Achondroplasia: effectiveness of an orthosis in reducing deformity of the spine.

Deformity of the spine and its complications have long been accepted as characteristics of achondroplasia. We have sought to prevent these with a spinal orthosis. This report includes a description of the orthosis and an analysis of its use in achondroplastic children and adults. Nineteen dwarfs between 11 and 52 months of age were fitted with a light truncal polyform orthosis. The effect on the thoracolumbar (TL) and lumbosacral curves (LS) in the seated and standing child were compared by measurements made from lateral roentgenograms with and without the orthosis. The group mean reduction in TL curve of the seated dwarfs was 23 degrees (range 2 degrees to 73 degrees) and the reduction in the LS curve in the standing position was 15 degrees (range 1 degree to 44 degrees). Seventeen older children aged 4-1/2 to 11-2/3 years were equipped with an aluminum version of the orthosis. Their TL curve sitting was reduced by a mean of 31 degrees (range 6 degrees to 45 degrees) and their LS curve standing was decreased by 16 degrees (range 6 degrees to 30 degrees). Thirty-one achondroplastic children and adults were braced for back pain and/or neurologic deficits. Most were relieved of their symptoms to some degree. These and other data lead us to conclude that this form of treatment reduces deformity and alleviates symptoms.