Paeds Spine (Complete) Flashcards
What are the unique anatomic and radiographic features of the pediatric cervical spine?
[JAAOS 2011;19:600-611]
- Synchondroses between ossification centres
- Neurocentral synchondroses – between posterior elements and body
- Dentocentral synchondroses – between dens and body of C2
- Normal = smooth with subchondral sclerotic lines
- Increased elasticity of ligaments, capsule and endplates
- Wedge-shaped vertebral bodies
* Normal = ≤3mm of anterior wedging - Horizontally-oriented facet joints
- Virtually absent uncinate processes
- Pseudosubluxation of C2 on C3
- C3 on C4 is second most common
- Caused by horizontal nature of facets
- Normal = spinolaminar line (Swischuk’s line) between C1-C3 should pass within 1mm of C2 spinolaminar junction
- Reduces with neck extension
- Abnormal >1.5mm of displacement
- Loss of cervical lordosis in neutral position
- Increased ADI
* Normal = 3-5mm
***NOTE: pediatric spine adopts a more adult configuration by age 8
What are the types of spondylolisthesis (Wiltse system)?
- Dysplastic (congenital)
* Dysplasia of the upper sacrum or neural arch (the pars is normal) - Isthmic
- A. Lytic – fatigue fracture of the pars
- B. Elongated but intact pars (due to repeated micro fractures and healing)
- C. Acute fracture of the pars
- Degenerative
- Traumatic (fracture other than the pars)
- Pathologic
- Iatrogenic
In pediatric population what are the risk factors for spondylolisthesis progression?
[AAOS comprehensive review 2, 2014]
- Adolescent growth spurt
- Lumbosacral kyphosis (slip angle >40)
- Meyerding grade >II
- Younger age
- Female
- Dysplastic posterior elements
- Dome shaped sacrum
What is the management of isthmic spondylolisthesis?
[JAAOS 2016;24:37-45]
- Nonoperative – first line
- Surgery
- Indications (Pediatric)
- i. Grade I and II slips with persistent symptoms despite >6 months of nonsurgical treatment
- ii. Grade III or higher slips
What is the classification of idiopathic scoliosis based on age?
[OKU Spine 5]
- Age 10-18 = adolescent idiopathic scoliosis
- Age 4-9 = juvenile idiopathic scoliosis
- Age <4 = infantile idiopathic scoliosis
What is the most common cause of painful scoliosis in the adolescent population?
Osteoid osteoma
What are the risk factors for curve progression in AIS?
[AAOS comprehensive review 2, 2014]
- Curve magnitude
- Thoracic curve >50° and lumbar curve >40° progress 1° per year after skeletal maturity
- Curve >30° at peak growth velocity will likely require surgery
- Skeletal maturity
- Tanner stage
- Females with Tanner <3 have greatest risk of progression
- Risser grade
- Peak growth velocity is Grade 0
- Age of menarche
- Peak growth velocity is just before onset of menses
- Triradiate cartilage
- Open triradiate have the greatest risk of progression
What should be evaluated during the physical examination in AIS?
[AAOS comprehensive review 2, 2014]
- Shoulder height
- Trunk asymmetry, scapular prominence, rib prominence
- Leg length, pelvic tilt
- Signs of spinal dysraphism
* Hairy patches, dimples, nevi, tumors over the spine - Cavovarus foot (particularly unilateral)
- Neurological examination
- Sensory, motor, reflexes
- Abdominal reflexes
- Adam’s forward bending test
What radiographs should be ordered for evaluation of scoliosis?
[AAOS comprehensive review 2, 2014]
- Full length standing 36 inch AP and lateral of entire spine
* Look for spondylolisthesis - Bending films are reserved for surgical planning
When should MRI be considered in evaluation of scoliosis?
[OKU Spine 5] [AAOS comprehensive review 2, 2014]
- Age <10
- Males
- Abnormal curve pattern
* Left thoracic or right lumbar curve - Rapid curve progression
- Abnormal neurological exam
- Apical thoracic kyphosis
- Persistent neck pain and headache
- Preoperative planning to evaluate for dural ectasia in patients with neurofibromatosis, Ehlers-Danlos and Marfans
What is the classification system for adolescent idiopathic scoliosis?
[AOfoundation]
Lenke classification
- Requires upright AP and lateral and supine left and right bending
- 4 steps
- STEP 1 – divide spine into 3 regions
- Proximal thoracic – Apex at T3, T4 or T5
- Main thoracic – Apex between T6 and the T11-T12 disc
- Thoracolumbar/Lumbar – T/L apex between T12 and L1, and lumbar apex between the L1-L2 disc and L4
- STEP 2 – determine the major and minor curves
- Curve with largest Cobb angle is the major curve
- Other curves are minor
- STEP 3 – determine if minor curves are structural or nonstructural
- Curve is structural if:
- Residual curve >25° in coronal plane on the bending film
- Kyphosis >20 in sagittal plane (regardless of coronal flexibility)
- Curve is structural if:
- STEP 4 – based on above information determine the curve type
- For LENKE 4 – Main Thoracic OR TL/L can be the Major Curve
- STEP 5 – determine lumbar and sagittal modifiers
- Lumbar modifier – draw the CSVL and compare to lumbar apical vertebra
- A = line is between pedicles of apical vertebra
- B = line touches pedicle
- C = line does not touch vertebra or pedicle
- Sagittal modifier – assess kyphosis from T5-T12
- ‘-‘ (hypo) = kyphosis <10
- ‘N’ (Normal) = kyphosis 10-40
- ‘+’ (hyper) = kyphosis >40
- Lumbar modifier – draw the CSVL and compare to lumbar apical vertebra
- STEP 1 – divide spine into 3 regions
What are the radiographic parameters to be evaluated during surgical planning in AIS?
[Scoliosis Research Society]
- Cobb angle
* Superior endplate of the upper end vertebra, to the inferior endplate of the lower end vertebra - End vertebra
- Define the ends of a curve in a frontal or sagittal projection
- Cephalad EV – first vertebra from apex whose superior surface is tilted maximally toward the concavity of the curve
- Caudal EV – first vertebra from apex whose inferior surface is tilted maximally toward the concavity of the curve
- Neutral vertebra
* Vertebra without axial rotation - Stable vertebra
* Thoracic or lumbar vertebra cephalad to a lumbar scoliosis that is most closely bisected by CSVL assuming the pelvis is level - Apical vertebra
* Vertebra most deviated laterally from the CSVL
When is bracing indicated for AIS?
[JAAOS 2016;24:555-564]
- Curves 20-40° and Risser 0-1
- Curves 30-45° and Risser 2-3 should also be considered for bracing
- Curves >25 during growth [SRS Guidelines]
What are the bracing options in AIS?
- Curve apex above T7 = Milwaukee CTLSO [Orthobullets]
- Curve apex below T7 = Boston TLSO [Orthobullets]
What are the technical points in bracing prescription for AIS?
[JAAOS 2016;24:555-564]
- Brace should be worn 16-18 hours per day
- The goal is in brace correction of 30-70%
- Followup should be every 4 months during peak height velocity then every 6 months
- Nighttime bracing can be used towards the end of treatment
- Bracing can be discontinued when the patient reaches skeletal maturity and curve has not progressed >50°
- In females, bracing can be discontinued when:
- Risser sign 4 to 5
- Postmenarche for >2 years
- Minimal height increase over 6 months
- In males, bracing can be discontinued when:
- Risser 5
- No evidence of height increase over 6 months
What is the number needed to treat (NNT) with bracing to prevent one surgery in AIS?
[JAAOS 2016;24:555-564]
NNT = 3
What were the results of the BRAIST trial (Bracing in Adolescent Idiopathic Scoliosis Trial)?
[JAAOS 2016;24:555-564]
- Study stopped early due to clear evidence of bracing effectiveness
- Bracing group (Boston-type TLSO) showed 72% of patients had curves <50 compared to non-braced group which had 48% of patients with curves <50
When is surgery indicated for adolescent idiopathic scoliosis?
[OKU Spine 5] [AAOS comprehensive review 2, 2014]
- Thoracic curve >50°
- Lumbar curve >45°
What are the goals of surgical management of AIS?
[JAAOS 2013;21:519-528]
- Maintain coronal and sagittal alignment
- Produce level shoulders
- Correct deformity
- Save motion segments
What are the considerations in surgical management of AIS?
- Approach
- Posterior instrumentation and fusion is the mainstay
- Anterior releases can be considered for large curves (>70°) and stiff curves
- Anterior discectomy and fusion can be considered for skeletally immature (open triradiate and Risser 0) to prevent crankshaft phenomenon
- Implant
* Segmental pedicle screw instrumentation is the standard - Selecting fusion levels [JAAOS 2013;21:519-528]
- Include all Lenke structural curves
- Include lumbar nonstructural curves >45° on standing PA radiographs
- Nonstructural curves can achieve up to 70% spontaneous correction without instrumentation
- Upper instrumented vertebra
- Structural proximal thoracic curve = T2
- Nonstructural proximal thoracic curve:
- Use T2-3-4 rule
- Assess height of left shoulder = “if high go high, if low go low”
- T2 for preoperative left shoulder elevation
- T3 for preoperative level shoulders
- T4 for preoperative left shoulder depression
- Exception is Lenke 5 = upper end vertebra (don’t end at apex of kyphosis)
- Use T2-3-4 rule
- Lower instrumented vertebra
- Simplified = go to stable vertebrae
- Generally, avoid lumbar fusion, leaving three mobile disks below the LIV if possible
- Nonstructural thoracolumbar/lumbar curves guided by lumbar modifiers
- Lumbar modifier A = the LIV is the vertebra touching the CSVL
- Lumbar modifier B + C = the thoracolumbar stable vertebra is selected as the LIV
- Structural thoracolumbar/lumbar curves = distal end vertebra
- Rarely below L3
- Can go one level above the distal end vertebra if it crosses midline and adequately derotates on convex bending radiograph
4. Neuromonitoring
- EMG, MEP, SSEP