Vertebral Body Tethering (VBT) A new fusionless treatment option for

Vertebral Body Tethering (VBT)
A new fusionless treatment option for
scoliosis in the growing spine
May 2012 (rev)
Shriners Hospitals for Children® - Philadelphia
Spinal Tethering
Old use: FDA approved as a “dynamic stabilizer”
in the posterior lumbar (lower) spine
New use: Physician directed scoliosis treatment
as a dynamic stabilizer in the growing
anterior thoracic (upper) spine
“Growth modulation”- partially restraining one side of the
spine to allow growth on the other side to
reverse the abnormal scoliosis growth pattern
Here is a bone model
of the tether (white
cord) attached to bone
screws in the vertebral
bodies of the spine
(anterior)
front of
the spine
(posterior)
back of
the spine
Components
• Titanium pedicle screws placed on the
convexity (outside) of the vertebrae causing
scoliosis
• Polyethylene-terephthalate (PET)* flexible
tether connects to each screw and when
tightened, compresses the adjacent screws to
help straighten the spine
– Cable safety extensively studied
– Animal and computer simulation models show scoliotic
correction
*Dynesys system by Zimmer spine
“Ideal” candidate
• Idiopathic scoliosis (adolescent or juvenile) or
Idiopathic “like” (i.e. post syrinx decompression)
• >8 yrs old with remaining spine growth
( > 10 yrs old may be preferred to decrease the risk of
overcorrecting the curve)
• Thoracic curve 35° to 55°
• OR curve <35° but does not bend below 20°
• As an alternative to VBS + hybrid rod
Tethering advantages
•
•
•
•
•
•
FUSIONLESS
Allows the spine to grow
One time surgery
No “lengthening” required (no rod)
Can be used with lumbar staples (VBS)
“burns no bridges”, can do a later fusion if
needed
Case #1 Feb 2011
12 yo female
Before surgery
5 days after surgery
During surgery
Tethering 
Staples 
Case #1
1 year post op
Pre op
35°
2°
35°
12°
Case #3 Aug 2011 14 yo male
9 months post op
1st erect
38°
17°
25°
9°
Case #8 Nov 2011 13 yo female
Before surgery
3 months after surgery
Providence TLSO
at night for lumbar curve
44°
10°
30°
18°
Unknowns
• Not currently using for thoracolumbar or lumbar
curves (but hope to in the future)
• New use of an existing technology
• No long-term follow-up
• Only a few cases so far
• Potential for overcorrection (curve opposite way)
• Refined criteria for “ideal” candidate
• Refined post op activity restrictions (temporary)
For More Information
If you have questions about tethering
(VBT), please feel free to call Janet
Cerrone, PA-C at 215 430-4067 or email
jane[email protected]