Background

The present specification relates to a suture retainer and an insertion tool therefore.

Sutures are typically used to connect soft tissue such as tendons and ligaments. These sutures are held in place with one or more suture retainers. Exemplary suture retainers are discussed, for example, in US 2004/0044366 A1 which is incorporated herein by reference. These suture retainers comprise a base and a cap, with the suture passing therethrough.

The cap is ultrasonically welded to the base in order to secure the suture.

Suture retention is an important consideration for such retainers. There are no knots or other physical barriers on the suture to prevent suture pull-out. Existing methods to avoid this include wrapping the suture around energy directors such as shown in Figure 16 of US 2004/0044366 A1 . However, this can still result in slippage and pull-out of the suture.

There is therefore a need for an improved suture retainer and insertion tool.

Summary

A suture retainer is provided according to claim 1 . This suture retainer improves the resistance to pull-out of the suture from the suture retainer.

The one or more notches may be formed on the upper surface and the one or more protrusions may be formed on the cap. This is a particular arrangement of the suture retainer.

The one or more notches may be: rectangular notches; triangular notches; and/or trapezoidal notches. The protrusions may be correspondingly shaped. In certain examples there may be a combination of one or more notch/protrusion shapes. These shapes have been shown to exhibit a strong resistance to pull-out of the suture from the suture retainer.

The one or more notches may be a plurality of identical notches. Such a suture retainer can exhibit a strong resistance to pull-out. The one or more notches may extend in a first direction to form one or more channels, wherein in use a suture may be secured between the cap and the upper surface such that it extends in a second direction transverse to the first direction.

The one or more notches may be a plurality of notches spaced in the second direction. This spacing is in the direction that the suture extends across the suture retainer. Spacing the notches in this manner can further improve resistance to pull-out of the suture.

The suture retainer may further comprise one or more energy directors for focusing ultrasonic energy in ultrasonic welding. Such energy directors help to provide a strong bond during ultrasonic welding.

The cap may comprise a domed upper surface. A domed upper surface can reduce the overall footprint of the suture retainer, thereby making insertion easier. It also removes sharp edges which could otherwise case some discomfort. Additionally, if the suture retainer is inadvertently rotated the domed upper surface could still allow the suture retainer to operate and secure tension in the sutures at multiple angles.

The base may comprise one or more indentations and/or protrusions on the lower surface. The lower surface is the surface which, in use, contacts the tissue when the suture retainer is inserted and sutures retained. These indentations and/or protrusions may allow for location of the suture retainer against the tissue in the surrounding area. They may also increase and/or modify the surface area of the suture retainer so as to optimise a degradation of the suture retainer.

The cap may comprise one or more indentations and/or protrusions, for example on its upper surface. These indentations and/or protrusions may allow for location of the suture retainer. They may also increase and/or modify the surface area of the suture retainer so as to optimise a degradation of the suture retainer.

The lower surface may be flat. A flat lower surface can allow for easy welding of the cap to the body and thereby simplify the insertion of the suture retainer.

The lower surface may be domed. A domed lower surface allows the suture retainer to rest on adjacent tissue at an angle, thereby ensuring that tension is not lost in the suture. A further suture retainer is provided according to claim 13. This further suture retainer has a domed lower surface allowing it to rest on adjacent tissue at an angle, thereby ensuring that tension is not lost in the suture.

The domed lower surface may be generally hemispherical, with the upper surface forming a face of the hemispherical domed lower surface. A hemispherical lower surface allows the suture retainer to rest at a variety of angles to avoid tension being lost in the suture.

The suture may be secured to span a diameter of the hemisphere. Having the suture span a diameter of the hemisphere means that regardless of the angle the suture length to the soft tissue is essentially constant - the radius of the hemisphere.

An insertion tool for inserting a suture retainer is provided according to claim 16. This insertion tool allows for the suture retainer with a domed lower surface to be effectively inserted into a recipient.

The insertion tool may be generally cylindrical and extending in the longitudinal direction defining a longitudinal axis, the first anvil arm biased from the longitudinal axis in a radial direction. This can help reduce the footprint of the insertion tool, thereby minimising the size of the incision required to insert the suture retainer.

The sheath may be slidable in the longitudinal direction to force the first anvil arm towards the second anvil arm for holding the suture retainer, and the sheath may comprise a pin extending between the first anvil arm and the second anvil arm for forcing the first anvil arm away from the second anvil arm. In this manner insertion of the suture retainer can be performed with moving parts only along the longitudinal axis such that insertion of the suture retainer does not result in the footprint of the insertion tool substantially increasing in size.

The sheath may comprise a cut-out section and the sheath may be rotatable about the longitudinal direction to selectively align the cut-out section with the first anvil arm and/or the second anvil arm. This is another arrangement for the sheath where insertion of the suture retainer does not result in the footprint of the insertion tool substantially increasing in size. A further insertion tool for inserting a suture retainer is provided according to claim 20. This insertion tool allows for the suture retainer with a domed lower surface to be effectively inserted into a recipient.

The first anvil arm may be pivotable with respect to the central body. Such a pivotable anvil arm can allow for effective release of the suture retainer from the insertion tool.

The insertion tool may further comprise a second anvil arm extending from the central body and comprising an anvil surface for supporting the domed lower surface of the suture retainer. Multiple anvil arms can allow for a stronger hold on the suture retainer.

The second anvil arm may be pivotable with the first anvil arm with respect to the central body. Pivoting the arms together means that they can each move with respect to the central body so as to release the suture retainer.

Each anvil arm may be connected to the central body via a resiliently deformable section. This is an effective way to pivot each anvil arm with respect to the central body.

Each anvil arm, the central body and the resiliently deformable section may be unitary or integral. That is, they may be formed of a single piece of material with no breaks or attachment points. This is an effective way to form the insertion tool.

Each anvil arm and/or anvil surface may be a conical section. A conical section is particularly useful to support a domed lower surface.

Brief Description of the Drawings

The present specification makes reference to the accompanying drawings, by way of example only, in which:

Figure 1 shows a perspective view of a suture retainer;

Figures 2A to 2F show cross-sectional view of various suture retainers;

Figure 3A shows a perspective view of a suture retainer;

Figure 3B shows a perspective view of a cap of the suture retainer of Figure 3A;

Figures 4A and 4B shows schematic side views of a suture retainer in use;

Figures 5A and 5B show schematic side views of a suture retainer in use; Figure 6A shows a perspective view of an insertion tool for a suture retainer;

Figure 6B shows the insertion tool of Figure 6A with a sheath removed;

Figures 7A to 7C show progressive perspective views of a suture retainer being delivered with the insertion tool of Figure 6;

Figures 8A to 8C show progressive cross-sectional views of a suture retainer being delivered with the insertion tool of Figure 6;

Figure 9 shows a front view of an insertion tool for a suture retainer;

Figure 10 shows a perspective view of an insertion tool for a suture retainer;

Figure 11 shows a close perspective view of the insertion tool of Figure 9;

Figures 12A to 12C show an insertion tool for a suture retainer;

Figures 13A to 13C show an insertion tool for a suture retainer; and

Figures 14A to 14F show progressive perspective views of an insertion tool delivering a suture retainer.

Detailed Description

The present description and drawings include a number of example suture retainers 100. Unless expressly stated to the contrary, any description in relation to one suture retainer 100 is equally applicable to any other suture retainer 100 described and shown herein.

Figures 1 and 1 B show a suture retainer 100 which can be used to secure one or more sutures 20. While Figures 1 A and 1 B show two sutures 20, the suture retainer 100 may be used with any number of sutures 20 including a single suture 20. Any reference to multiple sutures 20 below must be understood to be equally applicable to an example with a single suture 20.

The suture retainer 100 comprises a base 12 and a cap 14. The base 12 comprises an upper surface and a lower surface. The lower surface of the base is positioned, in use, on tissue.

The cap 14 is attachable to the upper surface of the base 12 in order to secure the cap 14 to the base 12. This may be, for example, via ultrasonic welding. However, any other suitable attachment method may also be used. The attachment may be exclusively with an axial movement of the cap 14 towards the base 12 - i.e. without any rotation. In further examples, the attachment may incorporate (potentially exclusively) rotational movement of the cap 14 with respect to the base 12. In ultrasonic welding, high frequency acoustic energy (in the region of 15 kHz to 250 kHz) is imparted to the base 12 and cap 14 while supported on an anvil via a sonotrode 40. While the anvil may be a component of an insertion tool 200 as discussed below, the anvil equally could simply be body tissue of the recipient of the suture retainer 100. The sonotrode 40 vibrates towards and away from the anvil at these high frequencies and thereby causes melting at the interface of the base 12 and cap 14 which then solidifies to fuse the base 12 and cap 14.

In order to facilitate this ultrasonic welding, the suture retainer 100 may comprise one or more energy directors 16. In the example of Figures 1 A and 1 B, the energy directors 16 are formed on the cap 14 but equally the energy directors 16 could be formed on the base 12. These energy directors 16 may be of any suitable shape or size. Generally, the energy directors 16 narrow to a point or ridge which acts as the contact between the base 12 and cap 14. This means there is a concentration of force applied over a small cross-sectional area when the cap 14 is welded to the base 12. The material of the base 12 and/or cap 14 thus first begins to melt at this concentration of force.

With the energy directors 16 formed on the cap 14 or base 12, the other of the base 12 or cap 14 may comprise one or more cavities 17 for receiving the energy directors 16. These cannot be seen in Figure 1 A, but can be seen in Figure 1 B. Figure 3A shows a further suture retainer 100 where the cavities 17 for receiving the energy directors 16 are visible. There may be a corresponding cavity 17 for each energy director 15. Alternatively, one cavity 17 may receive a plurality of energy directors 16.

The energy director 16 may comprise a cut-out section. For example, the energy director 16 may have a castellated shape. This can result in a smaller contact area between the energy director 16 and contact point of the base 12 or cap 14. As a result, less energy may be required to melt the material of the base 12 and/or cap 14.

A wall 18 may be formed on the suture retainer 100. This wall 18 may be used to separate sutures 20 when a plurality of sutures 20 are used with the suture retainer 100. The wall 18 may extend from the opposite of the cap 14 or base 12 to which the energy directors 16 extend from. The wall 18 may itself act as an energy director in certain examples. There may be a corresponding cavity formed in the opposite component to receive the wall 18. In certain examples, the sutures 20 may be wrapped around the energy directors 16. An example of this wrapping is shown in Figures 1 A and 1 B. In general, the sutures 20 may be wrapped around the energy directors 16 in any suitable configuration or pattern that still allows for the energy directors 16 to be used to weld the cap 14 and base 12 together.

In use, the suture retainer 100 with the sutures 20 is held in place as the sutures 20 are attached to the soft tissue. The sutures 20 are then tightened by pulling them through the suture retainer 100. The cap 14 is then attached to the base 12, such as via ultrasonic welding, to secure the sutures 20 in place.

Alternatively, or in addition to, using sutures 20 wrapped around energy directors 16 there are other ways in which the sutures 20 can be more securely fixed to avoid suture 20 pullout. Various examples will be described with respect to Figures 2A to 2F which show various suture retainers 100. Each of Figures 2A to 2F shows two views, the first with the cap 14 and base 12 inserted in to one another and the second with the cap 14 and base 12 in an exploded view.

Figure 2A shows a basic suture retainer 100, including an energy director 16. The suture 20 passes through the suture in a left to right or right to left direction as shown on the page.

The suture retainer 100 of Figures 1 A and 1 B is susceptible to suture 20 pull-out. This can be improved by introducing protrusions 15 and notches 13 such as in the suture retainers 100 of Figures 2B to 2F. While each of these Figures shows the protrusions 15 on the cap 14 and notches 13 on the base 12, it is noted that this may of course be the other way around with protrusions 15 on the base 12 and notches 13 on the cap 14. The notches 13 do not extend all the way through the corresponding base 12 or cap 14. The notches 13 may be formed in the upper surface of the base 12. The notches 13 may extend in a first direction to form one or more channels.

Figures 2B, 2C and 2D show example suture retainers 100 with rectangular notches 13. Figures 2E and 2F show example suture retainers 100 with triangular notches 13. For each example suture retainer 100 the protrusions 15 are shaped to correspond to the shape of the notches 13. Any other shape of notch 13 is also possible, including but not limited to trapezoidal notches. The notch 13 and protrusion 15 act to introduce a kink in the suture 20, thereby making it harder to pull the suture 20 from the suture retainer 100. The notch 13 and protrusion 15 can also help in guiding the suture 20 along a given path.

The notches 13 may extend in a first direction (into and out of the page as shown in the Figures) to form a channel in the first direction. The suture 20 then passes through the suture retainer 100 in a second direction which is transverse to the first direction (i.e. from left to right or right to left as shown in the Figures). This second direction may be perpendicular to the first direction. Figures 4, 5A and 5B show the path of a suture 20 through a suture retainer 100 including a notch 13 and protrusion 15.

In certain examples, such as those shown in Figure 2C and 2F, the suture retainer 100 may comprise a plurality of notches 13 and a corresponding plurality of protrusions 15. That is, there may be one protrusion 15 for each notch 13. The notches 13 may be spaced from one another in the second direction. The energy director(s) 16 may extend in the second direction.

Figures 3A and 3B show a further example suture retainer 100. For this suture retainer 100, there are four energy directors 16. These energy directors 16 are receiving in corresponding cavities 17. The energy directors 16 are arranged in a regular array. This forms one or more intersecting channels between the energy directors 16. Specifically, the channels may be generally perpendicular, or exactly perpendicular. The sutures 20 may be passed through the suture retainer 100 such that each channel has a corresponding suture 20. The sutures 20 may be transverse to one another. Specifically, the sutures may be generally perpendicular to one another, or exactly perpendicular.

For any of the suture retainers 100 discussed herein, there may be one or more indentations and/or protrusions formed on an outer surface thereof. Specifically, the outer surface may be a lower surface of the base 12 and/or an upper surface of the cap 14 which may collectively form this outer surface. That is, surfaces which are not covered in use. The upper surface of the cap 14 may be opposite to the lower surface of the base 12. These indentations and/or protrusions may allow for location of the suture retainer 100 against the tissue in the surrounding area. For example, an insertion tool used to insert the suture retainer 100 may have a corresponding protrusion and/or indention such that the suture retainer 100 can be positioned in a given orientation. This reduces the risk of a user misaligning the suture retainer 100. They may also increase and/or modify the surface area of the suture retainer 100 so as to optimise a degradation of the suture retainer 100 by increasing the surface area without increasing the total volume of the suture retainer 100.

Figures 4A and 4B show a further example suture retainer 100 in a schematic view of the suture retainer 100 in use. As can be seen, the suture retainer 100 of Figures 4A and 4B includes a notch 15 and a protrusion 13 as discussed above, and an energy director 16. Of course, other suture retainers 100 may be used without one or more of these features. Figure 4A shows this suture retainer 100 in an ideal position when the suture retainer is first released.

In this ideal position, the lower surface of the base 12 of the suture retainer 100 is fully against the tissue 30. That is, the lower surface of the base 12 of the suture retainer is generally parallel to the tissue 30.

This is the position in which, generally, it is desirable for the suture retainer 100 to sit when it is inserted.

However, when the suture retainer 100 is installed, it is common for the sutures 20 to be tensioned from an angle, and the suture retainer 100 is likewise attached (such as ultrasonically welded) at an angle. The forces applied by the sutures 20 on the suture retainer 100 can therefore result in the suture retainer 100 twisting in use. This is shown in Figure 4B. As can be seen, the forces applied by the sutures 20 on the suture retainer 100 have resulted in it twisting and no longer sitting fully against the tissue 30. Instead, the suture retainer 100 is sitting at an angle to the tissue 30. This results in the length of a path of the suture 20 varying greatly, thereby resulting in unwanted slack in the suture 20. This leaves a void between the suture retainer 100 and the tissue 30.

Figures 5A and 5B show a further suture retainer 100 which addresses this problem. The lower surface of the base 12 of the suture retainer is domed. This may be a generally hemispherical dome - that is the dome is half of a sphere. Alternatively, any other dome shape may be used such an ovular dome. In certain examples, this may be a generally hemicapsular dome - that is the dome is half of a capsule or stadium of revolution. As a result, regardless of the orientation of the suture retainer 100 to the tissue 30 the path of the suture 20 is generally constant. Thus, the void between the suture retainer 100 and the tissue 30 is not formed.

The suture 20 may span a diameter of the domed surface, particularly when the domed surface is a hemisphere. As a result, the profile a consistent distance (radius of hemisphere) is maintained between the suture 20 and the tissue 30. Thus, tension of the sutures 20 is not lost after attachment of the cap 14 and base 12. It also avoids the need for an additional incision to be formed just so as to perform the attachment normal to the tissue 30.

The suture retainer 100 may have one or more protrusions 15 and corresponding cavities 13 as discussed above. The suture retainer 100 may additionally or alternatively have one or more energy directors 16 as discussed above.

The cap 14 of the suture retainer 100 may itself be domed, particularly on its upper surface. This may be a complementary dome to correspond to the dome of the base 12. That is, each dome may be generally identical. Alternatively, the cap 14 may comprise a different dome. Again, this may be a generally hemispherical dome - that is the dome is half of a sphere. Alternatively, any other dome shape may be used such an ovular dome. In certain examples, this may be a generally hemicapsular dome - that is the dome is half of a capsule or stadium of revolution. For the avoidance of doubt, a domed cap 14 may be used with a suture retainer 100 whether or not the lower surface of the base 12 is domed. That is, the domed cap 14 may be used with any suture retainer described herein.

The upper surface of the cap 14 may be generally opposite the lower surface of the base 12. Collectively, once assembled the upper surface of the cap 14 and the lower surface of the base 12 may generally define an outer surface of the suture retainer 100.

This suture retainer 100 with a domed lower surface may be used with a specific insertion tool 200. Conventionally, the suture retainer 100 is inserted via the following steps. Firstly, the sutures 20 are attached to the soft tissue. The sutures 20 may be already received in the suture retainer 100. However, the base 12 and cap 14 will not be attached to one another such that the sutures 20 can be moved through the suture retainer 100. The sutures 20 are then tightened by sliding them through the suture retainer 100 to apply an appropriate tension to the soft tissue. With the sutures 20 tightened, the cap 14 is attached to the base 12 to retain the sutures 20 at this tension. For example, a sonotrode 40 may be applied to the suture retainer 100 to ultrasonically weld the cap 14 to the base 12. This requires an opposing anvil to support the suture retainer 100 on an opposite side to the sonotrode 40. As the sutures 20 must be tensioned, this is typically performed inside a patient - i.e. in vivo.

For a suture retainer 100 with a domed lower surface this may be trickier as the traditional flat anvil cannot be used to support this domed lower surface. An improved insertion tool 200 may therefore be used. Examples of various insertion tools 200 are shown in Figures 6A to 14F. Unless otherwise expressly indicated, any feature of one insertion tool 200 described herein may also be equally applied to any other insertion tool 200 described herein.

Figures 6A and 6B show a first insertion tool 200. A sheath 34 (discussed below) is omitted in Figure 6B to show details of the insertion tool 200 that would otherwise be covered by the sheath 34. The insertion tool 200 comprises a first anvil arm 32 and a second anvil arm 32. Each of the anvil arms 32 extend in a longitudinal direction. Each anvil arm 32 comprises an anvil surface which, in use, supports the domed lower surface of the suture retainer 100. The anvil surface may be generally concave to correspond to the domed lower surface of the suture retainer 100. That is, the anvil surface may be generally shaped to receive a portion of the domed lower surface of the suture retainer 100.

The first anvil arm 32 and the second anvil arm 32 are biased away from one another. This may be, for example, by having the first anvil arm 32 biased away from the second anvil arm 32 which is generally rigid or stationary in use. Alternatively, both the first anvil arm 32 and the second anvil arm 32 may be biased away from one another. For example, one or both of the anvil arms 32 may be formed of a resiliently deformable material which has a bias away from the other anvil arm 32. Additionally, or alternatively, the insertion tool 200 may comprising a biasing member, such as a spring, magnet, electromagnet, hydraulic bias or any other biasing element, which acts to bias the anvil arms 32 apart. One or both of the anvil arm(s) 32 may be biased away from a central longitudinal axis of the insertion tool 200.

The insertion tool 200 may be generally cylindrical and extend in an axial direction along a central axis. The axial direction may be the same as the longitudinal direction noted above. The anvil arms 32 may be biased such that one or more of the anvil surfaces is biased in a radial direction away from the central axis.

The insertion tool 200 further comprises a sheath 34. This sheath 34 is omitted in Figure 6B to show details of the insertion tool 200 that would otherwise be covered by the sheath 34. The sheath 34 surrounds the first anvil arm 32 and the second anvil arm 32. In examples where the insertion tool 200 is generally cylindrical, the sheath 34 may be a generally cylindrical shell.

The sheath 34 is movable. For example, the sheath 34 may be sliceable in the longitudinal direction. Additionally, or alternatively, the sheath 34 may be rotatable about the longitudinal direction. This movement of the sheath 34 forces the anvil arms 32 towards one another so as to hold and retain the suture retainer 100. That is, the sheath can force the anvil arms 32 towards one another against the bias discussed above.

For example, the sheath 34 may be a generally cylindrical shell having an inner diameter. The inner diameter may be smaller than the distance which the anvil arms 32 are biased towards. The sheath 34 may be selectively alignable (via sliding and/or rotation) with the anvil arms 32. When aligned with the anvil arms 32, the inner diameter of the sheath 34 contacts the anvil arms 32 to drive them together.

In certain examples, the sheath 34 may comprise one or more cut-out sections. These cutout sections may be selectively alignable with the anvil arms 32 via rotation of the sheath 34. When aligned with the anvil arms 32, the anvil arms 32 may move outward into the cutout sections. This allows the anvil arms 32 to release the suture retainer 100. This can be seen in Figure 6A, where the sheath 34 is rotatable to as to align a cut-out with the anvil arms 32. Figure 6A shows the cut-out of the sheath 34 aligned with the anvil arms 32 such that the anvil arms 32 can release the suture retainer 100.

The insertion tool 200 may comprise an insertion cavity for receiving a sonotrode 40 to use in ultrasonically welding the cap 14 to the body 12. For example, this insertion cavity may be a generally longitudinal cavity extending along a longitudinal axis of the insertion tool 200. Figures 7A to 7C and 8A to 8C show a suture retainer 100 being deposited by an insertion tool 200 across various stages. Figure 8A generally corresponds to the same stage of the process as Figure 7A. Figure 8B generally corresponds to the same stage of the process as Figure 7B. Figure 8C generally corresponds to the same stage of the process as Figure 7C. Any disclosure in relation to any of Figures 7A to 7C may equally apply to the corresponding of Figures 8A to 8C, where appropriate, and vice-versa.

The suture retainer 100 is held by the insertion tool 200 as shown in Figure 7A (or Figure 8A). This assembly of the suture retainer 100 and insertion tool 200 can be inserted into a patient to deliver the suture retainer 100.

The sutures 20 can be attached to the soft tissue and then pulled through the suture retainer 100 to tension the sutures 20. A sonotrode 40 can then be inserted through the insertion cavity of the insertion tool 200. In certain examples, the sonotrode 40 may already be within the cavity of the insertion tool 200 during the initial insertion. The anvil surfaces of the anvil arms 32 support the domed surface of the suture retainer 100 as the sonotrode 40 applies ultrasonic energy to the opposite surface of the suture retainer 100. This fixes the cap 14 to the body 12 to retain the sutures 20.

Following this attachment, the sheath 34 may be rotated about the longitudinal axis as shown in the movement between Figures 7A and 7B (or between Figures 8A to 8B). This rotation may align cut-out sections of the sheath 34 with the anvil arms 32. This may allow one or more of the anvil arms 32 to move under the bias away from the suture retainer 100. This releases the suture retainer 100 from the insertion tool 200.

With the suture retainer 100 released from the insertion tool, the insertion tool 200 can be removed to leave the suture retainer 100 in the patient, in vivo, as shown in Figure 7C (or Figure 8C).

A further example insertion tool 200 is shown in Figures 9 to 11 . Unless otherwise expressly stated, the insertion tool 200 may include any of the features discussed in relation to the other insertion tools 200 described herein. For this insertion tool 200 the sheath 34 moves by sliding along the anvil arms 32 in the longitudinal direction. When the sheath is nearer a distal end of the insertion tool 200, it forces the anvil arms 32 together to grip the suture retainer 100. The distal end of the insertion tool 200 is the end which, in use, is inserted into the patient.

The insertion tool 200 comprises a central body 36, from which the anvil arms 32 extend. Essentially, the central body 36 may split into the anvil arms 32, with a gap in between the anvil arms 32. The sheath 34 may comprise a pin or projection 35 which extends between the first anvil arm 32 and second anvil arm 32. That is, the pin 35 may extend through the gap between the anvil arms 32.

The gap between the anvil arms 32 may increase in size towards the distal end of the insertion tool 200. That is, the gap between the anvil arms 32 may increase with distance from the central body 36. In certain examples, the gap may have an end notch 36 at an end of the gap opposite to the distal end of the insertion tool 200. This end notch may be larger in size than the section of the gap immediately adjacent it. Thus, the gap may initially decrease in size before it begins to increase with distance from the central body 36.

In use, as the sheath 34 is slid in the longitudinal direction away from the distal end of the insertion tool 200, the pin 35 slides up the gap between the anvil arms 32. Towards the distal end, the gap may be larger than a width of the pin 35. As the pin 35 moves away from the distal end, the size of the gap adjacent the pin 35 reduces. At a certain point, the pin 35 contacts one or both of the anvil arms 32. For example, the gap may be smaller than the width of the pin 35. Further movement of the sheath 34 in this direction will then result in the pin 35 applying force to the anvil arm(s) 32 which is contacted. The force will then move the anvil arm(s) 32 against the bias to release the suture retainer 100.

A further insertion tool 200 is shown in Figures 12A to 12C. Unless otherwise expressly stated, the insertion tool 200 may include any of the features discussed in relation to the other insertion tools 200 described herein. This insertion tool 200 operates to release the suture retainer 100 via rotation of the sheath 34.

Figure 12A shows the insertion tool 200 holding a suture retainer 100 ready for insertion. The sheath 34 of the suture retainer may comprise a slot 37 (also referred to as a keyway) with a corresponding protrusion 38 formed on a central body 36, which may be the central body 36 from which the anvil arm(s) 32 extend. Of course, the slot 37 may be formed on the central body with the protrusion 38 formed on the sheath 34. Figure 12B shows the sheath 34 in isolation such that the slot 37 can be readily viewed. This slot 37 and protrusion 38 can act to restrict movement of the sheath 34 to rotational movement for releasing a suture retainer 100.

In use, the insertion tool 200 holding the suture retainer 100 is inserted into a patient in the configuration shown in Figure 12A. The sutures 20 can be attached to the soft tissue and then pulled through the suture retainer 100 to tension the sutures 20. A sonotrode 40 can then be inserted through the insertion cavity of the insertion tool 200. In certain examples, the sonotrode 40 may already be within the cavity of the insertion tool 200 during the initial insertion. The anvil surfaces of the anvil arm(s) 32 support the domed surface of the suture retainer 100 as the sonotrode 40 applies ultrasonic energy to the opposite surface of the suture retainer 100. This fixes the cap 14 to the body 12 to retain the sutures 20.

Following this attachment, the sheath 34 may be rotated about the longitudinal axis as shown in the movement between Figures 12A and 12C. This rotation may align cut-out sections of the sheath 34 with the anvil arm(s) 32. The anvil arm(s) 32 may be biased away from one another and/or away from a central longitudinal axis of the insertion tool 200. This may allow one or more of the anvil arm(s) 32 to move under the bias away from the suture retainer 100. This releases the suture retainer 100 from the insertion tool 200.

The slot 37 and protrusion 38 may co-operate so as to restrict movement of the sheath 34 to this rotational movement for releasing the suture retainer 100. In this way, inadvertent movement of the sheath 34 can be prevented.

A further insertion tool 200 is shown in Figures 13A to 13C. Unless otherwise expressly stated, the insertion tool 200 may include any of the features discussed in relation to the other insertion tools 200 described herein. This insertion tool 200 operates to release the suture retainer 100 via sliding of the sheath 34.

Figure 13A shows the insertion tool 200 holding a suture retainer 100 ready for insertion. The sheath 34 of the suture retainer may comprise a slot 37 (also referred to as a keyway) with a corresponding protrusion 38 formed on a central body 36, which may be the central body 36 from which the anvil arm(s) 32 extend. Of course, the slot 37 may be formed on the central body with the protrusion 38 formed on the sheath 34. Figure 13B shows the sheath 34 in isolation such that the slot 37 can be readily viewed. This slot 37 and protrusion 38 can act to restrict movement of the sheath 34 to sliding movement for releasing a suture retainer 100. That is, movement in the direction of the longitudinal axis of the insertion tool 200.

In use, the insertion tool 200 holding the suture retainer 100 is inserted into a patient in the configuration shown in Figure 13A. The sutures 20 can be attached to the soft tissue and then pulled through the suture retainer 100 to tension the sutures 20. A sonotrode 40 can then be inserted through the insertion cavity of the insertion tool 200. In certain examples, the sonotrode 40 may already be within the cavity of the insertion tool 200 during the initial insertion. The anvil surfaces of the anvil arm(s) 32 support the domed surface of the suture retainer 100 as the sonotrode 40 applies ultrasonic energy to the opposite surface of the suture retainer 100. This fixes the cap 14 to the body 12 to retain the sutures 20.

Following this attachment, the sheath 34 may be slid along the longitudinal axis as shown in the movement between Figures 13A and 13C. This sliding may disengage the sheath 34 from the anvil arm(s) 32. The anvil arm(s) 32 may be biased away from one another and/or away from a central longitudinal axis of the insertion tool 200. This may allow one or more of the anvil arm(s) 32 to move under the bias away from the suture retainer 100. This releases the suture retainer 100 from the insertion tool 200. The sheath may further comprise a pin or projection 35 as discussed above which can act move the anvil arm(s) 32, such as moving them apart, to release the suture retainer 100.

The slot 37 and protrusion 38 may co-operate so as to restrict movement of the sheath 34 to this sliding movement for releasing the suture retainer 100. In this way, inadvertent movement of the sheath 34 can be prevented.

A further insertion tool 200 is shown in Figures 14A to 14F. Unless otherwise expressly stated, the insertion tool 200 may include any of the features discussed in relation to the other insertion tools 200 described herein. Figure 14A shows the insertion tool 200 holding a suture retainer 100. The insertion tool 200 comprises a central body 36, from which one or more anvil arm(s) 32 extend. In the depicted insertion tool 200 there are two anvil arms 32. However, in further examples there may be a single anvil arm 32, or more than two anvil arms 32. These anvil arm(s) 32 support the domed surface of the suture retainer 100. In this insertion tool 200, the anvil arm(s) 32 may support the suture retainer 100 via an interference fit. For example, the anvil arm(s) 32 and/or anvil surface(s) may generally comprise a conical section. This conical section may be revolved around approximately 180°. An aperture may be formed at the distal end of the anvil arm(s) 32, the aperture smaller than a diameter of the suture retainer 100. The central body 36 of the suture retainer 100 may comprise an insertion cavity for receiving a sonotrode 40 to use in ultrasonically welding the cap 14 to the body 12.

In use, the insertion tool 200 and suture retainer 100 are inserted into a patient in a configuration as shown in Figure 14A.

The sutures 20 can be attached to the soft tissue and then pulled through the suture retainer 100 to tension the sutures 20. The sonotrode 40 then applied ultrasonic energy to the opposite surface of the suture retainer 100 while the anvil surfaces of the anvil arm(s) 32 support the domed surface of the suture retainer 100. This fixes the cap 14 to the body 12 to retain the sutures 20. This is shown in Figure 14B.

Following the welding, the sonotrode 40 is retracted away from the suture retainer 100 as shown in Figure 14C.

The insertion tool 200 is then pressed towards the tissue 30 as shown in Figure 14D. The suture retainer 100 thus is lifted away from the anvil arm(s) 32.

The insertion tool 200 is rotated in this position as shown in Figure 14E. The anvil arm(s) 32 are pivotable with respect to the central body 36. For example, the anvil arm(s) 32 may be attached to the central body 36 via a resiliently deformable section. In certain examples the central body 36, resiliently deformable section and anvil arm(s) 32 may be formed of the same material, for example they may be integral/unitary. In particular examples the anvil arm(s) 32 may be resiliently deformable. This movement can provide clearance between the insertion tool 200 and the suture retainer 100. Finally, the insertion tool 200 is then removed from the patient as shown in Figure 14F.

A further insertion tool 200 may also be used, similar to the insertion tool 200 of Figures 14A to 14F except for each anvil arm 32 not being pivotable with respect to the central body 36. For such an insertion tool 200, the suture retainer 100 may be released by manipulating the insertion tool 200 without any pivoting of the anvil arms 32.

While the insertion tools 200 are generally used with the suture retainer 100 having a domed surface, it is noted that similar insertion tools 200 could also be used for any other suture retainer 100, with suitably shaped anvil surfaces.

A method of inserting a suture retainer 100 is also provided. The suture retainer 100 may correspond to any of the examples discussed herein. The method comprises inserting a suture retainer 100 comprising one or more sutures 20 into a patient. The suture(s) 20 are then attached to soft tissue of the patient. The suture(s) 20 are tightened to apply a tension to the soft tissue, and the cap 14 is attached to the base 12 to secure the suture(s) at this tension. For example, the cap 14 may be ultrasonically welded to the base 12.

This method may be performed using any of the insertion tools 200 discussed herein. For example, the insertion tool 200 may be used to insert the suture retainer 100 into the patient. The insertion tool 200 may also support the suture retainer as the cap 14 is attached to the base 12. For example, the insertion tool 200 may act as an anvil opposing a sonotrode 40 used during ultrasonic welding.