Deformed upper arm bones. Coloured X-rays of the left (left) and right (right) arms of a patient with deformed upper arm bones (humeri). The top of the left humerus has been fractured (top left) as the deformity has led to brittle bones. This case was thought to be Lobstein's syndrome. This is an inherited condition, starting in childhood, with brittle bones, translucent skin, blue-coloured sclerae (whites of the eye) and joint instability. The elbow joints (lower left and right) are where the humeri connect with the two lower arm bones (the ulna and radius).