FR3087333A1 - KIT OF FEMALE HIP RODS COMPRISING A PLURALITY OF RODS OF DIFFERENT DIMENSIONS ONE OF THE OTHERS - Google Patents

Abstract

Kit or set of femoral rods comprising a plurality of femoral rods, each rod (1) consisting of a keel-shaped diaphyseal part (2) intended to be anchored in the patient's femur, of a metaphyseal part (3) which flares upwards, and from an upper part (4) of the neck, the metaphyseal part flaring up to a resection plane (5) from which the neck part extends, the shapes and dimensions of the rods of the kit being all identical except for the dimensions of the resection plane, which can be defined along two XY directions perpendicular to each other, characterized in that one of the dimensions of the resection plane along one of the two XY directions is the same for all rods in the kit, while at least one dimension along the other of the two directions varies from rod to rod in the kit.

Description

Description Title of the invention: Femoral hip rod kit comprising a plurality of rods of different dimensions from each other [00011 The present invention relates to a kit or set of hip femoral rods comprising a plurality of femoral rods, including sizes and / or dimensions vary from each other. [00021

[0002] A hip femoral stem conventionally comprises a lower part, called diaphyseal, in the shape of a keel intended to be anchored in the patient's femur, an intermediate part, called metaphyseal, extending above the diaphyseal part, and a neck-shaped upper part for cooperation with a head piece intended to penetrate into a complementary shaped cavity formed in a cup inserted in the acetabulum of the patient

[0003]

The femoral stem has an upper-lower or vertical axis, said neutral axis, along which the leg length is measured, and a mechanical or neck axis which corresponds to the orientation of the axis of the neck, the mechanical axis of the neck extending along the axis of symmetry of revolution of the coi and passes in particular through a point called the center of the head of the femoral part.

[0004]

The metaphyseal intermediate part is intended to be located in the metaphysis of Fos of the femur and is separated from the neck part by a resection plane. [) 005]

In general, this resection plane separates the outer surface of the rod into two parts, one comprising anchoring grooves intended to promote anchoring of the rod in the femur, in the shaft as in the metaphysis , and the other not comprising anchoring grooves, and in particular this other part of the outer surface is smooth.

In addition, this resection plane corresponds to the plane up to which the metaphyseal part ceases to flare and from which the coi part extends having its section which narrows.

In particular, the exterior surface of the metaphyseal part comprising an exterior flank, an interior flank and two lateral flanks, the terms interior and exterior being understood when the prosthesis is mounted in the femur. [00061

The outer flank extends upwards to the resection plane where it forms with the neck, seen in section, a corner or a cusp of the outer surface.

Of merit the inner flank extends upwards to the resection plane, where it forms with the neck, seen in section, a cusp of the outer surface.

The resection plane is the plane that passes through these cusps, [) 0071

[0007] Conventionally, a kit of femoral stems for a total hip prosthesis comprises a plurality of femoral stems which all have the same lines and external dimensions (leg length or height, thickness, inclination of the upper face, etc.) but whose dimensions of the section of the resection plane vary from one rod to another in the kit.

[0008]

[0008] Thus, in current kits, the dimensions of the section of the resection plane vary in all directions (media-lateral and antero-posterior).

It follows that these kits require for each size and / cm shape of rod, to have a large number of rods with variable section dimensions of the resection plane.

In addition, the surgeon must choose the dimension that best fits the bone in the metaphysis and face. with the large number of options, its task is not easy, because it must take into account several parameters, in particular the width and the length of the section of the resection plane of the rod that it wishes to use.

[0009]

The present invention aims to overcome the drawbacks of the anterior by providing a kit of femoral hip rods, which simplifies the work of the surgeon for the selection of the rod best suited to the bone in the metaphysis, while at the same time reducing the number of rods in a kit without restricting the choice of surgeon.

[0010]

According to the invention, a kit or set of femoral rods comprises a plurality of -femoral rods, each rod consisting of a diaphyseal part in the form of a keel intended to be anchored in the patient's femur, of a part metaphyseal which widens upwards, and from an upper part of the neck, the metaphyseal part widening out to a resection plane from which the neck part extends, the shapes and dimensions of the rods of the kit all being identical except for the dimensions of the resection plane, which can be defined in two KY directions. perpendicular to each other, for example anteroposterior and mediolateral respectively, is characterized in that one of the dimensions along one of the two XY directions is identical for all the rods of the kit, while at least one dimension along the other of the two directions varies from one rod to another of the kit.

[0011]

[0011] Thus, the surgeon has a much easier time choosing the most suitable rod, having only to be concerned with one dimension in one direction.

It turns out that for all that his choice is not restricted compared to the kits of the prior art and that he can always adapt it. better rod for each operated patient.

[00121 100121 According to a particularly preferred embodiment, the X direction along which the dimension of the resection plane in the XY plane is constant for all the rods of the kit is the largest dimension of the resection plane, or length of the resection plane.

100131 100131 According to a preferred embodiment of the invention, the resection plane is triangular in shape with rounded edges.

[00141 100141 In particular, the length or greatest dimension of the resection plane extends from a principal vertex to an opposite segment of the triangle. 1) 0151

According to a preferred embodiment of the invention, the two segments from the main vertex of the triangular section extend by making between them an angle which is the memo for all the resection planes of the kit, in particular equal to 20 '. [00161

Preferably, the length or greatest dimension of the resection plane is constant and is equal to 25.5min.

[0017]

In particular, the widths of the resection planes, that is to say the dimension measured in the plane along the Y direction perpendicular to the X direction increases in constant increments from one rod to the other of the kit, in particular including between 2 and lOrnm, for example of. 5mm.

[0018]

By way of example, a preferred embodiment of the invention will now be described with reference to the drawings, in which [00191

[0019] [Fig.1] Figure I is a side view, along the medio-lateral axis of a hip femoral stem of a kit according to the invention and [00201]

[0020] [Eig.2] Figure 2 is a sectional view along line B-B of the figure showing the sections of the resection planes of the different rods of the kit according to the invention. 100 111

In Figure 1, there is shown a femoral rod 1 consisting of a base body having a lower part 2 called epiphysealc, in the form of a keel intended to be anchored in the epiphysis of the patient's femur and a part 3 intermediate, called metaphyseal, intended to be anchored in the metaphysis. of the patient's femur.

Part 4 of. neck extends after the intermediate part 3, being separated from the latter by an interface 5 called the resection plane. [0022

The metaphyseal part is flared up to the plane 5 of the rese-tiot part (the neck has a section which straits from the resection plane.

The outer surface of the metaphyseal part comprises the outer blank 17, an inner side 18 and two lateral sides 19, 20.

The outer flank 17, in longitudinal section (cut in the plane passing through the neutral axis and the antero-posterior axis), is a straight line which extends upwards to a point 20 of cusp of the outer surface of the rod, this point of exterior cusp (which corresponds to a ridge line extending in the medio-lateral direction, perpendicular to the plane of the figure) passing through the plane 5 of resection.

[00241 100241 The inner flank 18, along the longitudinal section is an arc of a circle which extends upwards to a point 21 of cusp of the outer surface of the rod, this point 21 of inner cusp (which corresponds to a ridge line extending in the medio-lateral direction, perpendicular to the plane of FIG. 1) passing through the plane 5 of resection.

100251 100251 Thus, the resection plane 5 can be defined by the plane passing through the two ridge lines 20, 21.

In addition, below the resection plane, it is the upwardly flared metaphyseal part which extends, including on its outer surface grooves or notches or the like for anchoring, while above of the resection plane, it is the neck part which extends, having its section parallel to the resection plane which decreases, the neck part preferably not having at its outer surface grooves or notches or the like for anchoring, since in particular this part of the neck is not intended to be anchored in the femur.

[0026]

The femoral stem I has an upper-lower axis 4, or vertical in the figure, said axis. neutral, along which the length of the leg is measured, and a mechanical axis 11, or neck axis, which corresponds to the orientation of the axis of the neck from the plane 5 of resection of the rod, passing through a point 6 of the neck, called the center of the head of the femoral part.

The neck axis is not necessarily perpendicular to the resection plane 5, and, depending on the chosen neck, may be parallel to this perpendicular., Or slightly inclined with respect to this perpendicular,

[0027]

In Figure 2, there is shown a sectional view along the line B-B of Figure 1.

This sectional view thus represents the section of the plane 5 of resection of several rods, superimposed on each other.

The dimensions of the resection planes 5 of the rods of the plurality of rods of a kit according to the invention can thus be seen there in a superimposed manner.

Each resection plane 5 has, in its XY plane, a section of substantially triangular shape having a principal vertex 7 and secondary vertices 8, 9 on the opposite side.

Principal vertex 7 is the same for all resection planes of all rods in the kit.

On the other hand, the vertices 8, 9 vary for each section.

The vertices are rounded in shape.

The largest dimension in length (along the X axis), i.e. the L dimension, extending in the direction. going from point 7 main vertex to the point halfway between the two 8, 9 secondary vertices, is identical for all the resection planes of all the rods of the kit and in particular is equalized to 25.5 mm

[0028]

In addition, the u segments 20. 21 of the sec .aire, extending between the main vertex 7 and respectively the vertices 8, 9 secondary, form an angle with respect to each other which is constant (excluding rounded parts of segments) from one resection plane to another.

In particular, this angle is equal to 20 °.

100291 100291 Thus, by varying the thickness in the width direction, that is to say the Y direction perpendicular to the X direction in which the length L is measured, at the level of the rectilinear segments of the triangular section 20, 21. the area of the resection plane 5 has been varied.

However, it is possible to keep a smaller number of necks, all having the same length, and the necks all have a resection plane having a dimension in length equal to 25.5 mm and on the other hand a width which can adapt according to from the choice of the stem, a resection plane adapting to the chosen neck.

100301 100301 Thus, it is easy to choose the neck which is best suited to the Diorphology of the bone to which the rod of a given size has been anchored.

In addition, for a kit, one can provide sizes, including leg height, different keel and, for each keel size, resection planes having, as according to the invention, variable dimensions. 6

Claims (1)

Claims [Claim 1] Kit of femoral rods comprising a plurality of femoral rods, each rod (1) consisting of a part (2) diaphyseal in the form of a keel intended to be anchored in the femur of the patient, of a part (3) metaphyseal which s flares upwards, and from an upper neck part (4), the metaphyseal part widening up to a resection plane (5) from which the neck part extends, the shapes and dimensions of the rods of the kit being all identical except for the dimensions of the resection plane, which can be defined in two XY directions perpendicular to each other, characterized in that one of the dimensions of the resection plane in one of the two XY directions is identical for all the rods of the kit, while at least one dimension along the other of the two directions varies from one rod to the other of the kit. [Claim 2] Kit according to claim 1, characterized in that the direction X in which the dimension of the plane (5) of resection in the XY plane is constant for all the rods of the kit is the largest dimension of the plane of resection, or length of the resection plane. [Claim 3] Kit according to claim 1 or 2, characterized in that the resection plane is triangular in shape with rounded edges. [Claim 4] Kit according to claim 3, characterized in that the length or largest dimension of the resection plane extends from a main vertex (7) to an opposite segment of the triangle. [Claim 5] Kit according to claim 3 or 4, characterized in that two segments (20, 21) from a main vertex (7) of the triangular section extend at an angle between them which is the same for all the resection plans of the kit, in particular equal to 20 °. [Claim 6] Kit according to claim 5, characterized in that said an angle is equal to 20 °. [Claim 7] Kit according to one of the preceding claims, characterized in that the length or larger dimension of the resection plane is constant and is equal to 25.5mm. [Claim 8] Kit according to one of the preceding claims, characterized in that the widths of the resection planes, that is to say the dimension measured in the plane along the direction Y perpendicular to the direction X increases by constant increment from one rod to the other of the kit, in particular between 2 and 10mm, for example 5mm. i