 The cause of Köhler's disease, has thus far, been declared unknown by scientists.However, it is suspected that possible causes may be caused by strain on the foot and the blood vessels associated with it, before the bone is fully able to grow into its adult form (ossification).This bone ossification usually begins within the first 18 to 24 months of a female's life and the first 24 to 30 months of a male's life.