Spine Flashcards
Describe the imaging findings in this patient with progressive lower limb weakness
The MRI reveals a mass lesion below the conus medullaris that may be associated with either the filum terminale or a cauda equina nerve root. The lesion enhances homogeneously with contrast administration and the differential diagnosis includes a myxopapillary ependymoma, peripheral nerve sheath tumour such as a schwannoma or neurofibroma and meningioma.
During a lateral extracavitatory approach for a thoracic discectomy, which rib head is removed?
The T10 rib head overlies the T9/10 disc space. The T10 rib articulates with the demifacets on the T9 and T10 vertebral bodies and the rib tubercle articulates with the superior part of the T10 transverse process.
How are C1 and C2 combine fractures managed?
Based on the C2 fracture - most common combination is a C1 fracture with a C2 type 2 peg fracture
How are fractures of the C1 classified?
Jefferson’s (after Sir Geoffery Jefferson of QS)
1 - posterior arch
2 - anterior arch
3 - Anterior and posterior arches (burst)
4 - Lateral mass fracture
**Alternatively the Landell’s classification is also used**
How are Jefferson’s fractures managed?
Type 1/2 are isolated anterior or posterior arch fractures: managed in a hard collar or halo for 8-12 weeks
Type 3 are burst fractures: if transverse ligament intact then collar, if disrupted then halo or surgeyr
Type 4 are unilateral lateral mass fractures: hard collar for 8-12 weeks
How are occipital condyle fractures classified?
Anderson Montesano classification into 3 types:
1 - Comminuted fracture of the occipital condyle
2 - Linear basal fracture extending into the occipital condyle
3 - Avulsion fracture of the occipital condyle (at the alar ligament attachment)
How are scoliosis corrections approached?
<90 deg with posterior spinal instrumentation and fixation
>90 deg need combined anterior and posterior approaches
How can the integrity of the transverse ligament be identified?
- Rule of Spence (sum of the overlap of the C1 arches >6.9 mm on open mouth Xray although 8.1 mm with magnification correction)
- ADI >3 mm
- High STIR signal on MRI
How do you apply traction with Gardener Wells tongs?
Administer analgesis and muscle relaxants.
Pin placement 1 cm above the pinna inline with the EAM (anterior if you want ext and posterior if you want flex)
Tighten tongs to 31lbs of force (indicator becomes 1 mm proud)
Initial weight of 10lbs and then 10lb increments every 20 minutes until a max of 5lb per level. After 35lb repeat a cervical x-ray before adding more.
How do you assess basilar invagination?
- Wackenheims clival line
- Chamberlain line - middle of hard palate to middle of opisthion
- McRae line - Basion to opisthion
- McGregor line - Middle of hard palate to bottom of opisthion
- Height index of Klaus - distance from tip of peg to line through the dorsum sella
How do you classify idiopathic scoliosis by age?
<3 = infantile; 3-10 = juvenile; >10 = adolescent
OR
early onset <5 and late onset >5
How do you clear the spine in an obtunded patient?
Whole spine CT is usually sufficient.
An MRI scan should be performed if there is a high index of suspicion
How do you grade skeletal maturity?
Risser grading
How do you manage a cervical burst fracture?
Corpectomy and plating.
A posterior fixation may be needed if posterior lig complex involved.
How do you manage a cervical VB compression fracture?
If <25 deg loss of height - conservative with collar 6-12 weeks
If >25 deg loss of height - surgical stabilisation
How do you manage a flexion tear drop fracture?
ACDF +/- corpectomy as this mechanism involves disruption of the disc
How do you manage a Scheuermann’s kyphosis?
Brace = <75 deg and skeletal immaturity
Surgery = failure of bracing or >80 deg and skeletally mature; posterior fusion with excision of the ligamentum flavum at the apex should be performed to prevent neurological deficit due to buckling.
How do you manage a trauma patient with normal C-spine CT but on-going pain?
MRI +/- flexion-extension xrays
How do you manage adolescent idiopathic scoliosis?
Observation with orthosis to identify and document curve progression.
Surgical intervention based on natural history of the curve, cobb angle and skeletal maturity i.e.
Curve <20 deg = observation
20-40 deg = brace if skeletally immature
>40 deg = brace if skeletally immature; surgery if skeletally mature or fail bracing.
How do you manage an isolated C2 extension tear drop fracture?
Hard collar 8-12 weeks
How do you manage facet dislocations?
Closed reduction and then posterior decompression and fusion
If unable to reduce then open posteriorly, drill off facets and fix. Then flip and do A.CDF.
How do you measure ADI and PADI?
ADI is between anterior peg and back of C1 anterior arch
PADI is between the back of the peg and the from on the C1 posterior arch
How do you measure coronal balance?
A vertical line from the centre of C7 should pass within 2 cm of the centre of the S1 VB (center sacral vertebral line)
How do you measure the clival angle?
Between Wackenheim’s line and the anterior skull base. If angle >143 deg then = platybasia
How do you measure the cobb angle?
Measured between vertebral that are maximally tilted. It is measured as the angle between the superior endplate of the proximal and inferior endplate of the distal vertebra. The apex of the curve is the most lateral vertebra
How do you treat occipital condyle fractures?
Non-rigid immobilisation for all types of fracture.
Rigid immobilisation with halo should be considered if bilateral or displacement >2 mm
OC fusion should be performed if there is overt instability (based on ligamentous disruption on MRI), neural compression from a displaced fragment or other associated unstable injuries
How does a syrinx present clinically?
Suspended sensory level in a cape-like distribution with dissociation of pain and fine touch; motor impairment affects the UL>LL and distal>proximal. There is sacral sparing and can result in a Horner’s syndrome.
How does age at diagnosis impact scoliosis management?
The earlier the age of diagnosis the more likely the deformity is to progress and need treatment
How does an anterior cord syndrome present?
Paralysis, autonomic dysfunction and loss of pain but intact sensation - anterior spinal artery infarct occurs post AAA repair.
How does os odontoideum present?
- Occipital pain
- Myelopathy
- Intracranial symptoms from vertebrobasilar ischaemia
How does the rib articulate with the vertebra?
The 5th rib covers the T4/5 disc space and articulates with the tubercle on the TP of the 5th rib;
How far lateral is the V3 segment from the middle of C1?
14 mm
How is basilar invagination in RA (Cranial settling) treated surgically?
O-C2 fixation
How is os odontoideum managed?
Surveillance or surgery based on the degree of instability, neurological deficit or risk of future spinal cord injury.
C1/2 fixation is often recommended due to the risk of SCI with minor trauma.
Reduction is attempted. If irreducible then decompression with fusion is required.
PEG screws should NOT be used
How is the L5/S1 facet orientation different from the rest of the lumbar spine?
The lumbar spine has sagittally orientated facets. The L5/S1 has more coronally orientated facets to allow rotation
How is the optimal CPP calculated?
Measuring the PRx at a variety of different CPPs. The CPP with a 0 PRx is optimal.
How is the Stable vertebra defined in scoliosis?
The vertebra bisected by the centre sacral line
How long should you given LMWH prophylaxis for following SCI?
3 months
How should a neuromuscular scoliosis be managed?
MDT assessment of the spinal deformity and the underlying neuromuscular disease:
Observation if curve <30 deg
Spinal orthosis does not prevent curve progression but slows the progression.
Surgery is offered when the curve >40 deg, with earlier surgery in Duschenne’s MD (>20 deg).
Surgery should not be delayed until skeletal maturity.
How should AOD be treated?
OC fusion
How should occipital condyle fractures be imaged?
Fine cut CT of the CC junction
MRI for ligamentous injury
How should you manage patients with complete SCI (ASIA A) with unstable spines?
Internal fixation to allow early mobilisation and rehabilitation. Improves ability to care for patients and reduces risk of secondary complications (LRTI / DVT etc)
How would you manage this patient?
This imaging reveals an intradural extramedullary lesion. The patient should undergo intradural resection of the lesion under neurophysiological monitoring. It is important to completely expose the tumour to identify the proximal and distal connections. I would aim to perform an L1-3 laminoplasty followed by midline durotomy. I would aim to identify the structure it arises from. If arising from the filum terminale it likely represents a myxopapillary ependymoma and should be resected en-bloc without violation of the capsule to prevent a recurrence. If the lesion arises from a nerve root this likely represents a peripheral nerve sheath tumour and the root should be tested using neurophysiological monitoring. It is most likely to be a sensory nerve root which can be sacrificed.
In this case, you find the tumour is stuck to the conus without a clear cleavage plane. How do you proceed?
This most likely represents a filum terminal myxopapillary ependymoma. The aim of surgery would be an en-bloc resection without violation of the capsule, which would be curative. If a plane cannot be safely generated between the conus and the tumour capsule then a portion of the capsule should be left to prevent a permanent deficit and potentially treated with post-radiotherapy.
In trauma, when is it safe to not place a collar?
When the patient is alert, non-intoxicated and without a distracting injury where there is no neck pain and no neurology
In which group of Hangmann’s fractures should traction be avoided?
Type 2a as the C2/3 disc space is ruptured
Is an MRI needed prior to closed reduction of a fracture-dislocation?
No, traction reduction is safe in an awake patient. Failure to reduce with traction or low GCS due to head injury/intoxication should undergo MRI.
Label the spinal tracts
Answers
Name all the labels
With labels
Name all the labels.
Note the dorsal root is proximal to the DRG and the dorsal ramus is distal!
Regarding Type 2 peg fractures, which approach has a higher fusion rate?
Posterior > Anterior
(Anterior allows preservation of rotation but fracture line has to be perpendicular to screw trajectory and body habitus satisfactory)
Should bracing be used for congenital scoliosis?
NO!
What % of patients have a vertebral artery injury following C-spine trauma?
10%
What age does neuromuscular scoliosis develop?
<10 years of age and more likely to progress therefore compared to an idiopathic adolescent scoliosis
What anatomical factors prevent C2 peg screw placement?
Patient factors: Barrel chest, thoracic kyphosis and short neck
Fracture type: Oblique fracture in direction of the screw
Bone quality: osteoporosis
What are the attachments of the ALL?
From the anterior body of C2 to the sacrum binding the vertebral bodies and discs
What are the attachments of the PLL?
From the posterior body of C2 to the sacrum binding the vertebral bodies and discs
What are the BAI and BDI?
BAI = basion-axial interval and is measured by the distance between a straight line drawn up the back of C2 and the basion. If >12mm then suggests atlanto-occipital dislocation.
BDI = basion dental interval measured between the basion and tip of the peg. <12 mm on Xray and <8.5 mm on CT is normal.
What are the bail out options for a C2 pedicle screw?
- C2 pars screw
- Lamina screw
- OC-fusion
What are the branches of the V4 segment?
PICA and spinal arteries
What are the canadian C-spine rules?
Imaging is needed in any patient:
>65 years, dangerous mechanism or paraesthesia in the extremities.
Low risk factors are simple mechanism, ambulant after injury, delayed onset of neck pain with normal ROM and no paraesthesias
What are the causes of a neuromuscular scoliosis?
Muscular causes are muscular dystrophies such as Duschenne, myotonic dystrophy and congenital myotonia
Neurological causes are UMN = cerebral palsy, friedrich’s ataxa, syringomyelia and spinal cord injury <10 years of age; LMN = Spinal muscular atrophy and polio
What are the causes of congenital scoliosis?
Type 1 = Defects of formation = hemivertebrae, spina bifida and wedge
Type 2 = Defects of segmentation = block, unilateral bar, unilateral bar + hemivertebra
Type 3 = mixture of the above
What are the causes of hypotension following SCI?
- Trauma related (bleeding etc)
- Neurogenic shock
Keep the MAP 85-90 mmHg for the first 7 days!
What are the classical features of neuromuscular scoliosis?
Long sweeping C-shaped curves that extend to the pelvis. Most commonly occur in the thoracolumbar or lumbar spine
What are the clinical features of a syrinx associated scoliosis?
Rapidly progressive, left sided and associated with abnormal abdominal reflexes
What are the common causes of a positive Rhomberg’s test?
Loss of the dorsal columns secondary to Vit B12, neurosyphilis, sensory neuropathy e.g. CIDP, Friedreich’s ataxia and Meniere’s disease (loss of vestibular function)
What are the contraindications to bracing for adolescent scoliosis?
Skeletally maturity
>40 deg curve
Thoracic lordosis
What are the different types of adult scoliosis?
Type 1 = Adult degenerative
Type 2 = Idiopathic adolescent that progresses in adulthood
Type 3 = Secondary adult due to leg length discrepancy, hip pathology or metabolic bone diseases
What are the facet joint orientations in the subaxial spine?
45 deg sagittal
0 deg coronal
This allows flexion and extension (greatest at C5/6 and C6/7)
What are the features of infantile idiopathic scoliosis?
Male > female, left thoracic curve with plagiocephaly, developmental delay, congenital heart disease and developmental hip dysplasia
What are the imaging features of AOD?
Craniocervical SAH
Large prevertebral haematoma
Power’s ratio >1
BAI or BDI >12
Condyle-C1 interval >2 mm = atlanto-occipital interval (highest sensitivity in paediatric AOD)
What are the main features of adolescent idiopathic scoliosis?
Females > Males
Right > Left thoracic curves
No severe pain
Risk factors for progression are the skeletal maturity (Risser stage)
Curves 50-75 deg at skeletal maturity progress by 1 deg per year
Lumbar curves are more likely to progress than thoracic as they lack the stability provided by the rib cage
What are the management options for scoliosis prior to bone maturity?
Fusion is avoided to prevent restriction of the thoracic cage and lung development. Surgical options include the use of an expandable prosthetic titanium rib and posterior instrumentation with growing rods.
What are the NEXUS criteria?
Defines whether cervical spine imaging is required in trauma:
Absence of midline cervical tenderness with no neurological injury in an alert patient with no distracting injury or intoxication does not require c-spine imaging.
What are the two types of anterior cervical plates?
Static and dynamic.
With static plates, they are rigidly locked to the plate. Dynamic plates allow some movement between the plate and screw to facilitate load sharing.
What are the two types of basilar invagination?
Group A - both chamberlain’s lines and McRae’s lines are crossed.
Group B - Chamberlain but not McRae’s line is crossed.
Group B occurs when the clivus is abnormal and the Clival angle is low and there is basilar impression.
What are the two types of os odontoideum?
Orthotopic and dystopic
What are the types of Scheuerman kyphosis?
Type 1 = thoracic
Type 2 = thoracolumbar (more painful)
What BDI is associated with atlanto-occipital dislocation?
>10 mm
What brace should be used for idiopathic adolescent scoliosis?
If above T8 then CTLS (Milwaukee brace)
If lower than T8 then TLSO
What do non-decussating CST fibres do?
15%, these form the anterior CST and supply proximal muscles of the upper limb
What do side bending xrays tell you about scoliosis?
If the curve corrects then it is nonstructural; if it persists then it is structural
What do the different spinocerebellar tracts do?
Dorsal and ventral spinocerebellar tracts coordinate lower limb movement whilst the rostral spinocerebellar tract controls head and upper limb movement.
What does the lateral border of the pars align with?
The medial border of the pedicle
What factors are suggestive of non-union for peg fractures?
>5 mm displacement
Age >50
Comminuted fractures
Delay in treatment
What happens to the pedicle orientations in the lumbar spine?
Become more medially orientated from L1-L5
What happens to the vertebral body and ribs at the apex of a scoliosis?
The spinous process is pushed towards the concave side making the lamina narrower on that side. The VB is distorted to the convex side. the rib cage is narrowed on the convex side as the rib is pushed posteriorly.
What imaging is required in the investigation of a scoliosis?
MRI brain and spine to look for syrinx, chiari and tethered cord
What is a dystopic os odontoideum?
Where the os is fused to the basion so does not move with the C1 arch on flexion-extension views
What is a neutral vertebra in scoliosis?
The first non-rotated vertebral at the cranial and caudal ends of the curve.
What is a normal ADI?
<3mm in adults
<5 mm in paeds
What is a normal PADI?
>13 mm
What is a posticulus posticus?
Calcification of the oblique atlanto-occipital ligaments forming a bony bridge over the V3 segment of VA. This may mislead the surgeon when placing a C1 lateral mass screw and increase the risk of a VA injury
What is a tear drop fracture?
Flexion tear drop occurs at C4-6 and represent significant ligamentous injury with posterior displacement of the VB compared to the VB below.
Extension tear drop is less severe are represents disruption of the ALL.
What is an arcuate foramen?
Ponticulus posticus
What is an orthotopic os odontoideum?
Orthotopic is connected to the anterior arch of C1 so moves with it on cervical flexion-extension views
What is AOD more common in children?
Occipital condyles are smaller and flatter
What is Brown-Sequard syndrome?
Hemisection of the cord causing ipsilateral motor and sensory loss with contralateral pain loss. Think MS, tumour or trauma
What is cranial settling?
Basilar invagination due to RA
What is dynamic stabilisation?
Connecting pedicle screws with rods so that motion is constrained but not eliminated. This causes less strain on the adjacent vertebra and therefore less adjacent segment disease.
What is power’s ratio?
A measure of atlantooccipital instability
From posterior arch C1 to basion divided by anterior arch C1 to opisthion
What is Scheuermann’s kyphosis?
Kyphosis >45 deg with >5 deg wedging across 3 vertebrae
Commonest cause of thoracic back pain in children and adolescents
Cause is unknown but may be related to avascular necrosis of the vertebral body apophysis
This is not corrected by active extension
What is the action of the lateral (medullary) reticulospinal tract?
Acts on the flexors of the trunk and inhibits the extensors (similar to the rubrospinal tract)
What is the action of the medial reticulospinal tract?
Controls the extensors of the trunk (and inhibits the flexors) - this is the opposite to the rubrospinal tract
What is the advantage of placing a plate in the cervical spine?
Prevents implant subsidence, minimised collapse / kyphosis, improved fusion rates, no need for external immobilisation
What is the AO classification for thoracolumbar fractures?
A = Compression (1 = wedge, 2 = split and 3/4 = burst);
B = Distraction (1 = bony chance throughout, 2 = posterior lig complex rupture, 3 = rupture through the disc space);
C = Rotation (1 = rotation-compression, 2 = rotation-distraction, 3 = rotation-shear)
**Note in B there is failure of the anterior and/or posterior tension bands
What is the ASIA scale?
A = No sacral sparing
B = Sensory but not motor and includes sacral sparing
C = Motor preserved but more than half of the myotomes are <3 power
D = Motor preserved but more than half the myotomes are >3 power
E = Normal examination
What is the C7 plumb line?
Measures sagittal balance. A vertical line from the centre of C7 should lie within 2 cm of the back corner of the S1 VB
What is the classification for AOD?
Traynellis classification:
1 - Anterior displacement of occiput (Powers ratio >1)
2 - Distraction (BAI and occipitocervical distance increased)
3 - Posterior displacement of occiput
What is the classification system for Peg fractures?
Anderson D’Alonso
What is the course of the dorsal and ventral spinocerebellar tracts?
Dorsal = Clarke’s column > Inf cerebellar peduncle > vermis
Anterior = Lamina V-VII > contralateral Sup cerebellar peduncle > ipsilateral vermis (crosses over and then crosses back again)
What is the course of the dorsal spinocerebellar tract?
Clarke’s column > inferior cerebellar peduncle > vermis
What is the definition of a high riding vertebral artery at C2?
Isthmus height < 5mm
What is the definition of a scoliosis?
Cobb angle >10 degrees in the coronal plane
What is the definition of idiopathic scoliosis?
Spinal deformity characterised by lateral bending and fixed rotation of the spine in the absence of a known cause
What is the definition of stability?
According to Punjabi and White, this is the “loss of the ability of the spine under physiological loads to maintain relationships between the vertebrae to prevent pain, deformity or neurological injury”
What is the difference between a C2 pars and a C2 pedicle screw?
The C2 pars screw is shorter, stopping before the foramen transversarium and is unicortical.
The C2 pedicle screw is longer and bicortical.
What is the difference between a structural and non-structural curve?
Structural curves do no correct with bending to <25 deg i.e. correction from 70 deg to 40 deg
What is the difference between basilar invagination and basilar impression?
Basilar invagination is when C2 projects above the foramen magnum
Basilar impression is where the upward displacement is due to acquired softening of the bones at the base of the skull
What is the differences morphologically between a neuromuscular and idiopathic scoliosis?
Neuromuscular curves tend to be longer and involve more vertebrae that an idiopathic scoliosis
What is the differential diagnosis of a Jefferson fracture in a child?
Pseudo-spread of the atlas (due to physiological growing of C1>C2)
Normal synchondroses (there are 3 ossification centres - one in the body and one in each arch). The posterior synchondrosis (in the spinous process) fuses by age 3 years whilst the neurocentral synchondrosis (between the arches and the body) fuse by age 7 years.
What is the effect of inotropes on ISP and SCPP?
Increases ISP and MAP with a resulting increase in SCPP
What is the Effendi classification for Hangman’s fractures?
1 - Fracture through the pars <3 mm displacement
2 - Fracture through the pars with >3 mm displacement and rupture of the C2/3 disc
(Levine–Edwards) 2a - Very severe angulation of the C2 body (>11 deg)
3 - Locked facets at C2/3
What is the entry point for a C2 pedicle screw?
A verticle line through the C2 pars bisecting a horizontal line through the C2 lamina. This lies in the superior medial quadrant. The screw is angled 20 deg medial and superior angulation is parallel to the C2 pars on lateral fluoroscopy.
What is the entry point for a thoracic pedicle screw?
Junction of the facet joint and the TP. Entry is in the upper 1/3 of the TP at its base
What is the function of the cuneocerebellar tract?
Coordination of the movement of the upper limb
What is the function of the dorsal spinocerebellar tract?
Posture and coordination of the lower limb movements
What is the Heuter-Volmann principle?
Increased loading across an endplate accelerated growth, whilst decreased loading inhibits growth. Imbalance of forces due to neuromuscular diseases leads to scoliosis.
What is the Lenke classification for idiopathic scoliosis?
Based on AP, lateral and side-bending radiographs.
The Cobb angle for all the curves are measured and then whether they are structural or not.
There are 6 different curve combinations
There are also lumbar and T5-12 sagittal alignment modifiers
What is the main morbidity of an early onset progressive scoliosis?
Cor pulmonale, right heart failure and premature death
What is the management for Hangman’s fractures?
Type 1 and 2 - conservative with reduction and Halo provides healing rates >90%
Type 2a / 3 - do not apply traction! Healing rates are 30% with Halo so can be tried first but if fail then need surgery for chronic instability. Surgery is ORIF and posterior fixation C1-3 or C2-3.
Ref: Effendi 1981 - management of 131 patients
What is the management of a chronic type 2 peg fracture?
C1/2 fixation if >50 years due to the poor blood supply. If <50 years then halo immobilisation.
What is the management of suspected VA injury?
CT head, CT-A and antiplatelet therapy (to reduce stroke risk).
Endovascular stenting may be appropriate if there is a dissection.
What is the mechanism for facet dislocation?
Flexion and distraction
What is the mechanism of a hangmann’s fracture?
Hyperextension injury causes fracture of the pars bilaterally.
Secondary flexion causes a tear of the PLL and C2/3 disc space. The C2 VB and peg are angulated forwards therefore in Type 2 fractures. In type 3 fractures there is severe angulation and displacement with facet dislocation.
What is the most common incomplete spinal injury pattern?
Central cord syndrome (70%)
What is the most common pattern of instability with os odontoideum?
Anterior instability with the os translating forward in relation to C2 body
What is the name given to the continuity of the ligamentum flavum above C2?
Posterior atlanto-axial (C2-C1) and atlanto-occipital (c1-O) membrane
What is the natural history of adult scoliosis?
< 30 deg do not progress
30-50 deg progress 10-15% over lifetime
>50 deg progress at 1 deg per year
What is the natural history of AOD?
High mortality due to lack of ventilation.
Those that survive have lower cranial nerve dysfunction and quadriplegia
What is the natural history of lower cranial nerve deficits associated with occipital condyle fractures?
Usually, improve with non-rigid immobilisation
What is the presentation of a posterior column syndrome?
Impaired proprioception, sensory ataxia - Rhomberg’s positive and tactile hallucinations.
What is the PRx?
Pressure reactivity index and is the Pearson correlation between ICP and MAP. When +1 then ICP rises with MAP suggesting that there is loss of autoregulation.
What is the risk of a type 1 congential scoliosis (formation abnormality) ?
Sharp angulation that may result in paraplegia
What is the role of Onuf’s nucleus?
Lies in rexed lamina 9 of S2 and gives origin to the pudendal nerve controlling micturition and defecation
What is the role of the medial and lateral vestibulospinal tracts?
Medial controls head and neck movements while maintaining gaze fixation
Lateral controls limb extensors and inhibits flexors
What is the role of the rubrospinal tract?
Flexor tone (and inhibits extensor tone) of the upper limbs
What is the role of the tectospinal tract?
Reflex movements of the eyes, head and neck in response to external stimuli
What is the RVAD?
The rib-vertebra angle difference at the apex of the curve. Angles >20 degrees in infantile scoliosis is associated with progression of the scoliosis and therefore need for intervention.
What is the significance of a positive rhomberg’s test?
For balance 2 out of vision, vestibular and proprioception must be intact;
The patient is asked to stand an close their eyes. If the patient cannot maintain balance this suggests a proprioceptive loss.
What is the significance of pelvic obliquity in scoliosis?
The pelvis needs to be included in that fixation
What is the significance of the Risser grade?
Risser 4 = end of spinal growth in females
Risser 5 = end of spinal growth in males
The risk of progression is lower with greater spinal maturity
What is the SLIC score?
Subaxial injury classification sore
Fracture morphology (wedge =1, burst = 2, distraction = 3, rotation/translation = 4)
Discoligamentous complex ( indeterminate = 1, disrupted = 2)
Neurological status (root injury =1, complete SCI =2, incomplete SCI =3)
Modifier = continuous cord compression in the contexts of a neurological deficit = +1
(Scores <4 = non-operative; 4 = indeterminate and 5 or > = surgery)
What is the STASCIS trial?
Surgical timing in acute spinal cord injury study
What is the surface landmark for the torcula?
The inion
What is the treatment for congential scoliosis?
Surgery!
If <5 years with curve <50 deg then posterior in situ fusion
If >5 years or curve >50 deg then anterior and posterior fusion
What is VACTERL?
Congenital anomalies of 3 of the following:
Vertebral
Anorectal
Cardiac
Trachoeo-esophageal fistula
Extensions (lung / single umbilical artery)
Renal
Limb dysplasia
What line extends laterally from the inion?
The superior nuchal line
What long term outcome studies do you know for the treatment of occipital condyle fractures?
Maserati et al - 100 retrospective cases. 3 were treated surgically for increased craniocervlcal malalignment (gap between occipital condyle and C1 lateral mass >2 mm). None of the conservatively managed patients developed delayed instability.
What mechanism causes a Hangman’s fracture?
Hyperextension / Hyperflexion + distraction
What muscle attaches below the inferior nuchal line?
Medially = rectus capitus posterior minor
Laterally = rectus capitus posterior major
What muscle attaches between the superior and inferior nuchal lines?
The semispinalis capitus
What muscle attaches to the inferior bank of the superior nuchal line?
Trapezius in the midline and sternocleidomastoid laterally
What muscle attaches to the superior bank of the superior nuchal line?
Occipitalis
What pathologies cause a complete transection of the cord?
Trauma, transverse myelitis, infarction, tumour and abscess
What proportion of cervical flexion and extension occurs at C0-C1?
50%
What proportion of cervical rotation occurs at C1/2?
50%
What proportion of patients with a syrinx have an associated syrinx?
25-85%
What proportion of patients with jumped facets fail closed reduction?
1/3
What proportion of the axial load passes through the anterior column?
80%
What proportion of the CST decussates in the medullary pyramids to form to the lateral CST?
85%