Renal osteodystrophy: A combination of bone disorders usually caused by chronic kidney failure (renal disease). Can also occur because of abnormal kidney functioning at birth (congenital). When the kidneys have failed, death is imminent unless dialysis is given. Therefore, patients with osteodystrophy are usually on dialysis therapy. This bone disease, which is also simply called osteodystrophy, is common in patients on chronic hemodialysis.