Is it obligatory to wash or wipe over a prosthetic foot if a sock is worn over it?

If the leg is amputated from the shin, and the ankle and foot are gone, replaced by an artificial foot, then there is no obligation to wash it, nor to wipe over the artificial foot. However, if a part of the leg from the ankle downwards remains, then this remaining part must be washed. And one may wipe over the khuff (leather sock) or regular sock worn over it, in line with the remaining part.