Role of bone grafting in correction of protrusio acetabuli by total hip arthroplasty.

A study of 27 hip arthroplasties derived from a pool of more than 200 total hip arthroplasties performed between 1976 and 1981 was conducted to assess the need for and benefits of bone grafting in the surgical management of protrusio acetabuli. The objective of surgery and the reason for augmentation by bone graft was to lateralize the acetabular component, normalize the center of rotation of the hip, and strengthen the deficient medial wall. Based on this study, the authors recommend: when protrusion is less than 5 mm in either direction and the medial wall is reasonably strong, bone graft is not indicated; in protrusion greater than 5 mm with a thin but intact medial wall, autogenous bone graft is indicated but artificial fixation devices need not be used; and a grossly deficient medial wall requires reconstruction with bone graft and additional fixation devices to achieve normalization of the center of rotation of the hip joint.