Purpose: The purpose of this study is the analysis of the results of the surgical treatment of complex and displaced acetabular fractures.

Material: We have the results of thirty four comminuted acetabular fractures that were treated with open reduction and internal fixation. Most of them concerned fractures of both columns.

Method: Thirty two of the fractures were operated through one technique (Kocher-Langenbeck, ilioinguinal, expansive iliofemoral, or lateral by lifting the greater trochanter).The other two were operated with a double procedure (Kocher-Langenbeck and ilioinguinal). For the internal fixation reconstruction plates were used together with free screws and sometimes hook like wires.

Results: Anatomic reduction was performed in 24 cases. The result was graded as excellent in 42%, good in 34%, fair in 16%, and poor in 8% of the cases. Posttraumatic arthritis was seen in cases were anatomic reduction was not possible and the level of the arthritis was in absolute relationship with the quality of the reduction. In cases were the reduction was anatomic, posttraumatic arthritis was rare. The clinical results were in absolute relationship with the quality of the reduction and they were satisfactory as soon as the relationship of the weight bearing surface of the acetebulum and the femoral head is regular. Avascular necrosis of the femoral head was seen in two cases.

Conclusion: The anatomic reduction of displaced complex acetebular fractures prevents posttraumatic arthritis and ensures satisfactory clinical results. The aim of the operation must always be the anatomic reduction of the acetabular cup and the bone structures around it. When this is not technically possible we have to try for the restoration of the relationship between the femoral head and the acetabular roof.