Fatou, another child being treated in this Dakar clinic, has travelled 400 miles (644km) to get the same treatment for her right foot. Today is her 13th birthday but the day is starting with the removal of her fourth cast. The nurses saw through the plaster and then, in a cloud of dust, prise it off her leg. She winces a little, but the clinic’s head nurse, Nicanor Manga, reassures her that some pain is normal and it will be worth it in the end.