Lyophilized xenograft: a case series of histological analysis of biopsies.

The reconstruction of an acetabular bone defect is one of the most important aspects of revision total hip arthroplasty surgery. It can be done by the use of grafts. Therefore, many kinds of grafts may be used and lyophilized xenograft is an alternative example. The purpose of the study was to evaluate the histological findings of lyophilized bovine xenografts used in previous total hip arthroplasty revision surgery. A case series was carried out from July 2000 to April 2013 with the approval of the Hospital Ethics Committee. Fourteen subjects were analyzed. Of these, 64.3 % were female. The average age of the patients was 52.36 ± 18.55. Neoformed bone was present in 85.7 % of subjects, and constituted 61.79 % of the total bone matrix area. The diagnosis of xenograft absorption was present in 12 subjects. A strong inverse correlation between the percentage of neoformed bone and the percentage of xenograft in the total bone matrix by analysis of biopsies was found by the Pearson test (p = 0.001). No inflammatory response was found in the clinical status of the patients or in the histological analysis. Lyophilized bovine xenograft shown to be safe until the present moment, with acceptable results. Most of the cases presented new bone formation as expected (considered values greater than 30 %) and for this reason the xenograft has proven to be an osteoconductive compatible scaffold/trellis for the bone ingrowth. Therefore, it can be considered an alternative to other bone grafts in the treatment of bone loss.