Can avascular necrosis cause severe unbearable lower back pain?

No: Avascular necrosis commonly involves shoulder, hip and occasionally the knees but not the lower back.

Avascular necrosis: Avascular necrosis of the hip? Can definitely cause low back pain. In fact many patients come to the doctor complaining of back pain and not hip pain. But, many other things can cause low back pain as well. Have it checked to see if due to the avn or due to something else.