Hemivertebrae are usually wedge shaped vertebrae, in between other vertebrae.  There are three main types of hemivertebrae  -

·         Unsegmented -  this means that the hemivertebra is wedged between two bones without a growth plate.  The upper and lower bones are usually shaped to accommodate the hemivertebra in between.   This is the least common type of hemivertebra.

·         Semi-segmented -  the hemivertebra is fused to either the upper or lower vertebra and only has one growth plate. 

·         Fully segmented - the hemivertebra has a full growth plate on either side and has full growth potential.  This is the most common type of hemivertebra.

The unsegmented and semi-segmented hemivertebrae has less growth potential, and tend to cause less issues and a less severe curve.  Fully segmented hemivertebra can cause larger curves, and sometimes, with a sharp curve, you run the risks of spinal cord compression or other nerve issues.  Any signs of lower nerve issues to the legs, bowel and bladder should be reported to your doctor.

A – complete  unilateral (one sided) failure of formation produces  “hemivertebrae”

B – semi-segmented hemivertebra  fused onto the upper vertebra

C – partial unilateral failure of formation produces “wedge vertebrae”, shown here on either side of a hemivertebra

D – non segmented (also called “incarcerated”) hemivertebra

E – multiple hemivertebrae