Examples of three different migration patterns: x-ray examples and underneath the year; in the corresponding SlMULGRAF diagrams, one square equals one squared millimetre. Each cup-symbol represents one measurement in a different a.p. pelvic film. a: migration diagram of a patient with 1.5 mm of cup migration cranially, beginning one year after implantation. Restabilisation was achieved in the further follow up of .36 months. b: migration diagram of a patient without significant migration of < 1 mm cranially or horizontally. Follow-up was 3.5 years. c: migration diagram of a an implant with aseptic cup loosening. Note the progressively migrating implant during 21 months of follow-up. The patient underwent revision surgery and replacement of the loosened implant.