So I'm going through the game again trying to get 100% of the trophies (I'll never know how I'll get S rankings on the survival arenas) and I'm playing through chapter 2 currently. In one area, there's a hallway you must go down to kill a few brutes, flip a switch, and come back and kill off some corrupted minions. Killing the minions unlocks the door but there are also 4 spikes around the door that you can impale the minions onto. After multiple tries, I just managed to impale the minions on all 4 spikes but nothing seemed to happen. Did it open a secret room that I missed or were there absolutely no practical reasons for the spikes?

In that particular room, no practical reason for the spikes. The door will open whether or not you impale the enemies on them, and it doesn't trigger anything else special.

Ahhhh, oh well. Thanks for the answer Brick.