What kind of exercises can I do to get stronger knees?!

My knees used to dislocate three or four years ago, and last time I tried to do a cartwheel about three years ago, my kneecap dislocated. Ever since then I have been scared to do a cartwheel. I built up muscle around the knee, but I don't know which exercises to do to build up more muscle around my kneecaps, so they won't dislocate the next time I do a cartwheel. Any suggestions.? Health Question & Answer

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