Vertebral Body Tethering (VBT)In 2014

A fusionless treatment option for scoliosis in the growing spine

UPDATEDMarch 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

During surgery

Case #1 Feb 2011 12 yo female

Tethering

Staples

Before surgery5 days after surgery

Case #1

35°

35°

3 years laterBefore surgery

Case #3 Aug 2011 14 yo male

2 years later

38°

1st erect

25° 6°

Before surgery

Case #6 Oct 2011 13 yo female

Before surgery

44°

36°

6°

6°

2 years later

Case #11 Feb 2012 12 yo female

Before surgery 18 months later

50°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 contactJanet Cerrone, PA-C janetcerrone@comcast.netjcerrone@spineandscoliosis.com