How to perform tayammum for one who has a cast on one of his hands

Q: If I have a cast on one of my hands or on both, or if I have wounds on them that water would harm, how do I perform tayammum? Is the boundary of the face in tayammum the same as in wudu'?

A: Yes, the boundary of the face in tayammum is like that in wudu'. One wipes his face with dust from the top of the forehead to the beard, and from ear to ear. He wipes his hands, the outer and inner parts, from the wrist joint to the tips of the fingers. If there is a cast or wounds on his hands, wiping with dust over the cast and over them, if there are wounds, is sufficient. If one hand is sound and the other has wounds or a cast, he washes the sound one, wipes the wounded one with water, and wipes over the cast, just as if there were a splint made of rags or the like on both or on one of them.
If water harms him, or if water is not available, tayammum is sufficient for him.