Instrument for knee arthroplasty procedure

Abstract

To provide a spacer instrument allowing evaluating an extension gap and / or flexion gap between a femur and a tibia or the respective implants.SOLUTION: A spacer instrument 10 comprises: a spacer carrier device 16 with a first spacer component 18 having a first thickness T1 and a second spacer component 20 having a second thickness T2, the first thickness being different from the second thickness; and a rotative tibia component 28 rotatively attached to the spacer carrier device via a rotation mechanism 30. The rotative tibia component is movable between at least a first position and a second position. The first spacer component at the first position and the second spacer component at the second position are directly above the rotative tibia component, and the spacer components respectively can be temporarily positioned on the resected proximal portion 12 of a tibia 14 with or without the rotative tibia component.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a spacer device for use in knee arthroplasty procedures, which allows for the assessment of the extension and / or flexion gap between the femur and tibia or between the respective implants. Summary of the Invention

[0002] A first aspect of the present disclosure relates to a spacer device for use in a knee arthroplasty procedure, the spacer device comprising: a spacer carrier device including at least a first spacer component having a first thickness and a second spacer component having a second thickness, the first thickness being different from the second thickness, each of the spacer components configured to be temporarily positioned over a resected proximal portion of a tibia during a knee arthroplasty procedure; and a rotating tibial component, the rotating tibial component rotatably attached to the spacer carrier device via a rotation mechanism, the rotating tibial component movable to at least a first position and a second position, where in the first position the first spacer component is directly above the rotating tibial component and in the second position the second spacer component is directly above the rotating tibial component, each of the spacer components being temporarily positionable over the resected proximal portion of the tibia with or without the rotating tibial component.

[0003] By placed on top does not necessarily mean placed directly on the resected proximal portion. Each spacer component may be placed, for example, on a trial tibial plateau attached to the resected tibia, on a tibial implant attached to the resected tibia, or directly on the resected proximal portion together with a rotating tibial component.

[0004] The rotating tibial component has a thickness corresponding to a thickness of the trial tibial plateau and / or tibial implant. Thus, the rotating tibial component takes the place of the trial tibial plateau or tibial implant in an early stage of a knee replacement procedure before the trial tibial plateau or tibial implant is attached to the resected tibia. After the trial tibial plateau or tibial implant is attached to the resected tibia, each spacer component can be placed directly thereon without the rotating tibial component.

[0005] An advantage of the spacer instrument of the present invention is that it can be used to assess the extension and / or flexion gap at any stage of a knee arthroplasty procedure, such as, for example, at an early stage prior to attachment of a trial tibial plateau or tibial implant to the resected tibia, or at a stage after attachment of a trial tibial plateau or tibial implant to the resected tibia.

[0006] For example, each spacer component is a plate-like component having a substantially planar distal surface and a substantially planar proximal surface. The two spacer components are connected, for example, via a connecting portion of a carrier device. The connecting portion is, for example, a rod-like portion. The rotating tibial component is attached, for example, to the connecting portion via a rotating mechanism.

[0007] Advantageously, the rotation mechanism comprises a manually operable operating element capable of unlocking the rotating tibial component, the unlocking of which requires manually moving the rotation mechanism, the unlocking of which allows the rotating tibial component to be rotated.

[0008] Advantageously, the first and second positions are locked positions, and the rotating tibial component is rotatable between the first and second positions when the rotating tibial component is unlocked by the manipulation element. When the rotating tibial component is unlocked, the rotating tibial component can be manually rotated about the axis of rotation.

[0009] In some exemplary embodiments, the rotation mechanism includes a self-locking mechanism for automatically locking the rotating tibial component in the first and second positions. The self-locking mechanism is, for example, a snap-in mechanism that automatically locks in the first and second positions. When the rotating tibial component reaches the first or second position, the rotating tibial component is locked in that position without manual manipulation.

[0010] The rotating tibial component may be a plate-like component having a generally planar distal surface and a generally planar proximal surface. The rotating tibial component may be a hollow body bounded by at least a distal surface, a proximal surface, and a lateral surface. According to one example, at least one of said surfaces may comprise one or more openings, such as through holes. Such openings may be beneficial in terms of hygienic preparation and / or material savings and / or weight reduction.

[0011] According to a further preferred embodiment, the rotating tibial component comprises at least a plate-like base having a substantially planar distal surface and a side wall protruding proximally from the plate-like base. The height of the side wall defines the thickness of the rotating tibial component. The plate-like base and / or the side wall may comprise one or more openings, such as through holes. Such openings may be beneficial in terms of hygienic preparation and / or material savings and / or weight reduction.

[0012] Advantageously, the spacer instrument comprises connection means for detachably connecting a femoral cut compensation component, which allows the spacer instrument to be used before or after distal resection of the femur by adding a femoral cut compensation component. According to one example, the connection means comprises at least one T-slot, and the femoral cut compensation component comprises a corresponding T-member that engages with the T-slot. According to one example, each of the spacer components of the spacer instrument comprises a T-slot.

[0013] Advantageously, the spacer instrument and / or the femoral cut compensation component comprise attachment means for releasably attaching a femoral cutting block comprising corresponding attachment means. According to one example, the femoral cutting block provides a cutting guide for the femoral resection.

[0014] Advantageously, the spacer device comprises receiving means, in particular a through hole, for releasably receiving the alignment rod. According to one example, the spacer device comprises in particular two slots. According to one example, the two slots are located at the connection of the carrier device, one on each side of the rotation mechanism. The rotating tibial component may comprise corresponding receiving means, in particular a through hole. By means of the alignment rod, the alignment of the mechanical axis of the tibia can be checked.

[0015] A second aspect of the present specification relates to a spacer device set including at least two spacer devices according to any of the preceding embodiments, each of the at least two spacer devices comprising a first spacer component having a first thickness and a second spacer component having a second thickness, the first thickness and the second thickness defining a thickness pair for each spacer device, and at least two spacer devices of the set have different thickness pairs.

[0016] A third aspect of the present specification relates to a kit of parts comprising at least one spacer instrument according to an embodiment, at least one femoral cutting compensation plate, and / or a cutting block, and / or an alignment rod, and / or at least one further instrument, for example a measuring block or a sizing instrument.

[0017] Further advantageous embodiments can be derived from the following description of exemplary embodiments with reference to the drawings, in which: [Brief description of the drawings]

[0018] [Figure 1] 1A and 1B show schematic diagrams of a spacer device positioned over a resected proximal portion of the tibia at different stages of a knee arthroplasty procedure: (a) and (b). [Diagram 2] Schematic representation of a spacer device in various use situations (a), (b) and (c). [Diagram 3] Schematic showing an exploded view of the spacer device (a), components of the spacer device (b), detailed views of the spacer device (c), (d) and (e). [Figure 4] Schematic representation of components of a spacer device in different views (a) and (b). [Diagram 5] 5 shows the component according to FIG. 4 mounted in a spacer device diagrammatically in different views (a), (b) and (c). [Figure 6] Schematic diagram of a spacer device at different stages (a) and (b) of a knee arthroplasty procedure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] 1 illustrates a schematic diagram of a spacer device 10 for use in a knee arthroplasty procedure. According to this example, the spacer device is placed over a resected proximal portion 12 of a tibia 14.

[0020] The spacer device 10 comprises a carrier device 16 having at least a first spacer component 18 and a second spacer component 20. The first spacer component 18 has a first thickness T1 and the second spacer component 20 has a second thickness T2. The first thickness T1 and the second thickness T2 define a thickness pair, the first thickness T1 being different from the second thickness T2. According to an example, the thickness pair may be selected from the following thickness pairs: a first pair with T1=10 mm and T2=11 mm, a further pair with T1=12 mm and T2=14 mm, a further pair with T1=16 mm and T2=18 mm. In a further example, T1 or T2 may be 22 mm.

[0021] According to this example, each of the spacer components 18, 20 is a plate-like component having a generally planar distal surface 22 and a generally planar proximal surface 24. Each of the spacer components 18, 20 is configured to be temporarily placed over the resected proximal portion 12 of the tibia 14 with the distal surface 22 facing the resected proximal portion 12 of the tibia 14 during knee arthroplasty.

[0022] The two spacer components 18, 20 are connected via a connection portion 26 of the carrier device 16. The connection portion 26 is, for example, a rod-shaped portion.

[0023] The spacer instrument 10 includes a rotating tibial component 28. The rotating tibial component 28 is rotatably mounted to the spacer carrier device 16 via a rotation mechanism 30.

[0024] The rotating tibial component 28 is movable to at least a first position and a second position. In the first position, the first spacer component 18 is directly above the rotating tibial component 28 (see, e.g., FIG. 1(a)). In the second position, the second spacer component 20 is directly above the rotating tibial component 28 (see, e.g., FIG. 1(b)). This allows each of the spacer components 18, 20 to be temporarily positioned over the resected proximal portion 12 of the tibia 14 with or without the rotating tibial component 28.

[0025] 1(a), the first spacer component 18 is directly above the rotating tibial component 28, and the first spacer component 18 and the rotating tibial component 28 together are placed on the resected proximal portion 12 of the tibia 14. The rotating tibial component 28 takes the place of a trial tibial plateau 32 or tibial implant in the initial stages of the surgical procedure. The thickness TT of the rotating tibial component 28 corresponds to the thickness TP of the trial tibial plateau 32 or tibial implant (see FIG. 1(b)).

[0026] 1(b), the rotating tibial component 28 is moved to a second position with the second spacer component 20 directly above the rotating tibial component 28. The first spacer component 18 is positioned over the resected proximal portion 12 of the tibia 14 on a trial tibial plateau 32 or tibial implant that will be attached to the resected tibia at a later stage of the surgical procedure.

[0027] The rotation mechanism 30 includes an operating element 34 that can be operated by hand, and the operating element 34 can unlock the rotating tibial component. The operating element 34 is, for example, a button. To unlock the rotating tibial component 28, the rotation mechanism 30 needs to be moved by hand via the operating element 34. According to this example, the rotation mechanism 30 can be moved by hand by manually pushing the operating element 34 in a distal direction along a rotation axis 36. When the rotating tibial component 28 is unlocked, the rotating tibial component 28 can be rotated around the rotation axis 36. The first position (see FIG. 2(a)) and the second position (see FIG. 2(c)) are locked positions. When the rotating tibial component 28 is unlocked, the rotating tibial component 28 can be rotated around the rotation axis 36 by hand (see FIG. 2(b)).

[0028] The rotation mechanism 30 will now be described with reference to Fig. 3. In the assembled state, the operating element 34 is guided by a guide part 38, which receives the operating element 34 and allows the operating element 34 to move along and rotate about the rotation axis 36. In the assembled state, the rotating tibial component 28 is fixed to the guide part 38. For example, the rotating tibial component 28 is fixed to the guide part 38 via two pins 42 welded or glued to corresponding recesses 44, 46 of the rotating tibial component 28 and the guide part 38.

[0029] The rotation mechanism 30 comprises a self-locking mechanism that automatically locks the rotating tibial component in the first and second positions. According to the present example, the self-locking mechanism is realized by two protrusions 48 and a spring element 49 of the operating element 34. The two protrusions 48 are arranged in and pass through corresponding notches 50 of the guide part 38.

[0030] The spring element 49 is disposed between the rotating tibial component 28 and the operating element 34. A spring force acts on the rotating tibial component 28 and the operating element 34, thereby urging the operating element 34 in a proximal direction. When the rotating tibial component 28 reaches the first position or the second position and the operating element 34 is released, the two protrusions 48 of the operating element 34 enter the corresponding pockets 51 of the carrier device 16 (see FIGS. 3(b) and (c)). Thus, the rotating tibial component 28 is locked together with the carrier device 16 by the rotation mechanism 30.

[0031] Thus, by releasing the manipulation element 34, the self-locking mechanism automatically locks in the first and second positions and no manual manipulation is required to lock the rotating tibial component in position.

[0032] By pushing the operating element 34 distally along the rotation axis 36, the protrusion 48 moves out of the pocket 51 of the carrier device 16 (see Figures 3(d) and (e)), thereby allowing the rotating tibial component 28 to be manually rotated about the rotation axis 36.

[0033] According to this example, the rotating tibial component 28 includes at least a plate-like base 52 having a generally planar distal surface 54, and a side wall 56 protruding proximally from the plate-like base 52. The height of the side wall 56 defines a thickness TT of the rotating tibial component 28. In this example, the plate-like base 52 and the side wall 56 include a number of openings 58, such as through holes (see FIG. 3).

[0034] 4 illustrates a femoral cut compensation component 60. The femoral cut compensation component 60 may be removably connected to the spacer instrument 10, for example to the first spacer component 18 and / or the second spacer component 20. The femoral cut compensation component 60 allows for the use of the spacer instrument before or after distal resection of the femur, by adding the femoral cut compensation component.

[0035] The spacer instrument 10 comprises connection means for releasably connecting the femoral cut compensation components 60. According to the present example, the connection means comprises a T-slot 62 provided on each of the spacer components 18, 20 (see Figs. 5(a)-5(c)). The femoral cut compensation component 60 comprises a corresponding T-member 64 that engages with one of the T-slots 62 (see Figs. 4(a) and (b)).

[0036] According to this example, the spacer instrument 10, in particular the femoral cut compensation component 60, may comprise attachment means (not shown) for releasably attaching a further instrument, such as a femoral cutting block 68, which comprises corresponding attachment means. According to one example, the femoral cutting block 68 provides a cutting guide for the femoral resection (see FIG. 6(a)). FIG. 6(a) illustrates a stage of the knee arthroplasty procedure before the distal resection of the femur 40. FIG. 6(b) illustrates a stage of the knee arthroplasty procedure after the distal resection of the femur 40.

[0037] According to the present embodiment, the spacer device 10 comprises receiving means 70, in particular a through hole, for releasably receiving an alignment rod (not shown). According to the present embodiment, the spacer device 10 comprises in particular two slots 70. According to one embodiment, the two slots 70 are arranged in the connection part 26 of the carrier device 16, one on each side of the rotation mechanism 30. The rotating tibial component 28 comprises corresponding receiving means 74, in particular a through hole. By means of the alignment rod, the alignment of the mechanical axis of the tibia 14 can be checked.

[0038] A further embodiment relates to a set of spacer devices 10 comprising at least two of the spacer devices 10 described with respect to Figures 1 to 6. Each of the at least two spacer devices 10 comprises a first spacer component 18 having a first thickness T1 and a second spacer component 20 having a second thickness T2, the first thickness T1 and the second thickness T2 defining a thickness pair (T1, T2) of each spacer device 10, and the at least two spacer devices 10 of the set have different thickness pairs (T1, T2).

[0039] A further embodiment relates to a kit of parts comprising at least one spacer instrument 10 as described with respect to Figures 1 to 6 and at least one femoral cut compensation component 60, and / or a cutting block 68, and / or an alignment rod.

[0040] A method of performing a knee arthroplasty procedure includes the following steps.

[0041] One step of the procedure involves preparing the proximal portion 12 of the tibia 14 by resecting the proximal portion.

[0042] In one step of the procedure, the extension and / or flexion gap between the femur and tibia is assessed.

[0043] The step of assessing the extension and / or flexion gap may include positioning the spacer instrument 10, and in particular the first spacer component 18 or the second spacer component 20, over the resected proximal portion 12. The first spacer component 18 or the second spacer component 20 may be positioned directly above the rotating tibial component 28, and either the first spacer component 18 and the rotating tibial component 28, or the second spacer component 20 and the rotating tibial component 28 together, may be positioned over the resected proximal portion 12 of the tibia 14.

[0044] The step of assessing the extension and / or flexion gap may include rotating the rotating tibial component 28 from a first position to a second position and / or from the second position to the first position via the rotation mechanism 30. Rotating the rotating tibial component 28 may include manually manipulating the manipulation element 34, thereby unlocking the rotating tibial component 28 and allowing the rotating tibial component 28 to be manually rotated.

[0045] After rotating the rotating tibial component 28 from the first position to the second position and / or vice versa, the first spacer component 18 or the second spacer component 20 may be placed over the resected proximal portion 12 together with the rotating tibial component 28.

[0046] In one step of the procedure, a trial tibial plateau 32 or tibial implant may be attached to the proximal portion 12 of the tibia 14 .

[0047] In a further step of the procedure, the extension and / or flexion gap between the femur and the trial tibial plateau 32 or the tibia with the tibial implant attached is assessed using the previously described spacer instrument 10. The first spacer component 18 or the second spacer component 20 may be placed directly onto the trial tibial plateau or tibial implant without the rotating tibial component 28. The rotating tibial component 28 may be rotated as described above.

Claims

1. A spacer device (10) for use in a knee arthroplasty procedure, comprising: a spacer carrier device (16) comprising at least a first spacer component (18) having a first thickness (T1) and a second spacer component (20) having a second thickness (T2), said first thickness (T1) being different from said second thickness (T2), each of said spacer components (18, 20) being configured to be temporarily positioned over a resected proximal portion (12) of a tibia (14) during knee arthroplasty; a rotating tibial component (28); The rotating tibial component (28) is rotatably attached to the spacer carrier device (16) via a rotation mechanism (30); the rotating tibial component (28) is movable to at least a first position and a second position; In the first position, the first spacer component (18) is directly above the rotating tibial component (28); In the second position, the second spacer component (20) is directly above the rotating tibial component (28); A spacer instrument (10), wherein each of the spacer components (18, 20) is temporarily positionable over the resected proximal portion (12) of the tibia (14) with or without the rotating tibial component (28).

2. Each spacer component (18, 20) is a plate-like component having a generally planar distal surface (22) and a generally planar proximal surface (24); and / or The two spacer components are connected via a connection (26). The spacer device (10) of claim 1.

3. the rotation mechanism (30) includes a manually operable operating element (34) capable of unlocking the rotating tibial component (28); A spacer device (10) according to any one of claims 1 to 2.

4. the first position and the second position are locked positions; the rotating tibial component (28) is rotatable between the first position and the second position when the rotating tibial component (28) is unlocked via the manipulation element (34). A spacer device (10) according to claim 3.

5. the rotation mechanism (30) comprising a self-locking mechanism for automatically locking the rotating tibial component (28) in the first position and the second position; A spacer device (10) according to any one of the preceding claims.

6. The rotating tibial component (28) includes at least a plate-like base (52) having a generally planar distal surface (54) and a side wall (56) protruding proximally from the plate-like base (52). A spacer device (10) according to any one of the preceding claims.

7. The spacer device (10) comprises a connecting means (62) for releasably connecting a femoral cut compensation component (60), A spacer device (10) according to any preceding claim.

8. the spacer device (10) comprises receiving means (70), in particular a through hole, for releasably receiving an alignment rod, A spacer device (10) according to any preceding claim.

9. A set of spacer devices (10) comprising at least two spacer devices (10) according to any one of claims 1 to 8, Each of the spacer devices comprises a first spacer component (18) having a first thickness (T1) and a second spacer component (20) having a second thickness (T2); said first thickness (T1) and said second thickness (T2) define a pair of thicknesses (T1, T2) for each spacer device (10); At least two of the spacer devices (10) of the set have a pair of different thicknesses (T1, T2); A set of spacer devices (10).

10. A kit of parts comprising at least one spacer instrument (10) according to any one of claims 1 to 8, at least one femoral cut compensation component (60), and / or a cutting block (68), and / or an alignment rod, and / or at least one further instrument.

Images