Patent ID: 8454666

Claim:
A slideable cervical plate comprising: at least one anti-backout device ( 2 ) collaborating with at least two bores ( 4 ) positioned on one and the same axis AA′ parallel to that XX′ of said cervical plate ( 1 ), said anti-backout device ( 2 ) preventing the vertical displacements along the axis ZZ′ with respect to said cervical plate ( 1 ) of bone anchor screws ( 3 ) each positioned inside a bore ( 4 ) provided with a shoulder ( 5 ) against which the head ( 6 ) of said screw ( 3 ) presses when the screw ( 3 ) is tightened, wherein the anti-backout device ( 2 ) comprises: first means for vertical-blocking capable of deforming elastically in a first direction so that an anchor screw ( 3 ) can be introduced into the corresponding bore ( 4 ), and second means for vertical-blocking capable of deforming elastically in a second direction different than the first so that another anchor screw ( 3 ) can be fitted into another bore ( 4 ), said first and second means for blocking deforming elastically when a combined external load in a vertical direction along the axis ZZ′ and in rotation in the clockwise direction is applied to the anchor screws ( 3 ); in the thickness of said cervical plate ( 1 ), a housing ( 7 ) opening in a horizontal direction into each bore ( 4 ) via a slot ( 70 ) created above the corresponding shoulder ( 5 ), a tab ( 71 ) capable of deforming elastically between two bores ( 4 ) in the first direction, and a slide-forming platform ( 8 ) positioned inside the housing ( 7 ) so as to collaborate with the tab ( 71 ), wherein said slide platform ( 8 ) comprises: anti-backout stops ( 81 ) passing through each slot ( 70 ) to emerge inside the corresponding bore ( 4 ), a slot ( 83 ) delimiting a connecting bridge ( 88 ) allowing the platform ( 8 ) to deform elastically in the second direction different than the first, and in a middle of the slide platform ( 8 ), a slot ( 80 ) collaborating with the slot ( 73 ) of the tab ( 71 ) of the housing ( 7 ) so that said platform is guided inside said housing.