US20010014826A1 - Space holder, in particular for a vertebra or an intervertebral disk - Google Patents

Abstract

A space holder in particular for a vertebra or an intervertebral disk is provided. The space holder comprises a jacket (1) having apertures (9, 10) and a first and second edge (7, 8). The edge has circumferentially adjacent recesses (9, 10; 9′, 10′) each extending in direction towards the other edge and a stop provided at at least one of the edges spaced from the outer edge. In order to provide for an easy manufacture and operation of the space holder the stop is formed by a member (11, 13, 16, 22) having an outer contour corresponding to the inner contour of the jacket (1) and nose-like projections (15) for engaging the recesses (9, 10) are provided at those locations of the periphery of the stop which correspond to the recesses (9, 10; 9′, 10′).

Description

• The invention relates to a space holder according to the preamble of claim[0001]1.
• Such a space holder is disclosed for example in document EP-B-0 268 115. This space holder comprises a stop formed by a ring on its inner side spaced from the corresponding free end of the jacket. The ring is connected with the jacket by means of bolts. In a particular embodiment a base plate comprising openings is mounted on the ring.[0002]
• It is the object of the invention to simplify the space holder and make it more universally applicable.[0003]
• This object is achieved by the space holder defined in claim[0004]1.
• Embodiments of the invention are defined in the subclaims.[0005]
• Further features and advantages of the invention will stand out from the description of embodiments with reference to the Figures. In the Figures:[0006]
• FIG. 1 is a side view of the jacket of the space holder;[0007]
• FIG. 2 is a top view of a first embodiment of the member to be connected with the jacket;[0008]
• FIG. 3 is a top view of a second embodiment of the member;[0009]
• FIG. 3[0010]ais a sectional view along line IIIA-IIIA in FIG. 3;
• FIG. 4 is a top view of a third embodiment of the member;[0011]
• FIG. 5 is a sectioned lateral view along line V-V in FIG. 4;[0012]
• FIG. 6 is a sectional view along line VI-VI in FIG. 7 through a further modified embodiment;[0013]
• FIG. 7 is a top view of that embodiment;[0014]
• FIG. 8 shows a section along line VIII-VIII in FIG. 9;[0015]
• FIG. 9 is a top view of that further embodiment;[0016]
• FIG. 10 shows a section along line X-X in FIG. 11; and[0017]
• FIG. 11 is a top view of that further embodiment.[0018]
• As shown in particular in FIG. 1 the space holder comprises a closed jacket[0019]1. The cross-section perpendicular to the longitudinal axis2 of the jacket1 is shaped in usual manner, in particular cylindrical, oval or kidney-shaped. In the manner shown in FIG. 1 the jacket1 comprises diamond-shaped apertures3,4 having a longitudinal diagonal extending parallel to the jacket axis2.Adjacent rows3,4 of such diamonds are mutually offset by half a diamond height. In this manner a grid is formed havingwebs5,6 intersecting at an acute angle and including equal angles with the longitudinal diagonal of thediamonds3,4. Theupper edge7 and thelower edge8 both extend in a plane perpendicular to the longitudinal axis2. The size of thediamonds3,4 and of thewebs5,6 defining the diamonds is selected so that there is an integral number of diamonds in peripheral direction. Theedges7,8 generate always an even number of V-shaped recesses9,10 or9′,10′, resp., formed by the respective diamond base in peripheral direction. Owing to the above-described geometry the respective edge is quasi centrically symmetric to a point on the longitudinal axis2 lying in the plane of the edge.
• The first embodiment of a[0020]member11 forming a stop shown in FIG. 2 is formed as a plate-shaped ring. The outer contour of thering12 corresponds to the inner contour of the jacket1. Its dimensions are selected so that it can be pressed into the interior of the jacket but may also be pressed out again if desired, i.e. there is a frictional fit between the ring and the jacket1. Equidistant projectingnoses15 are provided at the outer edge of thering12 in peripheral direction. The distance between two noses in peripheral direction equals the distance between two peripherally adjacent V-shaped recesses9,10. The cross-dimensions of thenoses15 in the plane of the plate are such that the noses fit smoothly into the base of the V-shaped recesses9,10. The length of the projecting noses corresponds to about the wall thickness of the associated jacket.
• In use the jacket[0021]1 is brought to the desired length by severing theupper edge7 and thelower edge8. Then onering12 is pressed into the interior of the jacket at the upper end and a second ring is pressed into the jacket interior at the lower end in such a manner that thenoses15 of the rings engage the corresponding basis of the associated V-shaped recesses9,10 and9′,10′, resp.
• Owing to the integral number of the V-shaped recesses and the central symmetry resulting therefrom one and the[0022]same member11 may be used irrespective of the severing at theedge7 or at the lowerededge7′ indicated in broken lines. If the edge is formed at thelocation7′ rather than at thelocation7, then thering12 is inserted after rotation around its longitudinal axis, whereby using only one kind of rings the stock-keeping is reduced and the operation is simplified.
• FIG. 3 shows a[0023]member13 of a modified embodiment. Again it is a plate wherein the holes are formed by bore-shaped holes14 distributed over the plate. All further features correspond to themember11.
• The FIGS. 4 and 5 show a[0024]member16 according to a third embodiment. This member again comprises a plate which corresponds to the embodiment shown in FIG. 3 as regards theholes14 and thenoses15. Anouter ring17 is arranged around the plate. As best shown in FIG. 5, the outer ring has a ring wall extending perpendicular to the plane of the plate and therefore parallel to the outer surface of the jacket1. The length of thenoses15 is selected so as to be longer than the thickness of the jacket1 just by an amount to form aclearance18 between the plate, the noses and the ring which allows pushing the member onto the correspondingfree end7,8 of the jacket1 to fit thenoses15 into the base of the respective corresponding V-shaped recesses9,10,9′,10′. The inner surface of thering17 then sits close to the outer surface of the jacket1.
• In the FIGS. 6 and 7 a[0025]member19 according to a further embodiment is shown. It has a plate-shaped ring12 which is identical with the ring shown in FIG. 2. As best shown in FIG. 6 anedge portion20 having an outer contour which corresponds to the inner contour of the jacket1 is provided on one surface of this ring and the free end of theedge portion20 opposite to theplate12 hasequidistant prongs21 in circumferential direction. The height of theprongs21 above theplate12 is so that when inserted the prongs extend beyond theedge7 or8, resp., of the jacket1 almost to their base.
• The embodiment of a[0026]member22 shown in FIGS. 8 and 9 differs from the previously described embodiment only in that the base of the prongs is not in a plane parallel to theplate12, but in a plane which is inclined with respect to theplate12. The edge formed by the prongs lies also in a plane which is inclined with respect to the plate plane of thering12. The inclination is preferably between 8 and 10°.
• The embodiment of the[0027]member24 shown in FIGS. 10 and 11 differs from the embodiment according to FIGS. 8 and 9 in that theedge portion20 is inclined with respect to the plane of the plate, i.e. with an angle other than 90° with respect to the plate plane of thering12.
• In operation both embodiments, i.e. the[0028]members19 and22, resp., are inserted into the jacket in the same manner as the previously described embodiments so that the projectingnoses15 of thering12 lie in the lowermost parts of the V-shaped recesses9,10 and the prongs extend outwardly beyond the edge of the jacket. In the embodiment shown in FIGS. 6 and 7 theprongs21 or21′ may be cut to different lengths, for example along thebroken line23 to form a wedge-shaped insert. Similarly the edge of themember22 can be cut so that the predetermined angle between the outer egde and the plate-shaped ring12 is varied. In this manner it is possible to obtain, using few basic members, space holders having different wedge angles.
• The outer contour of the[0029]respective rings12 and13 is, of course, determined as a function of the respective inner contour of the associated jacket.
• According to modifications of the above-described particularly preferred embodiments the recesses of the edge may have other shapes in place of the V-shape, for example U-shaped or slit-shaped recesses.[0030]

Claims (15)

1. Space holder, in particular for a vertebra or an intervertebral disk, comprising a jacket (1) having apertures and a first and second edge (7,8) as well as adjacent recesses (9,10;9′,10′) arranged in peripheral direction and each extending in direction towards the other edge and a stop provided at at least one of the ends at a distance from the outer edge,

characterized in that the stop is formed by a member (11,13,16,19,22) having an outer contour corresponding to the inner contour of the jacket (1) and comprising nose-shaped projections (15) at locations of its periphery corresponding to the recesses (9,10;9′,10′) for engaging the recesses.

2. Space holder according to

claim 1

, characterized in that the recesses are each formed as V-shaped recesses (9,10;9′,10′) having equal distances from each other.

3. Space holder according to

claim 1

or

2

, characterized in that the outer periphery is dimensioned so that the member (11,13,16,19,22) is held by friction fit in the jacket (1).

4. Space holder according to any of the

claims 1

to

3

, characterized in that the jacket (1) is made as a grid having diamond-shaped apertures (3,4).

5. Space holder according to

claim 4

, characterized in that one diagonal of each diamond (3,4) extends parallel to the longitudinal axis (2) of the space holder.

6. Space holder according to any of the

claims 1

to

5

, characterized in that the member (11,13,16) is formed as a plate.

7. Space holder according to

claim 6

, characterized in that the plate (12) is ring-shaped.

8. Space holder according to

claim 6

, characterized in that the plate (13) comprises a plurality of adjacent holes (14).

9. Space holder according to any of the

claims 6

to

8

, characterized in that the length of the noses (15) is at least equal to the wall thickness of the jacket (1).

10. Space holder according to

claim 9

, characterized in that an outer ring (17) extending around the member (13) and having a contour corresponding to the outer contour of the jacket (1) is provided at the outer edges of the noses (15).

11. Space holder according to

claim 10

, characterized in that the outer ring (17) is connected with the noses (15) along its center line.

12. Space holder according to any of the

claims 1

to

11

, characterized in that a serrated edge (21,21′) projecting beyond the free end of the jacket (1) is provided at the side of the member facing the adjacent end.

13. Space holder according to

claim 12

, characterized in that the serrated edge extends parallel to the plate (12).

14. Space holder according to

claim 12

, characterized in that the serrated edge extends obliquely to the plate (12).

15. Space holder according to any of the

claims 1

to

14

, characterized in that the edge comprises an even number of equidistant recesses.

Images