Intraoperative Iso-C C-arm navigation
surgery for spinal and pelvic trauma
Yasuo Ito
K. Koshimune, T. Takigawa, S. Nakahara, T. Morita
Dept. of Orthopaedic Surgery, Kobe Red Cross Hospital
JAPAN
Kobe Red Cross
Hospital
Conflict of Interest
•
I (or a member of my immediate family) have not received anything of value from or stock in a commercial company or institution related directly or indirectly to the subject of this presentation.
Disclosure information
We (or a member of our immediate family) have not
received anything of value from or stock in a commercial
company or institution related directly or indirectly to the
subject of this presentation.
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Hospital
Background
Cervical pedicle screw has been shown to provide
excellent mechanical strength.
Abumi et al
Screw misplacement leads to injury of
the spinal cord, root, and vertebral artery.
Studies recommend navigation-assisted surgery
for cervical pedicle screw fixation in order to
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prevent complications and increase accuracy.
Limitations of conventional
CT-based navigation system
Special markers or anatomic landmarks are needed.
Manual matching (registration) is subject to
potential errors and time-consuming.
Repeated and segmented registration must be
needed for each vertebra.
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Changes in the anatomy cannot be detected intraoperatively.
Iso-C 3D with navigation system
2D projections in DR mode
(50 in 1 minute / 100 in 1-2 minutes)
3D reconstruction
approx. (12 cm)3
3D volume data
256 slices/scan
No manual registration !
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Entire spine is matched to navi. images !
3D images of intraoperative anatomy
can be detected !
Real Time Navigation !!
Objectives
To evaluate prospectively the accuracy,
feasibility, advantages and applications of
intra-operative Iso-C 3D
in cervical spinal surgery
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Hospital
Patients and Methods
290 cases
131:cervical, 126:thoracolumbar, 33:pelvic trauma
Pedicle Screws
1435 screws
cervical : 553 screws, thoracolumbar: 882 screws
Lateral mass screws
86 screws
Odontoid screws
6 screws
Iliac screws
112 screws
10 screws
Kobe Red Cross Iliosacral screws
Hospital
Post-operative evaluation of pedicle screws
(Thin-cut CT, 1.25mm)
Grade 1: screw threads cut into the cortex
Grade 2: screw perforation of the cortex by up to 2 mm
Grade 3: screw perforation of the cortex by more than 2 mm
Grade 2 and Grade 3 regarded as misplacements
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Grade 1
Grade ３
Results – pedicle screw
cervical
Grade 2 ( < 2 mm): 10 screws
Grade 3 ( > 2 mm): 4 screws
thoracolumbar
22 screws
7 screws
Cortical perforation up to 2 mm
43 / 1435 screws ( 3.0 %)
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No deterioration in the initial neurological status
No injured or irritated nerve root
No vascular injury
Clinical workflow
in registration-free 3D navigation surgery
The patient is positioned on a non-metallic carbon table
to maximize image quality and to minimize artifacts.
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Carbon table and Mayfield cramp
A reference arc is placed
on a spinous process
It takes 120 seconds to obtain
and reconstruct the 3D data.
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The image data is transferred directly to the navigation system.
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The screw trajectory is prepared using a cervical awl
by Kotani et al
Case Presentation
Case 1
55 y.o. Male Odontoid fracture
Intraoperative images of Iso-C
Images of the navigated awl
Case Presentation
Case 1
55 y.o. Male Odontoid fracture
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Intraoperative images of Iso-C
Postoperative sagittal image
Case Presentation
Case 2
76 y.o. Female Hangman fracture
Percutaneous awling
Percutaneous insertion of
the osteosythesis screw
Case Presentation
Case 2
76 y.o. Female Hangman fracture
Intraoperative images of Iso-C
Postoperative images
Advantages of Iso-C 3D C-arm
１． Accurate correlation between 3D
images and current patient anatomy
２． Navigational support based on
updated image data
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Educational tool
for mastering surgical technique
Applicable to minimally invasive surgery
Review of cervical or thoracic
pedicle screw literature
Thoracic
Weinstein et al (1988)
Vaccaro et al (1995)
Abitol et al (1996)
Liljenqvist et al (1997)
Xu et al (1998)
Cinotti et al (1999)
Cervical
Abumi et al (2000)
With Navi. ( Thoracic )
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Youkilis et al (2001)
Hospital
With Navi. and Iso-C (trauma)
Our cases
“Miss” Percentage
32 screws
90
48
120
95
126
21%
41%
50%
25%
54.7%
24%
669
6.7%
224
8.5%
1435
3.0 %
Disadvantages and Pitfalls
(Iso-C3D , navigation surgery)
• Image quality
• Cost
Navigation system, Iso-C3D, Carbon bed,
Mayfield headholder
• Operating staff for navigation surgery
• Mechanical or Human error
Interference between reference arc and probe
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Blurring of navigation images
Hospital
Eye movement between the operative
field and monitor
Conclusions
Registration-free navigation surgery with the Iso-C
was successfully used in 100 consecutive initial
patients with cervical lesions
Intraoperative 3D navigation showed significant
advance in the safety and accuracy of operative
procedures.
This system will assist in performing truly minimally
invasive surgeries.
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Hospital