hip/knee pain

to start this off i will give a brief background of my joint issues. about a year and a half ago i fractured my femoral head as well as my pelvis while wakeboarding (i am a 21 year old male... i know, it's almost unheard of for someone at my age to break a hip). long story short, i never had surgery because the orthopedic surgeon i saw recommended it healing on its own. well after about 5 months or so my hip was fully healed and i was back to normal again. the xrays showed absolutely no issues and my hip looked/felt perfect according to my surgeon. however, 6 months or so after my hip was "fully healed" i began to notice more pain again. i started waking up with a very sore hip in the mornings and the weirder thing is my knee started to hurt a lot too. i would feel a clicking feeling in my hip each time a took a step and there was a click in my knee as well when i would turn it to the right with my foot planted on the ground and when i would fully extend it and bend it. the pain in both my knee and hip would be significantly worse in the morning after waking up, after sitting down for long periods of time, etc. long story short again, i received a cortisone injection into my hip joint and that worked wonders. all of the pain in my hip and knee was completely gone a couple days after that cortisone shot. two month have past since that cortisone injection and now my knee pain is back. i noticed the knee pain as i have been playing a lot of golf lately. after walking 18 holes i felt a stiffness in my knee and pain on the sides/back/behind my knee. my hip pain is still nonexistent which is why i think its weird that my knee pain is back. any ideas what this knee pain can be? i know it is related to my hip fracture from last year but not sure what it could be... any thoughts?