M90: Osteopathies in diseases classified elsewhere

M90.5: Osteonecrosis in other diseases classified elsewhere

Osteonecrosis is a condition in which the lack of blood flow causes the bone to break down and die, eventually leading to the collapse of the bone, if unattended. This health condition, coded as M90.5 in the ICD-10 WHO 2016 classification, refers specifically to osteonecrosis that happens in relation to other diseases. The exact disease causing the osteonecrosis can vary widely and may include anything from cancer to lupus. Just as the diseases from which it can stem are wide-ranging, so, too, are the symptoms. These can include joint pain, limited range of motion, and eventual joint collapse if left untreated. While osteonecrosis can affect any bone in the body, it most commonly troubles the hip bone. It often occurs in people between 30 to 50 years old, affecting men and women equally.