The invention will be further illustrated by the following drawings, of which
FIG. 1 is a schematic side view of a first embodiment of the fixing device according to the invention;
FIG. 2 is a top view of said first embodiment;
FIG. 3 is a schematic side view of the first embodiment in the tensioned state.
FIG. 4 is a schematic side view of a second embodiment of such a fixing device;
FIG. 5 is a schematic side view of a third embodiment of such a fixing device; and
FIG. 6 is a top view of said third embodiment.
FIG. 7
a is a top view of a fixing plate according to the invention bearing a ridge;
FIG. 7
b is a side view of this fixing plate of FIG. 7a;
FIG. 8
a is a top view of a fixing plate according to the invention having a groove and being matching with the fixing plate of FIG. 7a; and
FIG. 8
b is a side view of this fixing plate of FIG. 8a.
In FIG. 1 the numbers 2 and 4 denote round fixing plates having a hole 6 resp. 8 surrounded by a ring 10 resp. 12. Between the fixing plates a removable bar 14 is present. Cable 16 surrounds bone parts 17 (not fully shown). One end of cable 16 runs along the trajectory in which parts (j) and (a) to (f) are distinguished. Herein part (j) runs from outside the outer edges underneath the second ring up to the second hole, part (a) runs upward from below through the holes 8 and 6, then bends to the right in an outward direction and runs as part (b) along the upper surface 18 of the ring 10 to the outer edge thereof, where it bends downward to run as part (c) along the outer circumference 20 and 22 of the rings 10 and 12. The cable then bends to the left in an inward direction and runs as part (f) along the lower surface 24 of ring 12 to the inner edge of this ring, where it bends upward to run as part (d) through hole 8 in plate 4. Finally the cable runs as part (e) through the gap 26 in outward direction bringing end 28 out of the gap. The other end of cable 16 follows a similar trajectory but reversed with respect to center of the holes. The ends 28 and 30 can be grabbed and handled to be drawn and tension the cable 16 around bone parts to keep these fixed with respect to each other. Bar 14 prevents the cable from being clamped already and hampering the tensioning of cable 16. In the surface of ring 10 of fixing plate 2 that faces fixing plate 4 a ridge 50 is present. Details of this groove are given in FIGS. 7 and 8. On the surface of ring 12 of fixing plate 4 a groove 52 is present, in position and dimensions matching with ridge 50. Thus the working end 28 of cable 16 will be clamped in the groove by the ridge when the cable is tensioned.
In FIG. 2 a top view of the embodiment of FIG. 1 is shown. Bar 14 can be seen through hole 6 in plate 2.
In FIG. 3 bar 14 has been removed and the plates are pressed together by the cable surrounding the plates. The cable is secured from slipping back by the pressure exerted by the plates on the cable at (e), gap 26 being closed now. In particular the cable being clamped by ridge 50 fitting tightly in groove 52 contributes to a large extent to the securing of the cable end 28 from slipping back. In FIG. 4 the same two plates in the same relative configuration as in FIG. 1 are present.
In FIG. 4 the numbers of corresponding items have been raised by 400, so 402 is the same item as 2 in FIG. 1 etc. One end of cable 416 runs along the trajectory in which parts (j) and (a) to (g) ((f) excluded) can be distinguished. Herein part (j) runs from outside the outer edges underneath the second ring up to the second hole, part (a) runs upward from below through the holes 408 and 406, then bends to the right in an outward direction and runs as part (b) along the upper surface 418 of the ring 410 to the outer edge thereof, where it bends downward to run as part (c) along the outer circumference 420 of ring 410. The cable then bends to the left in an inward direction and runs as part (e) through the gap 426 until it reaches the part of the gap between the holes where it bends downward to run as part (d) through hole 408 in plate 404. Finally the cable runs as part (g) in outward direction underneath lower surface 424 of ring 404 bringing end 428 out of the gap. The other end of cable 416 follows a similar trajectory but reversed with respect to center of the holes. The ends 428 and 430 can be grabbed and handled to be drawn and tension the cable 416 around bone parts 417 to keep these fixed with respect to each other. Bar 14 prevents the cable from being clamped already and hampering the tensioning of cable 16. Ridge 450 and groove 452 are located and function as in FIG. 1.
In FIG. 5502 and 504 are two asymmetric fixing plates having holes 506 and 508 respectively. The ring around each hole has a first part 510 resp. 512 the surface area of which is large enough to give sufficient clamping force on a cable following a trajectory as described before. In this FIG. 5 one end of the cable follows the trajectory described under FIG. 1. The part 532 resp. 534 of the rings at the opposite side of the hole with respect to the first part is smaller that the first part. A tensioning device 536 consists of a first part 538 in which a longitudinal bore is present provided with internal screw thread in which a hook 540 is mounted. The other end 530 of the cable has an eye 546 to which the hook 540 has been attached. The tensioning device 536 further consists of a second part that consists essentially of a recess 542 extending from about the center of the device to its end opposite of the side where the bore is present and extending over its full width. The recess ends at a wall 544. The thickness of this wall is such that it fits in the hole of the plates, leaving sufficient room for the cable to be guided through the holes along the clamping trajectory. Lower plate 504 forms part of the tensioning device. Plate 502 can move upward and downward with respect to plate 504. The bottom 544 of recess 542 is at the same level as the surface of plate 504. This allows ring 510 to be in contact over its complete surface area with ring part 512 of the lower plate when plate 502 is pressed downward when drawing on cable end 528 tensions the cable. Plate 502 is mounted on the tensioning device such that the wall 544 extends through hole 506. Turning hook 540 in a counter clockwise direction tensions the cable further. Ridge 550 and groove 552 are located and function as in FIG. 1 but they extend only across the parts 510 and 512 of the asymmetric fixing plates 502 and 504.
Further, also in this embodiment a bar can be inserted between the rings during the tensioning and then removed when the desired tension is applied.
In FIG. 6 in hole 606 of top plate 602 the top of wall 644 sticking through said hole, is visible. Cable end 630 with eye 646 is connected to hook 640.
In FIG. 7a 754 is a circular fixing plate consisting of a ring 756, surrounding a hole 758. On the surface 760 of ring 756 an also circular ridge 750 is present, the centerline of which coincides with the centerline of ring 756.
In FIG. 7b on ring 756 a ridge 750 is present having the shape of a triangle having a top angle of 90° and a rounded top 762.
In FIG. 8a 854 is a circular fixing plate consisting of a ring 856, surrounding a hole 858. In the surface 860 of ring 856 an also circular groove 852 is present, the centerline of which coincides with the centerline of ring 856.
In FIG. 8b in ring 856 a groove 852 is present having the shape of a triangle having a top angle of 90° and matching with the ridge 750 of FIG. 7b.
Patent Application
20080027440
