Cobb angle
Encyclopedia
The Cobb angle, named after the American orthopedic surgeon John Robert Cobb (*1903-1967), was originally used to measure coronal plane deformity on antero-posterior plain radiographs in the classification of scoliosis
. It has subsequently been adapted to classify sagittal plane deformity, especially in the setting of traumatic thoracolumbar spine fractures.
In the setting of spine trauma and assessing sagittal plane deformity, the Cobb angle is defined as the angle formed between a line drawn parallel to the superior endplate of one vertebra above the fracture and a line drawn parallel to the inferior endplate of the vertebra one level below the fracture.
The Cobb angle is the preferred method of measuring post-traumatic kyphosis
in a recent meta-analysis
of traumatic spine fracture classifications
There is much criticism of the Cobb angle for scoliosis diagnosis and even more criticism of the current surgical treatment of scoliosis. "The “prognostic” or “predictive” value of Cobb angle in curve progression is only slightly better than the odds of flipping a coin and ALL of the Cobb angle prognostic assumptions are based off a single study by Lonstein and Carlson in 1984, which has never been repeated or re-produced to this very day", according to Stitzel.
Additional concerns regarding post diagnosis protocols for scoliosis include dangers of surgical intervention and poor outcomes.
Scoliosis
Scoliosis is a medical condition in which a person's spine is curved from side to side. Although it is a complex three-dimensional deformity, on an X-ray, viewed from the rear, the spine of an individual with scoliosis may look more like an "S" or a "C" than a straight line...
. It has subsequently been adapted to classify sagittal plane deformity, especially in the setting of traumatic thoracolumbar spine fractures.
In the setting of spine trauma and assessing sagittal plane deformity, the Cobb angle is defined as the angle formed between a line drawn parallel to the superior endplate of one vertebra above the fracture and a line drawn parallel to the inferior endplate of the vertebra one level below the fracture.
The Cobb angle is the preferred method of measuring post-traumatic kyphosis
Kyphosis
Kyphosis , also called roundback or Kelso's hunchback, is a condition of over-curvature of the thoracic vertebrae...
in a recent meta-analysis
Meta-analysis
In statistics, a meta-analysis combines the results of several studies that address a set of related research hypotheses. In its simplest form, this is normally by identification of a common measure of effect size, for which a weighted average might be the output of a meta-analyses. Here the...
of traumatic spine fracture classifications
There is much criticism of the Cobb angle for scoliosis diagnosis and even more criticism of the current surgical treatment of scoliosis. "The “prognostic” or “predictive” value of Cobb angle in curve progression is only slightly better than the odds of flipping a coin and ALL of the Cobb angle prognostic assumptions are based off a single study by Lonstein and Carlson in 1984, which has never been repeated or re-produced to this very day", according to Stitzel.
Additional concerns regarding post diagnosis protocols for scoliosis include dangers of surgical intervention and poor outcomes.