Amputation of Retained Hind leg.
When it is not possible, for lack of room, to extend the hindlimb that is retained at the hock, the wire may be placed around the limb just distal to the tarsal joint. The distal portion of the leg can then be severed. It is important to make the cut distal to the tarsus, to leave a knob, to be able to keep the chain from slipping off during subsequent traction.
Bierschwal CJ and deBois CHW (1975)