The position of the sacrum and pelvis below the spine is important to maintain an upright, straight spine. Scoliosis or curvature of the spine may be linked to the position of the sacrum and pelvis. Studies have shown that the shape and position of the pelvis does affect the spine in normal children and adults. This study is an effort to see if there is a connection between the sacrum and pelvis and the development of scoliosis.
One measurement of sacral angle is called the pelvic incidence (PI). The PI is the angle formed by a horizontal line drawn across the base of the sacrum and a vertical line drawn through the femur (thigh bone). The angle is measured using X-rays viewing the sacrum, pelvis, and femur from the side. This is called a sagittal view.
In this study, rehab specialists look to see if the pelvic incidence determines the location of spinal curvature in children with scoliosis. Two types of scoliosis were compared. The first was in the thoracic spine. The second was lower in the area of the thoracolumbar spine.
X-rays taken in both groups and compared to normal children showed no difference in PI between the two types of scoliosis. There was an increased PI for all the children with scoliosis compared to the normal subjects.
The researchers still don’t know if the scoliosis is caused by the change in the pelvic and sacral alignment or the other way around. Pelvic incident does not appear to be the factor determining where the scoliosis occurs. More study is needed to answer this question.
The authors suggest the next study should look at what various pelvic sagittal measures that occur with scoliosis. It may be helpful to look at the pelvic incidence in many children without scoliosis and see if it changes for any who later develop scoliosis.