In 1977, the most popular of the TLSO (Thoraco Lumbar Sacral Orthosis) systems, the Boston Brace, was developed by Dr. John Hall and Mr. William Miller of Canada at The Boston Children's Hospital, it was the first brace to utilise symmetrical standardised modules eliminating the need for casting.
The Boston Brace is a snug fitting underarm brace made of high density polypropylene with a soft lining and is, therefore, very light weight.
The Boston Brace led to a series of underarm braces that lacked the metal superstructure of the Milwaukee, including the Rosenberger, Wilmington and Miami braces. These braces are widely used today and are less obtrusive in appearance. Patients find these braces more appealing because they can be worn under clothing, and patients can participate in sports and other activities with little difficulty. Underarm braces can be used for most types of scoliotic curves, unless the curve is extremely high on the spine.
The Boston Brace extends from below the breast to the beginning of the pelvic area in front and just below the scapulae to the middle of the buttocks in the back. It is designed to keep the lumbar area of the body in a flexed position by pushing the abdomen in and flattening the posterior lumbar contour. Pads are strategically placed to provide pressure to the curve, and areas of "relief" or "voids" are provided opposite the areas of pressure.
Orthotic treatment in adolescent idiopathic scoliosis is used to manage or even reduce spinal curvatures while waiting for skeletal maturation. By applying specific pressure points on the torso, the brace treatment attempts to modify mechanically the scoliotic spine shape and control progression of the spinal curvatures. Many clinical studies used standard radiographs to assess the brace effectiveness. But three-dimensional analysis of brace effect on scoliotic curvatures showed some limitations such as back flattening and limited axial derotation.
It is the brace of choice for most types of curves but it is not usually used for high thoracic and double curves. It is often prescribed for early progressive curves that are less than about 40º. It can be used for children with paralytic scoliosis and some young children. A Boston Brace is, however, difficult to fit to very small children because of their round body shape without hip projections. If the curve is very high it may be necessary to have a superstructure. Because of its close fit children can only tolerate wearing it for a few hours a day at first, but within a few weeks they should be able to wear it for the 20-22 hours a day and lead quite a normal life. Soft seam-free cotton vests should be worn under this brace too, and should be changed frequently to avoid skin irritations. There are special exercises to do when wearing this brace: they will help keep the spine flexible and therefore help the brace to work efficiently.