Reconstruction acetabular surgery with bone stock loss is still a difficult and challenging problem for the orthopaedic surgeon. The goals of acetabular revision are: stable bone coverage that can support the new acetabular component, restoration of the anatomy and bone stock for future revisions, equalization of leg length and restoration of the centre of hip motion. These goals are difficult to achieve when the pelvic defect is particularly severe. We examine the case of a female 73 years old who underwent a third revision arthroplasty of the hip joint because of extensive bony defect of the acetabular cavity (massive protrusio defect-type III –D’Antonio- combined segmental/cavitary acetabular defect). The femoral component which was revised in a previous operation with a mega stem (type Kotz), was radiologically stable and symptomless. Preoperative radiological assessment was performed using standard radiographic views, Judet views and CT scan. The surgical approach that we used was a slight modification of the previous incision achieving a better visualization of the entire acetabulum and iliac wing. The loose acetabular cup as well as soft tissue and debris were removed from the acetabulum. The large acetabular defect was filled with a massive allograft (tibial plateau) properly cut and shaped. The stability of the allograft was achieved fixing the allograft to the iliac bone with screws. A large amount of particulate allograft bone was placed in the depths of the acetabular defect restoring a proper level of the acetabular floor. Then a Burke-Schneider cage was firmly seated and fixed with screws in the prepared acetabular bed. A polyethylene cup was cemented into the acetabular shell. The superior part of the Kotz femoral prosthesis was also revised with a new one. Postoperatively we din not have any complications, the graft incorporation was successful with a satisfactory functional result. We believe that the use of structural allograft bone is essential for the reconstruction of large segmentalace-tabular defects. The results however are less predictable because of important technical difficulties and sometimes serious complications occur.
