Wednesday, June 6, 2018

Vertebral Body Stapling (VBS)      Part 2

1.  What is the success rate for VBS?  Two centers have reported their outcomes of VBS in patients (Washington University in St. Louis, and the Philadelphia Shriner’s).  Overall success rates for lumbar and thoracic curves are around 70%, which means the curve improved, did not change or changed less than 6 degrees.

2.  What is the success rate of bracing?  The highest level of evidence on bracing for idiopathic scoliosis is from the BRIAST study, which was a prospective study of scoliosis patients who wore a scoliosis brace and those who did not.  48% of non-braced patients did not have progression of their scoliosis and 72% of braced patients did not progress.

3.  So to conclude: the success rates for VBS and bracing appear to be equivalent.

4.  Why would a VBS be offered or performed if the results are similar to bracing?  Bracing is not an easy treatment for anyone.  VBS provides an option for those patients who cannot or will not wear a brace to control their scoliosis.  It is important to note VBS is not better than bracing, it is just a different treatment option.

5. Do the staples have to be removed in the future?  The answer is no.  The staples do not have to be removed.  The body will cover over the staple with scar tissue and the staple will gradually loosen in the vertebral body.  Due to the tines of the staple curving in the staples will not back out.

6.  What happens if the VBS does not control the scoliosis and a posterior spinal fusion is needed? Do the staples have to be removed at that time?  Again, no.  Since the staples are placed in the front of the spine they will not interfere with the instrumentation placed in the posterior (back) part of the spine.  Also the staples do not interfere with the ability to correct the scoliosis at the time of fusion.

7.  Who is a candidate for Vertebral Body Stapling?
     a.  Skeletally immature: since scoliosis mainly progresses due to growth, the use of VBS only is indicated during the growth.  There is no benefit of VBS in skeletally mature individuals

     b.   Scoliosis who Cobb measure is:
                                                    i.     </= 35 degrees in the thoracic spine
                                                   ii.     </= 40 degrees in the lumbar spine

     c.  Patients who cannot or will not wear a brace to halt the progression of scoliosis.
     d.  Diagnosis of idiopathic scoliosis or patients who have idiopathic-like scoliosis    

Who is not a candidate for VBS?
a.      Skeletally mature patients: Risser >/=3
b.      Diagnoses with poor bone quality, increased muscular tone, neurogenic scoliosis (patients with Chiari or syrinx), etc…
c.      Cobb measures >35 in the thoracic spine and >40 in the lumbar spine.
d.      Increased kyphosis of the thoracic spine >40 degrees (since the staples induce kyphosis)
e.      Those patients whose spine is excessively malrotated due to the scoliosis.  VBS will not significantly change this for the better.