Adjustment device for adjusting a joint prosthesis

Abstract

The invention relates to an adjustment device (1) for adjusting a joint prosthesis, the adjustment device (1) comprising an interface head (10) having an abutment surface (sb10); an insertion member (30) comprising an insertion portion (33) configured to be inserted into the interface head (10); and at least one removable intermediate element (50) having a bearing surface (sa50) offset by a predetermined height (h) relative to the second locking element (57) and being configured to bear on the abutment surface (sb10) of the interface head (10) so as to maintain an offset between the insertion member (30) and the abutment surface (sb10) of the interface head (10), this offset being determined by the predetermined height (h).

Description

[0001] DESCRIPTION

[0002] TITLE: Adjustment device for joint prosthesis

[0003] Technical field of the invention

[0004] The present invention relates to an adjustment device for a joint prosthesis, for example implantable orthopedic prostheses for the hip or shoulder.

[0005] State of the art

[0006] During a hip or shoulder prosthesis test or installation operation, a stem is usually implanted into the canal of a bone, such as the femur. Once the stem is inserted to the appropriate depth and orientation, a head or ball is attached to the proximal end of the stem. This head then fits into a socket, such as the acetabular socket of the hip, and allows movement between the prosthesis and the socket. A neck extends between the head and the stem. In most existing prostheses, this neck is usually cylindrical in configuration with one end connected to the head and one end connected to the stem.

[0007] Given the wide variation in physiology between patients, neck length can vary from one individual to another. It is therefore necessary to adjust the neck length according to the patient to ensure that the prosthesis implantation reproduces the original joint without injuring the patient.

[0008] To achieve this, it is known in the prior art to use heads with an internal cavity of predetermined length, which sets an offset to adjust the neck length. A typical joint prosthesis may include three to five heads with different offsets. For example, it is known to provide heads with offsets of -4 mm, 0 mm, +4 mm, +8 mm and +12 mm compared to a reference standard. These offsets must also be adapted to different internal head cavities, which not only multiplies the number of heads that each prosthetist practitioner must have, but also the number of manipulations to be performed on each patient before finding the right head. This number of heads and manipulations also increases with the expected accuracy for the final neck length.

[0009] There is therefore a need to find a system for finely adjusting, reliably and robustly, the length of a joint prosthesis (for example a neck), while limiting the number of manipulations on a patient, and limiting the number of types of head to be held for the prosthesis. Purpose of the invention

[0010] The present invention aims to propose a solution which responds to all or part of the aforementioned problems.

[0011] This aim can be achieved by implementing an adjustment device for adjusting a joint prosthesis, the adjustment device comprising: an interface head internally delimiting a receiving cavity, and externally having a contact surface intended to be turned towards a glenoid or a cotyle, the interface head further externally having a stop surface turned towards the side opposite said contact surface; an insertion member comprising a main body comprising an insertion portion configured to be inserted into the receiving cavity of the interface head along an adjustment axis, the main body internally delimiting a receiving cavity intended to receive an end portion of a stem of the joint prosthesis, the insertion member further comprising at least a first locking element;and at least one removable intermediate element comprising a second locking element cooperating with the first locking element of the insertion member so as to lock at least two degrees of freedom in translation between the at least one intermediate element and the insertion member along a locking axis, said at least one intermediate element further having a bearing surface offset by a predetermined height relative to the second locking element, the bearing surface being configured to come to bear on the stop surface of the interface head, so as to maintain an offset between the first locking element of the insertion member and the stop surface of the interface head along the adjustment axis, said offset being determined by said predetermined height.;

[0012] The arrangements described above make it possible to propose an adjustment device comprising a removable intermediate element making it possible to adjust a predetermined height between the first locking element of the insertion member and the abutment surface of the interface head. In this way, it is possible to adjust the total length of the adjustment device according to the intermediate element used, to more finely adjust the position of the joint prosthesis according to the physiognomy of the patient, and without requiring significant movement of the interface head, or of the stem of the joint prosthesis. This makes it possible to carry out the positioning and adjustment of the prosthesis while limiting the dislocation or reduction of the joint, to small movements. This is particularly advantageous during adjustment operations of trial prostheses.The locking of at least two degrees of freedom between the at least one intermediate element and the insertion member along a locking axis makes it possible to contain any unwanted movement between the insertion member and the intermediate element in order to be able to adjust the adjustment device more finely by limiting the risk of errors due to the sliding of the intermediate element relative to the insertion member.

[0013] It is therefore well understood that the second locking element cooperates with the first locking element of the insertion member so as to block a translation between the at least one intermediate element and the insertion member in both directions along a locking axis.

[0014] By “removable” insert element, we mean that the insert element is capable of being removed from the insertion member when the latter is inserted into the interface head.

[0015] The adjustment device may further have one or more of the following characteristics, taken alone or in combination.

[0016] According to one embodiment, the joint prosthesis is a hip prosthesis. In this case, the interface head is intended to cooperate with a hip acetabulum, or with a cup inserted into the hip acetabulum.

[0017] Generally, the contact surface is intended to face a glenoid, acetabulum, cup, insert or glenosphere.

[0018] According to one embodiment, the locking axis is parallel or coincident with the adjustment axis.

[0019] According to one embodiment, the offset is equal, to within 1 mm, to the predetermined height.

[0020] Generally speaking, the prosthesis stem is attached to a bone of the patient, for example the femur in the case of a hip prosthesis.

[0021] It is well understood that the insertion member is configured to be inserted at least partially into the receiving cavity of the interface head, in particular at the insertion portion.

[0022] According to one embodiment, the insertion portion is configured to pivot freely within the receiving cavity.

[0023] Alternatively, the insertion portion of the insertion member may be configured to fit into the receiving cavity of the interface head. For this, it may be provided that at least one of the insertion portion and the receiving cavity is provided with engagement means to allow the engagement of the insertion portion in the receiving cavity. In this way, it is possible to achieve a fitted insertion (or "pressfit" according to the established English terminology) of the insertion portion. According to one embodiment, the engagement means comprise grooves, adjusted radii of the insertion portion and the receiving cavity, or a surface roughness.

[0024] According to one embodiment, the insertion portion is configured to slide freely in the receiving cavity as long as the bearing surface of the intermediate element is not bearing on the stop surface of the interface head.

[0025] According to one embodiment, the intermediate element is disposed between the insertion member and the interface head. For example, the intermediate element is disposed between the first locking element and the abutment surface.

[0026] According to one embodiment, one of the first locking element and the second locking element comprises a projection from an external surface respectively of the insertion member or the intermediate element, and the other of the first locking element or the second locking element has a hollow configured to receive said projection, so as to block said at least two degrees of freedom between the at least one intermediate element and the insertion member along the blocking axis.

[0027] In this way, it is possible to carry out a simple mechanical locking of said at least two degrees of freedom between the at least one intermediate element and the insertion member along the locking axis.

[0028] According to one embodiment, the projection is a collar and / or the recess is a groove.

[0029] In this way it is possible to simply manufacture the first blocking element and the second blocking element.

[0030] According to one embodiment, the first locking element is a collar projecting from the main body, on the side opposite the receiving cavity of the insertion member.

[0031] For example, the first locking element comprises all or part of an annular collar.

[0032] According to one embodiment, the interface head and the insertion member have at least one part having a geometry of revolution around the adjustment axis.

[0033] In this way, it is possible to facilitate the movement of the interface head and the insertion member around the adjustment axis.

[0034] According to one embodiment, the receiving cavity has at least a partial geometry of revolution around the adjustment axis. For example, the receiving cavity has an at least partially cylindrical, or frustoconical shape. According to one embodiment, the insertion portion of the insertion member has at least a partial geometry of revolution around the adjustment axis. For example, the insertion portion has an at least partially cylindrical, or frustoconical shape.

[0035] By "cylindrical" shape, we mean a surface generated by a straight line, called a generator, which moves in a given direction based on a closed curved line called a directrix.

[0036] According to one embodiment, the generator of the cylindrical shape of the receiving cavity is the adjustment axis.

[0037] According to one embodiment, the generator of the cylindrical shape of the insertion portion is the adjustment axis.

[0038] According to one embodiment, the directrix of the cylindrical shape of the receiving cavity is a circle.

[0039] According to one embodiment, the directrix of the cylindrical shape of the insertion portion is a circle, in particular having a radius less than or equal to a radius of the directrix of the receiving cavity. More particularly, the radius of the directrix of the cylindrical shape of the insertion portion is equal to within a mechanical clearance of the radius of the directrix of the receiving cavity.

[0040] According to one embodiment, the cylindrical shape of the insertion portion is complementary to the cylindrical shape of the receiving cavity. In this way, it is possible to simply insert the insertion member into the receiving cavity.

[0041] According to one embodiment, the frustoconical shape of the insertion portion is complementary to the frustoconical shape of the receiving cavity. In this way, it is possible to simply insert the insertion member into the receiving cavity.

[0042] According to one embodiment, the insert element comprises a snap-in portion configured to be snapped around the insertion member.

[0043] According to one embodiment, the second locking element comprises the snap-in portion.

[0044] According to one embodiment, the snap-in portion comprises at least a portion of the second locking element.

[0045] According to one embodiment, the snap-on portion comprises a curved part having a circular shape over an angle of between 180° and 270°, and in particular substantially equal to 240°.

[0046] In this way, the spacer element can be easily snapped around the insert member, while being held in place around the insert member.

[0047] According to one embodiment, the intercalary element comprises a proximal end where the bearing surface is arranged, at least one distal end opposite the proximal end, and at least one intercalation ramp extending between the proximal end and the distal end and having a thickness at the distal end strictly less than a thickness at the proximal end.

[0048] It is thus possible to position the bearing surface in contact with the abutment surface by sliding the abutment surface along the intercalation ramp until it comes into contact with the bearing surface. In this way, the intercalation of the intercalation element between the insertion member and the interface head is facilitated.

[0049] According to one embodiment, the adjustment device further comprises a primary biasing element configured to bias the insertion portion towards the receiving cavity.

[0050] In other words, the primary return element tends to bring the insertion portion towards the receiving cavity.

[0051] In this way, it is possible to facilitate the insertion of the insertion portion into the receiving cavity, and the maintenance in position of the insertion portion in the receiving cavity, in particular when the bearing surface bears on the stop surface.

[0052] According to one embodiment, the primary return element comprises a spring, an extensible silicone link, an elastic, or any other means.

[0053] According to one embodiment, the primary return element comprises a first magnet disposed at the receiving cavity, and a second magnet disposed at one end of the insertion portion facing the receiving cavity, the first magnet having a polarity opposite that of the second magnet. Thus, the return function of the primary return element is a magnetic return.

[0054] According to one embodiment, the adjustment device comprises a secondary return element configured to bias the bearing surface towards the stop surface.

[0055] In other words, the secondary return element tends to bring the support surface towards the stop surface.

[0056] In this way, it is possible to facilitate the insertion of the intermediate element and its maintenance in contact with the interface head at the abutment surface.

[0057] According to one embodiment, the secondary return element comprises a spring, an extensible silicone link, an elastic, or any other means.

[0058] According to one embodiment, the secondary return element comprises a third magnet disposed at the abutment surface, and a fourth magnet disposed at the bearing surface, the third magnet having a polarity opposite that of the fourth magnet. Thus, the return function of the secondary return element is a magnetic return.

[0059] According to one embodiment, the predetermined height is between 2 mm and 20 mm, and in particular substantially equal to 4 mm, 8 mm, or 12 mm. Generally, the intermediate element makes it possible to adjust the predetermined height to adjust the total length of the adjustment device. It is therefore possible to use one or more intermediate elements having fixed predetermined heights.

[0060] For example, the predetermined height is substantially equal to 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, or 12 mm.

[0061] It is however well understood that the fixed predetermined height values ​​are not limiting, and that they can be adapted according to the joint prosthesis, and the patient. For example, a predetermined height accuracy can be 0.5 mm, and can vary up to 20 mm in total.

[0062] According to one embodiment, the adjustment device further comprises a gripping member, the intermediate element comprising a gripping agent configured to reversibly attach with the gripping member to allow removal of the intermediate element by pulling on the gripping member.

[0063] For example, the gripping agent comprises a tab or a slot, and the gripping member comprises a hook configured to grip the tab or slot. In this way, it is possible to more simply remove the interposed element when the first locking element cooperates with the second locking element.

[0064] According to one embodiment, the intermediate element may comprise a re-entrant portion configured to allow a greater amplitude of rotation of the adjustment device when it is placed at the joint. Said re-entrant portion being configured to delay contact with the cup, the glenoid, the insert, the acetabulum or the glenosphere. For example, the re-entrant portion may comprise a hollow formed externally on the intermediate element at the bearing surface.

[0065] Summary description of the drawings

[0066] Other aspects, aims, advantages and characteristics of the invention will appear better on reading the following detailed description of preferred embodiments thereof, given by way of non-limiting example, and made with reference to the appended drawings in which:

[0067] Figure 1 is an exploded schematic perspective view of the adjustment device according to a particular embodiment of the invention.

[0068] Figure 2 is a schematic side view of the adjustment device of Figure 1.

[0069] Figure 3 is a schematic perspective view of the adjustment device according to a particular embodiment of the invention.

[0070] Figure 4 is an exploded schematic perspective view of the insertion member of the adjustment device of Figure 1. Figure 5 is an exploded schematic perspective view of the insert member of the adjustment device of Figure 1.

[0071] Figure 6 is a schematic perspective view of the intermediate element of the adjustment device of Figure 1.

[0072] Detailed description

[0073] In the figures and in the remainder of the description, the same references represent identical or similar elements. In addition, the different elements are not shown to scale so as to enhance the clarity of the figures. Furthermore, the different embodiments and variants are not mutually exclusive and can be combined with each other.

[0074] As illustrated in Figures 1 to 6, the invention relates to an adjustment device 1 for adjusting a joint prosthesis. For example, the adjustment device 1 can be used for hip or shoulder prostheses. In the particular case of hip prostheses, the adjustment device 1 is intended to provide an interface between a cup arranged at the acetabulum of the hip bone, and a prosthesis stem denoted "T" which is secured to the femur. Figure 1 illustrates in particular an embodiment where only a part of the stem T is shown, and in particular the part corresponding to the neck of the femur. It is however clearly understood that the stem T also comprises another part intended to be inserted into the femur, and which forms an angle with the part forming the neck of the femur. Although this is not limiting, the adjustment device 1 according to the invention is particularly suitable for adjusting dimensions for trial prostheses.

[0075] For this purpose, the adjustment device 1 firstly comprises an interface head 10. Generally, the interface head 10 may have a geometry of revolution around an adjustment axis Xr. For example, an external surface of the interface head 10 may be a portion of a sphere. The interface head 10 externally has a contact surface sc10 intended to be turned towards a glenoid or an acetabulum. More generally, the contact surface sc10 is intended to be turned towards a glenoid, an acetabulum, a cup, an insert or a glenosphere. If the joint prosthesis is a hip prosthesis, then the interface head 10 is intended to cooperate with an acetabulum of the hip, or with a cup inserted into the acetabulum of the hip. In this case, the contact surface sc10 may be a portion of a sphere configured to cooperate with the cup having a complementary shape. Thus, the contact surface sc10 and the cup interact according to a ball joint function.

[0076] The interface head 10 furthermore has externally a stop surface sb10 facing the side opposite to the contact surface sc10. The stop surface sb10 is in particular configured to cooperate with an intermediate element 50 which will be described later. The interface head 10 internally delimits a receiving cavity 11. As can be seen in the figures, the receiving cavity 11 may have, at least partially, a geometry of revolution around the adjustment axis Xr. For example, the receiving cavity 11 has an at least partially cylindrical shape. In the remainder of the description, by “cylindrical” shape is meant a surface generated by a straight line, called a generator, which moves in a given direction by resting on a closed curved line called a director.In the embodiment shown in Figures 1 and 2, the generatrix of the cylindrical shape of the receiving cavity 11 is the adjustment axis Xr, and the directrix of the cylindrical shape of the receiving cavity 11 is a circle.

[0077] The adjustment device 1 also comprises an insertion member 30 comprising a main body 31, an insertion portion 33, and at least one first locking element 37.

[0078] The main body 31 internally delimits a receiving cavity 35 intended to receive an end portion of the rod T of the joint prosthesis. As illustrated in the figures, the receiving cavity 35 may have a shape adjusted to the shape of the end portion of the rod T, in order to allow easy cooperation between these two elements. For example, the receiving cavity 35 may have a truncated cone or cylindrical shape.

[0079] The insertion portion 33 is configured to be inserted into the receiving cavity 11 of the interface head 10 along the adjustment axis Xr, so that the insertion member 30 can be inserted at least partially into the receiving cavity 11. It is possible for the insertion portion 33 to be able to pivot freely inside the receiving cavity 11. However, it is advantageous to provide that the insertion portion 33 is configured to fit into the receiving cavity 11. For this, it may be provided that at least one of the insertion portion 33 and the receiving cavity 11 is provided with engagement means to allow the engagement of the insertion portion 33 in the receiving cavity 11. In this way, it is possible to achieve a fitted insertion, or “pressfit” according to the established Anglo-Saxon terminology, of the insertion portion 33 in the receiving cavity 11.For example, these engagement means may include grooves, adjusted radii of the insertion portion 33 and the receiving cavity 11, or surface roughness.

[0080] As illustrated in the figures, the insertion portion 33 of the insertion member 30 may at least partially have a geometry of revolution around the adjustment axis Xr. For example, the insertion portion 33 may have an at least partially cylindrical shape, the generatrix of the cylindrical shape of the insertion portion 33 being the adjustment axis Xr, and the directrix of the cylindrical shape of the insertion portion 33 being a circle. For example, said circle may have a radius less than or equal to a radius of the directrix of the receiving cavity 11. More particularly, the radius of the directrix of the cylindrical shape of the insertion portion 33 is equal to within a mechanical clearance of the radius of the directrix of the receiving cavity 11, to allow the insertion portion 33 to be fitted into the receiving cavity 11.In other words, the cylindrical shape of the insertion portion 33 is complementary to the cylindrical shape of the receiving cavity 11, and this can also apply if these elements are of frustoconical shape. In this way, it is possible to simply insert the insertion member 30 into the receiving cavity 11.

[0081] The adjustment device 1 also comprises at least one removable insert element 50. In the figures, only one insert element 50 is shown. Thus, in the remainder of the description, the terms “at least one” will not be repeated. It is however clearly understood that the adjustment device 1 may comprise one or more identical or different insert elements 50.

[0082] The intermediate element 50 comprises a second locking element 57 cooperating with the first locking element 37 of the insertion member 30 so as to lock at least two degrees of freedom in translation between the at least one intermediate element 50 and the insertion member 30 along a locking axis Xb. It is therefore clearly understood that the second locking element 57 cooperates with the first locking element 37 of the insertion member 30 so as to lock a translation between the at least one intermediate element 50 and the insertion member 30 in both directions along the locking axis Xb.

[0083] For example, the locking axis Xb is parallel or coincident with the adjustment axis Xr. Generally, all or part of the intermediate element 50 is arranged between the insertion member 30 and the interface head 10. For example, the intermediate element 50 is arranged between the first locking element 37 and the stop surface sb10.

[0084] Figures 1 to 6 show non-limiting variants of the adjustment device 1 according to the invention. According to these variants, one of the first locking element 37 or the second locking element 57 comprises a projection extending from an external surface respectively of the insertion member 30 or the intermediate element 50, and the other of the first locking element 37 or the second locking element 57 has a recess configured to receive said projection, so as to block said at least two degrees of freedom between the at least one intermediate element 50 and the insertion member 30 along the blocking axis Xb. More particularly in the figures, the projection is a collar, for example all or part of an annular collar, and the recess is a groove, for example all or part of an annular groove.As can be seen in particular in Figures 1 to 4, the first locking element 37 is a collar projecting from the main body 31, on the side opposite the receiving cavity 35 of the insertion member 30. The second locking element 57 can then be a groove formed in the intermediate element 50. In this way it is possible to carry out a simple mechanical locking of said at least two degrees of freedom between the at least one intermediate element 50 and the insertion member 30 along the locking axis Xb. The manufacture of the first locking element 37 and the second locking element 57 is thus simplified.

[0085] The intermediate element 50 further has a bearing surface sa50 offset by a predetermined height denoted “h” relative to the second locking element 57. This bearing surface sa50 is configured to bear on the stop surface sb10 of the interface head 10, so as to maintain an offset between the first locking element 37 of the insertion member 30 and the stop surface sb10 of the interface head 10 along the adjustment axis Xr, said offset being determined by said predetermined height h. More particularly, the offset is equal, to within 1 mm, to the predetermined height h. Generally, the predetermined height h is between 2 mm and 20 mm, and in particular substantially equal to 4 mm, 8 mm, or 12 mm. The intermediate element 50 makes it possible to adjust the predetermined height h to adjust the total length of the adjustment device 1.It is therefore possible to use one or more intermediate elements 50 having fixed predetermined heights h. For example, the predetermined height h is substantially equal to 2 mm, 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, or 12 mm. It is however well understood that the values ​​of fixed predetermined heights h are not limiting, and that they can be adapted according to the joint prosthesis, and the patient. For example, an accuracy of the predetermined height h can be 0.5 mm, and can vary up to 20 mm in total.

[0086] As can be seen in Figures 5 and 6, the insert element 50 may comprise a snap-fastening portion 51 which may comprise at least a portion of the second locking element 57, and which is configured to be snap-fastened around the insertion member 30. For example, the snap-fastening portion 51 may comprise a curved portion having a circular shape over an angle of between 180° and 270°, and in particular substantially equal to 240°. In this way, the insert element 50 can be easily snap-fastened around the insertion member 30, while being held in place around the insertion member 30.

[0087] The intermediate element 50 may also comprise at least one proximal end 53p at which the bearing surface sa50 is arranged, and at least one distal end 53d opposite the proximal end 53p. Figures 5 and 6 show in particular an intermediate element having two free distal ends 53d, and two proximal ends 53p connected to each other by the bearing surface sa50. Each pair of distal end 53d and proximal end 53p forms an intercalation ramp 53 extending between the proximal end 53p and the corresponding distal end 53d. Each intercalation ramp 53 has a thickness at the distal end 53d strictly less than a thickness at the proximal end 53p.It is thus possible to position the bearing surface sa50 in contact with the stop surface sb10 by sliding the stop surface sb10 along the intercalation ramp 53 until it comes into contact with the bearing surface sa50. In this way, the intercalation of the intercalary element 50 between the insertion member 30 and the interface head 10 is facilitated.

[0088] Finally, as illustrated in Figure 3, the intermediate element 50 may comprise a re-entrant portion 55 configured to allow a greater amplitude in rotation of the adjustment device 1 when it is placed at the joint. Said re-entrant portion 55 being configured to delay contact with the cup, the glenoid, the insert, the acetabulum or the glenosphere. For example, the re-entrant portion 55 may comprise a hollow arranged externally on the intermediate element 50 at the level of the bearing surface sa50.

[0089] In order to simplify the handling of the adjustment device 1, the latter may comprise a primary return element 40 configured to urge the insertion portion 33 towards the receiving cavity 11. In other words, the primary return element 40 tends to bring the insertion portion 33 towards the receiving cavity 11. In this way, it is possible to facilitate the insertion of the insertion portion 33 into the receiving cavity 11, and the maintenance in position of the insertion portion 33 in the receiving cavity 11 in particular when the bearing surface sa50 bears on the stop surface sb10. According to an embodiment not shown, the primary return element 40 may comprise a spring, an extensible silicone link, an elastic band, or any other means.Alternatively and as can be seen in Figures 1 to 6, the primary return element 40 may comprise a first magnet 41 arranged at the receiving cavity 11, and a second magnet 42 arranged at one end of the insertion portion 33 facing the receiving cavity 11. The first magnet 41 generally has a polarity opposite that of the second magnet 42. Thus, the return function of the primary return element 40 is a magnetic return.

[0090] Furthermore, the adjustment device 1 may comprise a secondary return element 60 configured to urge the bearing surface sa50 towards the abutment surface sb10. In other words, the secondary return element 60 tends to bring the bearing surface sa50 towards the abutment surface sb10. In this way, it is possible to facilitate the insertion of the intermediate element 50 and its maintenance in contact with the interface head 10 at the abutment surface sb10. According to an embodiment not shown, the secondary return element 60 comprises a spring, an extensible silicone tie, an elastic band, or any other means. Alternatively, and as shown in FIGS. 1 to 6, the secondary return element 60 may comprise a third magnet 63 arranged at the abutment surface sb10, and a fourth magnet 64 arranged at the bearing surface sa50. The third magnet 63 generally has a polarity opposite that of the fourth magnet 64.Thus, the recall function of the secondary recall element 60 is a magnetic recall.

[0091] Finally, as illustrated in FIG. 6, the adjustment device 1 may comprise a gripping member 70, and the intermediate element 50 may comprise a gripping agent 59 configured to reversibly attach to the gripping member 70 to allow removal of the intermediate element 50 by pulling on the gripping member 70. For example, the gripping agent 59 comprises a tab or a slot, and the gripping member 70 comprises a hook configured to grip the tab or the slot. In this way, it is possible to more simply remove the intermediate element 50 when the first locking element 37 cooperates with the second locking element 57.

[0092] The arrangements described above make it possible to propose an adjustment device 1 comprising a removable intermediate element 50 making it possible to adjust a predetermined height h between the first blocking element 37 of the insertion member 30 and the stop surface sb10 of the interface head 10. By “removable” intermediate element 50, it is meant that the intermediate element 50 is capable of being removed from the insertion member 30 when the latter is inserted into the interface head 10.

[0093] In this way, it is possible to adjust the total length of the adjustment device 1 according to the intermediate element 50 used, to more finely adjust the position of the joint prosthesis according to the physiognomy of the patient, and without requiring significant movement of the interface head 10, nor of the rod T of the joint prosthesis. This makes it possible to carry out the positioning and adjustment of the prosthesis by limiting the dislocation or reduction of the joint to small movements. This is particularly advantageous during adjustment operations of trial prostheses.

[0094] The blocking of at least two degrees of freedom between the at least one intermediate element 50 and the insertion member 30 along a blocking axis Xb makes it possible to contain any unwanted movement between the insertion member 30 and the intermediate element 50 in order to be able to adjust the adjustment device 1 more finely while limiting the risk of errors due to the sliding of the intermediate element 50 relative to the insertion member 30.

Claims

CLAIMS 1. Adjusting device (1) for adjusting a joint prosthesis, the adjusting device (1) comprising: - an interface head (10) internally delimiting a receiving cavity (11), and externally having a contact surface (sc10) intended to be turned towards a glenoid or a cotyle, the interface head (10) further externally having a stop surface (sb10) turned towards the side opposite said contact surface (sc10); - an insertion member (30) comprising a main body (31) comprising an insertion portion (33) configured to be inserted into the receiving cavity (11) of the interface head (10) along an adjustment axis (Xr), the main body (31) internally delimiting a receiving cavity (35) intended to receive an end portion of a rod (T) of the joint prosthesis, the insertion member (30) further comprising at least one first locking element (37); and - at least one removable intermediate element (50) comprising a second locking element (57) cooperating with the first locking element (37) of the insertion member (30) so as to lock at least two degrees of freedom in translation between the at least one intermediate element (50) and the insertion member (30) along a locking axis (Xb), said at least one intermediate element (50) further having a bearing surface (sa50) offset by a predetermined height (h) relative to the second locking element (57), the bearing surface (sa50) being configured to bear on the stop surface (sb10) of the interface head (10), so as to maintain an offset between the first locking element (37) of the insertion member (30) and the stop surface (sb10) of the interface head (10) along the adjustment axis (Xr), said offset being determined by said predetermined height (h).

2. Adjustment device (1) according to claim 1 wherein one of the first locking element (37) or the second locking element (57) comprises a projection from an external surface respectively of the insertion member (30) or the intermediate element (50), and the other of the first locking element (37) or the second locking element (57) has a hollow configured to receive said projection, so as to block said at least two degrees of freedom between the at least one intermediate element (50) and the insertion member (30) along the blocking axis (Xb).

3. Adjustment device (1) according to claim 2 in which the projection is a collar and in which the recess is a groove.

4. Adjustment device (1) according to any one of claims 1 to 3, in which the interface head (10) and the insertion member (30) have at least one part having a geometry of revolution around the adjustment axis (Xr).

5. Adjustment device (1) according to any one of claims 1 to 4, wherein the intermediate element (50) comprises a snap-fastening portion (51) configured to be snap-fastened around the insertion member (30).

6. Adjustment device (1) according to any one of claims 1 to 5, wherein the intermediate element (50) comprises a proximal end (53p) where the bearing surface (sa50) is arranged, at least one distal end (53d) opposite the proximal end (53p), and at least one intercalation ramp (53) extending between the proximal end (53p) and the distal end (53d) and having a thickness at the distal end (53d) strictly less than a thickness at the proximal end (53p).

7. Adjusting device (1) according to any one of claims 1 to 6, further comprising a primary return element (40) configured to urge the insertion portion (33) towards the receiving cavity (11).

8. Adjustment device (1) according to any one of claims 1 to 7, comprising a secondary return element (60) configured to urge the bearing surface (sa50) towards the stop surface (sb10).

9. Adjustment device (1) according to any one of claims 1 to 8, in which the predetermined height (h) is between 2 mm and 20 mm, and in particular substantially equal to 4 mm, 8 mm, or 12 mm.

10. Adjusting device (1) according to any one of claims 1 to 9, further comprising a gripping member (70), the intermediate element (50) comprising a gripping agent (59) configured to reversibly attach with the gripping member (70) to allow removal of the intermediate element (50) by pulling on the gripping member (70).

Images