Patent Publication Number: US-2022218497-A1

Title: Osteotome extractor

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of U.S. patent application Ser. No. 16/249,720, filed Jan. 16, 2019; Ser. No. 15/046,295, filed Feb. 17, 2016, now U.S. Pat. No. 10,213,243; and Ser. No. 13/553,610, filed Jul. 19, 2012, now U.S. Pat. No. 9,289,218; U.S. Provisional Patent Application No. 61/509,506 filed Jul. 19, 2011; and French Patent Application No. 20110057282, filed Aug. 10, 2011, which are all hereby incorporated by reference for all purposes as if fully set forth herein. 
    
    
     TECHNICAL FIELD 
     Embodiments of the present invention relate to a surgical tool for extraction of a prosthesis from a bony implantation site of that prosthesis as well as a surgical kit including such a surgical tool and such a prosthesis. 
     BACKGROUND 
     When a prosthesis has been implanted in a bone for a certain time, typically several years, it may prove necessary to remove the prosthesis for various reasons: for example, wear of the prosthesis, degeneration of the bony material of the prosthesis implantation site, trauma, and the like. The prosthesis removed is generally replaced by a revision prosthesis, the success and the implantation performance of which depend on the residual stock of bony material after removing the initial prosthesis. Consequently, surgeons aim to limit as much as possible any cutting of bony material necessary to free and extract the initial prosthesis. 
     With the arrival of prostheses with a porous surface or, more generally, adapted to have their surface colonized by the bone of the implantation site, extraction operations may prove particularly delicate. To this end, the surgeon generally employs osteotomes, the application of which may advantageously be guided to improve the precision of their action. Then, once the bonding interface between the prosthesis and the bony material has been cut in this way by these osteotomes, the surgeon uses another surgical tool to grasp and pull on the prosthesis in order to extract it. 
     SUMMARY 
     Embodiments of the present invention include a method for separating an implant from a bone, the method comprising: interfacing a tool with an implant including a flange, the flange including a proximal surface and a distal surface, the distal surface bearing on or facing the bone, the flange including an aperture defined through the flange; inserting an elongate element through the aperture from the proximal surface to the distal surface and into the bone; and partially separating a bonding interface between the implant and the bone using the elongate element. 
     Embodiments of the present invention include a surgical tool to extract an implant, the tool comprising: a main body; and a plurality of elongate elements extending distally from the main body along a direction that is substantially parallel to a longitudinal axis of the tool, each of the plurality of elongate elements including: a first edge extending in a longitudinal direction; a second edge opposite the first edge and extending in the longitudinal direction; and a distal edge extending between the first edge and the second edge; wherein each of the plurality of elongate elements is configured to extend through a corresponding one of a plurality of apertures of the implant; and each of the plurality of elongate elements are configured to at least partially separate an interface between the implant and bony material at an implantation site of the implant. 
     While multiple embodiments are disclosed, still other embodiments of the present invention will become apparent to those skilled in the art from the following detailed description, which shows and describes illustrative embodiments of the invention. Accordingly, the drawings and detailed description are to be regarded as illustrative in nature and not restrictive. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a surgical tool, according to embodiments of the present invention. 
         FIG. 2  is a perspective view as seen from a different angle and to a larger scale than  FIG. 1  of a portion of the surgical tool from  FIG. 1 , according to embodiments of the present invention. 
         FIG. 3  is a view in elevation in the direction of the arrow III in  FIG. 2 , according to embodiments of the present invention. 
         FIGS. 4 to 6  are views similar to  FIGS. 1 to 3 , respectively, showing the surgical tool from  FIG. 1  associated with a prosthesis to be extracted with the aid of that surgical tool. 
     
    
    
     While the invention is amenable to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and are described in detail below. The intention, however, is not to limit the invention to the particular embodiments described. On the contrary, the invention is intended to cover all modifications, equivalents, and alternatives falling within the scope of the invention as defined by the appended claims. 
     DETAILED DESCRIPTION 
     In  FIGS. 1 to 3  there is represented a surgical tool  1  for extracting a prosthesis from a bony implantation site of that prosthesis. As seen clearly in  FIG. 1 , this surgical tool  1  has an elongate overall shape, centered on a longitudinal axis X-X which, in use, extends in a direction which, at the proximal end, faces toward the surgeon and, at the distal end faces toward the bony implantation site of the prosthesis to be extracted. 
     The surgical tool  1  includes a shaft  2  that is centered on and extends lengthwise along the axis X-X and which includes a cylindrical rod of circular section. At its proximal end  2 A, the shaft  2  is provided with a fixed handle  4  arranged transversely to the axis X-X, in order to facilitate driving, for example manual driving, of the surgical tool  1  by a user. This handle  4  may be formed in the shape of a “T”. In its main part  2 B, the shaft  2  is fixedly provided with a shoulder  6  projecting radially from the rest of the shaft  2 . The shoulder  6  may be comprised of a disc centered on the axis X-X. Alternatively, shoulder  6  may be a cylindrical handle, a roughened surface, one or more indentations, one or more protrusions, or any other shape which permits shoulder  6  to receive a traction force and transmit the traction force to the shaft, according to embodiments of the present invention. 
     At its end  2 C, the shaft  2  includes a fixed head  8  that cooperates mechanically with a prosthesis to be extracted. As illustrated in  FIGS. 1 to 3 , this head  8  includes a main body  10  that is centered on the axis X-X and is generally disc-shaped. According to one embodiment, the head  8  includes three elements  12 , which may be separate and identical. In other embodiments, the head  8  may include one, two, three, four, five, six or more elements  12 . In still other embodiments, the elements  12  may not be identical and one or more element  12  may have different lengths, widths, thicknesses, curvatures, or other features as compared to one or more other elements  12 . Each element  12  may have a shape that is elongate in the direction of the axis X-X and projects in the longitudinal axial direction from the distal face  10 A of the main body  10  of the head  8 . According to some embodiments of the present invention, each element  12  projects from a portion of the external periphery of the distal face  10 A of the body  10 . Each element  12  as a whole corresponds to a portion of a tubular wall centered on the axis X-X and projecting axially from the exterior periphery of the face  10 A of the body  10 , according to embodiments of the present invention. Elements  12  may be referred to as cutting elements, according to embodiments of the present invention. 
     According to one embodiment, the three elements  12  are distributed, for example, in a substantially regular manner (e.g. separated by substantially the same radial angles) around the axis X-X. In particular, these three elements  12  may correspond to respective portions of the same tubular wall. According to other embodiments, the two or more elements  2  are distributed in an irregular manner on the distal head  8 , and are either not separated by similar radial angles, and/or are not situated about a perimeter of the distal head  8 . For example, the elements  12  may be positioned on distal head  8  at different or staggered radial distances from the axis X-X, and may be positioned at different or staggered radial separations with respect to the axis X-X. 
     As shown in  FIGS. 1 to 3 , each element  12  has, axially opposite its proximal end connecting the rest of the element to the main body  10  of the head  8 , a distal free edge  12 A along which a cutting edge is formed in a direction peripheral to the axis X-X. Each element  12  may be delimited in a direction peripheral to the axis X-X by two opposite longitudinal free edges  12 B and  12 C. The longitudinal edge  12 B, which is that oriented in the clockwise direction about the axis X-X when the head  8  is viewed from the proximal end  2 A of the shaft  2 , has, in its longitudinal direction, a distal end part  12 B. 1  along which a cutting edge is formed and a proximal end part  12 B. 2  in which a recessed notch  14  is delimited. Edge  12 B may also be referred to as leading edge  12 B, and edge  12 C may be referred to as trailing edge  12 C, according to embodiments of the present invention. 
     An example of use of the surgical tool  1  will now be described with reference to  FIGS. 4 to 6 . 
     In these  FIGS. 4 to 6 , the head  8  of the surgical tool  1  cooperates with a prosthesis  20  to be extracted including an anchor body  22  anchored in the bony material of an implantation site of the prosthesis. This anchor body  22  is provided with a flange  24  which bears on the aforementioned implantation site. In some embodiments of the present invention, when the prosthesis  20  is in an implantation configuration, its body  22  is engaged depthwise in the bony material of the implantation site and its flange  24  remains outside or partially outside the bony material of the implantation site, bearing on the perimeter surface of the hole at the implantation site in which the body  22  is housed. Consequently, if a surgeon wishes to extract the prosthesis  20  from the aforementioned implantation site, the proximal face  24 A of the flange  24  is directly accessible, whereas the distal face  24 B of the flange  24  bears on the bony material of the implantation site. Given the context of the surgical intervention, the interface between the prosthesis  20 , and more precisely the body  22  of that prosthesis, and the bony material of the implantation site proves resistant to extraction of the prosthesis  20  in the sense that, over time, a mechanical-biological bond has progressively formed at this interface between the prosthesis and the bony material. The strength of this bonding interface often proves particularly high in the situation in which the body  22  has a porous structure or, more generally, an exterior surface suitable for osteo-integration, as is generally the case when the prosthesis  20  is a prosthesis implanted without cement. 
     As used herein, the term “flange” is used in its broadest sense to refer to any structure or shape which has a proximal surface and a distal surface and is capable of contacting bone or being positioned on or near bone. For example, a flange may have a circular, square, rectangular, triangular, or other (regular or irregular) polygonal shaped cross-section along a dimension that is substantially perpendicular to the axis X-X, according to embodiments of the present invention. The perimeter of the flange may be smooth and/or continuously contoured, or may include straight segments, and/or may include a combination of both contoured and straight segments. 
     To extract the prosthesis  20 , the surgeon grasps the shaft  2  of the surgical tool  1 , notably by hand, and moves the head  8  toward the prosthesis  20 , substantially aligning the axis X-X with a central geometrical axis of the prosthesis  20 , in particular the central geometrical axis around which the flange  24  extends peripherally. The distal edge  12 A of each element  12  of the head  8  can then be used to cut at least in part the bonding interface between the prosthesis  20  and the bony material of the implantation site. To this end, the flange  24  is provided with three through-slots  26  each of which connects the proximal face  24 A and the distal face  24 B of the flange  24  to each other. Each slot  26  has a cross section allowing, or even in some cases guiding, introduction into this slot of one of the elements  12 , in a movement in translation oriented along the axis X-X and directed in the distal direction. In other words, each slot  26  may have a cross-sectional shape corresponding to a flat ring portion the width of which considered radially with respect to the axis X-X substantially corresponds to the radial thickness of each element  12  and the length of which, in a direction peripheral to the axis X-X, is substantially equal to the peripheral extent of the element  12 , as illustrated in  FIGS. 4 and 5 , according to embodiments of the present invention. 
     The distal edge  12 A of the elements  12  is introduced first into one of the slots  26  and projects therefrom, at the distal end, cutting the portion of the (bony) bonding interface between the prosthesis  20  and the bony material that it encounters on its trajectory in translation. The surgeon continues to drive the surgical tool  1  in translation distally along the axis X-X until the distal face  10 A of the body  10  comes to bear against or in the immediate vicinity of the proximal face of the prosthesis  20 , for example with the interior periphery of the proximal face  24 A of the flange  24 . 
     The surgeon then rotates the shaft  2  on itself about the axis X-X, in some cases using the handle  4  to increase the driving torque. In some cases, use of the handle  4  increases the driving torque tenfold. The head  8  is then driven in a similar rotary movement, causing the longitudinal edge  12 B of each of its elements  12  to follow a circular trajectory, centered on the axis X-X, and, in the embodiment shown, in the clockwise direction. The distal end part  12 B. 1  of each of the edges  12 B then cuts the part of the bonding interface between the body  22  of the prosthesis  20  and the bony material of the implantation site, situated on the circular trajectory of the edge  12 B. At the same time, each notch  14  of the longitudinal edges  12  mechanically engages the flange  24  in the direction in which, given the rotary movement of the head  8  on itself about the axis X-X relative to the prosthesis  20 , one of the peripheral ends of each slot  26  is introduced into the notch  14 . This cases the slots  26  to become engaged, in a direction peripheral to the axis X-X, axially between the opposite axial edges of the notch  14 . This rotation drive movement is continued by the surgeon so as to engage the flange  24  as far as to the bottom of the notches  14 . The surgical tool  1  and the prosthesis  20  are then in the configuration of use represented in  FIGS. 4 to 6 . 
     Although notch  14  is shown as having an “L” shape, notch  14  may alternatively have other shapes, according to embodiments of the present invention. For example, the shape of notch  14  may be fully or partially curved, for example in a “U” shape, or may be segmented, for example in a “V” shape, according to embodiments of the present invention. Notch  14  may include any shape which is capable of accepting at least a portion of the inside edge of an aperture  26  upon rotation of the head  8 , according to embodiments of the present invention. In one embodiment, the proximal end of notch  14  is delimited by a distal surface of the head  8  as shown in  FIG. 3 . In another embodiment, the proximal edge of notch  14  is located distally of the distal surface of the head  8 . The shape of the proximal edge of the notch  14  may also take numerous forms, for example straight, curved, or a combination of straight and curved, according to embodiments of the present invention. 
     Although clockwise rotation is described, one of ordinary skill will appreciate, based on the present disclosure, that the tool  1  may alternatively be configured for counterclockwise rotation, according to embodiments of the present invention. 
     Upon engagement of the tool  1  with the prosthesis  20 , the mechanical connection that the surgeon establishes between the head  8  of the surgical tool  1  and the flange  24  of the prosthesis  20  is a bayonet connection centered on the axis X-X, according to embodiments of the present invention. 
     The surgeon may exert a traction force along the axis X-X, directed in the proximal direction. The surgeon makes use of the shoulder  6 , for example by mechanically engaging this shoulder  6  with an ad hoc tool (not shown), enabling the surgeon to increase (e.g. tenfold) the applied force to apply to the shaft  2  axial traction loads directed in the proximal direction. As the bonding interface between the prosthesis  20  and the bony material of the prosthesis implantation site has been cut in several areas, by the successive action of the distal edges  12 A and the distal end parts  12 B. 1  of the longitudinal edges  12 B of the elements  12 , remaining uncut areas of this bonding interface are broken in a controlled manner as to their location, and easily, without the surgeon having to exert too great a traction force. 
     Thus the surgical tool  1  enables the prosthesis  20  to be extracted easily and quickly, it being noted that, due at least in part to its bayonet fixing, integrating partial cutting of the bonding interface between the prosthesis and the bony material of the implantation site, the surgeon does not need to use two separate instruments to turn and turn about to cut the aforementioned interface and then make the mechanical attachment to the prosthesis to be pulled. 
     Various modifications and additions can be made to the exemplary embodiments discussed without departing from the scope of the present invention. For example, while the embodiments described above refer to particular features, the scope of this invention also includes embodiments having different combinations of features and embodiments that do not include all of the described features. Accordingly, the scope of the present invention is intended to embrace all such alternatives, modifications, and variations as fall within the scope of the claims, together with all equivalents thereof.