CH711485B1 - Carpometacarpal joint implant - Google Patents

Abstract

The invention relates to a thumb saddle joint implant (10), comprising a distal joint element (11) having a first bone joining surface (12), a proximal joint element (15) having a second bone joining surface (16) and between the first distal joint element (11) and The second proximal joint element (15) and the intermediate element (20) each have a sliding surface (21; 22) each formed saddle-shaped and are mutually displaceable, and the intermediate element (20) has a contact surface (23) facing away from the sliding surface (22), which abuts against a contact surface (13) of the first distal joint element (11), wherein a rotational movement of the intermediate element (20) about a central axis (A) of the projection (20). 42) is limited by the guide means (40) by an anti-rotation device (30).

Description

Description: [0001] The invention relates to a thumb saddle joint implant comprising a distal joint element having a first bone bonding surface, a proximal joint element having a second bone bonding surface, and an intermediate element disposed between the first distal joint element and the second proximal joint element according to claim 1.

The wear or arthrosis of the thumb saddle joint is one of the most common reasons for a hand surgery and one of the most common arthritis diseases on the hand. This affects about 20-25% of women and 7-15% of all men. In addition to conservative, purely symptomatic measures such as the drug treatment by tablet or cortisone injections, in many cases an operative treatment is necessary. This usually involves an intervention that was developed in the 1970s and has since been regarded as a standard surgical treatment worldwide. In such surgical treatment, the osteoarthritis affected bone is removed and the joint is stabilized with a piece of tendon removed from the wrist.

The principle of resection suspension interposition arthroplasty is therefore that one of the two involved in the damaged joint bone, namely the large polygon, is removed. This can result in an instability of the thumb due to the lack of support. In order to minimize this effect, tendon parts from the immediate vicinity of the diseased joint are used to "hang" the first metacarpal bone on neighboring bone, thus preventing it from slipping off.

However, it has been shown that the stability of this so distant and partially replaced joint is significantly lower than in a real artificial joint replacement. This manifests itself i.a. in a significant loss of power of the thumb and fine motor disorders, because the thumb can be performed much worse. In addition, this surgical technique is often associated with months of rehabilitation, in which significant functional limitations are present.

From the above, the invention is based on the object to provide a replacement for diseased thumb saddle joints, so a thumb saddle joint implant, with which the aforementioned disadvantages can be overcome.

The described object with regard to a thumb saddle joint implant to be specified is achieved by a thumb saddle joint implant according to claim 1.

Thus, a thumb saddle joint implant comprises a distal joint member having a first bone joining surface, a proximal joint member having a second bone bonding surface, and an intermediate member disposed between the first distal joint member and the second proximal joint member. The proximal joint element and the intermediate element each have a sliding surface, each of which is saddle-shaped and can be displaced on one another. In other words, the proximal joint element has a saddle-shaped sliding surface and also the intermediate element has a saddle-shaped sliding surface. These two sliding surfaces extend approximately perpendicular to each other and are mutually displaceable.

The intermediate element of the thumb saddle joint implant has a contact surface facing away from the sliding surface, which bears against a contact surface of the first distal joint element. A rotational movement of the intermediate element about a central axis is limited by a rotation.

The inventive thumb saddle joint implant comprises in summary at least three components, namely a distal joint element, a proximal joint element and an intermediate element. Only the distal and proximal hinge elements come into contact with their bone bonding surfaces. The intermediate element is arranged between the two joint elements and serves u.a. for performing a thumb movement, wherein the movement or the rotational movement of the intermediate member is limited by means of a rotation, to reduce the direct power transmission and to ensure stability. It should be mentioned that this is a saddle joint and not a ball joint.

In one embodiment of the invention, the thumb saddle joint implant on a guide means which serves for positioning of the intermediate element in relation to the distal joint element. The guide means is preferably formed of at least one recess which is formed in the contact surface of the intermediate member or in the contact surface of the first distal joint member and a projection mounted in the recess, wherein the projection complementary to the recess either on the contact surface of the intermediate member or on the Contact surface of the first distal joint element is formed. The guide means accordingly comprises a recess and a projection mounted in the recess, wherein two different embodiments are conceivable with regard to the design or arrangement of the recess or of the projection.

If the recess is formed in the contact surface of the intermediate element, the projection is formed on the contact surface of the first distal joint element. If the recess is formed in the contact surface of the first distal joint element, the projection is formed complementary thereto on the contact surface of the intermediate element. Preferably, the recess has a circular cross-section. The recess may therefore be cylindrical and / or frusto-conical and / or conical. Complementarily, it is possible that the projection of the guide means has a circular cross-section. With regard to the projection, it is conceivable that this is cylindrical and / or frusto-conical and / or conical. The diameter or the dimensions of the projection are to be selected smaller than the cross-section or the dimensions of the recess, so that the projection is movably mounted in the recess, so that the intermediate element can rotate about the central axis A of the projection from the guide means.

To limit the rotational movement of the intermediate element about the central axis, the thumb saddle joint implant has an anti-twist device. With the help of the rotation, a rotational movement of the intermediate member about the central axis to ± 35 °, in particular to ± 30 °, in particular to ± 25 °, in particular to ± 20 °, in particular to ± 15 ° be limited.

The anti-rotation device preferably comprises at least one recess limiting the rotational movement and at least one movement means, wherein the at least one movement means is mounted in the recess and the recess is formed in the contact surface of the intermediate element and / or in the contact surface of the first distal joint element. Furthermore, the movement means may be formed on the contact surface of the intermediate element and / or on the contact surface of the first distal joint element. Accordingly, the two, an anti-rotation forming components, namely a movement ungs medium and a recess may be formed both on the contact surface of the first distal joint member and on the contact surface of the intermediate member. The two elements constituting the anti-rotation device are thus formed and arranged complementary to each other, that is, when the recess is formed on a first contact surface, the associated movement means is formed opposite to the other contact surface.

It can be provided that a plurality of rotational movement limiting recesses and a plurality of moving means form a rotation, wherein, for example, on a first contact surface, the recesses and on a second contact surface, the moving means are formed. Furthermore, it is conceivable that both recesses and moving means are formed on a first contact surface and also complementary recesses and moving means are formed on a second contact surface.

In one embodiment of the invention, the rotation can consist of at least two recesses and at least two movement means.

For example, it is conceivable that the at least one movement means as a projection of circular cross-section, and the at least one recess is formed as a curved groove, wherein the groove has a length such that the intermediate member is limited to the central axis A rotatable. The groove or curved groove preferably has rounded ends.

The rotation limiting the (n) recess (s) has or preferably have a larger cross-section than that or the complementary thereto formed (s) motion medium on. This is advantageous in that the movement means are movably arranged or mounted in the recesses. In the non-implanted state, the at least one movement means is movably arranged or mounted in the recess. Even in the implanted state, the at least one movement means and the at least one recess are movable in relation to one another, in which case two embodiments are to be distinguished. If the at least one movement means is formed on the contact surface of the distal joint element, the movement means in the implanted state due to the attachment of the distal joint element to the metacarpal I fixed and not movable. In this case, the at least one recess moves around the moving means. In the case that the moving means is formed on the contact surface of the intermediate member, the moving means moves in the recess in the limited predetermined extent.

Preferably, both the movement means or the movement ungs means and the rotational movement limiting (s) recesses or recess point-symmetrical to the contact surface intersecting, the central axis formed. Accordingly, a point-symmetrical arrangement of the recesses or recess as well as the movement means or the movement means to the guide means of the thumb saddle joint implant is possible. In other words, the recess or recesses and / or the movement means of the rotation can be formed point-symmetrical to the recess and the projection of the guide means.

The cross section or the length of the recess (s) of the rotation is preferably to be selected such that the rotational movement of the intermediate member about the central axis to ± 35 °, in particular to ± 30 °, in particular to ± 25 °, in particular to ± 20 °, in particular to ± 15 °, is limited. With the help of the length or the cross section of the recess, therefore, the extent of the rotational movement of the intermediate element is adjustable.

In a further embodiment of the invention, it is possible that the movement medium are formed as projections with a triangular and / or kreisbogenförmigem and / or kreissegmentförmigem and / or kreisringsegmentförmigem cross-section, wherein the complementary thereto formed recess (s) circular segmented and / or circular arc-shaped and / or annular segment-shaped and / or elongated hole-shaped. The cross section of the recess or the recesses is expediently larger than the cross section of the projections, such that the intermediate element is rotatable limited to the central axis. Consequently, variable execution options in terms of rotation are possible.

For example, two movement means may be formed, which are formed in the manner of a compass needle on a contact surface of the intermediate element or the distal joint element. Such Kompassnadelelförmiger projection, for example, in a slot-shaped recess with rounded ends, which is formed on the contact surface of the distal joint member or the intermediate member, rotatably disposed.

Furthermore, with regard to the movement means, a wing-like or propeller-like design is conceivable. An associated recess is preferably formed with a similar shape, wherein the cross-section or the surface of the recess is greater than the wing or propeller-like projection.

In a preferred embodiment of the invention, the saddle-shaped sliding surface of the proximal joint member is medial higher than lateral, in particular such that in an abduction of a thumb dislocation of the thumb can be prevented. The saddle-shaped sliding surface of the proximal hinge member is connected to the bone bonding surface by means of side surfaces. The height of the side surfaces of the proximal joint element forms the saddle shape or the saddle-shaped sliding surface. In other words, the medial side surface of the proximal joint member is higher than the lateral side surface of the proximal joint member. Although, due to this saddle shape, sliding of the sliding surface of the intermediate member on the sliding surface of the proximal hinge member is possible, however, the hyperbolic paraboloid is formed by asymmetrically forming the heights of the side surfaces so as to better guide the sliding surface of the intermediate member on the sliding surface of the proximal hinge member becomes. The risk of dislocation in connection with the inventive thumb saddle joint implant is consequently reduced. Due to the different side surface heights, a medial trapezium is formed. The intermediate element is movable despite this guide, with a rotational freedom of ± 35 °, in particular ± 30 °, in particular ± 25 °, in particular ± 20 °, in particular ± 15 °.

In a further embodiment of the invention, at least one anchoring system, which comprises at least one anchoring element and at least one additional anchoring element, may be formed on the first bone connecting surface and / or on the second bone connecting surface. In a preferred embodiment of the invention, at least two additional anchoring elements are provided.

The anchoring element may be a cylindrical or conical or frusto-conical projection, preferably extending through the projection, the central axis.

Preferably, at least two additional anchoring elements are formed, which are formed on a concentric to the central axis and thus concentric with the anchoring element extending circle as cylindrical and / or conical and / or frusto-conical projections.

Furthermore, it is conceivable that at least two additional anchoring elements are formed wing-shaped and / or pyramid-shaped, wherein the additional anchoring elements are preferably formed in relation to the anchoring element or in relation to the central axis opposite. The additional anchoring elements can be arranged, for example, in a star shape around the anchoring element. The additional anchoring elements can also be designed as fin-like projections.

Preferably, the anchoring element and the additional anchoring elements or the additional anchoring element are designed such that a cementless implantation of the thumb saddle joint implant is made possible. The anchoring element is preferably arranged or formed centrally on the bone connection surface. This anchoring element may also be referred to as a central anchoring pin and may have various shapes, in particular a rectangular or square cross-section. The additional anchoring element may be formed, for example, spikeartig.

The intermediate element described can also be referred to as an inlay. The intermediate element can be made of plastic, in particular polyethylene. The distal hinge element and / or the proximal hinge element is preferably made of chromium-cobalt-molybdenum, and only the back surface toward the bone has a sprayed-on titanium layer for good bone ingrowth behavior. Alternatively, the distal hinge elements and / or the proximal hinge element may also be made of titanium or a titanium alloy. Due to the formation of the intermediate element made of polyethylene, a particularly good sliding behavior of the intermediate element or of the inlay on the saddle-shaped sliding surface of the proximal joint element is possible.

The invention will be described with reference to embodiments, which are explained in more detail with reference to figures. Hereby show:

1 shows a left hand with upwardly directed palm for clarification of the medical information Rich;

Fig. 2 shows the name of the individual bones of a right hand and representation of the thumb saddle Lenk;

3a and 3b show an inventive thumb saddle joint implant in the installed state and as an exploded view;

4a-4g different embodiments with respect to the rotation; and

Fig. 5a-5d various embodiments with respect to the anchoring element and the additional anchoring elements.

In Fig. 1, a left hand is shown, with the palm facing up, so that in a plan view of the palm, the anatomical direction information is displayed.

In Fig. 2, the names of a right hand are shown. Also shown is the bone 5, which is removed during surgical treatment of a thumb saddle joint arthrosis. This is the so-called large polygonal bone (Ostrapezium). The removed bone is replaced with the aid of a thumb saddle joint implant 10 according to the invention.

As shown in Figs. 3a and 3b, the inventive thumb saddle joint implant 10 comprises a distal hinge element 11 having a first bone joining surface 12, a proximal hinge element 15 having a second bone joining surface 16, and one between the first distal hinge element 11 and the second The proximal joint element 15 and the intermediate element 20 each have a sliding surface (21; 22), which are each formed saddle-shaped and are mutually displaceable. The intermediate element 20 has a contact surface 23 which faces away from the sliding surface 22 and bears against a contact surface 13 of the first distal joint element 11. A rotational movement of the intermediate element 20 about the central axis A of the projection 42 from the guide means 40 is limited by an anti-rotation 30.

The distal joint element 11 and the proximal joint element 15 are made of metal in the example shown. Preferably, it is titanium and / or a titanium alloy. The intermediate element 20 is made of plastic, in particular polyethylene.

The three elements shown, namely the distal joint member 11, the proximal joint member 15 and the intermediate member 20 form the inventive thumb saddle joint implant 10, wherein the intermediate member 20 is rotatably mounted in relation to both joint elements 11 and 15. In order to prevent lateral displacement of the intermediate element 20, a guide means 40 is provided, which is formed from a recess 41 with a circular cross-section and a projection 42 mounted in the recess 41 with also circular cross-section. The recess 41 is formed in the contact surface 23 of the intermediate element, whereas the projection 42 is formed on the contact surface 13 of the distal joint element. The recess 41 is formed complementary to the projection 42, wherein the cross-sections of the recess 41 and the projection 42 are formed such that the projection 42 in the recess 41 is movable, in particular rotatable.

The two bone bonding surfaces 12 and 16 of the distal and proximal hinge elements 11 and 15 may be roughened to allow for improved ingrowth of the thumb saddle joint implant 10 into the bones.

The saddle-shaped sliding surface 21 of the proximal joint element 15 is higher on the medial side 17 than on the lateral side 18. Accordingly, a medial trapezium is formed. The asymmetrical height of the saddle-shaped sliding surface 21 of the proximal joint element 15 causes a better guidance on the medial side 17, so that the risk of dislocation is reduced in an abduction of the thumb. In other words, the proximal hinge member 15 comprises a saddle-shaped sliding surface 21, a bone joining surface 16, and the medial side surface 14 and the lateral side surface 19. The side surfaces 14 and 19 form the connection between the bone joining surface 16 and the saddle-shaped sliding surface 21. The medial side surface 14 is higher than the lateral side surface 19, so that the sliding surface 21 of the proximal joint member 15 is formed saddle-shaped, the saddle shape is medial higher than lateral.

Also shown is the anti-rotation device 30, which limits the rotational movement of the intermediate member 20 about the central axis A to ± 35 °, in particular to ± 30 °, in particular to ± 25 °, in particular to ± 20 °, in particular to ± 15 ° , The anti-rotation device 30 is formed in the illustrated example of two rotational movement limiting recesses 31 and two movement means 32, wherein the movement means 32 are mounted in the recesses 31. The recess 31 is formed in the contact surface 23 of the intermediate element 20, whereas the movement means 32 are formed on the contact surface 13 of the first distal joint element 11. The movement means 32 are formed as projections of circular cross-section, whereas the recesses 31 are formed as curved grooves, wherein the grooves have a length such that the intermediate member 20 is limited to rotate about the central axis A. The two illustrated recesses 31 and the curved grooves have rounded ends 33. With regard to the possible embodiments of an anti-rotation device 30, reference is made to FIGS. 4a-4g.

An anchoring system 44, consisting of an anchoring element 45 and two additional anchoring elements 46, is formed both on the first bone connecting surface 12 and on the second bone connecting surface 16. The anchoring elements 45 are formed as frustoconical projections, wherein the central axis A extends through the projections. The two additional anchoring elements 46 are formed on a concentric with the central axis A extending circle k as conical projections with rounded tips 47. The two additional anchoring elements 46 are formed in relation to the anchoring element 45 opposite or symmetrical to the anchoring element 45. With regard to the different embodiments of the anchoring and additional anchoring elements (45, 46), reference is made to FIGS. 5a-5b.

Different embodiments of anti-rotation devices 30 are shown in FIGS. 4a-4g. The lower element shown is always the intermediate element 20, the upper element is the distal joint element 11.

The embodiment according to FIG. 4a corresponds to the example of a possible anti-rotation device 30 shown in FIG. 3b. In the contact surface 23, a circular recess 41 of the guide means 40 is formed. On the contact surface 13, a frusto-conical projection 42 is shown, which forms the guide means 40 together with the recess 41. In the contact surface 23 of the intermediate element 20, two recesses 31 of the rotation 30 are formed. The recesses 31 are formed as curved grooves or curved slots. The recesses have rounded ends 33. The grooves are formed point-symmetrical to the recess 41 of the guide means 40. The recesses 31 are therefore arranged opposite one another. The moving means 32 are formed as projections of circular cross-section, which are formed opposite to the projection 42 of the guide means. The grooves or recesses 31 have a length such that the projections or movement means 32 are rotatable about the central axis A and about the recess 41, which applies only to the non-implanted state. In the implanted state, the recesses 31 move about the movement means 32nd

With the help of the length of the grooves, the rotational freedom of the intermediate element 20 about the central axis A of the projection 42 from the guide means 40 is adjustable. The longer the recesses 31, the greater the possible rotational movement of the intermediate element. The recesses 31 and the movement means 32 are arranged complementary to one another. This applies both to the shapes and cross sections of the recesses 31 and movement means 32 and the arrangement of a plurality of movement means 32 and recesses 31 in relation to the central axis A or in relation to the center of the intermediate element 20 and the distal joint element 11. These relationships apply to all in 4a and 4g possible embodiments with respect to a rotation 30th

In Fig. 4b, the projection 42 of the guide means 40 is also formed on the contact surface 13 of the distal joint member 11. Complementarily, the recess 41 is formed in the contact surface 23 of the intermediate element 20. On the contact surface 23 of the intermediate member 20 annular segment-shaped recesses 31 are formed. On the contact surface 13 of the distal joint member 11 are also annular segment-shaped projections formed as a means of movement 32. The projections 32 have a smaller area or a smaller cross section than the recesses 31. The moving elements 32 can therefore be rotated limited to the central axis A. The limiting elements 34 also have a circular ring segment shape.

In Fig. 4c, the projection 42 of the guide means 40 is formed on the contact surface 23 of the intermediate member 20, whereas the recess 41 is formed on the contact surface 13 of the distal joint member 11. The movement elements 32 on the contact surface 13 of the distal joint element 11 are formed as circular ring segments with a relatively small cross-section. Complementarily, recesses 31 in the form of circular ring segments are formed on the contact surface 23 of the intermediate element 20 in the outer edge region of the contact surface 23, the cross section of these recesses 31 being larger than the cross section of the movement means 32. The movement means 32 can be limitedly rotated in the recesses 31, so that the rotational movement of the intermediate element is limited. In this context, it should be noted that in the implanted state, the moving means 32 are moved in relation to the recesses 31. In fact, the distal joint member 11 is fixed so that the moving means 32 remain stationary and rather the recesses 31 are rotated about the central axis A.

In FIG. 4 d, the projection 42 of the guide means 40 is formed on the contact surface 13 of the distal joint element 11. The recess 41 is formed on the contact surface 23 of the intermediate element 20. The two movement means 32 have a triangular cross-section, wherein the triangular cross-sections are arranged in relation to the projection 42 such that they are arranged in the manner of a compass needle on the contact surface 13 of the distal joint member 11. The recess 31 of the rotation 30 is formed as a straight slot with rounded ends 33. In the slot shown, the recess 41 of the guide means 40. The slot 31 is rotated about the projection 42 in a possible thumb movement, so that the edges of the slot with maximum rotation possibility at the tips 35 of the moving means 32 strike.

In the illustrated embodiment according to FIG. 4e, the projection 42 of the guide means 40 and the movement means 32 of the anti-rotation device 30 merge into one another, that is to say the projection 42 and the movement means 32 are monolithic. Complementarily, the recesses 41 of the guide means 40 and the recess 31 of the rotation 30 are formed as a recess.

FIG. 4f shows another possible embodiment with regard to an anti-twist device 30. In this case, the protrusion 42 is formed on the contact surface 13 of the distal joint member 11. The recess 41 is located in the contact surface 23 of the intermediate element 20. The movement means 32 and the recesses 31 of the rotation 30 are formed as sprockets.

In FIG. 4g, the projection 42 of the guide means 40 is formed on the contact surface 13 of the distal joint element 11. The recess 41 is located in the contact surface 23 of the intermediate element 20. The recesses 32 of the rotation 30 are formed as circular ring segments, which do not extend to the outermost edge of the intermediate member 20, as for example in Figs. 4b, 4c and 4e the case is. The recesses 31 are formed point-symmetrical to the recess 41 of the guide means 40. The recesses 31 have a larger cross section than the movement means 32. The moving means 32 are also formed as circular ring segments. The projections, which constitute the movement means 32, are movable in the recesses 31, wherein in the implanted state, rather, the recesses 31 are movable about the projection 42, so that the movement means 32 remain unmoved. In the non-implanted state, the projections or movement means 32 are limitedly rotatable about the central axis A.

FIGS. 5a-5d illustrate possible anchoring systems 44, wherein these anchoring systems 44 consist of an anchoring element 45 and at least one additional anchoring element 46.

In Fig. 5a, a cylindrical anchoring element 45 is shown with an additional square additional anchoring element 46. Such an arrangement is to be regarded as a reference to the so-called Zweymüller hip stem. Such anchoring system 44 provides for cementless implantation with relatively short lengths of anchoring elements. It is also conceivable that the cross section of the anchoring element 45 corresponding to the cross section of the additional anchoring element 46 over the entire length is square or rectangular.

Also, the anchoring element 45 shown in Fig. 5b is formed as a cylindrical attachment or projection through which preferably the central axis A extends. There are four additional anchoring elements 46 provided, which have a pyramidal shape. The individual additional anchoring elements 46 are arranged in a star shape around the anchoring element 45, so that the cutting edges 48 of the pyramidal shapes provide additional stabilization during implantation.

In Fig. 5c, an anchoring element 45 is shown, which is designed as a frustoconical projection. On a circular line k, which is arranged concentrically to the anchoring element 45, there are two additional anchoring elements 46, which are formed as conical projections. The conical projections are arranged symmetrically to the anchoring element 45.

In Fig. 5d an anchoring system 44 is shown, which is formed from an anchoring element 45 and two additional anchoring elements 46. The anchoring element 45 is formed as a cylindrical projection, wherein the additional anchoring elements 46 are formed in relation to the anchoring element 45 opposite. These are wing-shaped and also have cutting edges 48, which cause additional stabilization during implantation, without a cementation is necessary.

LIST OF REFERENCES [0054] 5 large polygonal bone 10 thumb saddle joint implant 11 distal joint element 12 first bone joining surface 13 contact surface distal joint element 14 medial side surface 15 proximal joint element 16 second bone bonding surface 17 medial side 18 lateral side 19 lateral side surface 20 intermediate element 21 sliding surface proximal joint element 22 sliding surface intermediate element 23 contact surface Intermediate element 30 Anti-twist device 31 Recess Anti-rotation device 32 Movement means anti-rotation device 33 rounded end 34 delimiting element 35 tip 40 guide means 41 recess guide means 42 projection guide means 44 anchoring system 45 anchoring element 46 additional anchoring element 47 rounded tip 48 cutting edge A central axis K circular path k circular line

Claims (10)

claims A thumb saddle joint implant (10) comprising a distal hinge element (11) having a first bone joining surface (12), a proximal hinge element (15) having a second bone joining surface (16) and one between the first distal hinge element (11) and the second The second proximal joint element (15) and the intermediate element (20) each have a sliding surface (21; 22), which are each formed saddle-shaped and are displaceable on each other, wherein the intermediate element (20 ) has a contact surface (23) facing away from the sliding surface (22), which abuts against a contact surface (13) of the first distal joint element (11), wherein rotational movement of the intermediate element (20) about a central axis (A) of the projection (42) from the guide means (40) by an anti-rotation device (30) is limited. 2. thumb saddle joint implant (10) according to claim 1, characterized by, a guide means (40) for the positioning of the intermediate element (20) in relation to the first distal joint element (11), the at least one recess (41), preferably with a circular Cross-section formed in the contact surface (23) of the intermediate element (20) or in the contact surface (13) of the first distal joint element (11) and formed in the recess (41) projection (42), preferably circular in cross-section wherein the projection (42) is complementary to the recess (41) formed either on the contact surface (23) of the intermediate element (20) or on the contact surface (13) of the first distal joint element (11). 3. thumb saddle joint implant (10) according to claim 1 or 2, characterized in that the rotation (30), the rotational movement of the intermediate member (20) about the central axis (A) to a range of motion of ± 35 °, in particular ± 30 °, in particular ± 25 °, in particular ± 20 °, in particular ± 15 ° limited. 4. thumb saddle joint implant (10) according to one of claims 1 to 3, characterized in that the rotation (30) consists of at least one rotational movement limiting recess (31) and at least one movement means (32), wherein the at least one movement means ( 32) is mounted in the recess (31) and the recess (31) is formed in the contact surface (23) of the intermediate element (20) and / or in the contact surface (13) of the first distal joint element (11) and the movement means (32 ) is formed on the contact surface (23) of the intermediate element (20) and / or on the contact surface (13) of the first distal joint element (11). 5. thumb saddle joint implant (10) according to claim 4, characterized in that the rotation (30) consists of at least two recesses (31) and at least two movement center in (32). 6. thumb saddle joint implant (10) according to claim 5, characterized in that the movement means (32) are formed as projections of circular cross section and the recesses (31) as bent grooves, wherein the grooves have a length such that the intermediate element ( 20) about the central axis (A) is limited rotatable. 7. thumb saddle joint implant (10) according to claim 5, characterized in that the movement means (32) are formed as projections with triangular and / or circular arc-shaped and / or circular segment-shaped and / or annular segment-shaped cross-section and the recesses (31) circular segment and / or are formed circular arc and / or kreisringsegmentation and / or elongated hole-shaped, wherein the cross section of the recesses (31) is greater than the cross section of the projections, such that the intermediate element (20) about the central axis (A) is limited rotatable. 8. thumb saddle joint implant (10) according to one of the preceding claims, characterized in that the saddle-shaped sliding surface (21) of the proximal joint member (15) medial (17) is higher than lateral (18), in particular such that in an abduction of the At the same time a dislocation of the thumb can be prevented. 9. thumb saddle joint implant (10) according to any one of the preceding claims, characterized in that on the first distal bone connection surface (12) and / or on the second proximal bone connection surface (16) at least one anchoring system (44) is formed, which is an anchoring element ( 45) and at least one additional anchoring element (46). 10. thumb saddle joint implant (10) claim 9, characterized in that the anchoring element (45) is a cylindrical or conical or frusto-conical projection through which preferably the central axis (A) extends.