C1-C2 Fusion Techniques Current Concepts Alexander R Vaccaro, MD, - - PowerPoint PPT Presentation

▶
c1 c2 fusion techniques current concepts
SMART_READER_LITE
LIVE PREVIEW

C1-C2 Fusion Techniques Current Concepts Alexander R Vaccaro, MD, - - PowerPoint PPT Presentation

May 02, 2023 178 likes •663 views

C1-C2 Fusion Techniques Current Concepts Alexander R Vaccaro, MD, PhD, MBA Professor, Chairman Dept. Orthopaedic Surgery Thomas Jefferson University Rothman Institute Disclosure Grant Support/ Royalties/Stock options/Consulting/Editorial

slide-1
SLIDE 1

C1-C2 Fusion Techniques Current Concepts

Alexander R Vaccaro, MD, PhD, MBA

Professor, Chairman

  • Dept. Orthopaedic Surgery

Thomas Jefferson University Rothman Institute

slide-2
SLIDE 2

Disclosure

  • Grant Support/ Royalties/Stock
  • ptions/Consulting/Editorial Board:

Depuy, Nuvasive, Medronics, Stryker, Globus, Stout Medical, Aesculap, Alphatec, Paradigm Spine, Replication Medica, Spinology, Bonovo Spine, Dimension Orthotics, Gamma Spine, IT, SBI, RI related holdings, Gerson Lehrman, Guidepoint Global, Medacorp, ISD, ASIP, PST, ICOM, Orthobullets, Vertiflex, Vexim, SpineWave, Atlas Spine, Avaz Surgical, AO Spine, Spine, ESJ, JNS, PSI

  • Board Member: CSRS
  • Editor in Chief : Clinical Spine Surgery
  • President: Rothman Institute
slide-3
SLIDE 3

INTRODUCTION

  • Multiple Options
  • Wiring
  • Hooks
  • Magerl Transarticular Screws
  • Harms C1 lateral mass -C2 pars/pedicle

screw Technique

  • Translaminar

E

slide-4
SLIDE 4

Posterior Gallie Wiring

slide-5
SLIDE 5

Posterior Brooks Fusion

slide-6
SLIDE 6

Posterior C2/C1 Magerl Transarticular Screws

slide-7
SLIDE 7

C1-2 Transarticular Screws

  • Vertebral artery perforation: 4%
  • Neurologic deficit: 0.2%
  • Wright, J Neurosurg, 1998
  • Pre-operative CT with

reconstructions

  • 18-23% may not be candidates
  • Sonntag,J Neurosurg, 1996
slide-8
SLIDE 8

C1-2 Transarticular Screws

  • Starting point

– 3mm cranial and 2mm lateral to the inferior edge of the inferior articular C2 process

  • Average screw length 40-45 mm
  • If vertebral artery injury do not attempt
  • ther side
slide-9
SLIDE 9

Very steep angle needed:

T1

slide-10
SLIDE 10

Hooks

slide-11
SLIDE 11

Anterior C2/C1 Screw Fixation

slide-12
SLIDE 12

Anterior C2/C1 Screw Fixation

slide-13
SLIDE 13

Anterior C1/C2 Screw Fixation

slide-14
SLIDE 14

C1/C2 Lateral Approach

slide-15
SLIDE 15

C1/C2 Lateral Approach

slide-16
SLIDE 16

Anterior Transoral Plating

slide-17
SLIDE 17

C1-2 Anterior Plating

slide-18
SLIDE 18

C1 LATERAL MASS/C2 PEDICLE/PARS SCREW

Harms Technique:

  • 1st described by Atul Goel with plates in

1994

  • Popularized by Harms with Polyaxial

screws & rods in 2001

Harms, Spine, 2001 Goel, Acta Neurochir (Wien), 1994

slide-19
SLIDE 19

C1 Lateral Mass Screw

Two Options: 1.Thru Pedicle Analog 2.Below Confluence of post Ring

slide-20
SLIDE 20

C1 Lateral Mass Screw

Two Options: 1.Thru Pedicle Analog 2.Below Confluence

  • f post Ring
slide-21
SLIDE 21

For 3.5 mm screw: ARCH 14% feasible NOTCH 85% feasible

709 Specimens Measured

15% VA at risk even with Notch technique!!!

slide-22
SLIDE 22

Below Confluence

  • Palpate Midpoint of

LM with Penfield 4

  • Burr 2mm drill

seating

Hong X, et al. Spine. 2004 Liu G, et al. Spine. 2008

slide-23
SLIDE 23
  • Easy to violate Oc-C1

Joint

  • Avoid > 25o Medialization
  • Aim for cephalad 20-40% of C1

Ant Tubercle

Yeom, Spine J, 2009

Cranio-Caudal Angulation

slide-24
SLIDE 24

Hong X, et al. Spine. 2004 Wang M, Samudrala S. Neurosurgery. 2004 Murakami S, et al. Spine. 2008 Christensen D, et al. Spine. 2007

Medial Angulation

  • Initially, straight ahead, now 10-15o medial

– To avoid ICA – Avoid > 25o Medialization

slide-25
SLIDE 25

Bicortical C1 LM screws provide significantly better pullout strength

Eck, JSDT, 2007

slide-26
SLIDE 26

C1 ring- Internal carotid artery relationship

Currier, Spine, 2008

  • Highly variable
  • location. Near the

lateral edge of LM. Avg shortest distance from C1 anterior arch ~ 3mm.

  • Vulnerable with

bicortical screws

slide-27
SLIDE 27

Hypoglossal nerve also at risk

Ebraheim,Surg Neurol, 2000 Located on the lateral border of lateral mass Just medial to the C1 transverse process C

slide-28
SLIDE 28

Postoperative occipital neuralgia with and without C2 nerve root transection during atlantoaxial screw fixation

Yeom, Spine J, 2013

PROSPECTIVE STUDY N= 24 consecutive Transections N= 41 consecutive Preservations

~20-30% worse neuralgia at every timepoint up to 2 yrs postop (significant at each timepoint except 1 month)

slide-29
SLIDE 29

C2 root transection-necessary for joint distraction technique (Goel):

Goel, Neurol India, 2008

17 yo congenital anomalies and basilar invagination

slide-30
SLIDE 30

C2 Anatomy

slide-31
SLIDE 31

C2 Posterior Screw Fixation Techniques

  • C2 Pedicle Screw
  • C2 Isthmus Screw
  • C2 Angled Isthmus

Screw

slide-32
SLIDE 32

Posterior C2 screw Fixation Techniques

  • C2 pars
  • C2 pedicle
slide-33
SLIDE 33

Paramore, J Neurosurg, 1996

  • Ectasia: 20% at least 1 ectatic artery
  • Prevents safe placement past isthmus
  • RA: high-riding VA more likely

Vertebal Artery Anomalies

slide-34
SLIDE 34
  • Reformatted CT:
  • Adequate width
  • f C2 pars

interarticularis and pedicle

Preoperative Assessment

slide-35
SLIDE 35

Evaluate the sagittal CT recon

To determine feasibility of C2 pars screws:

slide-36
SLIDE 36

Scrutinize axial CT scans

To determine feasibility of C2 pedicle screws:

slide-37
SLIDE 37

P ARS PEDICLE

slide-38
SLIDE 38

C2 Pedicle Screw

  • Start: lat on C2 lateral mass
  • Palpate Isthmus
  • 15-45o Medial

– 28-35 mm screw – Longer when entering C2 body

  • 30o Cephalad
slide-39
SLIDE 39

Yoshida M, et al. Spine. 2006 Elliott RE, et al. J Neurosurg Spine. 2012 Abumi, et al. Spine. 1997

C2 Pars Screw

  • Pars screw less likely to injure VA
  • 0% vs. 0.3% with pedicle screws
slide-40
SLIDE 40

C2 Translaminar screws:

Unilateral or bilateral Technically very easy to do No fluoro needed

slide-41
SLIDE 41
  • Plan for 2 crossing screws

– One very high, other low

  • Modifications

– 2 ipsilateral, parallel screws

Translaminar Screw Technique

Jea, Spine J, 2008 Sciubba, J Neurosurg Spine, 2008 Dorward, Neurosurgery., 2011

slide-42
SLIDE 42

Biomechanics of C2 Translaminar screws:

Claybrooks,TSJ, 2007

C2 Pedicle C2 Translaminar

N=8 INSTRON testing

F/E = = Transl = = Bend + Rotation +

slide-43
SLIDE 43

C2 Translaminar screws:

Best indications:

Insufficient Pedicle or Pars due to medial VA aberrancy Salvage of failed Pedicle or Pars screws

slide-44
SLIDE 44

C2 Translaminar screws:

Downsides:

Harder to hook up to longitudinal rod fixation (usually need offest connectors) May not have enough room for two screws in one lamina

slide-45
SLIDE 45

Summary: Types of C2 fixation

Pars Pedicle Translaminar

Biomechanics ++ ++ + VA risk higher lower none SCI risk low low low but higher Anatomically feasible most pts most pts almost always Ease of rod hookup easy harder hardest

slide-46
SLIDE 46

Crosslink

slide-47
SLIDE 47

Thank You