How do I know if my knuckle is broken?

i got slashed in the hand in lacrosse and it has been getting worse day by day. it started to swell up then it got very bruised and now i can barely move my hand. it is my bottom knuckle of my middle finger so i need opinions. please help
How do I know if my knuckle is broken?
Updates
+1 y
i’ve been icing it so that helps me control the swelling and it is easier to bend my fingers but not very far because it causes pain
How do I know if my knuckle is broken?
Post Opinion