Title of Invention

"CLAMP FOR AN EXTERNALBONE FIXATION DEVICE"

Abstract

The clamp for an external fixation device comprises a parallelipipedic basic body (1) fitted with a first and continuous borehole (2) receiving a longitudinal support (3) and a second, continuous borehole (4) running perpendicularly to the first borehole (2) and partly passing through it. A tension bolt (5) fitted with a head (6) is insertable by its free end (7) into the second borehole (4), and its head (6) forms a stop against the basic body (1). At its free end (7), the tension bolt (5) is fitted with a thread (8) to engage a nut (9) forming a stop against the basic body (1). Underneath its head (6), the tension bolt (5) comprises a transverse borehole (10) receiving a bone fixation device (11). By means of the nut (9), the transverse borehole (10) can be moved into the zone of the second borehole (4), and in the process a bone fixation device (11) inserted into the transverse borehole (2) can be made to rest against the basic body (1). The basic body (1) furthermore comprises a threaded borehole (12) crossing both the first and second bore holes (2, 4) and terminating in the second, continuous borehole (4), and receiving a fixation screw (13). The diameter of the tension bolt (5) is less than the diameter of the second borehole (4) and the tension bolt (5) can be moved by the fixation screw (13) into the zone of the second borehole (2) to rest tangentially against the longitudinal support (3).

Full Text

The invention relates to a clamp for an external bone fixation device and defined in the preamble of claim 1. Open fractures of the 2nd and 3rd degrees, infection pseudoarthroses and corrective interventions for axial deviations and length differences are among the most important indications for external fixation devices. A number of clamps for such external fixation devices are already known in the state of the art, however they incur the drawback of requiring exceedingly accurate manufacture and being accordingly costly The objective of the invention is palliation. The basis problem addressed by the invention is to create a clamp for an external bone fixation device that, thanks to its simple design, allows easy-tolerance manufacture while nevertheless assuring optimal results. The problem addressed by the invention is solved by a clamp comprising the features of claim. Accordingly the present invention relates to a clamp for an external bone fixation device, comprising: a body having first, second and third boreholes extending therein; a longitudinal support; a coupling member for coupling to a bone fastener; and a tightening component, wherein the first borehole extends along a first longitudinal axis and is configured and dimensioned for receiving the longitudinal support, the second borehole extends along a second longitudinal axis and is configured and dimensioned for receiving the coupling member, and the third borehole extends along a third longitudinal axis and is configured and dimensioned for receiving the tightening component, with the first longitudinal axis being oriented at an angle with respect to the second longitudinal axis, and the third longitudinal axis being perpendicular to both the first and second longitudinal axes, and with the third borehole extending from a surface of the body to intersect the second borehole, and the first and second boreholes at least partially intersecting each others wherein the longitudinal support in the first borehole and the coupling member in the second borehole are simultaneously fixed in position when the tightening component bears against the member and the member bears against the longitudinal support. The clamp of the invention offers the following advantages: — a design free of tight tolerances, — applicability to all indications of external fixation devices; such versatility allows higher production runs and foremost simplifies logistics which is especially problematical in developing and threshold countries, — the clamp body is only used to receive the two tightening elements (one for the longitudinal support and the other for the bone screw), — the position of the tightening element of the bone screw is also fixed when the longitudinal support is fixed, — in spite of its simple, manufacturing-friendly design, the clamp of the invention provides as many degrees of freedom as conventional, costly clamps of the state of the art, — bone screws of different diameters can be tightened, — - the clamp design is size-independent, that is, the same clamp design is applicable to fractures of thighs, lower arms and fingers, — the generous tolerances relating to the various elements also allow for instance bending the longitudinal support to fit the anatomy; this feature is highly advantageous especially when tending to pelvic fractures; as regards devices of the state of the art, pelvic fractures can be treated only with pre-bent longitudinal supports or with several longitudinal supports mutually connected by articulating jaws In a further preferred embodiment, the clamp includes a bone fixation device, preferably composed of a material such as steel, harder than the basic body illustratively made of aluminum. By combining a comparatively hard with a comparatively soft material, for instance steel/aluminum, the clamp design is substantially simplified. When affixing the bone screw into the clamp, the bone screw is easily forced into the soft aluminum of the clamp. The longitudinal support is affixed in equally simple manner. The compression screw thereby forces the steel tightening element of the bone screw into the softer aluminum longitudinal support. Affixation of the bone screw to the longitudinal support is improved by means of these deformations over the case of mere frictional affixation. The state of the art implements geometric locking by serrating the various tightening elements and thereby incurs considerably higher manufacturing costs. The combination of steel/aluminum offers the further advantage that the clamps can be used several times. The threaded parts being made of steel, the danger of thread overloading or freezing is negligible. The invention and its further embodiments are elucidated below in relation to the partly diagrammatic views of several illustrative embodiments. Fig. 1 is a perspective of the clamp of the invention, Fig. 2 is a front view of the basic body of the clamp of Fig. 1, Fig. 3 is a cross-section parallel to the front surface of the basic body, Fig. 4 is a side view of the basic body of the clamp of Fig. 1, Fig. 5 is a cross-section parallel to the side surface of the basic body, and Fig. 6 is a longitudinal section of the tensioning screw of the clamp of the invention of Fig. 1 The clamp for an external bone fixation device shown in Figs. 1 through 5 in essence comprises a parallelipipedic and preferably aluminum basic body 1 having a front face 14, a rear face 15, two side faces 16 and 17, a rear surface 18 of a top surface 19 and a base surface 20. The basic body 1 is fitted with a first and continuous borehole 2 running from the front face 14 to the rear face 15 to receive a longitudinal support 3. The longitudinal support 3 may be solid or hollow and its surface may be smooth or rough. Preferably the longitudinal support 3 is made of aluminum. The basic body 1 is fitted with a second and continuous borehole 4 running perpendicularly to the first borehole 2 from the side face 16 to the side face 17 and partly crossing this borehole 2 as shown in Figs. 2 through 5. As shown in Figs. 1 and 7, a tension bolt 5 fitted with a head 6 (Fig. 6) is inserted by its end 7 fitted with a thread 8 into the second borehole 4. The tension bolt 5 is secured on one hand by its head 6 of which the diameter is larger than that of the second borehole 4 and forms a stop at the side surface 17 of the basic body 1, and on the other hand it is secured by the nut 9 threaded on the free end 7 of this bolt 5 and forming a stop at the opposite side surface 16 of the basic body 1. Preferably the tension bolt 5 is made of steel. In its circular shank 24 and underneath the head 6, the tension bolt 5 comprises a transverse borehole 10 to receive a bone fixation device 11, for instance a Schanz screw. After the bone fixation device 11 has been inserted into the transverse borehole 10, the tension bolt 5 can be displaced leftward by means of the nut 9 until the transverse borehole 10 enters the zone of the second borehole 4, whereby the bone fixation device 11 comes to rest against the side face 17 of the basic body 1 as shown in Fig. 7. Advantageously a bone fixation device 11 consisting of a harder material, such as steel, than the basic body 1 will be selected to achieve better clamping. The basic body 1 furthermore is fitted with a borehole 12 having a thread 21 running perpendicularly both to the first and second bore holes 2 and 4 and terminating in latter. This threaded borehole 12 receives a fixation screw 13 with a thread 22 that can be made to rest by its free end 23 against the tension bolt 5 inserted into the second borehole 4. The diameter of the shank 24 of the t( .on bolt 5 being smaller than the diameter of the second borehole 4, the tension bolt 5 can be forced by the fixation screw 13 into the zone of the first borehole 2 wherein it rests tangentially against the longitudinal support 3 therein, as a result of which the longitudinal support 3 is fixed in place axialiy and rotationally relative to the basic body 1. WE CLAIM: 1. A clamp for an external bone fixation device, comprising: a body having first, second and third boreholes extending therein; a longitudinal support; a coupling member for coupling to a bone fastener; and a tightening component, wherein the first borehole extends along a first longitudinal axis and is configured and dimensioned for receiving the longitudinal support, the second borehole extends along a second longitudinal axis and is configured and dimensioned for receiving the coupling member, and the third borehole extends along a third longitudinal axis and is configured and dimensioned for receiving the tightening component, with the first longitudinal axis being oriented at an angle with respect to the second longitudinal axis, and the third longitudinal axis being perpendicular to both the first and second longitudinal axes, and with the third borehole extending from a surface of the body to intersect the second borehole, and the first and second boreholes at least partially intersecting each others wherein the longitudinal support in the first borehole and the coupling member in the second borehole are simultaneously fixed in position when the tightening component bears against the member and the member bears against the longitudinal support. 2. The clamp as claimed in claim 1, wherein the third borehole is threaded and only extends to the intersection with the second borehole, with the tightening component also being correspondingly threaded to engage the threaded borehole. 3. The clamp as claimed in claim 1, wherein the coupling member has a first end and a second end, and a through hole proximate the first end for receiving a bone fixation device and the first and second boreholes are perpendicular to each other. 4. The clamp as claimed in claim 3, wherein the coupling member has a threaded portion proximate the second end. 5 The clamp as claimed in claim 4, having a nut for threadably engaging the threaded portion of the coupling member. 6, The clamp as claimed in claim 3, wherein the body (1) has six faces, with each face having smooth edges. 7. The clamp as claimed in claim 3, wherein the body (1) has six faces, with each face having beveled edges. 8, The clamp as claimed in claim 3, wherein the body has a parallelepiped shape. 9. The clamp as claimed in claim 3, wherein the coupling member is cylindrical and has a coupling member diameter, the second bore has a second diameter, and the coupling member diameter is smaller than the second diameter to permit the coupling member to freely move within the second bore. 10. The clamp as claimed in claim 9, wherein the through hole (2) has a hole diameter, the bone fixation device has a fastener diameter, and the hole diameter is about the same as the fastener diameter. 11. The clamp as claimed in claim 1, wherein the tightening component is formed of a first material and the body is formed of a second material, the first material being harder than the second material. 12. The clamp as claimed in claim 11, wherein the first material is steel and the second material is aluminum. 13. The clamp as claimed in claim 12, wherein the longitudinal support is formed of a third material, the first material being harder that the third material. 14. The clamp as claimed in claim 13, wherein the clamp has a threaded coupling member fastener and the coupling member has a first end, a second end, a through hole proximate the first end for receiving a bone fastener, and a threaded portion proximate the second end, the threaded portion being configured for threadably receiving the threaded coupling member fastener. 15. A clamp for an external bone fixation device substantially as hereinbefore described with reference to the accompanying drawings.

Documents:

628-DEL-1998-Assignment.pdf

628-del-1999-abstract.pdf

628-DEL-1999-Assignment.pdf

628-del-1999-claims.pdf

628-del-1999-complete specification (granted).pdf

628-DEL-1999-Correspondence-Others-(23-07-2010).pdf

628-DEL-1999-Correspondence-Others-(30-07-2010).pdf

628-del-1999-correspondence-others.pdf

628-del-1999-correspondence-po.pdf

628-del-1999-description (complete).pdf

628-del-1999-drawings.pdf

628-del-1999-form-1.pdf

628-del-1999-form-13.pdf

628-del-1999-form-19.pdf

628-del-1999-form-2.pdf

628-del-1999-form-26.pdf

628-del-1999-form-3.pdf

628-del-1999-form-4.pdf

628-del-1999-form-6.pdf

628-DEL-1999-GPA-(23-07-2010).pdf

628-del-1999-pa.pdf

628-del-1999-pct-409.pdf

628-DEL-1999-Petition Others-(30-07-2010).pdf

628-del-1999-petition-137.pdf

628-del-1999-petition-138.pdf