Fish Vertebrae or Codfish vertebrae is a classic radiological sign in which there is biconcave deformity of vertebral bodies. It commonly involves the Lumbar Vertebrae. This condition is usually seen in postmenopausal osteoporosis as well as disorders such as Hypoparathyroidism, Osteomalacia, Osteogenesis Imperfecta and Sickle cell anemia. Image: BMJ