A 12 year old female is tackled in a soccer game. She arrives with her knee in flexion and her patella laterally displaced. She is neurovascularly intact. Skin is intact. She cannot extend the knee. What is the diagnosis?

A. Patella Dislocation

B. Knee Dislocation

C. Quad Tendon Rupture

D. Patella Tendon Rupture

Answer is A - Patella Dislocation

Here is some information on Patella dislocation. 

Some additional information on patella fracture Here