Spinal Deformity Pathologies and Treatments

Scoliosis Spinal Deformity 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

Scoliosis C7 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 hypokyphosis and hypolordosis

Scoliosis 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 Think in 3 dimensions Rotational displacement Lateral displacement Sagittal displacement Rib hump Rib cage volume

Pediatric Congenital Scoliosis Malformation of spinal segments Idiopathic Adult Infantile (<3 years of age) Juvenile (3-10 years) Adolescent (>10 years) Idiopathic; former adolescent, now skeletally mature Degenerative; usually >age 40

Congenital Scoliosis 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

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

Adolescent Idiopathic Scoliosis 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 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

Idiopathic Adult Scoliosis Once an adolescent becomes skeletally mature, change diagnosis to adult idiopathic Degenerative Occurs over a long period time Usually concomitant with other conditions

Adult Scoliosis Failed conservative treatment (bracing) will lead to surgical treatment Decompression with fusion

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 PRO and cons CON Some strategies use only 1 or 2 principles, and some strategies will use a combination of principles

Surgical Correction of Scoliosis Curve 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 Scoliosis Curve 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

Surgical Correction of Scoliosis PRO CON CON CON 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 Principles 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

Surgical Correction of Scoliosis PRO PRO CON Posterior approach Translation (wires/cables) Pioneered by Luque Translation with wires at every level Low profile Inexpensive Long-term fixation can be difficult to maintain

Surgical Correction of Scoliosis PRO PRO CON Posterior 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

Surgical Correction of Scoliosis Posterior 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

Surgical Correction of Scoliosis PRO CON 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 PRO CON CON CON Principles 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

Surgical Correction of Scoliosis PRO PRO CON Principles 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

Surgical Correction of Scoliosis Posterior approach Translation (Cantilever) Dr Asher Concave side first PRO PRO PRO PRO 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

Surgical Correction of Scoliosis PRO Posterior approach Translation (Cantilever) Dr Asher Convex side next PRO PRO PRO 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

Surgical Correction of Scoliosis PRO Posterior approach Translation (Cantilever) Dr Asher Convex side next PRO T3 to T9 compression pulls lateral displacement into alignment, and brings distal rod end toward center line

Surgical Correction of Scoliosis Posterior approach Segmental Dr Shufflebarger Open the closed spaces, and close the opened spaces [segment by segment]

Surgical Correction of Scoliosis Anterior correction Mechanics limited to Segmental distraction and compression for correction of lateral displacement Derotate for correction of saggital displacement In situ bending CON Effective translation is very difficult