Chondral ulcer on knee

I have previously had once ACL tear which was fixed through reconstruction although i twisted the same knee three years later only to be told by radiologists and a consultant that it was gone again. Although after recently getting a second opinion it was found that these findings were incorrect and that my ACL was still intact. I did however have a chondral ulcer near the lateral side of my knee.From the small research i have done it is said that these ulcers form from degenerating of cartilage or a traumatic injury like ACL tear. But seeing as i dont have an ACL tear it does pose the question what the injury was. If i rewind back to the moment i could just remember my knee collapsing inwards after landing from a jump and it was as if my kneecap was moving from left to right. This was all accompanied by a pop of course which i think may have been the femur and tibia crashing together as i had bone odema in the MRI 2 days later. One possibility i have researched though is a sublaxation of the knee which is basically a partial dislocation. This is what i may have felt when my foot hit the ground but by the time i collapsed in pain my kneecap had gone back into place. At the moment I have played football again after a bit of rehab (Up until quarantine) and found that i had no problem turning etc. indicating a stable ACL but, i did find slight pain near the lateral side of the knee which is most likely the ulcer. Anyway i guess the main question im asking is does anyone know any other types of injuries that accompany a chondral ulcer and if anyone here has had one what is the best way to get over it?