secure in place

- pack with cancellous graft around op site

 

Post-op

- HTB for 3/12

 

Brooks and Jenkins

 

Indications

- C1/2 fusion with sublaminar wiring

- biomechanically superior to Gallie technique

- more rotational control

- able to use with posterior displacement of peg

 

Technique

- clear C1 and C2 post arches circumferentially

- 2 lateral wire loops around each lamina 

- 1.5 x 3.5cm wedged corticocancellous grafts between lamina C1 and C2 both sides

 

Trans-articular / Magerl Screws

 

Indications

- C1/2 fusion

- acute and chronic atlanto-axial instability

- suitable for posterior arch fracture and posterior dislocation

 

Disadvantage

- technically difficult

 

Preop CT

- determine sufficient bone for 3.5 mm screw / sagittal reconstructions

- exclude overriding vertebral artery / axial view

 

Technique

- patient prone

- ensure reduction with II

- flex neck

- approach midline occiput to C7

- expose posterior elements C1-C3 as above

- persistent anterior dislocation may be reduced by pushing on C2 SP or pulling on C1

- expose C2 lamina not out to vertebral artery

- under lateral image control pass 2.5mm drill C2 to C1

- entry at lower edge of caudal articular process C2 

- 3mm from inferior surface and 2mm lateral to medial edge

- drill passing through posteromedial surface of lateral mass atlas

– 25o cranially, under II

- drill to anterior cortex and place appropriate 3.5mm cortical screw

- following screw fixation posterior fusion performed

 

Post-op

- Collar 6-10 weeks

 

Harms Technique

 

Harms Technique C12 fusion

 

Indication

 

Technique

- C1 lateral mass screws

- C2 lateral mass screws

 

Ondontoid

 

Dens Screw

 

Advantage

- maintain motion

- less blood loss

 

Disadvantage

- technically difficult 

- 17% major complication rate 

 

Contra-indications

- obesity

- short fat necks

- irreducible fracture

- reverse obliquity

- comminution

- delayed or nonunion / unable to debride or bone graft

 

Technique

 

Approach

- anterior approach at level C5/6

- this allows correct angle for wire insertion

- split platysma, open deep fascia

- SCM and carotid sheath laterally

- blunt dissect to prevertebral fascia medially

- split prevertebral fascia / between longus colli

- palpate inferior aspect of C2

 

Reduction

- anterior displacement easy: extend neck

- posterior displacement more difficult: traction and bring head forward

 

Cannulated wire insertion

- need good AP and lateral x-rays

- wire inserted at C5/6 disc

- need sufficient anterior bone in C2 to prevent cut out

- 2 wires inserted for rotation control

- 1 single 3.5 mm cortical screw just penetrating tip for extra fixation

 

Lower C spine

 

Posterior Wiring C2-T1

 

Many techniques

- interspinous wiring simplest

- TBW of posterior elements

- Sublaminar wires here have high neurology rate

 

Technique

 

Midline posterior approach

- essential to identify correct level with II

- hole drilled in each side of spinous process of upper vertebrae of injured segment

- junction upper and middle 1/3's

- connect holes with towel clip

- 1.2mm wire is passed through hole and around inferior spinous process leaving interspinous soft tissue intact

- wires pulled tight then passed around inferior spinous process and tied superiorly

- lamina are decorticated and cancellous graft applied

 

Triple Spinous process wire

 

Concept

- through spinous process

- about bone graft each side

 

Technique

 

First wire through transverse hole base SP

- two rectangular graft blocks each side

- second wire through superior SP & each end into superior holes blocks 

- third wire through lower SP & bottom block holes 

- tie ends second and third wires together

- decorticate post laminae

 

Screw Fixation

 

Cervical Pedicle Screws

 

Lateral mass screws

- poly axial heads

 

Preoperative CT

- location and orientation of foramen and vertebral artery

 

Entry point

- middle of lateral mass / 1 mm medial to centre

- aim 10 - 15o lateral 

- parallel to superior articular facet

 

 

 

Upper Cervical Spine Fractures

Atlas Fractures

3 types

 

1. Posterior Arch

 

Mechanism

- axial compression with hyperextension

 

Associations

- 50% incidence other C1/2 fracture

- i.e. ondontoid fracture

 

Management

- stable

- soft / philadelphia collar

 

2. Isolated lateral mass fracture

 

Mechanism

- asymmetrical axial compression / lateral bend

- fracture runs anterior, posterior or through articular surface

 

3. Jefferson (3 or 4 part)

 

Jefferson Fracture 4 Part Axial CT

 

Jefferson Fracture

 

Mechanism

 

Symmetrical axial compression

 

Management depends on integrity of transverse ligament

 

Ruptured transverse ligament

 

1. Peg view

 

C1 lateral mass displacement

- C1 overlapping on C2 bilaterally

- > 6.9 mm displacement of both lateral masses in total

-  rupture of transverse ligament likely

 

Jefferson CT Peg View

 

2. > 5mm ADI on dynamic flexion / extension xray

 

3. Avulsed fragment on CT

 

MRI

 

Transverse ligament

- avulsion

- midsubstance tear

 

Treatment

 

1. Undisplaced

 

Manage with collar

 

2. Displaced

 

Reduce with ligamentotaxis / traction tongs

 

A.  HTB

- 8 weeks

- check flexion / extension views

 

Jefferson HTB XrayJefferson Fracture Flexion Extension Views Stabe0001Jefferson Fracture Flexion Extension Views Stabe0002

 

B.  Fuse if midsubstance tear transverse ligament

- unlikely to heal

- as opposed to avulsion

 

3. Peg + Jefferson

 

Unstable & requires fusion

 

NB Elderly > 70

- increased mortality with HTB 20 – 36%

- often don’t tolerate hard collar

- soft collar / trial of life

Background

Definition

 

Bony Occiput / Atlas / Axis

 

Anatomy

 

Occiput / atlas joint

- occipital condyles - lateral masses

- synovial joint

- often flatter in children which explains increased incidence of injury in children

 

Atlas / axis

- 3 synovial joints

- posterior atlas and dens

- lateral facet joints

 

Ligaments

 

1.  Extrinsic

- anterior tubercle attaches ALL and longus colli

- posterior tubercle attaches ligamentum nuchae

 

2.  Intrinsic (dorsal to ventral)

 

A. Tectorial Membrane

- continuation of PLL 

- posterior body of axis to anterior foramen magnum

 

B. Cruciate ligaments

- anterior to tectorial membrane / behind odontoid

- transverse ligament (posterior odontoid to anterior arch of atlas)

- vertical bands (from axis to foragmen magnum)

 

C. Odontoid ligaments

- from tip of odontoid

- paired alar ligs to occipital condyles (strong)

- small apical ligament to foramen magnum

 

Strongest

- Tectorial

- Alar

 

Movement

- 40 – 45o flexion / extension (equal between C0/1 and C1/2)

- 40 – 45o rotation (mainly C1/2)

 

Ossification

 

Atlas

- 3 parts 

- 2 neural arches and one body

 

Axis

- 4 parts

- dens + 2 neural arches and one body

 

Goals of treatment

 

Protect the neural structures

Reduce and stabilise injured segment

Provide long term stability

 

Clinical

 

Neck pain

Paraesthesia / Paralysis

Head / scalp lacerations

Palpate spine / Step-off Tenderness

 

X-ray

 

3 trauma series

 

Anterior Soft Tissue

- "6 at 2 and 2 at 6"

- 6 mm at C2 normal

- 2 cm at C6 normal

- not applicable in children

 

SAC / Space available for Cord

- PADI

- 1/3 Peg 1/3 Cord 1/3 Space

- if < 10mm cord compression

 

ADI

- children < 5mm

- Adults < 3mm

 

Stress Xray

 

High suspicion posterior ligamentous injury

- stretch test

- > 1.7mm increased disc space

- > 11° angle

 

Low suspicion ligamentous injury

- supervised flexion / extension view

- contra-indicated in decreased consciousness

 

CT Scan

 

To define bony fractures

- more sensitive upper cervical spine

 

MRI

 

To detect HNP prior to attempted reduction with incomplete lesion

Demonstrate oedema i.e. suspicious of C0-1 dislocation

 

 

Dens Fracture

Classification Anderson & D'alonzo

 

Type 1

 

Tip avulsion

- alar ligament avulsion

- fracture off one side of tip of dens

 

Management

- associated with atlantoaxial instability

- manage in collar

 

Type 2

 

Fracture of base of dens

 

Dens Fracture Type 2 Undisplaced0001Dens Fracture Type 2 Undisplaced0002

 

Type 3

 

Fracture through body of axis

- union rates 95%

 

Type 3 Dens Fracture Coronal CTType 3 Dens Fracture CT Coronal

 

Management

- elderly / Philidelphia collar

- young / HTB

 

Type 2 Dens Fracture

 

Issue

 

Undisplaced v displaced

- risk of nonunion 30% higher with displacement

 

Non-union

 

Risk factors

- > 65 years

- > 5 mm displaced

- >10° angulation

- posterior displacement

- comminution

- delay in treatment

- smoker

 

Type 2 Dens Fracture Displaced

 

Management Acute Fracture

 

1. Undisplaced 

 

HTB 3/12

 

Platzer et al Neurosurgery 2007

- 90 patients average age 69 years treated in HTB

- union in 84%

- non union associated with elderly / displacement / delay in treatment

 

2. Displaced

 

A.  Traction

- reduces dens

 

B.  Ondontoid screw

 

C.  C1/2 Fusion

 

Gallie / Brooks fusion

 

Magerl fusion

- trans-articular screws

 

Harms fusion

- poly axial screw and rod fixation

- C1 lateral mass screws

- C2 pedicle screws

 

Dens Nonunion C12 fusion

 

3.  Elderly

 

Issue

- high risk of failure of fixation due to poor bone

- risk of HTB

- risk of non union

 

Koech et al Spine 2008

- 42 patients > 70 treated in HTB or collar

- 50% osseous fusion and 90% fracture stability in collar

- 37% osseous fusion and 100% fracture stability in HTB

 

Ondontoid Screw Fixation

 

Advantages

- preserves motion compared to C1/2 fusion

- 50% rotation from C1/2

 

Contra-indications

- irreducible fracture

- comminution

- osteopenia

- ondontoid + transverse ligament injury / will remain unstable

- oblique fracture configuration / need to place screw perpendicular to fracture

 

Results

 

Platzer et al Spine 2007

- ondontoid screw fixation in 102 patients

- nonunion rate 4% in patients < 65

- nonunion rate 10% in patients > 65

 

Management Nonunion

 

Issues

- pain

- instability / myelopathy / risk sudden death

 

Type 2 Dens NonunionType 2 Dens Nonunion Coronal CT

 

1.  Patients < 65 years

 

C1/2 fusion

 

Dens Nonunion Instability0001Dens Nonunion Instability0002Dens Nonunion C12 fusion

 

2.  Elderly

 

Most patiens have a fibrous nonunion

- stable on flexion / extension views

 

Hart et al Spine 2000

- series of elderly patients with unstable nonunions

- treated non operatively

- no development of myelopathy or sudden death

 

 

 

Hangman's

Definition

 

Bilateral Pars Fracture C2

- traumatic axis spondylolisthesis

 

NHx

 

Neurological injury uncommon

- fragments separate and decompress

 

Different to judicial hanging where spinal cord is severed

 

Xray

 

Hangmans Fracture XrayHangmans Xray

 

Levine & Irving Classification

 

Type I

 

Vertical pars fracture with no displacement / <3mm

 

Hangmans CT Undisplaced0001Hangmans CT Undisplaced0002Hangmans CT Undisplaced0003

 

Type II

 

Vertical pars fracture translated anteriorly > 3mm

- hyperextension injury / windshield

 

Hangmans Fracture Type 2Hangman's Fracture Type 2 Axial

 

Type IIA

 

Oblique fracture pars with angulation and displacement

- flexion & distraction injury

- entire C2/3 Disc avulsed & fails in flexion

- only ALL left intact

 

Type III

 

Bilateral facet dislocation C2/3 and pars fracture

 

Management

 

Algorithm

 

Type I

- manage in semi-rigid collar 8/52

- flexion / extension views to ensure stability

 

Type II

- traction + extension

- application HTB 8/52

- flexion / extension views

 

Type IIA

- traction contra-indicated

- extension and HTB

- some centres advocated fusion if high level angulation

 

Type IIIA

- reduction / HTB or fusion

 

Results

 

Vaccaro et al Spine 2002

- HTB treatment of 27 type II and 4 type IIA

- all type IIA went on union

- 21 type II went on to union

- high initial degree angulation associated with failure treatment

 

Operative Management

 

Options

 

C2/3 instrumented fusion

C2 transpedicle stabilisation

Anterior cage and plate construct

 

Results

 

Ma et al Spine 2011

- C2/3 pedicle screw fusion for unstable hangman's fracture

- 35 patients, solid and stable union achieved in all patients

 

Hangmans Fracture Non Union Posterior Fusion

 

 

 

Occipital Condyle Fractures

Epidemiology

 

Rare

- unilateral

- bilateral

 

Mechanism

 

Compression

Lateral Compression

Rotation

 

Clinical

 

Skull base pain

Cock Robin

Cranial nerve injury

 

Classification Anderson & Montesano

 

Type I

 

Impaction of a condyle 

 

Management

- Stable / Brace 8/52

 

Type II

 

Condyle fracture associated with basilar / skull fracture

 

Management

- Stable / Brace 8/52

- Displaced / HTB 8/52

 

Type III

 

Condyle avulsions fracture secondary to rotation

- rupture strong alar ligaments

 

Management

- unstable 

- HTB / fusion (C0 - C2)

 

Results

 

Maserati et al J Neurosurg Spine 2009

- follow up of 104 occipital condyle fractures

- occipital-cervical fusion in 2 who had evidence of craniocervical malalignment

- remainder all treated with collar

- no late instability / malalignment / nerve compression

 

 

Occipito Atlantal Dislocation

Epidemiology

 

Deadly & rare

- usually post mortem

 

More common in children due to

- immature joints 

- larger head to body ratio

- relative ligamentous laxity

 

Aetiology

 

High velocity trauma

- MVA

 

Mechanism

- hyperextension, distraction & rotation

 

Types

 

Pure ligament injury usually

 

Direction

- anterior occipital displacement (most common / head anterior)

- vertical

- posterior (rare)

 

Diagnosis

 

Basion anterior to tip ondontoid

- most common is anterior occipital displacement

- should be located at tip of ondontoid

 

Basion-Dens Interval / BDI

- most sensitive

- from basion to dens

- assesses vertical displacement

- should be less than 12 mm

 

Basion-Axial Interval / BAI

- distance to posterior axial line / line posterior border ondontoid

- increased > 12 mm with anterior displacement

 

Power's Ratio BC/AO > 1 

- head goes anterior

- basion to posterior arch / opisthion to anterior arch

 

Management

 

Reduction / HTB

 

Reduce in OT

- II

- putting sandbags under thorax

- allows head to reduce posteriorly

- assess with II

- apply HTB

- add compression

 

HTB 3 months

- assess stabilty with flexion / extension views

 

Stabilisation

 

Is a ligamentous injury and inherently unstable

- may require atlanto-occipital fusion

 

 

Pseudo subluxation

Definition

 

Subluxation in children up to 8

- C 2/3 in 40% children

- C 3/4 14%

- up to 4 mm

 

Aetiology

 

Horizontal facet joints

- flat orientation of paediatric facets and laxity of ligaments

 

Become more vertical with age

 

Diagnosis

 

1. Swischuk's Line

- drawn along spinolaminar line C1 & C3

- C2 should be within 1.5 - 2mm of this line

 

2. Pseudosubluxation will reduce with extension

 

Rheumatoid Neck

Epidemiology

 

Neck involved in 86%

- second most common site after hands and feet

- closely associated with MCPJ subluxation

 

Associations

 

Males / Steroid use / Seropositivity Nodules / Severe long standing disease

 

Conditions

 

Atlanto-axial subluxation

Subaxial subluxation

Superior migration ondontoid

 

1.  Atlanto - Axial subluxation (AAI / AAS)

 

Aetiology

 

A. Attrition of transverse ligament

B. Erosion of peg

 

Epidemiology

 

Most common of RA cervical deformities

- occurs in up to 50% of patients

 

May cause myelopathy

 

Diagnosis

 

1.  Lateral view AADI

- anterior atlantodental interval

- AADI > 3 mm

 

Cervical Flexion Instability Increased AADI

 

2.  AADI

 

A.  Instability : > 3 mm difference in flexion / extension views

 

RA neck Flexion View AADA /> 3 mmRA Neck Extension View AADI 1 mm

 

B.  Severe instability: > 7 mm difference

 

AADI greater than 5 mm

 

3.  PADI

- posterior atlantodental interval / SAC (space available for cord)

- > 14 mm 94% predictive no neural deficit

- < 14 mm 97% predictive neural compression

 

2.  Superior Migration of Odontoid / Pseudobasilar Invagination / Atlantoaxial vertical subluxation

 

Superior Migration Ondontoid CT CoronalSuperior Migration Ondontoid CT Sagittal

 

Definition

- vertical translocation of Dens into foramen magnum

- compresses medulla

 

Pathology

- due to erosion of lateral masses of atlas and occipital condyles

- can lead to compression of brain stem

- risk of myelopathy / sudden death

 

Epidemiology

- seen in 40% of RA patients

 

Symptoms

- C1/C2 compression gives occipitocervical pain

- ventral pressure can compress respiratory centre and cause sudden death

 

Diagnosis

 

Superior Migration Ondontoid Lateral XraySuperior Migration Ondontoid Lateral Xray Close Up

 

Ranawat measurement < 13 mm

- line between anterior and posterior arch atlas

- centre of pedicle of C2

 

SMO Ranawat Measurement

 

McCrae

- line of foramen magnum

- tip of dens should not protrude above this line

 

SMO McCrae LineSMO McCrae Line CT

 

McGregor line > 4.5 mm

- line hard palate to posterior occiput

- if tip of dens > 4.5 mm above this line = vertical settling

- severe > 8 men or > 10 women

 

SMO McGregor Line

 

Redlund-Johnell measurement

- assesses entire occiput to C2 complex

- base of dens to McGregor line

- men <34mm & women <29mm = abnormal

- if abnormal -> highly correlated with severe disease & neurology

 

SMO Redlund-Johnell

 

3.  Subaxial Subluxation (SAS)

 

Definition

- anterior subluxation of one vertebral body on another

 

Rheumatoid Arthritis Subaxial InstabilityRheumatoid Arthritis Subaxial Instability Extension View

 

Diagnosis

 

A.  Instability on Flexion / Extension views

- > 3mm

- > 11o

 

B.  Space available for cord / SAC

- subaxial canal diameter on lateral

- < 13 mm high incidence neurology

 

RA Subaxial Subluxaton SAC

 

Aetiology

- facet erosions / ligament incompetence

 

Epidemiology

- 10-20% of RA patients

 

Pathology

- may see at multiple levels with stepladder type deformity & kyphosis

- occurs beneath previous cervical fusions

- anterior subluxation / destructive changes of facet joints / destruction of disc

- can result in 2° canal stenosis

 

Cervical Spine MRI Subaxial Subluxation

 

Neurological Classification Ranawat

 

I        No neurological deficit

II      Subjectively weak / hyperreflexia & dysesthesia

IIIA   Objectively weak / ambulatory

IIIB   Objectively weak / non ambulatory

 

Clinical Features

 

Pain

- neck radiating to shoulders / occipital headaches

- occipital neuralgia / greater occipital nerve compression

- ear pain / greater auricular nerve compression

- facial pain / trigeminal

 

Stiffness

 

Parasthesiae

- most common & earliest symptom 

- pain & temp / spinothalamic tract compression

 

Weakness

 

Frequency or retention / constipation

 

NHx

 

Incidence of cervical involvement increases with duration of disease

- after 10 years 60% will have AAS

 

Postmortem study of 104 patients with RA

- 10% died 2° medullary compression

- impossible to predict which patients will progress

 

MRI

 

Supplanted CT

- site of compression

- accurate SAC / account for soft tissue

 

Dimensions

1.  Foramen magnum SAC < 14 mm = neurological compression

2.  C1-2 SAC < 13mm

3.  Subaxial spine SAC < 12mm

 

Rheumatoid Arthritis Limited Space Available for Cord

 

Cervicomedullary angle (MRI)

- long axis brainstem to long axis cord

- normal angle is 135-175°

- <135° = vertical settling & is correlated with myelopathy

 

Management

 

Goals of Treatment

 

1. Prevent development of neurologic deficit

2. Prevent sudden death due unrecognised neurological compromise
- 10% of deaths in RA occur suddenly due neurological complications

 

Screening

 

Cervical spine flexion / extension xray

- mandatory in all patients pre-operatively

 

Management

 

2 Groups 

1.  Intractable pain or neurologic compromise -> fuse

2.  No pain & no neurology – controversial

 

AAS

 

Algorithm

1. PADI >14mm -> observe

2. PADI < 14mm MRI

3. Cervicomedullary angle <135° / SAC < 13 - fusion

 

Options

 

1.  C1/2 fusion

- if instability reducible / no decompression needed

 

2.  Occipito-cervical fusion

- instability irreducible

- must decompress / remove lamina C1

 

C1/2 fusion

- fusion in situ if reducible and no neurology

- laminectomy C1 + fusion if fixed deformity with neurology

 

A. Gallie / Brooks fusion

- contra-indicated if any displacement or neurology

- unable to perform decompression / laminectomy

 

C1 C2 Posterior Spinous Process WiringC1 C2 Posterior Spinous Process Wiring

 

B.  Transarticular / Mageryl screws

- 95% fusion rates

- +/- laminectomy of C1 if displaced or with neurology

- pannus resorbed in 19 of 22 patients with fusion

 

Occipitocervical fusion

 

C0 C3 fusion AAI Rheumatoid

 

Results

 

90% of pts improve 1 Ranawat grade if have neurology pre-op

- PADI < 10mm predicts patinet unlikely to improve

 

Problem

- due to bone erosion may be insuffiency bone quality for C1/2 fusion

- may need C0 - C3

 

SMO

 

More serious & should be treated more aggressively

- xray screening

- MRI in flexion to evaluate cord compression

 

Algorithm

1. No symptoms & no cord compression on MRI

-  observe

2. Cord compression

- occipitocervical fusion

- +/- C1 laminectomy +/- anterior dens excision if fixed deformity & neurology

 

Results

- 75% improve

 

Occipital Cervical Fusion LateralOccipito Cervical Fusion AP

 

SAS

 

Algorithm

- SAS >14mm & no symptoms -> observe

- SAS < 14, MRI for true SAC

- SAC < 13 or instability - surgery

 

Surgery

1.  Anterior decompression and fusion

 

Subaxial Stabilisation

 

2.  Posterior laminectomy and fusion

- may need long fusion to prevent SAS above and below

 

Cervical Spine Posterior Fusion for SASCervical Spine Posterior Fusion for SAS

 

 

Smith Robinson Approach

Via the carotid triangle

 

SCM / posterior belly digastric / superior belly omohyoid

 

Indication

 

Exposes inferior body C2 - T1

 

Position

 

1.  Supine in tongs

2.  Sit on head board with head taped and slightly extended

 

Table 30° up

Turn head away from side of incision

 

Which Side

 

Most surgeons approach from the left

- the course of the Recurrent Laryngeal Nerve / RLN is more predictable on left

 

Right sided approach

- used sometimes for C7/T1 to avoid thoracic duct

 

Recurrent Laryngeal Nerve

 

Right side

- given off the vagus at the level of the subclavian artery

- slopes from lateral to medial across lower part of wound to reach the oesophagus / trachea interval

- crosses the surgical approach in 50% of cases

- usually at C6/7

- may be at C5/6

 

Left side

- arises at the level of the aortic arch

- doesn't slope across the wound

 

3 Fascial layers

 

1.  Deep Cervical Fascia

- under the subcutaneous fat

- invests neck like collar

- clavicle / sternum / spine scapula - mandible / base of skull

- invests SCM & trapezius

- Have to incise so can retract SCM

 

2.  Pretracheal

- covers trachea

- deep to the strap muscles

- extends from hyoid into chest

- splits to enclose thyroid

- fuses laterally with carotid sheath

- have to divide to retract carotid sheath laterally

 

3.  Prevertebral

- base of skull to T3

- invests longus colli and sympathetics

- divide to separate longus colli muscles to approach verebrae

 

Landmarks

 

Medial border SCM

Carotid Artery lateral to SCM

 

Levels

- Hyoid = C3

- Thyroid Cartilage = C4/5

- Cricoid = C6

- Carotid Tubercle = C6

 

Incision

 

Inject LA with adrenaline

Transverse incision at level required from midline to posterior border SCM

 

Superficial Dissection

 

Divide Platysma vertically at anterior border SCM

 

Superficial plane

- through investing layer of deep cervical fascia

- between strap muscles (Sternohyoid & Sternothyroid) & anterior border SCM

 

Deep Dissection

 

Palpate the Carotid Artery 

- divide the pretracheal fascia medial to the Carotid Sheath

- open plane between carotid sheath & medial structures

- medially oesphagus, trachea & thyroid

- note that anterior carotid sheath fuses to pretracheal fascia

- retract the carotid sheath & SCM laterally

 

Vessels

 

C3/4

- superior thyroid artery / superior laryngeal nerve behind

- common venous trunk of superior thyroid / lingual / facial vein

 

C6/7

- ligate middle thyroid vein

- inferior thyroid artery

 

Blunt dissection medially

- behind the oesophagus

- expose the vertebrae covered by Longus Colli, prevertebral fascia & ALL

- sympathetic chain lies on the Longus Colli, just lateral to the vertebrae

- incise the Longus Colli in the midline

- subperiosteally expose the Vertebrae

- place retractors under Longus Colli

 

Check level with II

 

Dangers

 

1. Recurrent Laryngeal Nerve

- lies between trachea & oesphagus

- on right crosses field from subclavian artery at C6/7 with inferior thryoid artery

 

2. Superior Thyroid Artery/ Superior Laryngeal Nerve

- C3/4

- superior thyroid artery pass from the Carotid Sheath medially to the midline structures

- superior laryngeal nerve runs with artery

- can divide artery but must preserve nerve

- otherwise get dysphagia

 

3.  Inferior Thyroid Artery

- lower approach may pass from lateral to medial

 

4. Sympathetic Chain on transverse processes

5. Vertebral Artery

6. Carotid Sheath with Vagus inside

7. Oesophagus

8. Trachea

9. Thoracic duct on left at C7 / T1 level