AT524172A1 - Implant for fixation of a first bone part and a second bone part of a fractured bone - Google Patents

Abstract

The invention relates to an implant (1) for fixing a first bone part (2) and a second bone part (3) of a broken bone, comprising: - a first fastening element (4) for fastening in the first bone part (2); - A second fastening element (5) for fastening in the second bone part (3); - a connecting element (6) for connection to the first fastening element (4) and to the second fastening element (5), the connecting element (6) and the first fastening element (4) having first cooperating connecting means (7) and the connecting element (6) and the second fastening element (5) has second cooperating connecting means (8) so that a relative distance between the first fastening element (4) and the second fastening element (5) can be changed; characterized in that the first fastening element (4), the second fastening element (5) and the connecting element (6) have a bioresorbable material.

Description

The invention relates to an implant for fixing a first bone part and a second bone part of a fractured bone, having:

- a first fastening element for fastening in the first bone part;

- a second fastening element for fastening in the second bone part;

- a connecting element for connection with the first fastening element and with the second fastening element, wherein the connecting element and the first fastening element have first cooperating connecting means and the connecting element and the second fastening element have second cooperating connecting means, so that a relative spacing of the first fastening element and the two-

th fastener can be changed to each other.

In addition to plate osteosynthesis, it is known to treat bone fractures with locking intramedullary nails. For this purpose, the nail is introduced into the marrow cavity over the entire length of the bone and fixed by means of several locking bolts inserted transversely proximally and distally. These nails are made of solid

ven titanium alloys.

Furthermore, US Pat. No. 5,334,184 A shows a device for internally fixing two parts of a fractured long bone. With the device, however, the bone parts cannot be pulled against one another, but a distance remains between the parts. Therefore, in the long term, the device must replace part of the bone and not degrade. It is known, however, that bone degradation takes place disadvantageously due to the permanent relief of the bone in the case of marrow nails and in the case of devices such as those shown in US Pat. No. 5,334,184 A.

Furthermore, lengthening intramedullary nails for leg lengthening

know. The lengthening is done, for example, by a built-in motor or mechanically by a ratchet mechanism. All of these systems are removed again after the lengthening achieved and the bony healing, whereby the pro-

problem of bone loss. On the other hand, because of the

manoeuvrable removal, a new operation with the associated

going disadvantages necessary.

It is an object of the present invention to mitigate or obviate at least one disadvantage of the prior art. In particular, it is an object of the invention to propose an implant for fixing a first bone part and a second bone part of a broken bone, with which an improved and/or simplified treatment of the broken bone is possible. In particular, a stable fixation of the bone parts belonging to one another and a connection of the bone parts to one another in the correct or corrected position should be achieved. Furthermore, in particular, the need for a further operation and the bone resorption that begins with permanent relief of the bone should be considered at the same time

be avoided.

This is achieved by an implant as mentioned in the introduction, the first fastening element, the second fastening element and the connecting element being a bioresorbable material

exhibit.

The broken (fractured) bone can be fixed with the implant. The first fastening element is fastened in the first bone part and the second fastening element is fastened in the second bone part. Then the bone parts can be pulled together with the connecting element and brought into a correct position. Preferably, the bone parts can be drawn together to such an extent that they rest against one another (in particular at the breaking edges). Subsequent removal of the implant is advantageously not necessary since the first fastening element, the second fastening element and the connecting element have a bioresorbable material. The implant can therefore remain in the body or in the bone. Furthermore, the rigidity of the support of the bone or the fixation of the bone parts by the implant advantageously decreases over time due to the degradation of the bioresorbable material, so that degradation processes of the bone material resulting from permanent relief of the bone are avoided.

become the Furthermore, by providing a first and

second fastening element for fastening in the respective bone part does not affect the blood supply to the bone or only affects it to a lesser extent than in the case of a plate lying against the bone, which is fitted with screws

Bone is attached, the case would be.

Preferably, the fractured bone is a long bone (human or animal), i.e. a bone with a unitary marrow cavity, for example: humerus, ulna, radius, femur, tibia, fibula, metacarpal, metatarsal, phalanges, toes, clavicle. The first fastening element is preferably arranged and/or fastened at least partially in the marrow cavity of the first bone part and the second fastening element is at least partially arranged and/or fastened in the marrow cavity of the second bone part. The implant is particularly suitable for a fracture in the area of the bone shaft (diaphysis) or the metaphysis. However, other fractures, such as a femoral neck fracture, are also

xable.

Advantageously, the fastening elements are not introduced via the ends of the bone, but can be introduced into the medullary cavity of the respective bone part at the breaking edge and fastened there. If necessary (and not present anyway due to the medullary cavity), part of the bone part can be removed for this purpose, in particular milled out, in order to create a space for the respective fastening element. Preferably, the respective fastener is axially in the respective

ligous bones introduced.

A recess can then be provided in the radial direction in the first and/or second bone part in order to actuate the first and second cooperating connecting means. With the first and the second interacting connecting devices, in particular a relative distance between the first and the second fastening element can be changed in an axial direction of the fastening elements. In particular, the first and the second fastening element can be pulled together with the cooperating connection devices. The first

and/or the second cooperating connecting means

are preferably operable by rotating the connecting element (relative to the first and/or second fastening element). Preferably, the first and/or the second interacting connecting devices can be actuated from a radial direction. The first and/or the second interacting connecting devices are preferably set up to convert a circumferential force into a force in an axial direction of the respective fastening element. In the connected state (i.e. the connecting element is connected to the first and to the second fastening element), the connecting element can preferably transmit forces acting on the first fastening element, in particular forces acting in the radial direction, to the second fastening element and vice versa. In particular, the first fastening element cannot be tilted relative to the second fastening element in the connected state. In particular, the first fastening element and the second fastening element behave in the connected state (and before degradation of the bioresorbable material) as a one-piece unit with respect to a radial force application and/or an axial force application. The connecting element preferably has a first rod which can be accommodated in a (particularly complementary) recess of the first connecting element, and/or a second rod which can be accommodated in a (particularly complementary) recess of the second

Connecting element is receivable on.

The connecting element preferably lies entirely in a virtual cylinder, the diameter of which corresponds to twice, preferably 1.5 times, particularly preferably 1.3 times the minimum virtual cylinder that can be circumscribed around the first and second fastening element; wherein the height of each virtual cylinder is infinite and the central axis of each virtual cylinder runs through the central axis of the implant running from the first fastening element to the second fastening element. That is, the connecting element does not protrude too far radially. This will block the

Connection of the first and the second bone part prevented.

Under a bioresorbable (also biodegradable or bioabsorbable)

called bible) material is understood a material that over

a period of time in a physiological environment, in particular in the human and/or animal body, to at least 90% by weight, preferably essentially completely, degraded (dissolved, decomposed, split and/or eroded) by biological, chemical and/or physical processes. Degradation of the bioresorbable material may include and/or be followed by removal, restructuring, assimilation, and/or excretion of the degraded material, among other things. For example, the bioresorbable material can be a material that is at least partially, preferably essentially completely, replaced by bone and/or bone marrow during and/or after bioresorption. Replacement with bone and/or bone marrow may involve macroscopic, microscopic, and/or atomic restructuring of the bioresorbable material in situ and/or its removal. The bioresorbable material is preferably broken down into components that are metabolizable and/or excretable. The bioresorbable material is preferably within a period of less than 10 years, more preferably within a period of less than 5 years, even more preferably within a period of 2.5 years, to at least 90% by weight, preferably essentially completely, im adult human body degraded. The bioresorbable material is preferably a bioresorbable metal, a bioresorbable metal alloy, a bioresorbable polymer and/or a bioresorbable composite material. The bioresorbable material is preferably based on magnesium and/or iron. The bioresorbable material can have, for example, poly-L-lactide (PLLA), poly-D-lactide (PDLA) or poly-(L-co-D/L-lactide) (PLDLLA).

The bioresorbable material can have one or more bioresorbable substances. The first fastening element, the second fastening element and the connecting element preferably consist of at least 80% by weight, particularly preferably at least 90% by weight, even more preferably at least 95% by weight, of the bioresorbable material. The implant preferably consists overall of at least 80% by weight, particularly preferably at least 90% by weight, even more preferably at least 95% by weight, of the bioresorbable material. Preferably there is

first fastener, the second fastener, the

Connecting element and/or the implant made of the bioresorbable

material.

It is advantageous if a thread of the first fastening element and a first thread of the connecting element which is complementary to the thread of the first fastening element are provided as the first interacting connecting devices, and a thread of the second fastening element and a second thread of the connecting element which is complementary to the thread of the second fastening element are provided as the second interacting connecting devices are provided. Thus, in a simple manner, the relative distance between the first and the second fastening element

be adjusted to each other.

It is preferred if the first thread of the connecting element and the second thread of the connecting element are opposite threads and the thread of the first fastening element and the thread of the second fastening element are opposite threads. Ie, advantageously the first thread of the connecting element and the thread of the second fastening element are left-handed and the second thread of the connecting element and the thread of the first fastening element are right-handed, or the first thread of the connecting element and the thread of the second fastening element are right-handed and the second thread of the connecting element and the thread of the first fastener left-handed. Thus, by rotating the connecting element, an opposite movement of the first and second fastening element can be achieved, i.e. the two fastening elements are pulled together in one direction by rotating the connecting element and

pushed apart by a rotation in the other direction.

It is advantageous if the first thread and the second thread of the connecting element J] are each male (i.e. screw threads) and if the threads of the first fastening element and the thread of the second fastening element are each female (i.e. nut) threads. The connecting element can advantageously be partially accommodated in the first fastening element and partially in the second fastening

element can be picked up. It is advantageous if the first

7735

thread of the connecting element on the first rod of the connecting element and the thread of the first fastening element are provided in the recess of the first fastening element. It is advantageous if the second thread of the connecting element is provided on the second rod of the connecting element and the thread of the second fastening element is provided in the recess of the second fastening element. There is thus a particularly stable connection between the fastening element and the connecting element

achieved.

It is advantageous if the connecting element has a drive profile, in particular in the form of a toothed wheel, on a lateral surface. Thus, a force acting in the circumferential direction can easily be exerted on the connecting element, in particular in order to adjust the relative distance between the first and second fastening element with the first and second interacting connecting devices. In particular, the drive profile has at least one bulge or recess, which in each case extends in particular in the axial direction. In particular, the drive profile is set up so that a force can be exerted on the connecting element from the radial direction in the circumferential direction. A cutout or similar in the bone can be used for radial access to the connecting

element can be provided from at least one side.

It is preferred if the first fastening element has at least one spreading device for spreading in the first bone part. This allows compression to be exerted on the surrounding bone tissue. In particular, a circumference of the first fastening element can be increased with the spreading device, so that the first fastening element spreads in the bone. Thus, the first fastening element acts in particular as a dowel. It is preferred if a corresponding hole is first provided in the first bone part, into which the first fastening element can be inserted. The hole can already be completely or partially through the medullary cavity. After the introduction of the first fastening element, it is spread with the spreading device in the first part of the bone. When expanding, a circumference of the first fastening element presses

against the inner surface of the hole, causing it to frictionally engage

comes. Furthermore (as explained in more detail below), a form fit is also possible. Advantageously, predetermined breaking points occurring in the bone due to a cutting effect are avoided by fastening with the aid of the spreading device (for example in contrast to (self-tapping) screws). During the expansion, the circumference preferably increases, with the diameter being increased at least at one point to at least 1.01 times, preferably 1.05 times, particularly preferably 1.1 times, the original diameter. During expansion, the circumference increases, in which the diameter at least at one point decreases by preferably at least 0.1 mm, particularly preferably at least 0.3 mm, even more preferably at least 0.7 mm compared to the original diameter.

is increased.

It is advantageous if the expansion device has an expansion sleeve, in particular an expanding sleeve, and at least one first wedge element, the expansion sleeve being able to be pushed onto the first wedge element in the direction of an increasing cross section of the first wedge element. By pushing on the expansion sleeve in the direction of the increasing cross section of the first wedge element, expansion, i.e. an increase in circumference, can be achieved. The expansion sleeve preferably lies (at least along a section limited in the axial direction) on the lateral surface of a (virtual) cylinder or a (virtual) truncated cone. The expansion sleeve preferably has a thickness (in cross-section parallel to the axial direction) of between 0.1 and 5 mm. A lateral surface of the first wedge element is preferably frustoconical in a conical section. The expansion sleeve can already be partially on the first even when loosened

Be pushed wedge element.

It is preferred if the expanding device has a second wedge element, in which case the expanding sleeve can be pushed onto the second wedge element in the direction of an increasing cross section of the second wedge element. The direction of increasing cross-section of the second wedge member is preferably opposite to the direction of increasing cross-section of the first wedge member. Preferably, the increase in transverse

cut in the direction facing away from the other wedge element

tion. A spreading can thus take place at two ends or on two sides of the expansion sleeve, with the two sides having different, essentially mirrored, angles to the axial direction. The first wedge element and the second wedge element are preferably movable relative to one another. A lateral surface of the second wedge element is preferably frustoconical in a conical section. The expansion sleeve can also be partially pushed onto the second wedge element in the released state. The expansion sleeve preferably lies at least partially between the first and the second wedge element and/or

or connects them.

It is advantageous if the first fastening element has a pull rod with which the first wedge element can be displaced, so that the expansion sleeve is pushed onto the first wedge element in the direction of the increasing cross section of the first wedge element and so that the expansion sleeve is preferably pushed onto the second wedge element in the direction of the increasing Cross-section of the second wedge element is postponed. The expansion sleeve and the first wedge element can thus preferably be displaced relative to one another with the pull rod. However, the first and the second wedge element can also be displaced relative to one another, as a result of which the expansion sleeve is snapped onto the first and the second wedge element.

be practiced

It is preferred if the first wedge member and the tie rod have cooperating threads. The first wedge element can be displaced with the cooperating threads and the expansion sleeve can thus be pushed onto the first wedge element. Preferably, the pull rod on the one hand and the expansion sleeve or the second wedge element on the other hand each have a stop element which blocks displacement of the pull rod relative to the expansion sleeve or the second wedge element in at least one axial direction, with the direction preferably being in the direction of the increase in the increasing cross section of the first Wedge element on which the expansion sleeve is pushed shows. This ensures that when the wedge element is moved using the cooperating thread, the expansion sleeve on the first wedge element and preferably the second

Wedge element is spread. The pull rod can also be used with the

Expansion sleeve or the second wedge element made in one piece

be.

It is preferred that the tie rod has a screw head drive member at one end thereof. With this, a torque can be exerted on the pull rod at one end of the pull rod in order to move the first wedge element and to expand the expansion sleeve. The screw head drive element is in particular in the form of an internal screw head profile. The first fastening element is expanded in particular in the bone,

before it is connected to the connector.

It is advantageous if the screw head drive element is arranged radially inside the thread of the first fastening element. That is, the screw head drive member preferably has a smaller radial extent from a central axial axis than the threads of the first fastener. The thread of the first fastening element is preferably provided on (in particular in) the second wedge element. It can also be attached to the drawbar, the first wedge element or the expansion sleeve

be provided.

It is preferred if the expansion sleeve has at least two incisions running from an edge of the expansion sleeve that delimits the expansion sleeve in an axial direction. Wings are thus preferably formed between the incisions, which are spread open in particular when pushed onto the first wedge element. This prevents the expansion sleeve from spreading (even when using a very stiff material for the expansion sleeve).

simplified.

It is advantageous if the expansion sleeve has at least two incisions running from one expansion sleeve in the other axial direction-limiting edge of the expansion sleeve. In particular, wings are also formed between these incisions. This prevents the expansion sleeve from spreading outwards on both sides.

ate simplified.

It is preferred if the expansion sleeve of the expansion device

the outer lateral surface in the circumferential direction, in particular

has circumferentially running grooves and/or ribs. With these, the stability of the attachment of the first attachment element to the first bone part can be improved in the axial direction. In particular, a low form fit can thus also be achieved. The compression with the bone is improved by the grooves and/or ribs. The grooves and/or ribs running in the circumferential direction are formed by a height difference of preferably less than 2 mm, more preferably less than 1 mm, even more preferably less than 0.5 mm or less than 0.3 mm and/or preferably more formed as 0.05 mm. With these values, it is advantageously avoided that demolition edges/predetermined breaking points at the first node

small parts arise.

It is advantageous if the expansion sleeve of the expansion device has grooves and/or ribs running obliquely to the circumferential direction, in particular running axially, on the outer lateral surface. In this way, twisting of the expansion sleeve relative to the first bone can be prevented. The grooves and/or ribs running obliquely to the circumferential direction are formed and/or preferred by a height difference of preferably less than 2 mm, particularly preferably less than 1 mm, even more preferably less than 0.5 mm or less than 0.3 mm formed more than 0.05 mm. With these values, it is advantageously avoided that demolition edges/predetermined breaking points at the first node

small parts arise.

It is preferred if the first fastening element has at least one further spreading device for spreading in the first bone part, the further spreading device being designed in particular according to one of the embodiments described herein for the spreading device. The spreading device and the further spreading device preferably have the same features. Thus, the stability in the first bone part can be improved. Two or more further spreading devices can also

be provided.

It is advantageous if the additional expansion device has: an additional expansion sleeve,

another first wedge element, wherein the further expansion

sleeve can be pushed onto the further first wedge element in the direction of an increasing cross section of the further first wedge element, and

a further second wedge element, wherein the further expansion sleeve in the direction of an increasing cross-section of the further second wedge element on the further second wedge element

is slidable.

It is preferred if the further first wedge element can also be displaced with the pull rod of the first fastening element, so that the further expansion sleeve is pushed onto the further first wedge element and preferably the further second wedge element and spread open. It is preferred if the additional first wedge element and the tie rod have interacting threads with which the additional first wedge element can be displaced. In this case, the expansion sleeve can also be pushed onto the first wedge element without the first wedge element and the pull rod having cooperating threads, since tightening the first further wedge element can also result in compression in the area of the first wedge element. The further first wedge element is preferably arranged further away from the connecting element in the axial direction than

the first wedge element.

It is preferred if the first wedge element of the spreading device and the further second wedge element of the further spreading device are connected to one another, so that a displacement of the first wedge element of the spreading device leads to the same displacement of the further second wedge element of the further spreading device, with the first wedge element of the spreading device and the further second wedge element of the further spreading device are in particular made in one piece. In the case of a one-piece design, the first wedge element and the further second wedge element form, in particular, essentially

a double wedge.

It is advantageous if the bioresorbable material contains magnesium, preferably a magnesium alloy, in particular containing between 0.0 and 10.0% by weight zinc. the

Magnesium alloy preferably has (in % by weight):

optionally more than 0.0 up to 7.0% zinc; optionally more than 0.0 up to 1.0% zirconium; optionally greater than 0.0% up to 1.0% calcium; optionally more than 0.0 up to 1.0% manganese; optionally greater than 0.0% up to 0.5% silicon; optionally more than 0.0 up to 1.0% silver; optionally maximum up to 0.5% aluminum; and optionally at least one element selected from the group consisting of greater than 0.05% up to 0.6% yttrium; more than 0.05 up to 4.0% ytterbium;

more than 0.05 up to 4.0% gadolinium.

Preferably, the bioresorbable material comprises a magnesium alloy containing (in percent by weight): greater than 0.0% up to 7.0% zinc; optionally more than 0.0 up to 1.0% zirconium; optionally greater than 0.0% up to 1.0% calcium; optionally more than 0.0 up to 1.0% manganese; optionally greater than 0.0% up to 0.5% silicon; optionally more than 0.0 up to 1.0% silver; maximum up to 0.5% aluminum; and at least one element selected from the group consisting of greater than 0.05% up to 0.6% yttrium; more than 0.05 up to 4.0% ytterbium; more than 0.05 up to 4.0% gadolinium;

The remainder is magnesium and manufacturing-related impurities.

The bioresorbable material preferably has a magnesium alloy according to one of the embodiments described in AT 510087 A1.

tion forms.

The second fastening element can be designed according to an embodiment described in connection with the first fastening element. In particular, the second fastening element is designed like the first fastening element, but mirrored to this (to a running through the connecting element

plane of symmetry) formed.

The invention is described below with reference to a preferred exemplary embodiment illustrated in the drawings, to which

but should by no means be limited, explained in detail.

Fig. 1 schematically shows an embodiment of the implant in

a broken bone.

Fig. 2 shows schematically the same embodiment of the implant as in Fig. 1 in a sectional view along the plane A-A (without

Bone).

Fig. 3 shows schematically the same embodiment of the implant as Fig. 1, wherein the first fastening element, the connecting element and the second fastening element are not

who are connected.

4 schematically shows the same embodiment of the implant

as Fig. 1 in an exploded view.

1 shows an embodiment of the implant 1 for fixing a first bone part 2 and a second bone part 3 of a fractured bone in the bone (but in the non-expanded position). 2 shows the implant 1 in a sectional representation along the plane AA. Fig. 3 shows the implant 1 in a partially dismantled state and Fig. 4 shows that

Implant 1 in an exploded view.

The implant 1 has a first fastening element 4 for fastening in the first bone part 2 and a second fastening element 5 for fastening in the second bone part 5. In FIG. 1 these are shown in the state in which they are fastened in the bone. The first fastening element 4 and the second fastening element 5 are provided in particular in the medullary cavity of the respective bone part 2, 3. Furthermore, a connecting element 6 for connection to the first fastening element 4 and to the second fastening element 5 is provided. The connecting element 6 and the first fastening element 4 have first interacting connection devices 7 and the connecting element 6 and the second fastening element 5 have second interacting connections.

binding devices, with which a relative distance of the

first fastener 4 and the second fastener 5 can be changed to each other. Thus, after fastening the first fastening element 4 in the first bone part 2 and the second fastening element 5 in the second bone part 3, the first bone part 2 and the second bone part 3 can be pulled together, preferably in such a way that their breaking edges

touch each other.

The first fastening element 4, the second fastening element 5 and the connecting element 6 have a bioresorbable material. As a result, the implant 1 can remain in the bone and does not have to be removed. Furthermore, the relief of the bone decreases over time and with increasing degradation of the bioresorbable material, so that degradation processes of the bone substance that occur due to such a relief are avoided.

the or can be reduced.

As the first interacting connecting devices 7 , the first fastening element 4 has a thread 9 and the connecting element 6 has a first thread 10 complementary to the thread 9 of the first fastening element 4 . (The threads are each symbolized by thick lines.) As the second interacting connecting devices 8 , the second fastening element 5 has a thread 11 and the connecting element 6 has a second thread 12 complementary to the thread 11 of the second fastening element 5 . The first thread 10 of the connecting element 6 and the second thread 12 of the connecting element 6 are opposite threads and the thread 9 of the first fastening element 4 and the thread 11 of the second fastening element 5 are opposite threads. Thus, by rotating the connecting element 6, an opposite displacement of the first fastening element 4 and the second fastening element 5

be achieved.

The first thread 10 and the second thread 12 of the connecting element 6 are each external threads and the thread 9 of the first fastening element 10 and the thread 11 of the second fastening element 5 are each internal threads. The first thread 10 and the second thread 12 of the connecting element are

ments 6 each on a standing in an axial direction 33

Rod is provided and the first thread 9 of the first fastening element 10 and the thread 11 of the second fastening element 5 on the inner surface of a recess of the respective fastening element 4, 5 which is complementary to the rod the second fastener 5 and vice versa improved. The axial direction 33 is indicated by a double arrow (cf. FIG. 2). Under the axial direction

33 both orientations can be understood.

The connecting element 6 has a drive profile 14 in the form of a toothed wheel on a lateral surface 13 . With this, a torque can be applied to the connecting element 6 and this ro-

be animal.

The first fastening element 4 has a spreading device 15 and a further spreading device 27 for spreading in the first bone part 2 . The expanding device 15 has an expanding sleeve 16 and a first wedge element 17, the expanding sleeve 16 being able to be pushed onto the first wedge element 17 in the direction of an increasing cross section of the first wedge element 17. Furthermore, the spreading device 15 has a second wedge element 18, wherein the spreading sleeve 16 can also be pushed onto the second wedge element 18 in the direction of an increasing cross section of the second wedge element 18. The direction of increasing cross section of the second wedge element 18 is opposite to the direction of increasing cross section of the first wedge element 17

puts.

The further spreading device 27 has a further spreading sleeve 28 . Furthermore, the further spreading device 27 has a further first wedge element 29, wherein the further spreading sleeve 27 can be pushed onto the further first wedge element 29 in the direction of an increasing cross section of the further first wedge element 29. Furthermore, the further spreading device 27 has a further second wedge element 30 , wherein the further spreading sleeve 28 can be pushed onto the further second wedge element 30 in the direction of an increasing cross section of the further second wedge element 30 . The first wedge element 17 of the spreading

device 15 and the further second wedge element 30 of

further spreading device 27 are connected to one another, so that a displacement of the first wedge element 17 of the spreading device 15 leads to the same displacement of the further second wedge element 30 of the further spreading device 27 . In this embodiment, the first wedge member 17 is the spreader 15 and the further second wedge member 30 is the further

Spreader 27 made in one piece.

The first fastening element 4 has a pull rod 19, with which the first wedge element 17 of the expanding device 15 (and thus likewise the further second wedge element 30 of the further expanding device 27) and the further first wedge element 29 can be displaced, so that the expanding sleeve 16 onto the first wedge element 17 and the second wedge element 18 and the further expansion sleeve 28 is pushed onto the further first wedge element 29 and the further second wedge element 30 in the direction of the increasing cross section of the respective wedge element 16, 17, 29, 30. For this purpose, the tie rod 19 and the further first wedge element 29 have threads 34 that work together. Furthermore, the pull rod 19 on the one hand and the second wedge element 18 on the other hand each have a stop element 31, 32. The stop elements 31, 32 block a displacement of the pull rod 19 in relation to the second wedge element 18 in at least one axial direction, with the axial direction being in the direction of the increase in the increasing cross section of the first wedge element 17 or of the further first wedge element 29, onto which the expansion sleeve 19 or The further expansion sleeve 28 is pushed on, shows. Thus, the additional first wedge element 29 can be pulled together to form the second wedge element 19 with the pull rod 19, whereby the expansion sleeve 16 is expanded on the first wedge element 17 and the second wedge element 18 and the additional expansion sleeve 28 on the additional first wedge element 29 and the additional second wedge element 30

is spread.

The displacement of the first wedge element 17 to the second wedge element 18 is approximately half the displacement of the further first wedge element 29 to the second wedge element 18. The first wedge element 18 is essentially also partially displaced by the further expansion sleeve 28. The restoring forces of

further expansion sleeve 28 and the expansion sleeve 16 ensure

that both expansion sleeves are spread to a similar extent. Alternatively or additionally, the first wedge element 17 and the tie rod 19 can also have cooperating threads, which in this embodiment should be designed in such a way that the rotation of the tie rod 19 through a certain angle causes a displacement of the first wedge element 17 that is about half as large like the displacement of the other first wedge element 29

is.

To facilitate rotation of the drawbar 19, the drawbar 19 has a screw head drive member 21 at one end thereof. The screw head drive element 21 is arranged radially inside the thread 9 of the first fastening element 4

not.

The expansion sleeve 16 has at least two incisions 23 running from an edge 22 of the expansion sleeve that delimits the expansion sleeve 16 in an axial direction 33, between which incisions 23 are formed. Furthermore, the expansion sleeve 16 has at least two incisions 25 running from an edge 24 of the expansion sleeve 16 that delimits the expansion sleeve 16 in the other axial direction 33, between which in turn wings (looking in the other axial direction) are formed. With these, the expansion sleeve 16 is expanded by the first wedge element 17 (with respect to the incisions 23) and by the second wedge element

18 simplified (with respect to the incisions 25).

Furthermore, the expansion sleeve 16 of the expansion device 15 has grooves running in the circumferential direction on the outer lateral surface 26 .

The other expansion sleeve 27 is designed the same as the expansion sleeve 16 . The second fastening element 5 is analogous to the first fastening element 4, mirrored around the connecting element

6, executed.

Claims (20)

Patent Claims: 1. Implant (1) for fixing a first bone part (2) and a second bone part (3) of a fractured bone, having: - A first fastening element (4) for fastening in the first bone part (2); - A second fastening element (5) for fastening in the second bone part (3); - a connecting element (6) for connection to the first fastening element (4) and to the second fastening element (5), the connecting element (6) and the first fastening element (4) having first cooperating connecting means (7) and the connecting element (6) and the second fastening element (5) has second cooperating connecting means (8) so that a relative distance between the first fastening element (4) and the second fastening element (5) can be changed; characterized in that the first fastening element (4), the second fastening element (5) and the connecting element (6) a bioresorbable have material. 2. Implant (1) according to claim 1, characterized in that a thread (9) of the first fastening element (4) and a first thread (10 ) of the connecting element (6) are provided and as second interacting connecting devices (8) a thread (11) of the second fastening element (5) and a thread (11) of the second fastening element (5) complementary second Thread (12) of the connecting element (6) are provided. 3. Implant (1) according to claim 2, characterized in that the first thread (10) of the connecting element (6) and the second thread (12) of the connecting element (6) are opposite threads and that the thread (9) of the first fastening element (4) and the thread (11) of the second fastening element (5) are opposite threads. 4, implant (1) according to one of claims 2 or 3, characterized in that the first thread (10) and the second thread (12) of the connecting element (6) are each external thread and that the thread (9) of the first fastening element ( 10) and the thread (11) of the second fastening element (5), respectively are internal threads. 5. Implant (1) according to any one of the preceding claims, characterized in that the connecting element (6) on a lateral surface (13) has a drive profile (14), in particular in the form a gear wheel. 6. Implant (1) according to any one of the preceding claims, characterized in that the first fastening element (4) has at least one spreading device (15) for spreading in the first Has bone part (2). 7. The implant (1) according to claim 6, characterized in that the expansion device (15) has an expansion sleeve (16), in particular an expansion sleeve, and at least one first wedge element (17), the expansion sleeve (16) having an increasing cross section of the first wedge element (17) on the first Wedge element (17) can be pushed. 8. Implant (1) according to claim 7, characterized in that the expansion device (15) has a second wedge element (18), the expansion sleeve (16) further in the direction of an increasing cross-section of the second wedge element (18) on the second wedge element (18) can be pushed on. 9, implant (1) according to one of claims 7 or 8, characterized in that the first fastening element (4) has a pull rod (19) with which the first wedge element (17) can be displaced, so that the expansion sleeve (16) onto the first wedge element (17) is slid in the direction of the increasing cross section of the first wedge element (17) and so that preferably the expansion sleeve (16) onto the second wedge element (18) in the direction of the increasing cross section of the second wedge element (18) is postponed. 10. Implant (1) according to claim 9, characterized in that the first wedge element (17) and the pull rod (19) interact have kende thread. 11. Implant (1) according to one of claims 9 or 10, characterized in that the pull rod (19) has a screw head drive element (21) at one of its ends. 12. Implant (1) according to claim 11 and according to claim 3, characterized in that the screw head drive element (21) is radially inside the thread (9) of the first fastening element (4). is arranged. 13. The implant (1) according to any one of claims 7 to 12, characterized in that the expansion sleeve (16) has at least two edges delimiting the expansion sleeve (16) in an axial direction (22) of the expansion sleeve running incisions (23). 14. Implant (1) according to claim 13, characterized in that the expansion sleeve (16) has at least two of the expansion sleeve (16) in the other axial direction limiting edge (24) of the Expansion sleeve (16) running incisions (25). 15. Implant (1) according to any one of claims 7 to 14, characterized in that the expansion sleeve (16) of the expansion device (15) on the outer lateral surface (26) in the circumferential direction has running grooves and / or ribs. 16. Implant (1) according to one of claims 7 to 15, characterized in that the expansion sleeve (16) of the expansion device (15) on the outer lateral surface (26) running obliquely to the circumferential direction, in particular axially running, grooves and / or has ribs. 17. Implant (1) according to one of Claims 6 to 16, characterized in that the first fastening element (4) has at least one further spreading device (27) for spreading in the first bone part (2), the further spreading device (27) being in particular according to according to one of claims 7 to 16 is. 18. Implant (1) according to claim 17, characterized in that the further spreading device (27) has: another expansion sleeve (28), a further first wedge element (29), wherein the further expansion sleeve (28) can be pushed onto the further first wedge element (29) in the direction of an increasing cross section of the further first wedge element (29), and a further second wedge element (30), wherein the further expansion sleeve (28) in the direction of an increasing cross-section of the further second wedge element (30) onto the further second wedge element (30) can be pushed. 19. Implant (1) according to claim 18, characterized in that the first wedge element (17) of the spreading device (15) and the further second wedge element (30) of the further spreading device (27) are connected to one another, so that a displacement of the first wedge element ( 17) of the spreading device (15) leads to the same displacement of the further second wedge element (30) of the further spreading device (27), the first wedge element (17) of the spreading device (15) and the further second wedge element (30) of the further spreading device (27 ) in particular in one piece are executed. 20. Implant (1) according to one of the preceding claims, characterized in that the bioresorbable material comprises magnesium, preferably a magnesium alloy, the magnesium alloy preferably comprising: optionally more than 0.0 up to 7.0% zinc; optionally more than 0.0 up to 1.0% zirconium; optionally greater than 0.0% up to 1.0% calcium; optionally more than 0.0 up to 1.0% manganese; optionally greater than 0.0% up to 0.5% silicon; optionally more than 0.0 up to 1.0% silver; optionally maximum up to 0.5% aluminum; and optionally at least one element selected from the group consisting of greater than 0.05% and up to 0.6% yttrium; more than 0.05 up to 4.0% ytterbium; more than 0.05 up to 4.0% gadolinium.