A spinal osteotomy is a surgical procedure used to correct deformities in the spine. Bone is removed from the back of the vertebral arch to correct long, gradual curves of kyphosis like those produced by Scheuermann’s kyphosis or ankylosing spondylitis.
The majority of procedures that treat spinal deformities are types of osteotomy. These include posterior column osteotomy (PCO), pedicle subtraction osteotomy (PSO) and vertebral column resection (VCR).
When is a spinal osteotomy performed?
Proper spinal alignment is important for pain-free functioning of the spine. The slight lordosis (curve inwards) of the neck and lumbar (lower) spine are balanced by a slight kyphosis (curve outwards) of the thoracic (upper) spine. These curves work in harmony to keep the body’s centre of gravity aligned over the pelvis.
A reduction in lordosis in the lower region of the spine (also known as flatback syndrome) or an excess in kyphosis in the upper region of the spine (known as hyperkyphosis) results in spinal misalignment. This is called sagittal imbalance and can cause fatigue, pain and compression of organs such as the heart and lungs.
During a spinal osteotomy, the surgeon removes a wedge-shaped section of bone from the back of the spine. Closing this wedge either adds lordosis or reduces kyphosis. This disc in front of the removed bone must accommodate the new position of the bones, so a spinal osteotomy requires a flexible disc between the target vertebrae.
A PCO usually provides a patient with 10-20 degrees of correction, but this procedure is often performed at multiple spinal levels. Depending on where and how much correction is needed, a series of PCOs can ‘add up’ to the desired correction.