Hairline fracture, soft tissue injury or something else in knee?

I dance and in my solo's I have to fall on my knee. My lower knee (Almost my shin) has been swollen for months and its black and blue. The weird thing is that it's been swollen so long. I guess it's because I "injure" it frequently. Does anyone know if it's possible to tell if it's a hairline or soft tissue injury besides an xray?