Core decompression, the classic preservation treatment for steroid – associated osteonecrosis (SAON), only addresses biological environment of the necrostic head and cannot treat the collapse caused by the biomechanical failure of the femoral head. Prof. QIN Ling and his research team in CUHK have developed a Mg-based composite device of magnesium hip stents, for supporting the subchondral plate during structural reconstitution of the underlying cancellous bone, which can augment core decompression. Besides, the injectable bone cement may fill the gap through the holes on the perforated and cannulated stent, to maintain, consolidate and strengthen the support of the implant. In accordance with previous studies, the Mg ions released from the Mg-based implants during in vivo degradation may prevent the femoral head collapse. This device has been validated on large animal model of the bipedal emu.