Which came first–the chicken or the egg? Thin bones, or adolescent idiopathic scoliosis (AIS)? According to this study, the answer to the last question seems to be thin bones.
AIS is an abnormal side-to-side curving of the spine that occurs in adolescence. “Idiopathic” means that the cause of the problem is not understood. This study looked closely at the bones of youngsters with AIS to try to understand the condition’s cause. The 24 girls and four boys in this study were between the ages of 11 and 20. Researchers used two different methods to study the bones. Bone density was measured with a scan that uses low-radiation X-rays. Bone samples from an earlier back surgery were also studied using a high-powered electronic microscope.
Although bones seem hard and dull, they are actually very much alive. Bones are in a constant state of change. Osteoclasts are cells that break down bone tissue, while osteoblasts rebuild new, healthy bone. In this study, the microscopic look at AIS bone showed an imbalance in the way bone was being broken down and built up, resulting in abnormal bone growth.
The bone density scan confirmed this as a thinning of the bone, a condition called osteopenia. The bones of all 28 children showed both the imbalance and osteopenia. This is pretty typical of girls with AIS, as they show less bone and lower body height for their ages.
The authors believe that bone thinning was likely one of several factors that led to AIS. Heredity, hormones, and nutrition are also known to contribute to the development of AIS. The authors hope this research contributes to answering the puzzling question about the possible causes of AIS.