Survival of primary ankle replacements: data from global joint registries by Perry, TA, Silman, A, Culliford, D, Gates, L, Arden, N, Bowen, C, Harris, IA, Dyer, CN, Beischer, A, Ackerman, I, Furnes, O, Hallan, G, Mäkelä, KT, Stenholm, M, Henricson, A, McKie, J, Muir, D