What Causes Pain In Ankle And Hip Bone?

i have a problem with my knee..what is wrong? it started in softball when i fell and i was not able to walk for a while. Then i had minor pain for a year or so. About five months ago the pain has progressively gotten worse and is causing ankle and hip to hurt when i walk and play sports. my knee has been buckling and would give out only once in a while. Hip just started hurting with in the last week.