Corkscrew Claw.

Corkscrew claw (CSC) is a conformational abnormality of the digit and affecting mostly but not exclusively the claws of the back leg, first reported during the 1950s in Dutch black and white cattle. The affected claws are longer and narrower than the claw and have an inward and upward spiral rotation of the toe. Similarly, the bearing surface of the wall is displaced inward. The animal starts to bear weight on the abaxial wall surface, particularly the caudal segment, and the sole may become completely non-weight bearing. The axial wall is displaced dorsomedially and a fold develops in the wall.