Vertiflex is a surgical procedure that treats spinal stenosis by expanding the spinal canal. The spinal canal is the space that houses the spinal cord, connecting the vertebrae in the lower back all the way down to the sacrum. In people who suffer from spinal stenosis, the spinal canal becomes narrowed, compressing the spinal cord and causing a variety of unpleasant symptoms, including pain, weakness, numbness, and difficulty walking.