Cobb Angle
The standard radiographic measurement used to quantify the degree of spinal curvature in scoliosis, measured between perpendicular lines drawn from the end vertebrae of the curve.
Full Definition
The Cobb angle is the internationally accepted metric for measuring spinal curvature on a frontal (posteroanterior) radiograph in scoliosis assessment. It is calculated by drawing lines parallel to the superior endplate of the uppermost tilted vertebra and the inferior endplate of the lowermost tilted vertebra, then measuring the angle between perpendiculars to those lines. In orthotic documentation, Cobb angle values guide bracing decisions and are used to monitor treatment progress. Editors should always present Cobb angle values with the degree symbol (e.g., '32°') and capitalise 'Cobb' as a proper eponym. The term is not hyphenated.
Usage
Usage note: 'Cobb' is a proper eponym and must be capitalised. Values must always include the degree symbol (°). Do not confuse with the Risser sign, which measures skeletal maturity rather than curve magnitude.
In Context
- "At follow-up, the Cobb angle had decreased from 36° to 28°, suggesting a positive response to bracing." — Scoliosis monitoring report
- "'Cobb' must be capitalised throughout; check that no instance has been lowercased by autocorrect." — Proofreading checklist