Spine Flashcards
SPORT trial outcome for degenerative spondylolisthesis
For degenerative spondylolisthesis:
Decompression WITH fusion - 80% satisfactory outcomes
Decompression WITH fusion - Standard of care
Instrumentation - Better fusion rates, but no better outcomes and higher re-operation rates
Decompression WITHOUT fusion - 70% satisfactory outcomes
What is the most common level for Degenerative Spondylolisthesis vs. Isthmic Spondylolisthesis
Degenerative = L4/5 Isthmic = L5/S1
How to draw Pelvic Incidence
Line 1: Center of S1 endplate to center of femoral heads
Line 2: Line perpendicular to the center of the S1 endplate
Pelvic incidence = Pelvic tilt + Sacral slope
Pelvic incidence is independant of the position of the pelvis
How to draw Sacral slope
Line 1: Parallel to S1 endplate
Lene 2: Horizontal line
How to draw Pelvic tilt
Line 1: Center of the S1 endplate to the center of the femoral heads
Line 2: Vertical line through the femoral heads
Yearly rate of curve progression in Adult Idiopathic Scoliosis (Thoracic / Thoracolumbar / Lumbar)
Thoracic = 1 degree per year for curves > 50 degrees Thoracolumbar = 0.5 degrees per year Lumbar = 0.25 degrees per year
Note: Degenerative scoliosis more likely to progress than Idiopathic Adult
Wiltse Classification of Spondylolisthesis
1 = Dysplastic 2 = Isthmic 3 = Degenerative 4 = Traumatic (post-traumatic) 5 = Pathologic 6 = Surgical (post-surgical)
Radiographic parameters to aim for in correction of Adult Scoliosis
Saggital vertical axis within 50mm of the L5/S1 disc
Pelvic tilt less than 25 degrees
Diagnostic criteria for Scheuermann’s Kyphosis
- Kyphosis >45 degrees (norm = 40)
- > 5 degrees wedging at 3 or more adjacent vertebra
- > 30 degrees Thiraco-Lumbar kyphosis (norm = 0)
(from Sorensen 1964)
Other features: Schmorl's nodes Irregular and flat vertebral endplates Increased AP diameter of Apical vertebra Narrow disc spaces Spondylosis in adults
More than 80, operatey
Central cord syndrome - What tract is affected, what is clinically weak?
Lateral Corticospinal tract
Upper limb weakness > Lower limb weakness
Distal weakness > Proximal weakness (Fingers > Shoulder)
Differential diagnoses for Myelopathy
Stroke Ageing Amyotrophic Lateral Sclerosis Multiple Sclerosis Movement disorder Vitamin B12 deficiency
Simple argorithm for Cervical decompression
1 to 2 levels = Anterior alone ok
3+ levels + >10 degrees Kyphosis = A and P
3+ levels + <10 degrees Kyphosis = Posterior alone ok
Definition of spinal shock
Temporary physiological stage of the acutely traumatized spinal cord, manifested by the transient absence of reflexive function caudal to the spinal cord injury.
In what clinical situation is an MRI not necessary with bifacet / unifacet C-spine dislocation / listhesis prior to attempt at reduction
Complete spinal cord injury - nothing to lose, just go ahead and reduce it.
Ankylosing spondylitis Non-Orthopaedic manifestations
Anterior Uveitis (20-40%) Aortitis Aortic regurgitation Aortic calcification Pulmonary fibrosis
Aortic calcification is a relative contraindication to thoracic kyphosis correction
Ankylosing spondylitis skeletal manifestations
Setonegative (RF -ve) spondyloarthropathy
Enthesitis Sacroiliitis Klebsiella pneumoniae synovitis Spinal kyphosis Arthritis Spinal ankylosis Costovertebral joint ankylosis (loss of chest expansion) Hip FFD
Indications for surgery in spine infection
NBACK
Neurology Biopsy Abscess Continued symptoms despite ABs Kyphosis
Numbers to know in atlantoaxial subluxation
Related to Rheumatoid neck mostly.
ADI >3mm = abnormal
ADI >7mm = severe
ADI >10mm = high risk or paralysis
PADI / SAD <14mm = neural compression
What is the CervicoMedullary angle
Angle between anterior line of brainstem and anterior line of spinal cord at the Ocipito-Cervical junction
Less than 135 degrees = high rate / risk if myeolopathy
Usually relevant in Rheumatoid c-spine
What is the slip angle in spondylolisthesis?
Line 1: along posterior sacrum
Line 2: perpendicular to Line 1
Line 3: along inferior border or slipped vertebra
Slip angle between Line 2 and Line 3
> 30 degrees = high risk of progression
Risk factors for non-union of Type 2 dens fractures
Displacement > 5 mm Distraction > 2 mm Posterior displacement Angulation >11 degrees Comminution Reverse oblique pattern Age >40 Delayed presentation
What are the components of the Posterior Ligamentous Complex of the spine?
SUPRAspinous ligaments
INTERspinous ligaments
Ligamentum flavum
Facet joint capsules
Posterior cord syndrome. What’s gone, what’s left, what’s the cause?
Gone: vibration and proprioception
Intact: motor (can have bladder issues)
Cause: Tabes dorsalis, friedreich ataxia, AIDS, multiple sclerosis, cervical myelopathy
Anterior cord syndrome. What’s gone, what’s left, what’s the cause?
Gone: motor, pain, temperature (urinary retention)
Intact: proprioception
Cause: anterior spinal artery infarct, disc herniation, radiation
Central cord syndrome. What’s gone, what’s left, what’s the cause?
Gone: motor weakness (arms > legs)
Intact: sensation
Cause: syrinx, tumor, cervical spondylosis
How are pelvic incidence and lumbar lordosis related?
Lumbar lordosis should be Pelvic Incidence +/- 9 degrees
This is relevant for planning deformity correction
Non-Structural causes of scoliosis?
CHIPS
Compensatory (LLD) Hysterical Irritative (Tumor, infection) Postural Sciatic (Nerve root)
Structural causes of scoliosis?
NIC NAOMI
Neuromuscular
Idiopathic
Congenital
Neurofibromatosis Achondroplasia Osteogenesis Imperfecta Marfan's Irradiation
Neuromuscular causes of scoliosis
Myopathic (Muscular dystrophy, Polio, SMA)
Neuropathic (CP, Syrinx, Spina bifida)
Mixed (NSMNs)
3 types of idiopathic scoliosis
Infantile (5%) ( < 4 yo )
Juvenile (15%) ( 4 to 10 yo )
Adolescent (80%) ( > 10 yo )
What is the indication for surgery in congenital scoliosis
Progression
> 4-6 degrees per year
It is better to operate early to fuse the segment than wait too long and not be able to achieve correction.
What is the RVAD angle of Mehta
In Early-Onset (infantile) scoliosis (Not congenital)
Angle between inferior endplate of vertebra and its rib, subtract from the same angle of the other rib.
If < 20 degree difference, then 90% chance of spontaneous recovery
If > 20 degree difference, then likely to need surgery
What is a Phase 2 rib?
In Early-Onset (infantile) scoliosis (Not congenital)
On an AP X-ray:
Phase 1: rib head does not overlap vertebra
Phase 2: rib head overlaps vertebra
Phase 2 = high chance of needing surgery
What is the difference between degenerative and isthmic spondylolisthesis?
Degenerative = no pars defect Isthmic = pars defect
Degenerative can be due to:
Facet degeneration, horizontal orientation, disc degeneration or ligamentous laxity
Isthmic is due to microtrauma
Indications for spondylolisthesis fusion
Failure of non-op after 6 months
Neurologic deficit progression
Instability (slip progression)
Cauda equina
In adult spinal deformity, what are the indications to extend fusion to S1 (not stop at L5)?
C7 plumb line not restored Sacral slope not restored Any disease of L5/S1 - disc - spondy - facet arthropathy Prior L5/S1 laminectomy
