WO2025196417A1

WO2025196417A1 - A surgical device and a surgical assembly

Info

Publication number: WO2025196417A1
Application number: PCT/GB2025/050552
Authority: WO
Inventors: George Desoutter
Original assignee: De Soutter Medical Ltd
Current assignee: De Soutter Medical Ltd
Priority date: 2024-03-22
Filing date: 2025-03-18
Publication date: 2025-09-25
Anticipated expiration: 2026-09-22
Also published as: GB202404119D0; GB2639664A

Abstract

A surgical device for use in the seating of implants, the device comprising: a first part comprising: an elongate first body defining an axis, a first connector configured to engage an implant at an end of the first body, and a first strike plate; a second part comprising: a second body, a second connector configured to engage a surgical impactor at an end of the second body, and a second strike plate; wherein the second part is configured to slidingly engage the first part along the axis and move along the axis between a first arrangement, in which the second strike plate abuts the first strike plate, and a second arrangement, in which the second strike plate is separated from the first strike plate.

Description

A surgical device and a surgical assembly

FIELD

The present disclosure relates to surgical devices and assemblies, specifically surgical devices and assemblies for the use in the seating of implants.

BACKGROUND

The seating of implants, such as an acetabular cup implant, often requires the implant to be inserted and located in a socket in a bone. In order to ensure performance, the implant and socket usually have an interference fit, to resist movement of the implant relative to the bone. In order to correctly seat the implant, impulse forces are applied to the implant to urge it into the correct location.

Historically, these forces are applied by hitting a connector attached to the implant with a hand-held mallet. The connector is a generally elongated tool that has an attachment interface at one end for connection to the implant and a surface at the other end that can be struck by a mallet. More recently, pneumatic or electrically powered surgical impactors have been introduced in order to apply consistent, predictable axial impulses to a connector. The connectors for use with surgical impactors have an attachment interface at one end for connection to the implant and an attachment interface at the other end for connection to the surgical impactor.

Surgical impactors are relatively heavy and, as such, can be tiring to hold in the correct position for seating the implant for long periods of time. It is desirable for the surgeon to quickly and easily remove the impactor from the implant, to enable the surgeon to perform other surgical tasks such as checking implant position with fluoroscopy. It is also not possible to release the surgical impactor and allow it to be supported by the friction between the implant and the socket, given the weight of the surgical impactor. Even when using an impactor, it is still often desirable to apply lateral or torque forces to the implant by hand - either to test that the implant is seated correctly, or to adjust the seating using a hand-held mallet. It is therefore common to install an implant using a combination of a surgical impactor and hand-held tools. To achieve this, a user will typically attach the implant and surgical impactor to a connector; use the surgical impactor to partially seat the implant and then disconnect the surgical impactor from the connector to test the seating or adjust it by hand. Disconnecting the surgical impactor from the connector is not straightforward. It takes some amount of time and the user must be careful to support the surgical impactor throughout the process to avoid any movement of the heavy surgical impactor disturbing the seating of the implant. It is then either necessary to attach a different component to allow the connector and implant to be struck by a hand-held mallet, or strike the existing connector with a mallet. This process is therefore cumbersome and often results in the seating of the implant being disturbed.

SUMMARY

The present disclosure provides a surgical device and surgical assembly that simplifies and streamlines the seating of surgical implants.

According to the disclosure is a surgical device for use in the seating of implants. The device comprises a first part comprising an elongate first body defining an axis, a first connector configured to engage an implant at an end of the first body, and a first strike plate. A second part comprises a second body, a second connector configured to engage a surgical impactor at an end of the second body, and a second strike plate. The second part is configured to slidingly engage the first part along the axis. The second part is configured to move along the axis between a first arrangement, in which the second strike plate abuts the first strike plate, and a second arrangement, in which the second strike plate is separated from the first strike plate.

The surgical device may be an acetabular cup seating device.

The device may be configured to connect to an implant, e.g. an acetabular cup, at a first end and transfer axial force applied to the other end of the device to the acetabular cup to insert and seat it within a socket. Advantageously, the device may allow a user to quickly switch between applying force using a hand mallet and a surgical impactor without the need to disconnect the device from the acetabular cup. Although an acetabular cup implant is provided as a specific example of a suitable implant, it will be understood that the present disclosure may be suitable for use with a wide range of implants.

A surgical impactor may refer to a pneumatic or electrically powered tool configured to apply axial impact forces for use in the seating of implants. Surgical impactors can be relatively heavy and unwieldy, and so it is desirable to provide a flexible solution to implant seating, for example that allows a user to quickly and easily connect and disconnect the surgical impactor from the implant while minimising the risk of unintentionally misaligning the implant during the process.

The first and second parts both comprise a strike plate - e.g. an axially-facing (flat, textured, contoured or curved) surface - for being struck to exert an axial force to the part or between parts.

The first part may be for connecting to an implant. The first connector may comprise a screw thread or other connecting interface to attach the implant. The second part may be for connecting to a surgical impactor. The second part may comprise a spigot, screw thread, bayonet or other interface for attaching to a surgical impactor.

The first and second parts may be configured to move towards and away from each other such that the first and second strike plates engage and disengage. This may allow the surgical impactor to impart a repetitive impulsive force onto the first part, via the second part, by means of the abutting strike plates. The impulsive force may drive the implant into a socket.

As the first and second strike plates may be free to axially separate from each other when pulled part, the device may ensure that an axial force is applied to an attached implant in only one direct (e.g. driving the implant into the socket). The implant is not unintentionally pulled away from the socket as the second part is drawn back towards the surgical impactor.

In the second arrangement, the second part may be disengaged from the first part. The second part may be disengaged from the first part such that it is entirely disconnected from the first part. The second part may be freely (i.e. without additional user intervention) engaged and disengaged from the first part by axial movement of the second part relative to the first part. One of the first and second parts may be configured to slide into and out of the other of the first and second parts. The second part may be disengaged from the first part as the second part is moved axially away from the first part.

This may allow a user to disconnect the surgical impactor from the implant and first part simply and quickly by moving the surgical impactor and second part axially away from the first part, without needing to apply a rotation or sideways motion to the device, which can disturb the seating of the implant.

Disengaging the second part from the first part may also allow a user to apply forces manually to the implant - e.g. to test the seating of the implant.

The second part may be disengaged from the first part to (axially) expose the first strike plate. Disengaging the second part from the first part may provide a user access to strike the first strike plate with a hand mallet in order to adjust the seating of an implant.

The device may comprise an interface between the first and second parts. The interface may be configured to facilitate the sliding engagement between the first and second parts. The interface may be configured to permit relative movement of the first and second parts along the axis.

The interface may be configured to resist relative movement of the first and second parts perpendicular to the axis.

The interface may be configured to allow relative rotation of the first and second parts about the axis.

The second part may be configured to rotate relative to the first part. This may prevent a user inadvertently applying an undesirable torque to the implant during use. The interface may be configured such that the first part and second part can be selectively engaged and disengaged at any orientation. This may simplify engagement of the first and second parts.

The interface may be configured to resist relative rotation of the first and second parts about the axis.

The device may be configured to resist, limit or prevent rotation of the second part relative to the first part. This may allow a user to intentionally apply torque forces to an implant, where required.

The device may be configured to selectively move between a mode in which relative rotation is permitted, and is resisted. The device may comprise a latch or locking device for moving the device between the two modes. This may include keyways, flats, splines provided by the interface (e.g. on either or both of the first and second parts).

The interface may comprise: a male engagement profile on one of the first part and second part; and a female engagement profile on the other of the first part and second part. One of the first and second parts may comprise a rod and the other of the first and second parts may comprise a complementary guide channel.

The male engagement profile and/or female engagement profile may have a circular cross section perpendicular to the axis. A circular engagement profile may allow relative rotation of the first and second parts. Alternatively, the male engagement profile and female engagement profile may have a non-circular cross section perpendicular to the axis. A non-circular engagement profile may resist relative rotation of the first and second parts.

The interface, e.g. one of the male and female engagement profiles, may comprise a strike plate. Having the interface both facilitate engagement of the first and second parts and provide a strike plate provides an advantageous dual function which allows a simplified and more compact design. An axially-facing rim of the female engagement profile may define one of the first and second strike plates. Alternatively, an axial end face of the male engagement profile may define one of the first and second strike plates.

The strike plate on the first part may be at an opposing end of the first part to the first connector, such that it is exposed when the second part is disengaged from the first part.

The device (e.g. the first part) may comprise a bump stop configured to locate the first connector within the implant. The bump stop may be made of plastic and may ease the connection of the implant to the first part and avoid unintentional damage to the implant through unintentionally collision with the first part.

The first part (or other part of the device) may comprise a handle or grip for being held by a user. The handle or grip may allow a user to align the first part and attached impactor when applying axial loads via a surgical impactor or hand-held mallet.

The first and second parts may comprise or be made of stainless steel.

The device may comprise a lock configured to be moved between a locked and an unlocked configuration. In the locked configuration, the lock may limit or prevent axial movement of the second part away from the first part. In the unlocked configuration, axial movement of the second part away from the first part may be unrestrained.

The lock may permit only a fixed range of axial movement of the second part relative to the first part. Alternatively, the lock may prevent axial movement of the second part relative to the first part. This may allow a user to lock the first and second parts together. This may be useful for removing implants - for example by reversing the movement profile of the surgical impactor in order to urge the implant out of a socket.

The user may be able to selectively switch between the locked and unlocked arrangement, allowing a user to selectively move between an implant seating and implant removal modes.

The device may further comprise a lock configured to be moved between a locked and an unlocked configuration, wherein in the locked configuration, the lock limits or prevents rotational movement of the second part relative to the first part; and in the unlocked configuration, rotational movement of the second part relative to the first part is unrestrained.

The lock configured to limit or prevent rotation may be the same lock as that which limits or prevents axial movement, or it may be an additional, second, lock.

The device may comprise an acetabular cup implant engaged with the first connector of the first part.

Further according to the disclosure is a surgical assembly comprising a surgical device as described anywhere herein, connected to a surgical impactor.

Further disclosed is a method of seating an implant. The method comprises connecting a surgical device to an implant at one end and a surgical impactor at the other, using the surgical impactor to at least partially insert the implant in the socket, disconnecting the surgical impactor from the implant by moving the surgical impactor axially away from the implant, applying additional force to the implant to correctly seat it either by hand or using a hand-held mallet. The surgical device may be as described herein.

Further according to the disclosure is a surgical part for a surgical device. The surgical part may be the first part as described anywhere herein, or the second part as described anywhere herein.

BRIEF DESCRIPTION OF DRAWINGS

Figure 1 is a side view of a surgical device;

Figure 2A is a cross-sectional view of the surgical device of Figure 1 ;

Figure 2B is an enlarged view of part of Figure 2A;

Figure 3 depicts a surgical assembly comprising the surgical device; and

Figure 4 depicts a surgical assembly comprising the surgical device. DETAILED DESCRIPTION OF DRAWINGS

Referring to Figures 1 and 2A, Figure 1 is a side view of a surgical device 10 for use in the installation of acetabular cup implants 40 (see Figures 3 and 4), according to the present disclosure. Figure 2A is a cross-sectional view of Figure 1. The surgical device 10 includes a first part 12 and a second part 14.

The first part 10 includes an elongate body 26, a first connector 16 and a first strike plate 18. The elongate body 26 is configured to define an axis “A” extending along the length of the body. The elongate body 26 can, for example, be made of a solid metal rod, e.g. stainless steel, but the structure and material of the elongate body is not limited to that shown in the Figures.

The elongate body comprises a hand-grip 24. The hand-grip 24 may allow a user to firmly grip the first part 12 to orient the surgical device 10. The structure and material of the hand-grip may be the same or different to the rest of the elongate body 26.

At an end of the elongate body 26, there is a first connector 16 configured to connect to an implant 40 (not shown in Figure 1). In Figure 1 the connector 16 comprises a screw thread for fastening to acetabular cup implants but it can be appreciated that the disclosure is not limited to the connection means or type of implant shown in the figures.

At an opposite end of the elongate body 26, a first strike plate 18 is provided. In other examples the strike plate 18 may be located somewhere other than at an end of the body 26. The first (and second) strike plate 18 is configured to receive an impulse force and apply this to an implant 40 attached to the connector 16. In the present case, the strike plate 18 is an exposed flat surface arranged perpendicular to the axis A. The first strike plate 18 of Figure 1 is configured to abut the second strike plate 22 of the second part 14 when the surgical device 10 is being used. The first strike plate 18 is also configured to be impacted by a surgical mallet 60 during manual use. These interactions are discussed in more detail below.

The first part 12 of the surgical device 10 also comprises a bump stop 28. The bump stop 28 is configured to locate the connector 16 within an implant 40 and avoid a misaligned connector 16 damaging an implant 40 during connection to the implant 40. The bump stop 28 is a generally toroidal component comprising plastic, preferably acetal. The bump stop 28 is arranged to surround the elongate body 26, spaced slightly from the connector 16.

The second part 14 includes a body, a second connector 20 and a second strike plate 22.

The second connector 20 is provided at an end of the body. It is configured to connect to a surgical impactor 50. The second connector 20 may comprise a screw thread, bayonet, spigot or any other mechanical fastening for fixing the surgical device 10 relate to a surgical impactor 50. In the present example, the second connector 20 comprises a spigot.

The body of the second part 14 includes a frusto-conical section. The second strike plate 22 is provided on an axial end face of the frusto-conical section facing the first part 12 during use. The second strike plate 22 is flat. The shape of the frusto-conical section optimises the efficient transfer of energy, which provides a greater impact force on the first strike plate 18 during use than would otherwise be possible.

As noted above, the first and second strike plates 18, 22 are configured to receive and impart impulse forces (respectively). The second strike plate 22 is therefore axially aligned and parallel with the first strike plate 18.

The second part 14 is configured to move axially with respect to the first part 12 between a first arrangement, in which the second strike 22 plate abuts the first strike plate 18, and a second arrangement, in which the second strike plate 22 is separated from the first strike plate 18.

The surgical device 10 defines an interface between the first part 12 and second part 14 that facilitates the relative axial movement. The interface comprises a first engagement profile on the first part 12 and a second engagement profile on the second part 14.

In the present example, the first engagement profile is a guide channel 32. The guide channel 32 is a cylindrical recess extending along the axis A of the first part 12. The guide channel 32 is configured to be the female member of a two-part male-female interface. In the example shown, the guide channel 32 is provided extending into the first part 12 from the first strike plate 18. That is, the first strike plate 18 is provided as a circumferential surface surrounding the guide channel 32. This provides a particularly compact arrangement.

In the example of Figure 1 , the second engagement profile is a rod 30. The rod 30 extends from the second strike plate 22. Again, having the rod 30 extend from the strike plate 22 is not essential, but provides a particularly compact arrangement. The rod 30 extends along the axis A. The rod 30 is configured to be the male member of the two- part male-female interface.

During use, the rod 30 of the second part 14 is received within the guide channel 32. The guide channel 32 and rod 30 allow relative axial movement of the first and second parts 12, 13, but resist movement perpendicular to the axis A. The interface of the present example is configured to allow relative rotational movement between the first and second parts. This may be advantageous to allow the two parts to engage at any relative orientation. However, in some embodiments, the interface may be configured to limit or prevent relative rotation between the first and second parts 12, 14. This may be achieved through the inclusion of a locking mechanism such as a key or spline to resist rotation. Similarly, a separate or combined lock may be provided that selectively limits, or prevents, relative axial movement of the first part 12 and second part 14. This may, for example, allow the first and second parts 12, 14 to be locked together, in order to use the surgical device for the removal of an implant 40.

The interface of the present example permits relative axial movement of the first and second parts 12, 14. As such, when the second part 14 is connected to an impactor 50, the impactor 50 can reciprocally urge the second part 14 axially towards and away from the first part 12. At the end of each movement towards the first part 12, the second strike plate 22 hits the first strike plate 18, imparting an axial impulsive force. The second strike plate 22 repeatedly strikes the first strike plate 18. This can act to drive the implant 40 into a socket to seat the implant 40.

The surgical device 10 of Figure 1 , and specifically the interface, is configured to not limit relative axial movement of the second part 14 away from the first part 12. In other words, the second part 14 is free to move axially away from the first part 12 such that it disengages from the first part 12.

Here, the term “engagement” is used to describe a relative arrangement of the first and second parts where some form of interaction between the parts is possible in order to restrict relative movement. For example, in the present example, the second part 14 may be considered to be engaged with the first part 12 while the rod 30 is at least partially located in the guide channel 32 in order to resist relative movement of the first and second parts 12, 14 perpendicular to the axis A.

In the shown example, the second part 14 is free to move axially away from the first part 12 beyond the limit of the travel provided by the rod 30 and guide slot 32 such that The rod 30 leaves the guide slot 32 entirely and the two parts are separated. This may allow a user to readily connect and disconnect the second part 14 (and connected surgical impactor 50) from the first part 12 (and connected implant 40). This means that the surgical impactor 50 can be entirely disconnected from the implant 40 simply by moving the surgical impactor 50 and second part 14 axially away from the implant 40 and first part 12, to disengage the two parts 12, 14. The ease with which this is achieved avoids inadvertently moving the implant 40 during a convoluted disconnection action or due to the need to support the weight of the surgical impactor 50 for a prolonged period of time. It also greatly simplifies and speeds up the process of separating the surgical impactor 50 from the

Beneficially, disengaging the second part 14 from the first part 12 allows a user to test and manipulate the first part 12 and implant 40, without the heavy surgical impactor 50 being attached. It is difficult to get a proper “feel” for the seating of the implant 40 with the heavy surgical impactor 50 attached, since its inertia dominates any tactile feedback.

Furthermore, disengaging the second part 14 from the first part 12 exposes the first strike plate 18. In particular, the first strike plate 18 is exposed such that a user can strike it with a hand-held mallet, to fine tune the seating of the implant 40 (or to impart higher impulsive forces than are possible using a surgical impactor 50).

Turning to Figure 2B, the guide channel 32 comprises a liner 34. The liner 34 covers the inner surface of the guide channel 32. The liner 34 may be made from a material that is different to the material of the elongate body 26 of the first part and/or guide rod 30 of the second part. The liner 34 may comprise a low-friction material (e.g. lower friction than the material of the first part 12). In the present example, the liner 34 is made of a polymer, such as acetal. The liner 34 is pressed in or held in place by a retaining means such as glue, retaining ring or screw ring. The liner 34 is configured to provide a smooth surface to slidingly engage the guide rod 30.

The interaction of the guide rod 30 and liner 34 reduces wear on the guide channel 32 and on the guide rod 30. The reduction in wear of these components ensures that the tolerances to which the components of the device are machined persist or substantially persist over repeated use of the surgical device 10. It also provides a smoother reciprocal action.

At the open end of the guide channel, the liner 34 may be positioned sub-flush to the first strike plate 18 to avoid being damaged by repeated manual or powered impactions.

In Figure 3, a surgical assembly is shown comprising a surgical device 10 as described above, connected to an acetabular cup implant 40 at one end, and a surgical impactor 50 at the other. Figure 3 shows the first strike plate 18 and second strike plate 22 in contact with each other, with the rod 30 fully inserted into the guide channel 32

In Figure 4, a surgical assembly is shown comprising a surgical device 10 as described above, connected to an acetabular cup implant 40 at one end. The second part 14 of the surgical device 10 is disengaged with the first part 12, such that the first strike plate 18 is exposed. A hand-held mallet 60 is shown, in position to manually strike the first strike plate 18.

The present invention has been described above purely by way of example. Modifications in detail may be made to the present invention within the scope of the claims as appended hereto. Furthermore, features from one example may be combined with an alternative example unless such a combination is explicitly precluded.

Claims

1. A surgical device for use in the seating of implants, the device comprising: a first part comprising: an elongate first body defining an axis, a first connector configured to engage an implant at an end of the first body, and a first strike plate; a second part comprising: a second body, a second connector configured to engage a surgical impactor at an end of the second body, and a second strike plate; wherein the second part is configured to slidingly engage the first part along the axis and move along the axis between a first arrangement, in which the second strike plate abuts the first strike plate, and a second arrangement, in which the second strike plate is separated from the first strike plate.

2. The device of claim 1 , wherein in the second arrangement, the second part is disengaged from the first part.

3. The device according to claim 1 , further comprising an interface between the first and second parts; wherein the interface is configured to facilitate the sliding engagement between the first and second parts; and the interface is configured to permit relative movement of the first and second parts along the axis but resist relative movement of the first and second parts perpendicular to the axis.

4. The device according to claim 3, wherein the interface is configured to allow relative rotation of the first and second parts about the axis.

5. The device according to claim 3, wherein the interface is configured to resist relative rotation of the first and second parts about the axis.

6. The device of any of claims 3 to 5, wherein the interface comprises: a male engagement profile on one of the first part and second part; and a female engagement profile on the other of the first part and second part.

7. The device according to claim 6, wherein the male engagement profile and/or female engagement profile has a circular cross section perpendicular to the axis.

8. The device according to claim 6, wherein the male engagement profile and female engagement profile have a non-circular cross section perpendicular to the axis.

9. The device according to any of claims 6 to 8, wherein: an axially-facing rim of the female engagement profile defines one of the first and second strike plates; or an axial end face of the male engagement profile defines one of the first and second strike plates.

10. The device according to any one of the above claims, wherein the strike plate on the first part is at an opposing end of the first part to the first connector, such that it is exposed when the second part is disengaged from the first part.

11 . The device according to any one of the above claims, further comprising a bump stop configured to locate the first connector within the implant.

12. The device according to any one of the above claims, wherein the first part comprises a handle or grip for being held by a user.

13. The device according to any of the above claim, further comprising a lock configured to be moved between a locked and an unlocked configuration, wherein in the locked configuration, the lock limits or prevents axial movement of the second part away from the first part; and in the unlocked configuration, axial movement of the second part away from the first part is unrestrained.

14. The device according to any of the above claim, further comprising a lock configured to be moved between a locked and an unlocked configuration, wherein in the locked configuration, the lock limits or prevents rotational movement of the second part relative to the first part; and in the unlocked configuration, rotational movement of the second part relative to the first part is unrestrained.

15. A surgical assembly comprising a surgical device according to any of the preceding claims, connected to an acetabular cup implant.

16. A surgical assembly according to claim 15, further comprising a surgical impactor.