hi...seems to be OSTEOCHONDRITIS
DESSICANS,a condition in which there is degeneration of cartilaginous cap of the aarticular surface of femur
most commonly on the lateral part of medial femoral condyle.can be treated arthroscopicaly....get consultation with the orthopaedic surgeon
......at the same time it also has signs of osteoarthritis
of patellofemoral surface. wish you health..