did the other knee cap dislocate before? how old are you? do you get pain every day? if so with what activity or position?

if you dislocated that easily (no twist etc) then it is likely that you have underlying boney deformity. this can be slight, moderate, or severe in terms of the changes and cannot be fully verified without x-ray, Wikipedia reference-linkMRI, CT scan or some other test to visualize the bones. there are so many possible problems here that it is impossible to give good advice without doing a thorough evaluation. is say this not only a physio that has studied orthopedics extensively but as a patellar dislocation patient myself. i have dislocated each patella dozens of times and had a corrective surgery on the left knee. i enjoy treating this diagnosis both because it can be challenging and because it is a personal topic for me. unfortunately, there isn't really any good research on how best to treat this problem. this is probably mostly a result of the fact that there are so many reasons why a knee cap can dislocate. how do you study/treat something that is so variable? the answer is that you can only do a very thorough ankle, knee, hip, and low back evaluation, find the individual problems for each patient, and treat what can be treated. all of that having been said there can be lots of things that aren't even treatable such as underlying boney shape.

on a general note: lots of people that get pain between the knee cap and femur are helped greatly by a quad stretch (lie on stomach, pull heel to the butt for example). they typically also benefit from strengthening the hip and knee muscles, stretching the calf and the structures on the lateral side of the thigh, and correction of flat feet if present (among many other possible options).

ask any question you want but i assure you there are no easy answers