Cobb angle

It is defined as the greatest angle at a particular region of the vertebral column, when measured from the superior endplate of a superior vertebra to the inferior endplate of an inferior vertebra. However, the endplates are generally parallel for each vertebra, so not all sources include usage of a superior versus inferior endplate in the definition. Unless otherwise specified it is generally presumed to refer to angles in the coronal plane, such as projectional radiography in posteroanterior view. In contrast, a sagittal Cobb angle is one measured in the sagittal plane such as on lateral radiographs. Cobb angles are preferably measured while standing, since lying down decreases Cobb angles by around 7–10°. ==Uses==

It is a common measurement of scoliosis. The Cobb angle is also the preferred method of measuring post-traumatic kyphosis in a recent meta-analysis of traumatic spine fracture classifications. ==Severity==

Those with Cobb angle of more than 60° usually have respiratory complications. ==History==

The Cobb angle is named after the American orthopedic surgeon John Robert Cobb (1903–1967). It was originally used to measure coronal plane deformity on radiographs with antero-posterior projection for the classification of scoliosis. It has subsequently been adapted to classify sagittal plane deformity, especially in the setting of traumatic thoracolumbar spine fractures. ==References==