A correlation study of global and local descriptors of the scoliotic spinedeformity

An in vivo study investigated 2D and 3D relationships between global and lo cal vertebral and discal descriptors of the scoliotic spine deformity. It w as performed on a cohort of 40 patients representing a wide range of thorac ic curve progression. Global descriptors referred to Cobb angle in PA view as well as corresponding Cobb angle in the plane of maximum deformity and i ts angular orientation. Local descriptors included vertebral axial rotation , wedging angles in the global and local vertebral frontal planes as well a s a 3D maximum wedging angle and its angular orientation. Statistical analy ses indicated that, at the thoracic level, vertebral wedging and axial rota tion increase with curve severity. The 3D maximum wedging tends to shift to wards the left posterolateral vertebral region with curve severity, with si multaneous displacement of the plane of maximum deformity toawrds die coron al plane. These results confirm the importance of 3D measurements in the un derstanding of biomechanics of idiopathic scoliosis.