Avascular necrosis (AVN), also known as osteonecrosis, is a painful condition that causes bone tissue death in the hip joint. It occurs when blood flow to the bone is disrupted, usually due to a blockage. Symptoms include: Pain in the hip, groin, thigh, knee, or buttocks Pain that worsens over time Pain that occurs even when you're resting Limited range of motion Limping Difficulty climbing stairs, standing, or walking Early recognition and treatment of AVN is important because it can lead to deformity and joint collapse. Treatment options include: Conservative treatment: Rest, physical therapy, and using crutches to limit weight on the hip Medications: Statins and bisphosphates can help slow or repair AVN Hyperbaric oxygen therapy: This non-surgical treatment can help reduce pain and inflammation Surgery: Options include core decompression, bone grafting, osteotomy, or total hip replacement To lower your risk of AVN, you can: Cut back on alcohol, Keep your cholesterol in check, Use steroids carefully, and Don't smoke.