scoliosis ppt

Adolescent Idiopathic Scoliosis

January 21, 2011

Meghan N Imrie, MD

Pediatric Orthopaedic Surgery

Lucile Packard Children’s Hospital

Disclosures

none

Introduction

Definition Etiology Prevalence/Natural History Screening/Evaluation Treatment

– Non-operative– Operative

On the Horizon…

Definition Scoliosis

– Derived from Greek for “crooked”

– Coronal plane deformity > 10o

• < 10o = spinal asymmetry• Measured by the Cobb method

– 3-dimensional deformity– Clinical sign, not an outright

diagnosis• Four main categories

– Congenital– Degenerative– Neuromuscular/syndromic– Idiopathic

Definition - continued “idiopathic”

– What must be ruled out?• Neurofibromatosis• Marfan syndrome• Ehlers Danlos syndrome• Intraspinal abnormalities

– Tumors– Tethered cord– Syrinx

Varies by age:– Infantile - birth to age 2 years– Juvenile - from about 2 to 8 or 9 years– Adolescent - greater than 9 or 10 years, but not an adult

Overview



On the Horizon…

Etiology

Numerous theories, none proven Answer is there…

– Male: female ratio1

• 1:1 for minor curves• 1:8 for treatable curves

– Family history• 27% prevalence of scoliotic curves >15 degrees in

daughters of scoliotic mothers2

– Curve type• Majority right thoracic (about 98%)

– Left thoracic is red flag for possible intraspinal abnormality1. Bunnell WP Spine 1986;11:773-6.

2. Harrington PR Clin Orthop 1977;126:17-25.

Etiology

?

Overview



On the Horizon…

Prevalence

Varies significantly based on degree of curvature:– >10o = 0.5-3%– >30o = 1.5-3/1000

Male to female ratio:– 1:1 for minor curves– 1:8 for those

requiring treatment1

1. Bunnell WP Spine 1986;11:773-6.

Natural History

Progression– Before skeletal

maturity– After skeletal

maturity

Natural History

Progression before skeletal maturity– Many unknowns– Some knowns

• Growth remaining• Size of curve• female

From Lonstein JE and Carlson JM JBJS Am 1984;66:1061-71.

Natural History

Risser sign– Radiographic

measurement based on ossification of iliac apophysis

Natural History

Clues to skeletal maturity and peak height velocity (PHV)– Radiographic measures

• Risser sign • Triradiate cartilage (TRC)• (Elbow ossification)

– Menarche in girls– Tanner staging

Natural History


Natural History Progression after skeletal

maturity– Some variability– Weinstein and Ponseti data

most frequently used1

• Curves <30o do not progress

• Thoracic curves >500 progress average 10 per year

– 50o at 18 -> 90o curve at 58

• Lumbar curves >30o progress about 0.5o per year

1. Weinstein SL and Ponseti IV JBJS Am 1983;65:447-55.

Natural History Adults with untreated AIS:

– No increased rate of mortality (all comers with AIS)1

– Respiratory failure if curve >110 degrees2

• Increased risk of shortness of breath, especially if thoracic curve >80 degrees3

– Chronic back pain4

• Common• Not related to size or location of curve• Usually does not interfere with ability to work

1. Pehrsson K et al Spine 1992;17:1091-6.

2. Pehrsson K et al Thorax 1991;46:474.

3. Weinstein SL et al JAMA 2003;289:559-567.

4. From Tachdjian’s Pediatric Orthopaedics 269.

Natural History

Back pain in adults with untreated AIS:

Weinstein SL et al JAMA 2003;289:559-567.

Natural History Adults with untreated AIS:

– Demographics similar to control group• Education level

• Marriage

• Children– Lower C section rate

– Rate of depression similar– Body satisfaction

• AIS slightly dissatisfied to slightly satisfied

• Control slightly satisfied to satisfied

– Perception of limitation due to scoliosis• 32% reported such issues as difficulty in

purchasing clothes, decreased physical capacity, and self-consciousness

Weinstein SL et al JAMA 2003;289:559-567.

Natural History

In summary:– Trying to prevent curves from

reaching at skeletal maturity:• >50 degree thoracic• >40 or 45 degree lumbar

– Because these curves continue to progress in adulthood

– Adults with untreated, more mild scoliosis do well in adulthood (at least in Iowa…)

Overview



On the Horizon…

Screening Somewhat controversial

– AAOS, SRS, POSNA and AAP currently recommend1:

• Females screened twice at ages 10 and 12

• Males screened once, at age 13 or 14

– British Orthopaedic Association and British Scoliosis Society advise against screening

– United States Preventive Services Task Force (USPSTF) in 2004 recommended against screening

• AAOS, SRS, POSNA, AAP responded with 2008 information statement1

1. Richards BS and Vitale MG JBJS Am 2008;90:195-8.

Screening - controversy In summary:

– Screening is fairly reliable to detect curves (though not terribly accurate)

– Early detection could result in improved health outcomes (by potentially avoiding surgery)

– Brace therapy is likely effective in altering natural history for many patients (but not all)

Most organizations continue to recommend screening

Evaluation History

– Reason for presentation (in patient or parent’s own words

– Pain• Red flag warnings: positive finger test, night pain, non-activity

related pain

– Age– Family history– Pubertal status– Rate of progression– Any neurologic complaints

• Radicular symptoms• Bowl/bladder incontinence

Evaluation Back pain and AIS

– 23% have pain at presentation1

• Only 9% of these had underlying pathological condition

– 9% have pain during course of observation1

– Significant association if1:• > 15 years• Risser 2 or more• Post-menarchal status• History of injury

– Painful left thoracic curve or abnormal neuro exam more likely to have neuro-axis problem

1. Ramirez et al JBJS Am 1997;79:364-8.

Evaluation - radiographs

Cobb Angle - inter/intra observer error 5o

Evaluation Indications for MRI

– Atypical, specific pain– Neuro abnormality

• Abnormal reflexes• Ataxia• weakness• Progressive foot deformity

(cavus feet)

– Left thoracic curve– Rapidly progressive curve– ?males

• Routinely recommended, but minimal data to support1

1. Nakahara D et al Spine 2010 (epub ahead of print)

Evaluation

Classification systems– King-Moe– Lenke

Overview



On the Horizon…

Treatment

A lot of information on the internet

Three main treatments:– Observation– Bracing

• Daytime• Nighttime• Spine-Cor

– Surgery

Treatment

11-25o 25-45o >40-50o

Skeletal maturity?* Skeletal maturity?

yes yesno no

F/u as needed

F/u every 4-6 mos until skeletal maturity

F/u q5 yrs to assess progression

Consider bracing, f/u q 4-6 mos

Consider surgical intervention

*skeletal maturity = Risser 3 or greater

Natural History


Treatment - bracing

Types– Full-time bracing

• Boston• Milwaukee (if apex

higher than T7)

– Night-time bending brace

• Charleston• Providence

– Others• Spine-Cor

Treatment - bracing

TLSO (Boston-type)– Worn as much as

possible• Can take off for

sports, sleepovers etc

– Want at least 50% correction in brace

Treatment - bracing

Milwaukee brace– For refractory curves– Apex >T7– Not really tolerated in

our patient population

Treatment - bracing

Night-time bending braces:– Overcorrects the curve– Only worn at night– Probably not as efficacious

• Price et al1 - 66% success, only 17% requiring surgery

• Randomized study - Charleston vs Boston brace2

– 41% vs 61% success (<5 degrees progression)

– 31% vs 19% required surgery

1. Price CT et al JPO 1997;17:703-707

2. Katz DE Spine 1997;22:1302-12.

Treatment - bracing

SpineCor– Well advertised– Soft straps, so more

easily worn under clothers/during physical activity

– Originators report only 40% progressed, only 23% needed surgery1

• Other authors have found no better results with SpineCor2

1. Christine C et al. Stud Health Technol Inform 2008;135:341-55.

2. Wong MS et al Spine 2008;33:1360-5.

Treatment - bracing Brace efficacy -

– Data all over the place, both for and against– Meta-analysis by Rowe et al1

• 1910 patients in 22 studies on non-operative treatments– Weighted mean proportion of success

» 0.93 for bracing» 0.49 for observation» 0.39 for electrical stimulation

– Prospective international study2

• Boston brace in girls with 25-35 degree curves– 74% success vs 34% with observation alone

– Prospective study of Boston brace with heat sensor (compliance)• >12 hours/day: 82% success• <7 hours/day: 31% success• Patients who went on to surgery: 24% compliance• Patients who did not progress to surgery: 42% compliance

1. Rowe DE et al JBJS Am 1997;79:664-74.

2. Nachemson AL et al JBJS Am 1995;77:815-22.

3. Katz DE et al JBJS Am 2010;92:1343-52.

Treatment - bracing Best for:

– Girls1

• Boys only 38% compliant with brace wear

• 30 degree curve 50% chance of surgery

– Lower BMI2

• BMI >85th %ile --> 2.5x risk of failure, double surgical rate

– More flexible curves– Younger patients

• Many studies• Higher rate of progression by

natural history

1. Karol LA Spine 2001;26:2001-5.

2. O’Neill PJ et al. JBJS Am 2005;87:1069-74.

Treatment - bracing Summary:

– Probably alters natural history in some but not all

• Especially if patient young, thin, and compliant

• Curve can definitely still progress

– Only tool we have to prevent progression

– Success = prevent progression• Never corrects the curve!

– Prospective, blinded, randomized controlled study needed

• BRAiST underway• Enrollment has been difficult

Treatment - surgery Indications for surgery:

– Thoracic curve >40-45 degrees in skeletally immature patient

– Thoracic curve >50 degrees in skeletally mature patient

– Lumbar numbers: usually around >40 degrees

– Double curves more well tolerated

Goals of surgery:– Achieve solid fusion SAFELY!– (improve cosmesis, body

image)

Treatment - surgery

Treatment - surgery No long-term, prospective controlled

studies to support hypothesis that surgery for AIS is superior to natural history– Reliably prevents progression– Achieves permanent correction– Improves appearance

Not a small undertaking– 4-7 day hospital stay– 6 months out of contact sports– Complications:1

• Infection 0-6%• Pseudarthrosis 2-7%• Reoperation rate 5-7%• Possibility of permanent neurologic

injury

– Expensive to health care system1. Westrick ER and Ward T JPO 2011;31:S61-8.

Treatment - surgery

A brief history of correction:– All methods at core the same:

• Expose the spine (facet joints)• Get correction

– Coronal plane (Cobb angle)

– Axial plane (rotation)

– Sagittal plane (maintain normal kyphosis/lordosis relationship)

• Wait for the fusion

Treatment - history of surgery

(Brief) history of correction– 1958, Moe

• Risser cast, bed rest, no instrumentation

• Ave correction 43%





– 1964, Moe• Harrington rods, Risser

cast

• Ave correction 55% --> 41%





– 1964, Moe• Harrington rods, Risser cast

• Ave correction 55% --> 41%

– 1992, Lenke• CDI - Cotrel Dubousset

instrumentation



(Brief) history of correction– 2004, Luk et al

• Comparative studies of 4 different systems (CD Horizon, Moss-Miami, TSRH, Isola)

• Ave correction: 63% for CD Horizon, Moss-Miami vs 58% for TSRH, Isola

• Equal when matched against bending films


(Brief) history of correction– 2004, Luk et al

• Comparative studies of 4 different systems (CD Horizon, Moss-Miami, TSRH, Isola)

• Ave correction: 63% for CD Horizon, Moss-Miami vs 58% for TSRH, Isola

• Equal when matched against bending films

– 2005, Suk• Introduction of pedicle screw• Ave correction 62%

– Other pedicle screw correction rate: 62-76%

Treatment - current techniques

Approach:– Posterior vs– Anterior

• Open vs• Thoracoscopic

– Combined approach• For very big, stiff curves• Younger patients

– To prevent crankshaft


Standard posterior approach– Positioning

• Prone• neuromonitoring

– Approach• Posterior exposure• Careful at most cephalad and caudal ends to

avoid unnecessary exposure• +/- Use of C-arm


Preparing the spine for fusion– Facetectomies

“loosening up the spine”– Ponte osteotomies– Allow for better Cobb

correction and kyphosis creation


Screw placement– Free-hand– With C-arm– With O-arm– Definitely dealer’s choice

Correction– In 3 planes

• Coronal (straight rods)• Axial (derotation)• Sagital (rod contour)

Treatment - current technique

Screw types– Monoaxial– Uniplanar– Polyaxial

Ways to reduce the screws to the rods– Reduction screws– Reduction tools

• Each company has their specific types


Preparation for fusion– Facetectomies– Decortication

• Various techniques

– Addition of bone graft• Autograft (iliac crest)• Allograft

– Many options!

Closure!– +/- drain– +/- brace


“MIS” scoliosis surgery– Applying some adult

techniques to pediatric scoli

– At cephalad levels mostly

– ? Fusion rates?

Overview



On the Horizon…

On the Horizon Scoli score = developed by Axial Biotech/Jim Ogilvie and

crew– Saliva test– Predictive of progression– For Caucasian girls, age 9-13, with curves between 10 and 25

degrees• Likelihood will progress to surgical curve

– Based on 53 genetic markers– Log scale from 0 to 200– Very high and very low scores helpful, middle score unclear– Not widely used or accepted– Expensive– May be more helpful in research

• Ie are curves with high scores those that progress despite a brace?

On the Horizon “Fusionless”

techniques:– Compressing anterior

overgrowth• Vertebral stapling• Spinal tethering

– Newton et al» Encouraging

results in animal model

» Human trials just starting

“Fusionless” techniques:– Compressing anterior

overgrowth• Vertebral stapling• Spinal tethering

– Newton et al» Encouraging

results in animal model

» Human trials just starting

Summary AIS

– 3-dimensional deformity– Defined as 10 degrees of curve on PA xray– Exact cause unknown; watch for red flags– Screening controversial but still recommended by

most• Girls at 10 and 12 years (younger better)• Boys at 13 or 14 years

– > 7 degrees on Adams forward bend, consider xray vs referral to orthopaedist

– Treatment• Based on age and size of curve• Includes observation, bracing, and surgery

Thank you

scoliosis ppt

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