Thoracic Lumbar Sacral Orthosis or TLSO is a device that is used for stabilizing or supporting the thoracic, lumbar and sacral area. That covers the area between collar bone and pelvis.

Boston Brace - An Example of TLSO Brace
Boston brace shown in above image is an example of TLSO brace.
Thoracic Lumbar Sacral Orthosis are used in spinal trauma and scoliosis correction.
Image Credit: http://www.plattners.com/tlso.shtml
[...] is required every 6 months to lengthen the construct. A TLSO is needed for at least the first 6 months to protect the [...]