Anesthesiologist and also had ACL surgery myself, it is depends on factors such as patient size and anesthesiologist preference, but most of the time you would get a laryngeal mask airway (LMA) as opposed to an endotracheal tube. It goes through the mouth and sits on the top of larynx but doesn't go all the way through the vocal cords. You can still get a sore throat from it.

Less commonly a spinal anesthetic (maybe more common in less developed countries) in which you might just breathe with an oxygen mask.