Challenges in EOS Early Onset Spinal Deformity Treating very Many - - PDF document

11/8/2013 1

Behrooz A. Akbarnia, MD

Clinical Professor, University of California, San Diego Medical Director, San Diego Center for Spinal Disorders La Jolla, California

Magnetically Controlled Growing Rods (MCGR) for Early Onset Scoliosis (EOS)

UCSF Practical Course in Advanced Spinal techniques Las Vegas, November 8, 2013

Disclosures (Growing Spine)

Growing Spine Foundation (a) DePuy Spine (a,b) Ellipse Tech. (a,b) K2M (a,b) Kspine (b)

a. Grants/Research Support b. Consultant c. Stock/Shareholder d. Speakers’ Bureau e. Other Financial Support

Treating very young children with progressive EOS remains challenging…

Early Onset Spinal Deformity Challenges in EOS

• Many etiologies
• Many different treatments
• High rate of complications
• Limited outcome measures
• Comparisons difficult!

11/8/2013 2

• Options between growing rods, nonoperative

treatment, VEPTR, Shilla, and fusion.

• Practical variation exists (as each patient needs

special consideration) but consensus exists on the utility of GR in EOS specifically about starting age, curve and etiology.

• Vitale Study

J Ped Ortho 2010

No Evidence Based (EBM) Data

OBM (Opinion Based)

Literature Review

Growing Spine Study Group Growing Spine Foundation

Growing Spine Organization

Acknowledgement

GSSG Sites

11/8/2013 3

GSSG- San Diego Site

Rady Children’s Hospital EOS Program

Development and Initial Validation of a Novel Classification System in Early Onset Scoliosis

Brendan A. Williams1, MD; Hiroko Matsumoto1, MA; Daren J. McCalla1, BS; Behrooz A. Akbarnia2, MD; Laurel C. Blakemore3, MD; Randal R. Betz4, MD; John M. Flynn5, MD; Charles E. Johnston6, MD; Richard E. McCarthy7, MD; David P. Roye Jr.1, MD; David L. Skaggs8, MD; John T. Smith9, MD; Brian D. Snyder10, MD, PhD; Paul D. Sponseller11, MD, MBA; Peter F. Sturm12, MD; George H. Thompson13, MD; Muharrem Yazici14, MD; Michael G. Vitale1, MD, MPH.

Cobb Angle Etiology

Congenital/Structural Neuromuscular Syndromic Idiopathic

Results

Not Useful Useful Essential CVR Sum of Ranks COBB 1 14 0.87 29 ETIOLOGY 3 12 0.60 27 KYPHOSIS 4 11 0.47 26 AGE 5 10 0.33 20 PROGRESSION 3 5 7

• 0.07

19 CHEST WALL ABNORMALITIES 2 9 4

• 0.47

17 FLEXIBILITY 4 6 5

• 0.33

16 OTHER CO-MORBIDITIES 3 8 4

• 0.47

16 PULMONARY FUNCTION 3 9 3

• 0.60

15 AMBULATORY ABILITY 2 12 1

• 0.87

14 NUTRITIONAL STATUS 5 8 2

• 0.73

12 MENTAL FUNCTION 10 5

• 1.00

5 BONE QUALITY 11 4

• 1.00

4

Vitale et al

Etiology

Congenital/ Structural Neuromus cular Syndromic Idiopathic

Cobb Angle

1: <20° 2: 21-50° 3: 51-90° 4: >90°

Kyphosis

(-): <20° N: 21-50° (+): >50°

APR Modifier

P0: <10°/yr P1: 10-20°/yr P2: >20°/yr

Classification of EOS (C-EOS)

11/8/2013 4 Validation Studies

(ICEOS)

Risk by Classification: Lower Risk of Rapid Failure

• Congenital (21-50& 51-90); C2, C3
• Syndromic (21-50); S2
• Idiopathic (51-90); I3

Higher Risk of Rapid Failure

• Congenital (>90); C4
• Neuromuscular (>51-90); N3
• Neuromuscular (>90); N4
• Syndromic (51-90); S3

Flynn, Vitale et al.

Questions to be addressed:

• Why children with EOS need

treatment?

• What are the goals of treatment?
• What are the treatment options

including growth friendly options?

• What are the expected outcomes?
• Can we minimize complications?
• What to expect in the future?

Questions to be addressed:

• Why children with EOS need

treatment?

• What are the goals of treatment?
• What are the options?
• Non-fusion options
• Can we minimize complications?
• What is the expected outcomes?
• What to expect in the future?

Natural History Untreated Scoliosis

• Infantile: 0 to 3 years
• Juvenile: 4 to 9 years
• Adolescent: 10 to 16 years

Pehrsson, Larssson, Oden & Nachemson, Spine, 1992

11/8/2013 5 Thoracic Insufficiency Syndrome The Inability of the Thorax to Support

Normal Respiration Or Lung Growth

Campbell, Smith, et al. J BJS Mar, 2003 J BJS Aug, 2004

Thoracic Insufficiency Syndrome Poor Quality of Life

• Among the

lowest

• bserved in

pediatrics

– Asthma – JRA – Heart transplant

QOL in Pediatrics

53 75 69 63 85

20 40 60 80 100 TIS Asthma JRA Heart X Norms

Vitale, JPO, 2008

Questions to be addressed:

• Why children with EOS need

treatment?

• What are the goals of treatment?
• What are the options?
• Non-fusion options
• Can we minimize complications?
• What is the expected outcomes?
• What to expect in the future?

Treatment Goals

 Deformity Correction ( spine and chest )

and maintenance of correction  Improve pulmonary and spinal function  Normalize the spinal growth and avoid early fusion (maintain mobility)  Minimize complications  Improve quality of life and the care of the patient

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Fusing scoliosis early may contribute to shortening of the thoracic spine, TIS, and respiratory insufficiency

• 28 pts, early thoracic fusion before the age 9 years,

– evaluated by pulmonary function testing at a minimum of 5 years f/u – compared to age matched controls

• Average age at surgery was 3.3 yrs and at follow up was 14.6 yrs.
• Thoracic spinal height FVC < 50%

< 18 cm 63% pts 18 to 22 cm 25% pts 22 cm to normal† 0% pts

† normal 28 cm males, 26 cm females

Karol, et al., JBJS 2008, 90: 1272-1281.

Deceased

13 cm

Questions to be addressed:

• Why children with EOS need

treatment?

• What are the goals of treatment?
• What are the options?
• Non-fusion options
• Can we minimize complications?
• What is the expected outcomes?
• What to expect in the future?

Treatment Options

• Non-operative treatment (cast, Brace,

traction)

• Spine based growing rods
• Rib-based distraction
• Hybrid?
• Growth modulation
• Guided growth
• Early fusion

History

11/8/2013 7 Casting and Bracing is well tolerated

Questions to be addressed:

• Why children with EOS need

treatment?

• What are the goals of treatment?
• What are the options?
• Non-fusion options
• What is the expected outcomes?
• Can we minimize complications?
• What to expect in the future?

Growth Friendly Implant Classification

• 1. Distraction based

– Growing Rods – VEPTR – MCGR

• 2. Guided Growth

– Luque-Trolley – Shilla

• 3. Tension Based

– Tether – Staple >age 8 Non-congenital < age 8 ? All etiologies < age 9 ? All etiologies < age 9 ? All etiologies

Skaggs

ONLY VEPTR IS APPROVED in USA

Indications for Growth-Friendly Surgery

• Progressive curves not controlled or

amenable to bracing or casting

• Curves where growth preservation

would be beneficial

• Curves that require management of

both the chest wall and the scoliosis

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Absent Ribs: Expansion Thoracoplasty by Multiple Devices Shilla

3 level fusion compression distraction derotation

Open Screws – no fusion no bone exposed allow rod to slide multiaxial

Richard McCarthy

Preop Postop 1 year Postop Newton

Single Rod Techniques

Growing Rods

11/8/2013 9

Growing Rods Distraction Based – Rib Anchors

+/- thorocotomy Comparison of spine and Rib anchors

• All specimens eventually failed at the bone-anchor interface.

No failures were observed in the instrumentation utilized.

• Young’s Modulus was calculated for each construct type and

no statistically significant difference was determined.

Construct Type Maximum load for failure (Mean & Standard Deviation) (Screw-Screw) SS 349  89 N (Laminar Hook-Hook) HH 283  48 N (Rib Hook-Hook) RR 429  133 N (Transverse Process-Laminar Hook-Hook) TPL 236  60 N

Rib to Spine

11/8/2013 10

Questions to be addressed:

• Why children with EOS need

treatment?

• What are the goals of treatment?
• What are the options?
• Non-fusion options
• What is the expected outcomes?
• Can we minimize complications?
• What to expect in the future?
• EOSQ being collected prospectively

Quality of Life Outcomes RESULTS (cont’d)

GROUP Cobb Angle

(Pre-Initial to Post Final)

% Correction Increase in T1-S1 Length Single with apical 85° → 65 ° 23% 6.4cm Single w/o apical 61° → 39 ° 36% 7.6cm Dual w/o apical 92° → 26° 71% 11.8cm

Growth per Year (cm)

• Total Group

1.21

• Under 5 years

1.19

• 5-10 year

1.13

• Under treatment

1.01

• Post final fusion group

1.66

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250 270 290 310 330 350 370 390 410 Apr-98 Dec-98 Oct-99 Oct-99 Sep-00 May-01 Oct-01 Sep-01 May-03 Feb-04 Jan-05 Dec-06 10 20 30 40 50 60 70 80 90 100 T1-S1 Length Length of Implant Cobb Angle

Age 3 +11 Age 12 + 7

3 + 10 Year Old Girl With Marfan’s 7 + 8 yrs Follow Up

Final Fusion

13 cm

RESULTS

mm

.00 10.00 20.00 30.00 40.00 50.00 60.00 70.00 80.00

Change in T1-T12

(Pre-op to Latest Follow-up)

∆ in T1-T12 was greater in the 4-6 and ≥7 groups (p<0.001)

3

(n=17)

4-6

(n=19)

>7

(n=15)

Number of Spinal Distractions

Mean # of distractions = 5.4 (Range: 3–11)

Early onset scoliosis treated with Growing Rods has more growth and better Cobb correction but more surgeries compared to Shilla

• 37 GR 37 Shilla
• Same FU (4.1 vs 4.6)
• T1-S1 ( 8.5 vs 6.4)
• Cobb angle Change ( 36 vs 23)
• Number of surgeries (7 vs 2.8)

Lindsay M. Andras, MD1; Elizabeth R. A. Joiner, BS1; Richard E. McCarthy, MD2; Scott J. Luhmann, MD3; Paul D. Sponseller, MD4; John B. Emans5, MD; David L. Skaggs, MD1 and Growing Spine Study Group ICEOS 2012

Progression 86°

103 33

128

134 2+6

11/8/2013 12

No Trach. Normal activity

Questions to be addressed:

• Why children with EOS need

treatment?

• What are the goals of treatment?
• What are the options?
• Non-fusion options
• What is the expected outcomes?
• Can we minimize complications?
• What to expect in the future?

Adequate or Classic Inadequate

Supra-laminar Infra-laminar

Cross link

ANCHORS

11/8/2013 13 Significance of sagittal alignment

• Syndromic patients with early onset scoliosis

with thoracic kyphosis over 40 degrees who undergo growing rod treatment should be monitored very closely for complications, particularly for implant failure

Final outcome at final FU

GR treatment abandoned in 11 out of 42 patients (26%)

Questions to be addressed:

• Why children with EOS need

treatment?

• What are the goals of treatment?
• What are the options?
• Non-fusion options
• Can we minimize complications?
• What is the expected outcomes?
• What to expect in the future?

Magnetically Controlled Growing Rod (MCGR)

Phenix MAGEC

11/8/2013 14

• The use of remotely controlled

lengthening devices has been previously reported. (Takaso et al., Soubeiran et al.)

• Goal of MCGR: To reduce

frequency of surgeries while still providing distraction

Introduction

• The complication risk increased by 24% for each additional

surgical procedure.

• Growth-guided procedures, may reduce the number of

procedures, but do not provide any distraction.

December 2010

Growth modulation with current Growing Rod (GR) techniques require frequent surgical lengthening and has a high risk of complications

Introduction

2012

• Magentically controlled growing rods (MCGR) were

developed to allow for non-invasive lengthening

• Pre-clinical studies has shown promising results

INTRODUCTION

Spine 2012

• 7-9 levels were un-

instrumented between cephalad and caudal foundations

• 7 mm of remote distraction was

performed weekly for 7 weeks in EG under sedation

• Implants were removed at

week #7

• Animals were sacrificed 3

weeks after implant removal

METHODS

11/8/2013 15

• MCGR was shown to be safe and effective in this

study

• No complication resulted directly from distraction
• MCGR distinguishes itself by:
• Distraction accuracy / prediction
• Ability to shorten

CONCLUSIONS

• MCGR Technology

Implantable spinal rod with magnetic actuator External remote controller

non-invasive adjustment Example of current physician directed adjustable rod. Requires surgical intervention for adjustment MAGEC

• This study was designed to evaluate the

safety and efficacy of the MCGR technique in patients with early onset scoliosis

• 33 MCGR patients in 4 centers (Hong

Kong, London, Cairo and Ankara)

• 14 patients met the inclusion criteria

(1) EOS of any etiology (2) Minimum of 3 distractions

• T1-T12, T1-S1 and height of

instrumented spine was measured

Materials and Methods

Instrumented height of the spine Actuator expansion

T1-T12 T1-S1

11/8/2013 16

• 14 patients:(7 M, 7 F)
• Mean age: 8 y+10 m

(3 y+6 m to 12 y+7 m)

• 14 initial surgeries
• 68 distractions

Materials and Methods

36% 29% 14% 14% 7%

Etiology

Idiopathic Neuromuscular Congenital Syndromic NF

• 5 single rod (SR) and 9 dual rod (DR)
• Average of 10 months follow up (6-18).
• An average of 4.9 distractions per patient
• Mean interval between index MCGR and the

first distraction was 66 days

• Mean interval between two subsequent

distractions was 43 days

Results

• Initial and final Cobb correction were significant in each group.
• Curve correction from initial post-op to final was maintained in both SR

and DR groups.

Results (Height)

T1-T12 (mm) T1-S1 (mm) Pre index Post index Final Total Growth* Monthly Growth P value Pre index Post index Final Total Growth* Monthly Growth P value Total 177.9 197.7 208.2 10.5 1.65 <0.05 292.4 322 338 16 2.44 <0.05 Single 177.8 196.4 204 7.6 1.09 <0.05 295 322 331 9 1.27 <0.05 Dual 178 198.4 210.5 12.1 1.97 <0.05 290.6 322 342.2 20.2 3.09 <0.05

P > 0.05 P < 0.05

11/8/2013 17

1.27 mm 3.09 mm 2 mm 1.2 mm 1.22 mm Mean Monthly T1-S1 Height Change (mm/mo) MCGR Single Rod MCGR Dual Rod Dimeglio 0-5 years Dimeglio 5-10 years Original GR (Akbarnia) N=9 N=5 N=23

Results - Mean Monthly T1-S1 Height Change

P<0.05

Case one: 5.5 y/o Female (NM)

T1-T12: 176 mm T1-S1: 251 mm T1-T12: 181 mm T1-S1: 261 mm

45° 21°

Pre Index Post Index ∆T1-T12: 5 mm ∆T1-S1:10 mm

Case one: A 5.5 y/o NM female

Post Index Latest Follow up

21° 9°

T1-T12: 181 mm T1-S1: 261 mm T1-T12: 193 mm T1-S1: 292 mm

∆T1-T12: 11 mm ∆T1-S1: 31 mm

Comparison Data

Pre-operative Most recent Result GSSG Data (average follow up 28 months) Cobb Angle (°) 77.6 ± 16.7 41.3 ± 16.6 47% deformity correction Thoracic Spine Height (mm) 165.6 ± 22.1 203.5 ± 27.5 23% Increased thoracic spine height MAGEC Data (average follow up 7.6 months) Cobb Angle (°) 58.8 ± 12.3 31.4 ± 9.3 47% deformity correction Thoracic Spine Height (mm) 186 ± 28 212 ± 28 14% Increased thoracic spine height

11/8/2013 18

MCGR

Cheung, Cheung, Samartzis, Mak, Wong, Cheung, Akbarnia, Luk (Lancet April 19,2012)

• Five patients , 2 with over 24 months follow

up

• Monthly distractions
• Scoliosis from 67 to 29 at 2 years
• 1.9 mm increase per distraction
• No Anesthesia, No pain
• No complications

Scoliosis Spinal Length

MCGR (Case 1)

11/8/2013 19

MCGR (Case 1)

MCGR (Case 2)

Pre Op AP Post Op AP

MCGR- Case 2

12.3 mm 14.5 mm

Post Distraction June 2010

Courtesy of Ken Cheung, MD, University of Hong Kong, HK

• B. A. Akbarnia, K. Cheung, G. Demirkiran, H. Elsebaie
• J. Emans, C. Johnston, G. Mundis, H. Noordeen, J. Pawelek
• M. Shaw, D. Skaggs, P. Sponseller, G. Thompson, M. Yazici,

Growing Spine Study Group

Traditional Growing Rods Versus Magnetically Controlled Growing Rods in Early Onset Scoliosis: A Case-Matched Two Year Study

48th Annual Meeting of Scoliosis Research Society September 18-21, 2013 – Lyon, France

11/8/2013 20

2012-13

• Early clinical results of MCGR:
• Safe and effective
• Significant reduction in the number of surgical procedures

INTRODUCTION

• The purpose of this study was to perform a

case-matched comparison of MCGR and TGR patients with 2 years of follow-up

INTRODUCTION

MCGR TGR

NOT FDA APPROVED FOR USE IN U.S.

• Retrospective review of MCGR patients who met the

following criteria:

• < 10 years old
• Major curve >30º
• No previous spine surgery
• > 2-year follow-up
• 17 MCGR patients met the inclusion criteria
• 12 of 17 patients had complete data available for

analysis

METHODS

• Each MCGR patient was matched to a TGR patient by:
• Etiology
• Gender
• Single vs. dual rods
• Pre-op age (+/-10 months)
• Pre-op major curve (+/- 20º)
• Etiologies were classified per C-EOS (Vitale):
• Idiopathic
• Congenital/Structural
• Neuromuscular
• Syndromic
• One male MCGR patient was matched to a female TGR

patient since a male-male match could not be found

METHODS

11/8/2013 21

Spinal growth calculation: “Annual T1-S1 Growth”

METHODS

Δ in T1-S1 from post index to latest F/U Length of follow-up

Annual T1-S1 Growth

(mm/year)

=

• MCGR patients:
• Mean age = 6.8 years
• Mean follow-up = 2.5 years
• Follow-up was greater for TGR patients by 1.6 years
• Distribution of etiologies:
• 4 Neuromuscular
• 4 Syndromic
• 3 Idiopathic
• 1 Congenital

RESULTS

Pre-op (mean) Post-op (mean) >2 Yr Post-op (mean) Overall Change

Major Curve

MCGR 59° 32° 38° TGR 60° 31° 41°

T1-S1 Spinal Length

MCGR 270 mm 295 mm 307 mm TGR 264 mm 311 mm 347 mm

RESULTS

35% 32% 38 mm 77 mm p=0.01

RESULTS

• Overall curve correction

– Similar between groups throughout treatment (p>0.1)

• Overall increase in T1-S1

– Greater in TGR compared to MCGR (p=0.01) – Possibly due to additional follow up of TGR patients (1.6 years)

• Annual T1-S1 growth

– 7 mm/year for MCGR – 11 mm/year for TGR patients – This difference did not reach statistical significance due to sample size (minimum 10 mm/year to show significance)

11/8/2013 22

Total Open Surgeries Total Lengthenings

MCGR 16 137

(non-invasive)

TGR 78 49

RESULTS (Procedures) RESULTS (Procedures)

Implant Complications Wound Complications Medical Complications Number of Revisions

MCGR 10 1 3

4

TGR 15 3 5

23

• MCGR revisions included: anchor pull out, prominent implants and

collapse of device (all cases were generation 1 devices)

• TGR revisions included: anchor pull out, rod breakage, prominent

implants, planned surgery to exchange connector

Compassionate Use in U.S.

8+11 year old boy with Idiopathic EOS

top right left

Compassionate Use in U.S.

8+11 year old boy with Idiopathic EOS

11/8/2013 23

top right left

Compassionate Use in U.S.

8+11 year old boy with Idiopathic EOS

• Major curve correction was similar between MCGR and

TGR patients throughout treatment

• Overall gain in T1-S1 was greater in TGR compared to

MCGR, however, TGR had longer follow-up

• MCGR patients had 62 fewer surgical procedures than

TGR patients and more non-invasive lengthenings

• Need to build consensus and develop practice

guidelines for non-invasive lengthenings to reduce surgeon variability and improve reproducibility

Summary MCGR

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