My doctor said i have Patellar Subluxation what exactly is that?

"when i straighten my knee my kneecap pushes out to the right" -is patellar subluxation.I also think its Quads strengthening rather than hamstring as strong quads stabilise patella.If you are high level athlete you should see specialist sports physical therapist,if not standard physio should help.Wearing a neoprene knee support with patellar cut out may help during quads exercises.