[Acetabulum revision. Classifications and treatment possibilities].

Several different defect classifications have been published. The most commonly used are described. For clinical practice, differentiation between "contained" and "noncontained" or segmental defects has proven useful. If the acetabular rim provides support, press-fit cups can be used without screws. With an appropriate reaming technique, it is possible to create a sufficiently supportive bed for the implant in many cases. This allows the use of a press-fit acetabular component over a wide range of defects as long as a tilting of the cup can be avoided. Between 1988 and 1995, 439 acetabular cups were revised at the Orthopedic University Clinic in Basel, 171 of them using the Morscher press-fit cup. After a mean follow-up of 7.1 years, not a single cup had to be revised for aseptic loosening. The 9.5% dislocations were due to abductor insufficiencies because of trochanteric pathologies or muscular alterations from former approaches.