BONE ANCHORING DEVICE

The invention concerns a bone anchoring device (1; 10) comprising a first (2a; 12a) and a second (2b; 12b) arm defining between them a first slot (3a; 13a) of depth p extending along an axis (x-x'). The first (2a; 12a) and second (2b; 12b) arms respectively bear a first (4a; 14a) and a second (4b; 14b) branch extending outside of said first slot (3a; 13a). The first branch (4a; 14a) is designed so as to define, together with the arm (2a, 12a) which bears it, a second slot (3b; 13b) and the second branch (4b; 14b) is designed so as to define, together with the arm (2b; 12b) which bears it, a third slot (3c; 13c). The device (1; 10) is also designed so that, in a rest position: the orthogonal projection onto the axis (x-x') of the bottom of each of the second (3b; 13b) and third (3c; 13c) slots is situated in said first slot (3a; 13a) at a distance from the bottom of this slot of at least 10%, preferably at least 20%, preferably at least 30%, preferably at least 40%, more preferably at least 50% of the depth p; and the distances d1 separating the bottom of said second slot (3b; 13b) from the portion of the end of the branch (4a; 14a) defining it which is furthest from it and d2 separating the bottom of said third slot (3c; 13c) from the portion of the end of the branch (4b; 14b) defining it which is furthest from it, being such that each of the ratios d1/p and d2/p is greater than or equal to 0.3, preferably greater than or equal to 0.4, more preferably greater than or equal to 0.5. L'invention concerne un dispositif d'ancrage osseux (1; 10) comprenant un premier (2a; 12a) et un second (2b; 12b) bras définissant entre eux une première fente (3a; 13a) de profondeur p s'étendant selon un axe (x-x'). Les premier (2a; 12a) et second (2b; 12b) bras portent respectivement une première (4a; 14a) et une seconde (4b; 14b) branche s'étendant à l'extérieur de ladite première fente (3a; 13a). La première branche (4a; 14a) est agencée de manière à définir avec le bras (2a, 12a) qui la porte une seconde fente (3b; 13b) et la seconde branche (4b; 14b) est agencée de manière à définir avec le bras (2b; 12b) qui la porte une troisième fente (3c; 13c). Le dispositif (1; 10) est également agencé de sorte que, en position de repos: la projection orthogonale sur l'axe (x-x') du fond de chacune des seconde (3b; 13b) et troisième (3c; 13c) fentes se situe dans ladite première fente (3a; 13a) à une distance du fond de cette fente d'au moins 10%, de préférence d'au moins 20%, de pré