Osteonecrosis of the Knee
Osteonecrosis, which literally means "bone death", is a condition in which a segment of bone loses its blood supply. Without adequate blood, the bone cannot survive and begins to die.
Osteonecrosis of the knee is 3 times more common in women than men, and mostly affects people over the age of 60 years.
In your knee, it usally affects the end of your femur (thigh bone), called the femoral condyles.
If the bone dies and collapses, it can lead to osteoarthritis of your knee.