DESCRIPTION

This application claims the priority of Spanish Utility Model application U202230524, filed 30 March 2022.

The present description refers to the closure of the sternum through the use of fixation elements. In particular, the present description refers to an excision tool for sternal fixation elements after a sternotomy procedure.

BACKGROUND

The operation to close parts of the sternum, after having been opened following a sternotomy surgical procedure, for example, to perform cardiac or thoracic surgery, should be carried out in such a way that the parts of the sternum that have been separated are positioned in such a way accurately and correctly set again, one against the other.

This operation is normally accomplished using a series of fixation elements configured to hold together the parts of the sternum that were previously opened to perform the sternotomy process as stated above. Said fixation elements are suitably designed to apply a continuous and dynamic force on the parts of the sternum.

In the case of some types of fixation elements, once they have been applied and closed, there remains a fragment of excess material that corresponds to a free end projecting outwards the fixation element. It is normally desirable to excise such a fragment from each applied fixation element in order to avoid excess material remaining and so that the dimensions of the applied fixation elements appropriately correspond to the variable width of the sternum.

In practice, it has been found that it is not easy to split or cut the free ends of the fixation element once applied, especially if the fixation elements are made of a polymeric material or a composite material containing carbon fibers. As a result, the fixation elements, once applied and closed, are structural elements with an outwardly projecting free end. Said free end involves an excess of material that can prevent suitable functionality of the device, as well as pose a risk to patient safety. In some cases, the excision or cutting of the free ends of the fixation element may be carried out through a cutting tool or means that cause a shearing of the free end of the fixation element. A disadvantage in these tools lies in the fact that they do not allow a clean and reliable cut of the free ends of the fixation element due to low plasticity of the material from which the fixation elements are made, which may end up compromising the patient safety.

SUMMARY

A tool is therefore required that allows the free ends of the fixation element to be safely and efficiently excised once applied or implanted after a sternotomy process. This object is achieved through an excision tool for sternal fixation elements such as the one described herein below.

The excision tool disclosed herein has a general configuration comprising a first portion, a second portion, and an actuating mechanism.

At least one of the first portion or the second portion has an excision element. The excision element is intended to impact on a region of a free end of the sternal fixation element. Said excision element may be, for example, a sharp body, although it may have any suitable configuration to impinge on a portion of a free end of the sternal fixation element for excision thereof.

The other of the first portion or the second portion has a receiving area for said free end of the sternal fixation element. The receiving area is advantageously configured in such a way that said free end of the sternal fixation element may pass there through. Said receiving area may be suitably configured to at least partially surround said free end of the fixation element that is received therein.

In one example, the receiving area has a configuration adapted to receive the free end of the sternal fixation element in an insertion direction at an insertion angle with respect to said excision direction. The insertion angle is preferably 60-120° although optimally the insertion direction is perpendicular to the excision direction.

Based on dimensions in some types of sternal fixation elements used in sternotomy processes, the receiving area has a geometry defined by a first dimension extending along the insertion direction of the free end of the sternal fixation element, a second direction, and a third dimension. Said dimensions may be perpendicular to each other, or they may form angles other than 90° to each other. The second and third dimensions of the receiving area define a suitable space for the passage of the free end of the fixation element. The first dimension preferably has a value between 2 and 12 mm, the second dimension preferably has a value between 2.5 and 5 mm, and the third dimension preferably has a value between 6 and 15 mm. With the described configuration, the receiving area allows one of the sternal fixation elements used in sternotomy procedures to be appropriately received.

The first portion of the present tool is slidingly displaceable longitudinally with respect to the second portion. The relative longitudinal movement of the first and the second portion of the tool is carried out by means of the above mentioned actuating mechanism. Actuating the actuating mechanism results in said relative longitudinal displacement of the first and second portions of the excision tool. This, in turn, causes the excision element and the receiving area to move closer to each other in an excision direction until the excision element comes to impinge on the area of said free end of the sternal fixation element which is received in said receiving area. The action of the excision element on the free end of the sternal fixation element causes a bending thereof until excision.

Preferably, the excision element is formed in the first portion and the receiving area is formed in the second portion. However, the case in which the receiving area is formed in the first portion and the excision element is formed in the second portion is envisaged.

The tool described herein advantageously has a clamp-like configuration. In one example, the actuating mechanism comprises two arms that are pivotable relative to one another by being hinged at a hinge point. Each arm has an actuating end and an opposite end associated with the first portion and the second portion, respectively. In this way, a force applied to the actuating ends of the hinged arms results in a corresponding displacement of the first portion with respect to the second portion along the excision direction in order to bring the excision element closer to the receiving area until the excision of the free end of the sternal fixation element occurs. The force on the actuating ends of the hinged arms may be applied by the user by compressing the two hinged arms directly by hand. Alternatively, the force on the actuating ends of the hinged arms may be applied by turning a thread mounted on a shaft connecting the two hinged arms. In this way, as the thread is turned, it moves along on the shaft, causing the hinged arms to progressively move closer to each other.

Advantageously, guide means for guiding the first portion along the second portion are provided. Said guide means may comprise a groove formed in one of the first portion or the second portion and a dovetail longitudinal projection formed in the other of the first portion or the second portion.

The tool described herein may include indications associated with at least one of the first portion or the second portion to show the user the relative position between them and thus appropriately control the excision process.

With the tool that has been described herein, it is possible to effectively perform an excision of the excess fragment of the sternal fixation element once applied after a sternotomy process. With the present tool, the excision is carried out by bending, until the yield strength of the material of the fixation element has been reached. This makes it possible to considerably reduce the presence of sharp edges.

Consequently, the tool described herein allows an extremely clean cut of the material of the excess fragment corresponding to the free end of the fixation element.

In a further aspect of the present disclosure, a variant of the excision tool for fixation elements of the sternum after a sternotomy procedure is provided herein.

In this variant, the tool comprises a first portion, a second portion, and an actuating mechanism. At least one of the first portion or the second portion has an excision element. The excision element is intended to impinge on a region of a free end of the sternal fixation element. The other of the first portion or the second portion has a receiving area for said free end.

The first portion and the second portion are configured in such a way that, when the actuation mechanism is actuated, the excision element and the receiving area move closer to each other so that the excision element comes to impinge on the area of said free end received in the receiving area causing said area of the free end to be bent until excised. In this variant, the excision tool may be configured as a clamp so that the first portion and the second portion are hinged. In this way, moving the excision element and the receiving area closer to each other is carried out by relative rotation of the first portion and the second portion when actuating the actuating mechanism.

The excision element may be formed in the first portion and the receiving area may be formed in the second portion. However, the receiving area may be formed in the first portion and the excision element may be formed in the second portion.

The receiving area is preferably designed in such a way that the free end of the sternal fixation element is allowed to pass through the receiving area. An optimal configuration may be one in which the receiving area at least partially surrounds the free end of the sternal fixation element received therein.

With said variant described herein it has been found that advantages associated with the previous variant are also achieved. Excision is also carried out in this case by the material of the fixation element up being bent until the yield strength is reached. This allows efficient and clean excision of the excess fragment of the sternal fixation element, reducing the presence of sharp edges that may put the patient's health at risk.

With both variants of the excision tool for sternal fixation elements described herein, it is no longer necessary to use a plurality of fixation elements of different sizes to suitably accommodate the varying width of the sternum. Fixation elements of the same size can be used with both variants of the excision tool, the excess ends of which are excised or cut off after sternotomy procedure. This considerably reduces the overall cost of the sternotomy process.

Further objects, advantages, and features of embodiments of the excision tool will be apparent to those skilled in the art from the following description or by practice of the description.

BRIEF DESCRIPTION OF THE DRAWINGS

Specific examples of the present disclosure will be described in the following, with reference to the appended drawings, in which:

Figure 1 is a general perspective view of a first example of the excision tool where a sternal fixation element to be received in the tool for excision is partially shown; Figure 2 is an elevational view of the excision tool in figure 1 ;

Figure 3 is a broken away plan view showing the receiving area of the free end of the fixation element of the excision tool in figures 1 and 2;

Figure 4 is a general perspective view of a second example of the excision tool;

Figure 5 is an elevational view of the excision tool in figure 4; and

Figure 6 is a broken away plan view of the excision tool in figures 4 and 5 taken along line AA in figure 5 showing the receiving area of the free end of the fixation element.

DETAILED DESCRIPTION OF EXAMPLES

Non-limiting examples of an excision tool for fixation elements of the sternum after a sternotomy procedure are described below.

In the figures and throughout the description, like reference numbers have been used to depict the same elements.

In a first example that is illustrated in figures 1-3 of the drawings, the excision tool 10 has a general clamp-like configuration formed by a first portion 20 where an excision element 25 is provided. The excision element 25 has an inclined surface with a leading edge to impinge on an area 115 of a free end 110 of a sternal fixation element 100, as shown in figure 1.

The general configuration of the excision tool 10 also has a second portion 30. The second portion 30 includes a receiving area 50 intended to receive a free end 110 of a sternal fixation element 100.

Referring to figure 3 of the drawings, the receiving area 50 formed in the second portion 30 of the excision tool 10 has an open, C-shaped configuration. In such configuration, a space is defined so that said free end 110 of the sternal fixation element 100 is allowed to pass there through along an insertion direction D, as shown in figures 1 and 2. The insertion direction D is defined as the direction along which a free end 110 of a sternal fixation element 100 extends when received in the receiving area 50 of the excision tool 10.

The insertion direction D, along which the free end 110 of the sternal fixation element 100 is inserted into the receiving area 50 of the excision tool 10, forms an insertion angle a = 60-120° with respect to an excision direction E, as illustrated in figure 2. In an optimal example, the insertion angle is a = 90°. The excision direction E is defined as the direction along which the first portion 20 of the excision tool 10 moves.

In the non-limiting example shown in figures 1-3 of the drawings, the geometry of the receiving area 50 is defined by three mutually orthogonal dimensions h, a, b. More specifically, the geometry of the receiving area 50 is defined by a first dimension h = 2-12 mm extending along the insertion direction D, a second dimension a = 2.5-5 mm, and a third dimension b = 6-15 mm. The second dimension a, and the third dimension b, define a space through which the free end 110 of the sternal fixation element 100 is allowed to pass through.

The described excision tool 10 is further provided with an actuating mechanism 40 intended to cause the displacement of the first portion 20 of the excision tool 10 along the excision direction E. The actuating mechanism 40 consists of two arms 60, 70 hinged at a pivot point 90. The arms 60, 70 have an actuating end 65, 75 and an opposite end 66, 76 associated with the first portion 20 and the second portion 30, respectively. Such structure of arms 60, 70 and pivot point 90 defines the above mentioned general clamp-like configuration of the excision tool 10.

Between the arms 60, 70 a damping member 95 is provided. The damping member 95 is intended to apply an elastic force that opposes a force F applied by the user on the actuating ends 65, 75 of the arms 60, 70. In the example shown in figures 1 and 2, said damping member 95 is formed by two flexible plates 95a, 95b. Each flexible plate 95a, 95b has a first end attached to the actuating end 65, 75 of the arms 60, 70, respectively, and a second end 96. The flexible plates 95a, 95b are hinged together at said second end 96. With such configuration of the damping member 95 with flexible plates 95a, 95b, it is possible to suitably control the excision tool 10 to accurately perform an excision operation.

Other alternative configurations for the actuating mechanism also exist. One of said alternatives for actuating, not shown in the figures, includes a shaft, not shown, that would connect the arms 60, 70. In particular, the shaft could have a threaded outer area, and it would rest on an arm 60 and it would pass through the other arm 70. An actuating member would be mounted on said shaft with an internal threaded area that would be screwed on said external threaded area of the shaft. In this way, as said actuation part is rotated by the user, it would be advanced along the shaft causing the arms 60, 70 to progressively move closer to each other. In this way, application of the force F for driving the excision tool 10 in a more controlled manner can advantageously be achieved.

The first portion 20 of the excision tool 10 can be displaced longitudinally relative to the second portion 30 along the excision direction E. The longitudinal displacement of the first portion 20 on the second portion 30 is carried out by the actuating mechanism 40, as stated above, in cooperation with guide means 80. Said guide means 80, in the example shown, comprise a groove formed in the second portion 30 and a dovetail longitudinal projection formed in the first portion 20.

To perform excision of the free end 110 of the sternal fixation element 100 with the excision tool 10 disclosed herein, the excision tool 10 is first positioned by the user so that the free end 110 of the sternal fixation element 100 is received in the receiving area 50, passing there through, along the insertion direction D. The position of the excision tool 10 relative to the sternal fixation element 100 is such that the arms 60, 70 are located away from the sternotomy, with the arm 60 associated with the first portion 20 located closest to the sternotomy site. Once the free end 110 of the sternal fixation element 100 is received in the receiving zone 50 of the excision tool 10 and with the tool 10 aligned with the sternal fixation element 100, a force F is applied by the user on the actuating ends 65, 75 of the arms 60, 70 of the excision tool 10 causing a displacement of the first portion 20 relative to the second portion 30 in the excision direction E shown in figure 3. The displacement of the first portion 20 on the second portion 30 along the excising direction E causes the excision element 25 associated with the first portion 20 to move closer the receiving area 50 associated with the second portion 30. The displacement occurs until the excision element 25 impinges on the area 115 of the free end 110 of the sternal fixation element 100, causing said area 115 to be bent until the free end 110 of the sternal fixation element 100 is excised. Following excision, the free end 110, which is the excess fragment of the sternal fixation element 100, is removed.

The excision is produced by bending of the material caused by the action of the excision element 25 against the area 115 of the free end 110 of the sternal fixation element 100. Said action of the excision element 25 by applying a force F on the ends 65, 75 of the arms 60, 70 without changing the position of the tool 10 causes said area 115 to be bent until bending cannot be resisted and breaks, resulting in excision by bending of the free end 110 of the sternal fixation element 100, which is displaced upwards in figures 1, 2. By repeating the operation for all the fixation elements of the sternum 100, these remain free of protruding ends.

Although not shown, either the first portion 20 or the second portion 30 may be provided with indications to show the user the relative position of said portions 20, 30 along the excision direction E. This allows an accurate control of the excision operation of the free end 110 of the sternal fixation elements 100.

A second example of the excision tool 10 is illustrated in figures 4-6 of the drawings. In said second example, the excision tool 10 also has a general clamp-like configuration formed by a first portion 20 and a second portion 30.

In the first portion 20, an excision element 25 is provided having an inclined surface intended to impinge on an area 115 of a free end 110 of a sternal fixation element 100.

In the second portion 30 an area 50 for receiving the free end 110 of the fixation element of the sternum 100 is provided.

The excision tool 10 in this example illustrated in figures 4-6 of the drawings is also provided with an actuating mechanism 40 comprising two arms 60, 70. The arms 60, 70 are hinged at a pivot point 90. The arms 60, 70 have an actuating end 65, 75 and an opposite end 66, 76 which is associated with the first portion 20 and the second portion 30, respectively. This structure defines a general clamp-like configuration as in the first example of the excision tool 10 illustrated in figures 1-3 of the drawings.

In the second example illustrated in figures 4-6 of the drawings, the first portion 20 and the second portion 30 of the excision tool 10 are respectively formed as an extension of the ends 66, 76. Thus, when a force F is applied by the user on the actuation ends 65, 75 of the hinged arms 60, 70, a relative rotation of the first portion 20 and the second portion 30 is caused around said pivot point 90. The relative rotation of the first portion 20 and the second portion 30 causes the excision element 25 formed in the first portion 20 to move closer the receiving area 50 formed in the second portion 30. Said approaching occurs until the excision element 25 impinges on the area 115 of the free end 110 of the sternal fixation element 100 that is received in the receiving zone 50. As a result, bending of said area 115 of the free end 110 of the sternal fixation element 100 occurs until its excision. Referring to figure 6 of the drawings, the receiving zone 50 formed in the second portion 30 of the excision tool 10 has, also in this example, an open, C-shaped configuration. In said configuration, a passage is defined so that said free end 110 of the sternal fixation element 100 is allowed to pass there through along an insertion direction D, as shown in figure 5.

In the non-limiting example shown in figures 4-6 of the drawings, the geometry of the receiving area 50 is defined by three orthogonal dimensions h, a, b. More specifically, the geometry of the receiving area 50 is defined by a first dimension h = 2-12 mm, which extends along the insertion direction D, a second dimension a = 2.5-5 mm, and a third dimension b = 6-15 mm. The second dimension a, and the third dimension b, define a space for the free end 110 of the sternal fixation element 100 to pass through along the insertion direction D.

To perform the excision of the free end 110 of the sternal fixation element 100 with the excision tool 10 according to the example of figures 4-6, the excision tool 10 is first arranged by the user so that the free end 110 of the sternal fixation element 100 is received in the receiving area 50, passing there through along the direction of insertion D. The position of the excision tool 10 relative to the sternal fixation element 100 is such that the arms 60, 70 are located away from the sternotomy, with the arm 60 associated with first portion 20 positioned closer to the sternotomy site. Once the free end 110 of the sternal fixation element 100 is received in the receiving zone 50 of the excision tool 10 and with the tool 10 aligned with the sternal fixation element 100, a force F is applied by the user on the actuating ends 65, 75 of the arms 60, 70 of the excision tool 10 which causes a relative rotation of the first portion 20 and the second portion 30 around the pivot point 90. As a result, the excision element 25 associated with the first portion 20 moves closer the receiving area 50 associated with the second portion 30 until the excision element 25 impinges on the area 115 of the free end 110 of the sternal fixation element 100. This causes said area 115 to be bent until excision of the free end 110 of the sternal fixation element 100. Once excision has occurred, the free end 110, which is the excess fragment of the sternal fixation element 100, is removed.

In this case, the excision is also produced by bending of material due to the action of the excision element 25 against the area 115 of the free end 110 of the sternal fixation element 100. Said action of the excision element 25 by applying a force F on the ends 65, 75 of the arms 60, 70 without changing the position of the tool 10 causes bending of the free end 110 until it breaks, that is, breaking of the excess fragment of the fixation element 100. Repeating the operation for all the fixation elements 100, these remain free of protruding ends.

In this example, indications, not shown, may also be provided to show the user the relative angular position of the portions 20, 30 and accurately control the excision operation of the free end 110 of the sternal fixation element 100.

With both described examples of the excision tool 10, it is possible to efficiently perform an extremely clean excision of the excess fragment of the sternal fixation element 100 by bending, up to the yield strength of the material, advantageously reducing the presence of sharp edges and, therefore, risks to the patient.

Although particular examples of the excision tool have been disclosed herein, it will be apparent to those skilled in the art that further alternative embodiments thereof are possible as well as obvious modifications and equivalent elements. The present description covers all possible combinations of the particular embodiments that have been described. Reference signs related to drawings and placed in parentheses in a claim are solely for attempting to increase the intelligibility of the claim and shall not be construed as limiting the scope of the claim. The scope of the present invention should not be limited to particular embodiments but should be determined only by a fair reading of the claims that follow.