Bone graft incorporation after reconstruction of bony defects with impacted morselized bone graft. Histology of animals and patients.

The major problem in revision total hip surgery is the loss of bone stock, which is induced by various factors: the loosening process itself, osteolysis, infection and manipulations during removal of the prosthesis components and the cement. The instability of the implant leads to progressive bone loss and a vicious cycle is initiated in which a combined central and peripheral cavitary segmental defect may develop in the acetabulum. With the technique of impacted bone grafts and cement, it is possible to replace the loss of bone and to repair normal hip mechanics in combination with a standard hip prosthesis, achieving a long-lasting stable reconstruction. In this paper we present the histological data of patient-material and of various animal experiments to support this technique. From the results of this histology it could be concluded that in animals complete incorporation into a new bony structure took place. After incorporation the newly formed bone structure obeys Wolffs law. In the biopsies of patients, also an almost complete incorporation was found of the impacted morsellized bone graft. Base on the good results of the histology and based on the very good clinical follow-up data in the acetabulum of patients revised with this technique of impaction grafting, we strongly advocate the use of this technique in revision arthroplasty of the acetabulum.