Regenerative medicine in treatment of osteonecrosis of the hip: morphogenetic proteins’ role

Introduction. Osteonecrosis of the hip is a disease that if left untreated evolves into a structural failure of the proximal and secondary osteoarthritis. In recent years in literature has been associated with foraging the infiltration of autologous concentrated bone marrow. Materials and methods. The aim of our study was to evaluate the effectiveness of the use of bone morphogenetic protein 7 (Osigraft) associated with core decompression in the treatment of osteonecrosis of the hip. From 2006 to 2010 we treated 23 patients (28 hips) with osteonecrosis of the proximal femur in Steinberg stage II. The core decompressionwas performed with dedicated instruments ofWright (XReamer) which create a tunnel of 9 mm in diameter in the femoral neck until the necrotic areawhich is subsequently removed with an expandable milling cutter. Subsequently the vacuum created was filled with a compound of autologous concentrated bone marrow and lyophilized tissue homologous or with an autologous concentrated bone marrow and Osigraft. The bone tunnel was then sealed with a compound of calcium phosphate (Prodense,Wright). We treated 11 patients with bone marrow concentrate and Osigraft and 16 cases with concentrated bone marrow and freeze-dried bone. The bilateral cases received only a vial of Osigraft that had not been used in the second treated hip. Results. At a minimum distance of 24 months we observed healing intended as the disappearance of symptoms and failure to progress of the lesion in 79 % of cases. We found a cure rate of 82 % healing in cases treated with Osigraft, a difference not statistically significant. The use of a scaffold in the compound injected into the area of necrosis is instead a significant result, since in all cases of failure no type of any scaffold had been used, but only the infiltration of bone marrow concentrate added or not to the Osigraft. Discussion. The use of concentrated autologous bone marrow is a valuable option with 79 % of success in treating early stage of hip osteonecrosis. Osigraft gives better results, but negative results were related to the lack of scaffold. Conclusions. The Osigraft improves the cure rate in core decompression and injection of concentrated bone marrow, but in bilateral cases it can only be used once. Our experience leads us to always recommend the use of a scaffold.