What Causes Severe Leg Pain?

I cannot abduct or adduct my left leg without excruciating pain and having it get stuck and then snap. I have to be very careful everytime from sitting. I can walk with a limp but the hip flexor area and crotch area deep inside where psoas is soar and tight. Hurts to lay down flat. no way can I laydown and abduct. have to pull knee up to roll over. I had injury on christmas where my knees separated when I fell. Had femoral neck repair , 2 screws. the surgury feels fine but this tendon/muscle whatever is worse than prior to surgery. My ortho cant figure it out.