Vertebral Body Tethering (VBT)
In 2014
A fusionless treatment option for
scoliosis in the growing spine
UPDATED
March 2014
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
– Early adolescent cases show scoliotic correction
*Dynesys system by Zimmer spine
“Ideal” candidate
• Idiopathic scoliosis (adolescent or juvenile) or
Idiopathic “like” (i.e. post syrinx decompression)
• >10yrs old with remaining spine growth
( done TOO young increases risk of overcorrecting the
curve)
• Thoracic, thoracolumbar or lumbar curves
30° to 60°
Tethering advantages
•
•
•
•
FUSIONLESS
Allows the spine to grow
Allows the spine to move and bend
Most are one time surgery ( may need an
adjustment of tether if overcorrection seen)
• “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
Before surgery
35°
35°
3 years later
Case #3 Aug 2011 14 yo male
Before surgery
2 years later
1st erect
38°
25°
6°
Case #6 Oct 2011 13 yo female
Before surgery
44°
2 years later
6°
36°
6°
Case #11 Feb 2012 12 yo female
Before surgery
50°
18 months later
3°
Case #65 Nov 2013 12 yo female
Before surgery
6 weeks later
Unknowns
•
•
•
•
•
New use of an existing technology
No long term follow-up
Potential for overcorrection (curve opposite way)
Refined criteria for “ideal” candidate
Quicker return to all activities (currently 6 weeks)
For More Information
If you have questions about tethering
(VBT), please feel free to contact
Janet Cerrone, PA-C
janetcerrone@comcast.net
jcerrone@spineandscoliosis.com