A Southwick angle is a radiographic angle used to measure the severity of a slipped capital femoral epiphysis (SCFE) on a radiograph.
It was named after Wayne O. Southwick, a famous surgeon.
The angle is measured on a frog lateral view of the bilateral hips.
It is measured by drawing a line perpendicular to a line connecting two points at the posterior and anterior tips of the epiphysis at the physis.
12° is the normal control value and can be used in the case of bilateral involvement.