Upload
others
View
8
Download
0
Embed Size (px)
Citation preview
Spinal Deformity Pathologiesand Treatments
Spinal Deformity• Scoliosis
– 3-dimensional deformity affecting all 3 planes
– Can be difficult to visualize with 2-dimensional radiographs
• Kyphosis– Deformity affecting the sagittal plane
• Neuromuscular– Results from neurologic or muscular
diseases, such as cerebral palsy, muscular dystrophy, or polio
Types of Scoliosis• Adult• Congenital
– Abnormal development of the spine resulting in:
• A missing portion• Partial formation• Lack of separation of the vertebrae
• Idiopathic– Infantile– Juvenile– Adolescent
• Neuromuscular– Results from neurologic or muscular
diseases, such as cerebral palsy, muscular dystrophy, or polio
Scoliosis“Normal” alignment• Spinous processes all line
up in a straight line over the sacrum
Normal sagittal alignment• Visibly balanced; a vertical line from
the midpoint of the C7 body to the posterior superior corner of the sacrum
• Coronal plane deformity almost always correlates with sagittal plane deformity, specifically hypokyphosisand hypolordosis
ScoliosisC7
Lateral displacement
Scoliosis
Angular displacement
Scoliosis
Structural curves (curve stiffness)• Some curves are structural
curves, while others are nonstructural (often the minor curves)
• Determined with bending films (x-rays taken while the patient is bending to each side)
• Stiffness of a curve will influence surgical strategy
Scoliosis
ScoliosisThink in 3 dimensions• Rotational
displacement• Lateral displacement• Sagittal displacement
• Rib hump• Rib cage volume
ScoliosisThink in 3 dimensions• Rotational
displacement• Lateral displacement• Sagittal displacement
• Rib hump• Rib cage volume
Scoliosis• Pediatric
– Congenital• Malformation of spinal segments
– Idiopathic• Infantile (<3 years of age)• Juvenile (3-10 years)• Adolescent (>10 years)
• Adult– Idiopathic; former adolescent,
now skeletally mature – Degenerative; usually >age 40
• Abnormal development of the spine resulting in:– A missing portion– Partial formation– Lack of separation of
the vertebrae
Congenital Scoliosis
Failure of Formation Failure of Segmentation
Congenital Scoliosis
Risk of progression• >30° = 50% • 5-30° = 25% • 25% are nonprogressive
Congenital Scoliosis
Pediatric Idiopathic Scoliosis• Idiopathic
– Infantile/congenital (<3 years of age)• More boys than girls• 80% resolve without
treatment– Juvenile (3-10 years)
• Equally affects boys and girls
– Adolescent (>10 years)• 80% of patients are girls
• Frequency and prognosis (within the general population)– ≤ 10º occurs in 5.0% – ≤ 20º occurs in 0.5%– ≤ 30º occurs in 0.2% – ≥ 40º occurs in 0.1%
• Most patients with scoliosis have small curves• The greater the degree of curve, the more likely
the progression• The greater the amount of growth after the
onset of the curve, the more likely the progression
Adolescent Idiopathic Scoliosis
Adolescent Idiopathic Scoliosis• Treatment options
– Observation • Curves <25° with follow-up radiographs at regular intervals
– Bracing • Curves that range from 25°-40° with flexibility• Curves from 40°-50°• Smaller curves 20°-25° that demonstrate rapid progression
– HIGH NONCOMPLIANCE RATE
– Surgical intervention • Inflexible curves that exceed 40°• Virtually any curve that exceeds 50°
Adult Scoliosis• Idiopathic
– Once an adolescent becomes skeletally mature, change diagnosis to adult idiopathic
• Degenerative– Occurs over a long period time– Usually concomitant with other conditions
• Failed conservative treatment (bracing) will lead to surgical treatment– Decompression with fusion
Adult Scoliosis
Kyphosis• A spine affected by kyphosis shows
evidence of a forward curvature of the vertebrae in the upper back area, giving a "humpback" appearance
• Causes– Metabolic problems– Neuromuscular conditions– Osteogenesis imperfecta, also called
“brittle bone disease”; a condition that causes bones to fracture with minimal force
– Spina bifida– Scheuermann's disease, a condition that
causes the vertebrae to curve forward in the upper back area; the cause of Scheuermann's disease is unknown and commonly seen in males
Principles of Deformity Correction• There are a number of strategies that can
be used to correct spinal deformity• Each of the strategies has its own
pros and cons
• Some strategies use only 1 or 2 principles, and some strategies will use a combination of principles
PRO
CON
Surgical Correction of ScoliosisCurve stiffness• “Stiff” (usually the major
curve); some are “flexible”(often the minor curves)
• Determined with bending films (x-rays taken while the patient is bending to each side)
• Stiffness of a curve will influence surgical strategy
Surgical Correction of ScoliosisCurve stiffness • The stiffness of a curve
will influence surgical strategy because a stiff curve resists correction– Posterior articular
facetecomy– Anterior release– Costal facet releases– Rib osteotomy
Principles of correction• Pioneered by Harrington
– Distract concave side– Compress convex side
• Can correct lateral and angular displacement
• High stress on bones and hardware
• Straight rod = straight spine = “flat back”
• Does not correct rotational deformity
Surgical Correction of Scoliosis
PRO
CON
CON
CON
Surgical Correction of ScoliosisPrinciples of correction• Pioneered by Luque• Translation: bring
the spine to the rod• Can correct lateral and
rotational deformity• High stress on bones
and hardware• Long-term maintenance
of correction is difficult
PRO
CON
CON
Surgical Correction of ScoliosisPosterior approach• Translation (wires/cables)• Pioneered by Luque
– Translation with wires at every level
• Low profile• Inexpensive• Long-term fixation can be
difficult to maintain
PRO
CON
PRO
Surgical Correction of ScoliosisPosterior approach• Translation (wires/cables)• Pioneered by Luque
– Segmental translation with wires at every level
• Low profile• Inexpensive• Long-term fixation can be
difficult to maintain
PRO
CON
PRO
Surgical Correction of ScoliosisPosterior approach• Translation (wires/cables)• Pioneered by Luque
– Segmental translation with wires at every level
• Low profile• Inexpensive• Long-term fixation can be
difficult to maintain
PRO
CON
PRO
Surgical Correction of ScoliosisPosterior approach• Spinal-sacro-pelvic fixation• Also known as Luque-
Galveston• Rods (or bolts) extend into
the iliac crest (between the cortical walls), connect to sacrum, then extend up along the spine; this is state-of-the-art for neuromuscular patients
Principles of correction• Pioneered by Cotrel
and Dubousset– Derotation; proper sagittal
contour (kyphosis and lordosis) approximates spinal deformity when rotated 90º; translate spine to rod, then rotate rod in axial plane
• Simple and quick• High stress to bones and
hardware
Surgical Correction of Scoliosis
CON
PRO
Surgical Correction of ScoliosisPrinciples of correction• Pioneered by Cotrel
and Dubousset– In situ bending; spine is
fixed to rod, then rod is bent to the desired shape
• Will correct lateral deformity• High stress on bones
and hardware• Difficult over long curves• Difficult with titanium rods
CON
PRO
CON
CON
Surgical Correction of ScoliosisPrinciples of correction• Pioneered by Shufflebarger
– Segmental; distraction, compression, and translation applied to each level; segment by segment
• Comprehensive• Lower stress on bones and
hardware means that smaller rods and lower profile connectors can be used
• Complex
PRO
CON
PRO
Surgical Correction of ScoliosisPosterior approach• Translation (Cantilever)• Dr Asher• Concave side first
– T3 down-going lamina hook
– T4 up-going lamina hook
– Wires or cables at curve’s apex
– L1 and L2 pedicle screws and slotted connectors
PRO
PRO
PRO
PRO
Surgical Correction of ScoliosisPosterior approach• Translation (Cantilever)• Dr Asher• Convex side next
– T3 down-going lamina hook• Compress toward T9
– T9 up-going lamina or pedicle hook (at the convex apex)
• Compress toward T3– L1 and L2 pedicle screws
with slotted connectors
PRO
PRO
PRO
PRO
Surgical Correction of ScoliosisPosterior approach• Translation (Cantilever)• Dr Asher• Convex side next
– T3 to T9 compression pulls lateral displacement into alignment, and brings distal rod end toward center line
PRO
PRO
Surgical Correction of ScoliosisPosterior approach• Segmental• Dr Shufflebarger
“Open the closed spaces, and close the opened spaces [segment by segment]”
Surgical Correction of ScoliosisPosterior approach• Segmental• Dr Shufflebarger
“Open the closed spaces, and close the opened spaces [segment by segment]”
Surgical Correction of ScoliosisPosterior approach• Segmental• Dr Shufflebarger
“Open the closed spaces, and close the opened spaces [segment by segment]”
Surgical Correction of ScoliosisPosterior approach• Segmental• Dr Shufflebarger
“Open the closed spaces, and close the opened spaces [segment by segment]”
Surgical Correction of ScoliosisPosterior approach• Segmental• Dr Shufflebarger
“Open the closed spaces, and close the opened spaces [segment by segment]”
Surgical Correction of ScoliosisPosterior approach• Segmental• Dr Shufflebarger
“Open the closed spaces, and close the opened spaces [segment by segment]”
Surgical Correction of ScoliosisAnterior correction• Mechanics limited to
– Segmental distraction and compression for correction of lateral displacement
– Derotate for correction of saggital displacement
– In situ bending– Effective translation is very
difficultCON