I hit my knee 3 weeks ago while doing the polar plunge and since then I have had swelling and pain over the knee cap itself. I did have it xrayed and there is no sign of fracture. I finally went to the Ortho dr and he said that it is prepatellar bursitis (caused by the blow to the knee) as well as a possible bone bruise. I have been trying to get back to exercise and the inflammation isn't letting up. I started with swimming and then water running as I was in training for a 1/2 marathon then I moved to the treadmill and found that my knee wasn't ready for the impact. the dr said that I am ok to run and to exercise as normal but i am looking for other opinions of actual runners that have went through something similar with bursitis. I am not able to have a cortisone injection because the location of the bursitis is very prone to infection. Have you had a knee flare up and if so how soon did you get back at it?
Does the doctor know you are training for a Half, and how much running that requires? Exercise "as usual" might have been advice for normal people, not us crazy runners. I'm not sure you have a lot to gain by spending that much time running through the pain. You certainly have a lot to lose, because you will most likely change the way you run, consciously or unconsciously, to minimize that pain. Even if the run itself is no longer detrimental to your healing, those adaptations could cause new problems of their own.
You've been injured, with continuing evidence of physical trauma. I've had to skip events before due to injury, and I have no regrets about it. There are plenty more races to come, and if I were you, I'd skip this one and continue with whatever training or competition feels tolerable. Don't let your schedule take precedence over your health. It's not worth it. Good luck with your recovery!