Acetabular reconstruction using structural grafts in total hip replacement: a 12 1/2 year follow-up.

We reviewed 34 patients who had structural acetabular grafts used in conjunction with total hip replacement. Two patients died and eight were lost to follow-up, leaving 24 patients with 24 grafts who were followed-up for a minimum of 10 years and an average of 12 1/2 years. There were 8 primary hips and 16 revisions. Twenty-two (92%) of the grafts united. The two non-unions were in patients with sepsis. Six grafts (26%) failed. Two failed because of sepsis and four were aseptic failures. All the aseptic failures were the results of technical errors. Two grafts were of poor quality and all of the aseptic failures had transverse trabeculae and transverse screws. There were 10 (41%) loose acetabular components. Two were loose because of sepsis. Of the eight aseptic failures, four were caused by failure of the graft and in the other four, the graft remained intact but the cemented acetabular components loosened. There was no correlation between the percentage of component coverage by the graft and component failure. The average preoperative Harris rating was 43 and the postoperative rating was 81, including the failures. If the failures were eliminated, the rating of the remaining patients was 93. Structural acetabular grafts are rarely necessary. However, they do work and their success is clearly related to technique. Important technical factors include: the graft must be of good quality, the trabecula must be oriented in the line of weight-bearing forces, the graft must accurately fit the defect, the graft must be supported by a host buttress, and the graft should be fixed with lag screws that are oriented in a line of weight-bearing. If these criteria are met, early weight-bearing is important to stimulate graft healing and remodeling.