What Would Be An Output Of Derotational Femoral Osteotomy Procedure?

I am suppose to go in for derotational fermeral osteomoty procedure this July, i am 16 years old and i don't know what to expect, i am keep getting mixed opinions whether to go ahead with the procedure or not. The reason for me getting the operation is due to my knee caps frequently dislocating making me unable to participate it simple day to day things, and also sports etc. Could you tell me abit more about the procedure please before i decide to definately have it done, and i'm abit uncertain at the moment.