BTW, if you’re not familiar with the story, the gist of it is that there was this young man named Leonardo who cut his leg off after he had kicked his mother in anger - after all, that’s what the gospel says, right? (cf. Matthew 5:29-30) This young man went to the confessional and confessed that he had kicked his mother; St. Anthony then upbraided him: “The foot of one who kicks his mother or father deserves to be cut off.” The boy however was upset and seemed to take his rebuke a bit too literally and really chopped his leg off.

The horrified mother however begged St. Anthony to restore the boy’s leg. He took the amputated leg, prayed, and the leg was miraculously reattached.
Perhaps the reason why he was skeptical of the above story is because it’s highly similar to another story which is told about St. Peter of Verona, aka St. Peter Martyr (incidentally, Peter and Anthony are the two fastest canonized saints - just less than a year after their deaths): miraculously healing a young man who, remorseful for having kicked his mother, had chopped off his leg. St. Peter is also involved in another leg healing for the record after his death: only this time, he had appeared to a boy and healed his foot which was about to be amputated the next day.
There was also this medieval legend about a third century deacon named Justinian who was dying of gangrene. It so happened that Pope Felix I (reigned 293-294) had constructed a church in honor of the recently-martyred doctor-saints Cosmas and Damian (died ca. 287). Justinian went to the church and asked for their intercession. One night the two saints appeared before the deacon and discussed with each other how to deal with his leg. They finally arrived at a solution: they decided to take the leg of a recently-deceased ‘Ethiopian’ (a Moor) who had just been buried nearby and use it to replace Justinian’s gangrenous leg. When the deacon woke up, he found his leg completely replaced by the new one and completely healthy. When the Moor’s tomb was opened they found one of his legs missing and the sick man’s old leg in the tomb beside them.