MXPA00011059A - Cheek for a one-sided external fixation system for traumatology and orthopedics - Google Patents

Abstract

The invention relates to a device for external fixation of parts of broken bones, which can be fixed to a connecting element (1) and which comprises a cheek (35), an upper pivoting element (4), a middle pivoting element (5) and a lower pivoting element (6), wherein said pivoting elements (4;5;6) are arranged along an axis (38). At least two bone screws or pins (3) can be fixed between the cheek (35) and a clamping surface (47) arranged on the upper pivoting element (4). The upper pivoting element (4) can rotate around an axis of rotation (60) in relation to the middle pivoting element (5), said axis of rotation extending perpendicular to the axis, and can be fixed on the first front face (61) of the middle pivoting element (6) which is located crosswise in relation to the axis (38). The lower pivoting element (6) can be rotated around the axis (38) in relation to the middle pivoting element and can be fixed on its second front face (62).

Description

A DEVICE FOR THE EXTERNAL FIXATION OF BROKEN BONE PARTS The invention relates to a device for the external fixation of parts of broken bones according to the exordium of the rei indication 1. From the state of the art, EP 0 011 258 At ORTHOFIX, a device for external fixation of broken bone parts is known. This known invention comprises a longitudinally extended middle body, which is composed of two parts slidable with respect to each other parallel to the longitudinal axis thereof, each middle body part carrying a fastening device for nails or bone screws that can be inserted in a part of the body. bone, and a pressure and traction device that acts on both parts of the middle body. The clamping devices are seated by means of universal or spherical joints at the outer ends of the sliding parts of the middle body, which makes it possible for the clamping devices and the nails or screws that can be inserted in the parts of the bone can rotate with three degrees of freedom. The disadvantage of this known invention consists in that the clamping devices can only be fixed by means of friction closure, which considerably reduces the sliding resistance of the device after its fixation. Another device for the external fixation of bones by means of pins, known from the state of the art, is disclosed in the U.S. 5,160,335 WAGENKNECHT. This known invention comprises a fixing rod, which can also be telescopic, with fastening elements for supporting the bone bolts, connecting parts with curved support surfaces for the fastening elements, and clamps for fixing the fastening elements with the joint parts on the fixing rod. The connecting parts are formed in such a way that the clamping elements can rotate with respect to the clamps with three degrees of freedom. Again, the disadvantage of this invention is that the pivoting joints can only be fixed to each other by friction closure and that three screws must also be tightened to lock the fastening elements.

The present invention wishes to remedy this disadvantage. It is the object of the invention to enable, on the one hand, the fixing of the rotating joints by means of a positive locking connection and, on the other hand, to enable a removable lock of two or more rotational degrees of freedom with a single fixing screw. The invention solves the proposed problem with a device for the external fixation of parts of broken bones that has the features of claim 1. Further advantageous embodiments of the invention are characterized in the secondary claims. In a preferred embodiment of the device according to the invention, it comprises a jaw and three rotating elements arranged along an axis, so that between the jaw and a clamping surface in the upper rotating element can be fastened screws for bones or bolts, and the entire device can be fixed on a longitudinal joint element. The upper rotating element can rotate with respect to the middle rotating element about an axis of rotation that runs transversally with respect to the axis, and can be pressed against a surface of the rotary means formed as a rotating joint, and be fixed in a desired position. The lower rotating element can be rotated about the axis with respect to the middle rotary element and can be pressed against a second front surface of the middle rotating element and fixed in a desired position. A through hole in the lower rotary element which runs thru the shaft, allows the lower rotating element, and therefore the entire device according to the invention, can be placed on a joint element, be slid on it, be rotated around the axis of the perforation, and be fixed in any desired position. The fixing of the lower rotating element on the connecting element is carried out by means of a fixing screw with which the lower rotating element is clamped on the connecting element. The fixing of the rotating elements between them is carried out by means of another fixing screw, with which the contact surfaces of the rotating elements can be pressed against each other when tightening said fixing screw. To form a positive connection by locking between two of the rotating elements, these are provided on the respective contact surfaces with gears. Another embodiment of the device according to the invention differs from the embodiment described above only in that the rotary axis between the upper and middle rotating elements passes through the axis along which they are arranged. The rotating elements. Again, another embodiment of the device according to the invention differs from the embodiments described above only in that the perforation which makes it possible to place the lower rotating element on the joining element passes pe r pend to the axis a along which the rotating elements are arranged. Another embodiment of the device according to the invention differs from the embodiments described previously only in that the front surface of the middle rotating element in contact with the upper rotating element and the front surface of the rotating element half in contact with the lower rotating element are parallel. Again another embodiment of the device according to the invention differs from the previously described embodiments only in that the fixing of the three rotating elements to each other and the fixing of the lower rotary element to the joint element are carried out jointly by means of a single fixing screw. Again another embodiment of the device of the invention differs from the embodiment described previously only in that said single fixing screw rests with the head thereof on a surface in the lower rotating element perpendicular to the axis, and can be screwed in a thread corresponding to the thread of the fixing screw in a bearing insert rotatably seated in the upper rotating element. Again another embodiment of the device of the invention differs from the embodiment previously described only in that said single fixing screw rests with the head thereof on a surface of the insert of support in the form of circular segment rotatably seated in the upper rotating element, and can be screwed into a thread corresponding to the thread of the fixing screw in the lower rotating element. Again another embodiment of the device according to the invention differs from the previously described embodiments only in that the lower rotating element is provided with a side with a continuous groove that reaches the perforation and that a fixing screw allows the slot, and therefore also the perforation, be narrowed by tightening. In this way it is possible to clamp the lower rotary element in a desired position on the connecting element. Again another embodiment of the element according to the invention differs from the previously described embodiments only in that the gears provided in the lower rotating element in the contact surface with the middle rotating element and the gears provided in the middle rotating element on the contact surface with the rotating element The lower ones are conformed in the form of a circular ring concentrically to the axis. Again another embodiment of the device according to the invention differs from the previously described embodiment only in that the gear provided in the middle rotating element in the contact surface with the upper rotating element is shaped as a segment-shaped cavity circular with a rotary axis perpendicular to the axis, and the gear provided in the upper rotating element on the contact surface with the middle rotary element is shaped as a semicircular bulge with a rotation axis perpendicular to the axis. Again another embodiment of the invention according to the invention differs from the previously described embodiments only in that the screws for fixing the bones can be fixed between the clamp and the upper rotary element by fastening elements, preferably clamping screws , independently of the fixing of the rotating elements.

Again another faith "3 of execution of the device according to the invention differs from the embodiments previously described only in that the clamping surface provided in the upper rotating element and the clamp on the side facing the clamping surface of the The upper rotating element is provided in its width with parallel cavities for the partial reception of the screws for the fixation of bones Once again another embodiment of the device according to the invention differs from the previously described embodiments only in that the screw of Fixation is provided on each of its two front surfaces with means for receiving a tool for loosening and tightening the fixing screw, which means may be formed, for example, as an internal hexagon, a screw slot or a cross slot The advantages achieved by the invention must be seen essentially in that, due to the device according to the invention, the jaws and the rotating elements that hold the screws for fixing bones and join them with the longitudinal connecting element are provided with rotating joints that can be fixed positively by insertion. In addition, the swivel joints integrated in the device by means of fixing elements are shaped in such a way that two or all three rotational degrees of freedom can be blocked with a single fixing screw. The invention and the improved embodiments thereof are explained in more detail below with the help of the partially schematic representations of several exemplary embodiments. Figure 1 shows a top view in section of an embodiment of the device according to the invention with a joining element; Figure 2 shows a sectional view of an embodiment of the device according to the invention; Figure 3 shows a sectional view of another embodiment of the device according to the invention; and Figure A shows a sectional view of another embodiment of the device according to the invention.

Figure 1 shows an embodiment of the device 2 according to the invention that can be slid and fixed on a connecting element 1. The device 2 is provided with three rotating elements 4; 5; 6, whereby a movement of the screws for fastening the bones 3 held in the device 2 with three rotational degrees of freedom with respect to the connecting element 1 is made possible. The rotary element 4 is shaped in such a way that it can be fastened four screws for fixing bones 3. The screws for fixing bones 3 are clamped between the clamping surface 47 on the rotating element 4 and the clamp 35, for which, the clamp 35 is pressed against the rotary element 4 by means of fastening screws 18. Figure 2 represents an embodiment of the device according to the invention. The rotating elements 4; 5; 6 enable mobility of device 2 with three rotational degrees of freedom. The rotating element 6 is composed of a base body and is provided with a through hole 36 whose diameter is shaped so that the rotary element 6 can be slid and rotated on the connecting element 1.

In a desired position on the connecting element 1, the rotary element 6, which is provided on one side with a continuous groove 37 which reaches the perforation, can be clamped on the connecting element 1 by means of the fixing screw 14. Because of this removable clamping connection, rotation of the device 2 is possible around the central axis 7 of the bore 36 provided in the rotary element 6. The rotary elements 4; 5; 6 of the device 2 are arranged for the central axis 7, so that each of the elements 4; 5; 6 is in contact with the adjoining one through a contact surface. The rotary element 5 can rotate with respect to the rotating element 6 around an axis 38, which allows an additional rotational freedom of the device 2. The contact surfaces between the rotary elements 5 and 6 are provided with gears 11; 12 that mesh with each other forming a positive connection by insertion. The rotating shaft of this rotary joint between the rotary elements 5 and 6 coincides with the axis 38 of the rotary element 5. The contact surfaces between the rotary elements 4 and 5 are shaped in the form of a circular segment, so that in the rotating element 4 a t-shaped or semicircular ram 39 is provided which is inserted in a cavity in the form of a circular segment 40 in the rotary element 5 and enables a rotary movement of the standard clamp with a third degree of freedom. the contact surfaces between the rotating elements 4 and 5 are also provided with gears 9; 10 that mesh with each other forming a positive connection by insertion. The two unions by tightening 41; 42 are fixed by means of a single fastening element 13 formed as fixing screw, whose head 44 is seated on the rotary element 4 by means of a support insert 43 and whose threaded rod is screwed into the rotary element 6. rotating element 4 is provided on the width of the clamping surface 47, opposite the bulge 39 in relation to the axis 38, with cavities 45 for partial reception of the screws for fixing bones 3. The screws for fixing bones 3 are inserted between the rotating element 4 and a jaw 35, which is also provided with parallel cavities 46, and are fastened by means of fixing screws 18, whose heads rest on the jaw 35 and which are screwed into the element rotary 4. In the jaw 35 there is an opening 48 that allows a tightening or loosening of the fastening element 13, even if the jaw 35 is fixedly screwed on the rotating element 4 and the screws for fixing bones 3 are clamped between the rotary element 4 and jaw 35. In this way, a movement of the screws is possible for fixing bones 3 firmly fastened with respect to the connecting element 1 with two rotating degrees of freedom by loosening only one fixing element 13 The embodiment of the device according to the invention shown in Figure 3 differs from the embodiment shown in Figure 2 only in that between the support insert 43 in the form of a circular segment in the rotary element 4 and the element 6 is arranged only a single fastening element 15 formed as fixing screw. This fixing screw 15 runs along the axis 38. The screw head 49 rests on a cavity 52 at the lower end 51. The thread 50 of the fixing screw 15 is screwed into the support insert in the form of a circular segment 43. The screw fixing 15 fixes all three rotary elements 4; 5; 6. When tightening the fixing screw 15 it is narrowed by tightening the slot 37 in the rotating element 6, whereby the rotary element 6 is fixed on the connecting element 1. Simultaneously, when tightening the fixing screw 15, they are blocked both the rotating union 41 between the rotary elements 6 and 5, comprising the gears 11 and 12 which mesh forming a positive connection by locking, as well as the rotary union 42 between the rotating elements 5 and 4, comprising the gears 9 and 10 that also mesh forming a positive connection by insertion.

The embodiment of the device according to the invention shown in FIG. 4 differs from the embodiment shown in the embodiment shown in FIG. 3 only in that the fastening element 64 formed as fixing screw is screwed from the rotary element 4. in the thread 67 that is. found in the rotating element 6. The screw head 68 of the screw 64 bears on the bearing insert 43 in the form of a circular segment which is seated rotatably in the rotary element 4. The fixing screw 64 is provided on each of the two front surfaces with an average 65; 66 to receive a tool for loosening and fixing the fixing screw, which means here is formed as an internal hexagon, and therefore the screw can be tightened or loosened both from the rotary element 4 and also from the rotary element 6.

Claims (17)

CLAIMS Having described and determined the nature and scope of the present invention and the manner in which it is to be put into practice, it is hereby declared that what is claimed as an invention and exclusive property is:

1. A device for the external fixation of broken bone parts which can be fixed on a longitudinal connecting element and which comprises a jaw, an upper rotating element, a medium rotating element and a lower rotary element (or), the rotating elements being arranged , along at least one axis so that two contiguous rotating elements touch each other, so that A) between the jaw and a clamping surface disposed on the upper rotating element can be clamped by tightening at least two screws for bones or bolts; B) the upper rotating element can be rotated with respect to the middle rotary element about a rotary axis running transversely with respect to the axis, and can be clamped against the first surface front, transversal to the axis, of the middle rotating element (S); C) the lower rotating element can be rotated with respect to the middle rotary element about the axis, and can be clamped against the second front surface of the middle rotary member; D) the lower rotating element is provided with a through hole running transversely to the axis, which allows the lower rotating element (or) to be slid over the joint element and can be rotated about the central axis of the perforation with respect to to the joining element; and E) the lower rotating element can be fixed on the joining element with the device characterized, because F) at least two of the rotating elements are provided on the contact surfaces that touch each other with gears to form a positive connection by embedded in each case, two rotating elements in contact with each other, and all, the three rotating elements can be fixed to each other and the device can be fixed on the element of union by means of two element. of fixation at most.

2. A device according to claim 1, characterized in that the rotary axis runs perpendicularly to the axis.

3. A device in accordance with the rei indication 1 or 2, characterized in that the perforation in the lower rotating element passes pe r pendi on to the axis.

4. A device according to one of claims 1 to 3, characterized in that the front surfaces of the middle rotary element are parallel.

5. A device according to one of claims 1 to 4, characterized in that the fastening elements are fixing screws.

6. A device according to one of claims 1 to 5, characterized in that all three elements. rotary can be fixed each other and the device can be fixed on the connecting element with a single fixing element.

7. A device according to the claims, characterized in that the single fixing element is supported with the screw head on a surface perpendicular to the axis in the lower rotating element and can be screwed into a thread corresponding to the thread of the fixing screw in an insert of support in the form of a circular segment, rotatably seated in the upper rotating element.

8. A device according to claims 5 and 6, characterized in that the single fixing element is supported with the screw head on a support surface of the bearing insert in the form of a circular segment, rotatably seated in the upper rotating element and can be screwed in a thread corresponding to the thread of the fixing screw in the lower rotating element.

9. A device according to one of claims 1 to 5, characterized in that the The rotary element is provided with a side with a continuous groove that reaches the bore and a fixing element makes it possible for the groove, and therefore also the bore, to be tightened by tightening.

10. A device according to one of claims 1 to 9, characterized in that the gear provided in the lower rotating element on the contact surface with the middle rotating element is shaped in a circular ring and concentric to the shaft.

11. A device according to one of claims 1 to 10, characterized in that the gear provided in the middle rotary element on the contact surface with the lower rotating element is shaped in a circular ring and concentric to the shaft.

12. A device according to one of claims 1 to 11, characterized in that the gear provided in the middle rotating element on the contact surface with the upper rotating element is shaped as a cavity in the shape of circular segment with the rotary axis that runs for the first time with the axis.

13. A device according to one of the claims 1 to 12, characterized in that the gear provided in the upper rotating element on the contact surface with the middle rotating element is shaped as a semicircular shape with the rotating axis running parallel to the rotating element. Arm yourself with the shaft.

14. A device according to one of claims 1 to 13, characterized in that the screws for fastening bones can be clamped between the clamp and the upper rotating element by means of fixing screws independently of the fixing of the rotating elements.

15. A device according to one of the rei indications 1 to 14, characterized in that the clamping surface provided in the upper rotating element is provided in its width with parallel cavities for the partial reception of the screws for fixing bones.

16. A device according to one of the rei indications 1 to 15, characterized in that the jaw is provided in the width of the side facing the clamping surface in the upper rotating element with parallel cavities for partial reception of the bone screws.

17. A device according to one of the claims 1 to 16, characterized in that a fastening element formed as a fixing screw is provided with one of both front surfaces with a means for receiving a tool for loosening and tightening the screw. fixation. j ^ jg ^ jjg ^^ SUMMARY A device (2) for the external fixation of parts of broken bones that can be fixed on a longitudinal attachment element (1) and that comprise a jaw (35), an upper rotating element (4), a medium rotating element ( 5) and a lower rotary element (6), the rotating elements (4; 5; 6) being arranged along an axis (38). Between the clamp (35) and a clamping surface (47) disposed on the upper rotating element (4), at least two bone screws (3) or bolts can be clamped. The upper rotating element (4) can be rotated with respect to the middle rotating element (5) about a rotating shaft (60) that runs transversely with respect to the shaft (38), and can be clamped against the first frontal surface ( 61), transverse to the axis (38), of the middle rotating element (5). The lower rotating element (6) can be rotated with respect to the middle rotating element (5) about the axis (38), and can be clamped against the second front surface (62) of the middle rotating element (5). In addition, the lower rotating element (6) is provided with a through hole (36) which It is then passed through the shaft (38) that allows the lower rotary element (6) to be slid over the connecting element (1) and rotated about the central axis (7) of the perforation ( 36) with respect to the connecting element (1). The lower rotary element (6) can be fixed on the connecting element (1). The rotating elements (4; 5; 6) are provided on the contact surfaces touching each other with gears (9; 10; 11; 12) to form a positive connection by fitting, in each case, two rotating elements (4; 5; 6) in contact each other, and all three rotary elements (4; 5; 6) can be fixed to each other by means of two fasteners (13; 14; 15; 64) at most.