Focal osteoporosis defects play a key role in hip fracture حسب Poole, K, Skingle, L, Gee, A, Turmezei, T, Johannesdottir, F, Blesic, K, Rose, C, Vindlacheruvu, M, Donell, S, Vaculik, J, Dungl, P, Horak, M, Stepan, J, Reeve, J, Treece, G