A man got hit in the back of the head causing some wood splinter to get into his head. The Doctor seemed to cut the top of his head open, take it out and put some metal round thing over the wound. What is that all about?
You might be interested in u/Celebreth’s fantastic series of answers about Roman treatment of wounds here, including a followup about the medical procedure you’re asking about, which is called “trepanning.”
Edit: Also, for more details on trepanning check out these answers from u/BedsideRounds and u/Iatros here and here respectively.