Orthoroentgenogram is a radiographic study used to evaluate anatomic leg length and calculate leg-length discrepancies. This study utilises a long ruler placed on the film, and three radiographs including bilateral hips, knees and ankles.
Similar studies used to evaluate true leg length include:
- teleoroentgenogram: performed as a single-exposure weight-bearing study
- scanogram: low-radiation technique similar to an orthoroentgenogram utilizing three exposures
- computed tomography (CT): possibly the most accurate technique, removing possible measurement error from limbs not being parallel to a ruler or in the plane of imaging