Hemivertebra is a congenital (present at birth) deformity. It means that only half of the vertebra (spinal bone) has formed. The other side is missing, which causes the bones above and below the half-vertebra to tip or collapse to one side. The result is a curved spine.
If this problem is diagnosed early (before age six), the deformed half of a vertebra can be removed surgically. Studies show that these children have excellent results with this procedure.
But this approach doesn’t work when the problem isn’t recognized until the child is older or as in your case, other methods of treatment are tried first without success. Treatment is especially challenging if the spine has matured (bone growth is complete or nearly complete).
Your surgeon may be referring to a procedure called a subtraction osteotomy. Instead of cutting out the deformed vertebra, a wedge- or pie-shaped piece is removed. The surgeon then guides either side of the remaining bone fragments to move together — enough to close the gap formed by removing the piece of bone.
The end result is correction of the curve. It’s called a subtraction osteotomy because only a portion of the deformed vertebra is removed or taken away (subtracted).
Doing the procedure this way saves the bone and the discs between the deformed hemivertebra and the spinal bones above and below it. Having those discs in place helps stabilize the spine.
The procedure has the advantage of being simpler than removing the deformed hemivertebra with less time in the operating room. The risk of bleeding is less and there are fewer other complications compared with removing the entire half-vertebral body.