Got kneed in upper quad while playing basketball. Hurts bad at muscle level. I'm limping. Is this a Charlie horse? Am I now at risk for DVT??

Charlie horse! theoretically you are at a 'slightly' increased risk for DVT from the trauma but as long as you keep moving, you should be good. YOu probably have a pretty good bruise in that muscle. Try ibuprofen for pain and Heat and stretching (if it has been a few days since the injury) if not improving or worse see your MD.