Version is the measure of the rotation of a joint socket along its transverse axis, and is the opposite of torsion, which measures the rotation of a long bone along its longitudinal axis. Abnormal angulation of a joint socket results in early mechanical dysfunction, instability, impingement, and accelerated degenerative changes.

Retroversion indicates an abnormal posterior angulation of a joint socket, and is commonly encountered in the hip and shoulder.

See also