Kindly discuss with the surgeon who is going to operate.

Grade 3 ACL tear requires a reconstruction surgery using a graft and screws may or may not be used to fix the graft. There's a technique called All-inside technique where screws need not be used. We use just wires to hold the graft, buts more expensive than screws. Screws have been used for a very long time and they have good results.

There are techniques which use metallic screws. But there also are techniques which use bio absorbable screw; and some don't use screws at all, instead use metallic buttons which sit over the top of the bone surface for ACL reconstruction surgery. It all depends on the surgeon preference.

Trust and believe your doctor.

Yes screws are used for fixation Apart from screw many other fixation devices/ material can be used for fixation. Please talk to your doctor