[Fracture of the acetabular cup as an early complication of total hip replacement]

The authors have presented 12 patients with non traumatic fracture of the acetabular cup of the Weller hip prosthesis. All the fractures have occurred 10 to 40 months following hip arthroplasty 9 of the broken sockets have been removed at the time of revision arthroplasty. They showed marked destruction with multiple fragmentation of the polethylen. The area of the destruction was surrounded by active tissue reaction described as resorbtion granulation. The remowed fragments of the polethylen have been examined physicochemically and showed marked increase in the degree of crystalisation. The authors have come to the conclusion that the main reason for the failure of the presented series of the polietylene cups was defect of the material used in their production.