All patients reporting at the ED in the AMC after an ankle sprain are eligible for inclusion. Their condition may vary from a severe sprain to an ankle fracture. All patients will be checked for ankle fractures using the Ottawa Ankle Rules (OAR). In 5-20% of cases a fracture is present with positive OAR, or there is doubt on the presence of a fracture and an x-ray will be taken. However there is always a chance of false positive results on the OAR. In these cases there is may have been a severe ankle sprain without intraarticular pathology visible on the x-ray. These are concluded to be severe sprain cases the investigators will extract for this study to include them in a questionnaire follow-up on the development of CAI.