JP2008531127A - Joint surface implant - Google Patents

Abstract

  The present invention relates to an implant for replacing a portion of an articular surface, including a load bearing surface and a bone abutment site. The load bearing surface has a contour defined by a first curved chord line based on a contour of the articulating surface that is replaced in the first plane. The load bearing surface of the implant is further defined by the contour of the articulating surface replaced in the second plane, where the first plane and the second plane are planes that intersect each other.

Description

  The present invention relates to a system and method for accessing an articular surface. The present invention further relates to a method and system for replacing at least a portion of an articular surface.

  Articular cartilage (found at the ends of the connecting bones of the body) usually consists of hyaline cartilage, which allows it to function effectively as a smooth and tangled load bearing surface. Has many different and unique characteristics. In particular, hyaline cartilage problems in knees, hip joints, and shoulder joints are generally severe (sudden), such as those caused by rheumatoid arthritis or wear (degenerative arthritis) or associated with injury. Or it is caused by periodic and chronic (ongoing) diseases. Such cartilage disease or degradation can damage the joint surface, which causes pain and eventually the joint fails. As a result, various approaches have been developed to treat and repair damaged or destroyed articular cartilage.

  For small defects, the traditional option for this type of problem is to leave the lesion or injury intact and live with it, or to perform a treatment called abrasion arthroplasty or abrasion cartilage transplantation. Is mentioned. The principle behind this procedure is an attempt to mimic natural treatment. The surface of the bone is drilled using a high speed rotating bar or cutting tool, and the surgeon removes approximately 1 mm of bone from the surface of the lesion. This forms an exposed costal cartilage bed that is accompanied by bleeding and initiates the fibrocartilage fusion reaction. One problem associated with this procedure is that, as a result of drilling and burring, which tends to leave a series of irregularities, the exposed bone is not as smooth as it was originally, and the durability of the fibrocartilage reaction is reduced. It has an adverse effect. Moreover, although this treatment can produce good short-term results (1-3 years), fibrocartilage rarely can withstand long-term load bearing, which wears out, softens and deteriorates Tend.

  Another procedure called Microfracture involves some of the principles involved in drilling, grinding and cartilage transplantation. During the procedure, the calcified cartilage layer at the cartilage defect is removed. Several paths or “microfractures” are formed against the subchondral hemorrhage bone bed by impacting a metal pick or surgical cone at a minimal number of locations within the lesion. By causing bleeding within the lesion and forming a pathway to costal cartilage, the fibrocartilage fusion reaction is initiated and an alternative surface is formed. The results for this technique would be expected to be similar to curettage cartilage transplantation.

  Another technique used to treat damaged articular cartilage is cartilage transplantation. In essence, this procedure involves the movement of cartilage from an external supply source or from another knee or from the same knee into the defect. This is usually done by moving the peg of the cartilage with the underlying bone and fixing it in place using screws or pins or by fitting. While useful for small defects, large defects pose problems. This is because this procedure requires a donor peg commensurate with the receiving bed. Large diameter lesions may outweigh the ability to borrow from within the same knee joint, and may make borrowing from other supply sources impossible.

  But larger defects generally require more aggressive intervention. Treatment usually involves replacing the articular surface with an implant or prosthesis having an outer layer of material that provides a smooth load bearing surface in the vicinity of a polished or intact cartilage surface. . In order to remove the damaged cartilage, it is first necessary to cut the damaged area, drill it, and spread it with a reamer. A recess for receiving the implant or prosthesis is formed at the site of damage. The implant or prosthesis is then secured to the bone at the appropriate location within this recess.

  Generally speaking, the present disclosure may provide an implant for replacing at least a portion of an articular surface. Furthermore, the present disclosure is also directed to a general design method for creating and creating a surface profile of an implant for replacing at least a portion of an articular surface. An implant associated with the present disclosure can be provided as having a load bearing surface configured to interact with a cooperating articulation mechanism. Cooperating articulation mechanisms may include, for example, cooperating articulating surfaces, cooperating surfaces of implants that replace at least some of the cooperating articulating surfaces, and the like. In certain embodiments, the portion of the articular surface that is replaced by the articular surface implant is identified using non-invasive surgical procedures as much as possible, eg, using diagnostic devices and / or arthroscopy. Can be exchanged. Generally speaking, an implant according to the present disclosure may have a load bearing surface, which may be based on the original geometry of the articulating surface replaced by the implant.

  Hereinafter, the subject matter of the present disclosure will be described with reference to the drawings and using corresponding embodiments. With reference to FIGS. 1-4, an embodiment of an implant system 100 is schematically shown as viewed from various directions. The implant system 100 can be used to replace at least part of an articular surface, for example at least part of the articular surface of a joint. As shown, the implant system 100 can generally comprise an articular surface implant 102 and an anchoring element 104. The anchoring element 104 may be capable of coupling the implant 102 to bone and / or other tissue in a region of the portion of the articular surface that is to be replaced by the implant 102. As shown with respect to the embodiment of FIG. 1, the anchoring element 104 can be provided as a separate component from the implant 102. In such embodiments, anchoring element 104 may be coupleable to implant 102 and couple to bone and / or tissue in the entire area of the portion of the articular surface that is replaced by implant system 100. It may be possible.

  The articular surface implant 102 may generally include an implant body 106. The implant body 106 can have a load bearing surface 108 and a bone abutment region 110. The load bearing surface 108 is generally configurable to interact with cooperating articulation mechanisms such as articulating surfaces, cooperating joint surface implants, and the like. In certain embodiments, the implant body 106 can be at least partially contained within an implantation site provided by resecting at least a portion of the articular surface and the underlying bone. In such embodiments, the load bearing surface 108 is positionable to generally replace at least a portion of the resected articular surface. In this embodiment, the bone abutment region 110 can engage and / or abut the costal cartilage within and / or forming at least a portion of the bottom of the implantation site.

  As mentioned above and in connection with the illustrated embodiment, the anchoring element 104 may be provided as a separate component from the implant 102. Providing the anchoring element 104 as a separate component from the implant 102 can facilitate the installation of the implant system 100. The anchoring element 104 can first be coupled to bone and / or other tissue within and / or around the implantation site. The implant 102 can subsequently be positioned relative to the surrounding articular surface and the implant 102 can be coupled to the anchoring element 104. In this way, the implant 102 can be fixed at an appropriate position with respect to the joint surface.

  In the illustrated and described embodiment, the fusing element 104 is shown as a screw mechanism. In connection with this illustrated embodiment, anchoring element 104 is threadably engageable with bone and / or other tissue within and / or around the implantation site. In addition to engagement with bone and / or other tissue, the screw-type anchoring element 104 can also facilitate depth positioning of the anchoring element 104 relative to the articular surface, and thus depth positioning of the implant 102. . Suitable screw-type fixing elements are known, for example, from the specification of US Pat. No. 6,520,964, issued February 18, 2003. In connection with various alternative embodiments, the anchoring element is configured as having a barbed member or other similar mechanism that can engage bone and / or other tissue within and / or around the implantation site. be able to. In still other embodiments, the anchoring element may include a mechanism that can be adhesively coupled to bone and / or other tissue within and / or around the implantation site.

  As illustrated and described, in embodiments consistent with the present disclosure, the implant 102 and the anchoring element 104 can be provided as separate components. The implant 102 can be coupled to the anchoring element 104 to (at least partially) secure the implant 102 in place within the implantation site. The implant 102 and the anchoring element 104 can thus include an interaction mechanism, in which case the implant 102 and the anchoring element 104 can be coupled together. An embodiment of the implant 102 can be provided that includes a post 112 extending from the implant body 106. The fuser element 104 can include an opening 114 that can accommodate at least a portion of the post 112. In such an embodiment, post 112 and opening 114 can be provided as having complementary precision taper. The implant 102 and the anchoring element 104 can be coupled to each other, for example, by applying an impact force by inserting the post 112 into the opening 114 and pressing them together. The precision taper of the post 112 and the opening 114 can provide a positive friction interaction between the implant 102 and the anchoring element 104.

  Within the scope of the present disclosure, various additional and / or alternative mechanisms and / or structures for coupling implants and anchoring elements may be utilized. Further, in various embodiments where the implant and anchoring element are provided as separate components, the implant and anchoring element can be assembled together prior to installation at the implantation site. In connection with some such embodiments, the anchoring element is configured to engage and / or be coupled to bone and / or tissue within and / or around the implantation site during placement. May be. In some such embodiments, the anchoring element can comprise a hooked post or similar mechanism. According to yet another embodiment, the implant and anchoring element can be provided as a single structure (integral structure).

  The implant system 100 illustrated in FIGS. 1-7 has an implant 102 configured to replace a portion of the articular surface of the talus. In particular, the implant system 100 illustrated in FIGS. 1-7 is configured to replace at least a portion of a lateral bulge of the talar pulley-like surface (which meshes with the tibia). The damage to the lateral bulge of the talar pulley-like surface can include damage or detachment of a portion of the bulge caused by trauma. From a general point of view, the load bearing surface 108 is capable of cooperating with an interacting articulating mechanism including a cooperating articulating surface, at least a portion of an implant replacing at least a portion of the cooperating articulating surface, and the like. May have a good contour and / or geometric shape. In the category of the illustrated and described embodiment, the load bearing surface 108 may have a contour and / or geometric shape that may be capable of cooperating with the tibial interacting articulating surface. According to related embodiments within the scope of the illustrated and described embodiments, the load bearing surface 108 of the implant 102 can cooperate with an implant interaction surface that replaces at least a portion of the articular surface of the tibia. May include any geometric shapes and / or contours.

  In connection with the foregoing description, the implant may include a load bearing surface having a contour and / or geometry that may be capable of cooperating with the interactive interface. In certain embodiments, the load bearing surface generally approximates and / or may be based on the contour and / or geometric shape of a portion of the articulating surface that is replaced by the implant. It may have a specific shape. In certain embodiments, the portion of the articular surface to be replaced may be a variety of known for quantitatively and / or qualitatively evaluating the contour and / or geometric shape of the portion of the articulating surface that can be replaced by the implant. It is possible to survey using this method. The implant can be formed and / or selected from a set of implants having various contours and / or geometric shapes. In connection with such embodiments, the load bearing surface of the implant may be based on the contour and / or geometric shape of the portion of the articular surface that is replaced by the implant. In alternative embodiments, the implant can be manufactured from or selected from a set of standard size and / or shape implants to provide an approximate approximation of the articulating surface to be replaced. The choice and / or manufacture of the implant can depend on varying degrees of quantitative criteria for the joint surface to be replaced without considering quantitative criteria for the joint surface.

  With reference to FIGS. 1-4, in accordance with the first aspect, the contour and / or geometry of the load bearing surface 108 of the implant 102 generally includes a first curved chord line 116 and a second curved chord line 118. May be defined by As used in the embodiments herein, a curved chord line may include a single curve and / or multiple curves joined together in a plane. The first curved chord line 116 and the second curved chord line 118 that roughly define the contour and / or geometric shape of the load bearing surface 108 may be disposed in intersecting planes. In the illustrated and described embodiment, the plane related to the first curved chord line 116 and the plane related to the second curved chord line 118 may be generally orthogonal to each other. Various other angular relations of the plane including the first curved chord line 116 and the second curved chord line 118 can be adopted as appropriate.

  A design method capable of realizing the load bearing surface of the implant is to provide curved chords that define the contour and / or geometry of the load bearing surface, and the intersecting contour and / or geometry of the load bearing surface Moving (sliding) the curved chord line along other curved chord lines that define. As described above, the curved chords that define the contour and / or geometry of the load bearing surface may be a mapped curve, and / or a portion of the articulating surface to be replaced, a portion of the cooperating articulation mechanism. Can be obtained based on an approximation of curvature, such as In some such embodiments, a contour and / or geometric measurement of a portion of the articulating surface to be exchanged can be performed. Measuring the contour and / or geometric shape of a portion of the joint surface that is replaced by the implant uses direct contact contour mapping of the joint surface, for example by measuring the relative heights of various regions of the joint surface, And / or by using various imaging techniques, such as radiation imaging techniques.

  According to certain embodiments, the load bearing surface 108 is contoured and / or geometrically corresponding to the second curved chord line 118 lofted on the first curved chord line 116. You may have. In certain such embodiments, the contour and / or geometric shape of the load bearing surface 108 is increased along the first curve 116 while maintaining the second curve 118 and the first curve 116 orthogonal. This can be realized by moving two curved chord lines 118. In such embodiments, the first curve 116 may be provided in a first plane, such as a plane defined by the X and Z axes. The second curve 118 can be provided in an orthogonal plane. The angular pitch of the orthogonal plane relative to the first plane is along the first curve 116 in order to keep the second curve 118 orthogonal to the first curve 116 along the curvature of the first curve 116. May change. According to other embodiments, the second curve 118 can move along the first curve 116 with the first curve 116 and the second curve 118 being in an orthogonal plane. . For example, the first curve 116 can be provided in a first plane, such as a plane defined by the Y and Z axes, and the second curve 116 can be in an orthogonal plane, such as the plane defined by the X and Z axes. Can be provided. As shown in FIGS. 3 and 4, the embodiment of the implant provided in connection with the design method is generally symmetric with respect to each of the planes including the first curved chord line and the second curved chord line. Also good.

  In other embodiments, the load bearing surface 108 has a contour and / or geometric shape derived from a shaping transition between the first curved chord line 116 and the second curved chord line 118. Also good. That is, the contour and / or geometric shape of the load bearing surface 108 is such that the first curved chord line 116 and the second curved chord 116 in each quadrant between the first curved chord line 116 and the second curved chord line 118. It may be provided by a smooth transition between the curved chord line 118. In a similar embodiment, providing a shaping transition between the first curved chord line and the second curved chord line can be achieved using various averaging techniques known for surface generation. A variety of such averaging techniques are commonly employed in commercial surface finish design methods and solid modeling computer aided drafting software packages.

  The implant 102 may include a cut edge 120 so as to surround the load bearing surface 108. The ablated edge 120 may include a rounded over, such as a rounded edge, a chamfered edge, or the like. According to certain aspects, when the implant 102 is placed on the joint surface and replaced with at least a portion of the joint surface, the ablated edge 120 around the load bearing surface 108 is between the implant and the surrounding joint surface. As a result, it is possible to prevent a sharp edge from being present as much as possible at the transition portion. Reduce and / or eliminate damage to the interacting joint surface during articulation by reducing and / or removing sharp edges at the transition between the load bearing surface of the implant and the surrounding joint surface Can do. Further, the ablated edge 120 can meet manufacturing and / or assembly tolerances. The resected edge 120 may be used in a situation where the implant 102 is placed with the raised slightly above the surrounding articular surface and / or slightly under the surrounding articular surface. Will enable smooth operation.

  With particular reference to FIGS. 5-7, a load bearing surface 108 of the implant is shown. As described above, the illustrated implant system 100 can replace a portion of the talus lateral pulley ridge. In certain embodiments, the implantation site can be pre-processed using a rotary cutting instrument, such as a cutting blade that rotates about an axis. Thus, the implantation site may include a circular cut formed along the axis of rotation of the cutting blade. In such embodiments, the cross-sectional geometry of the implant may generally correspond to the intersection of the talar articular surface with the circular cut formed. Various additional and / or alternative ablation site preparation tools and techniques are also foreseen by the present disclosure, along with attendant changes to the implant shape.

  The position of the anchoring element and the orientation of the load bearing surface relative to the anchoring element can be selected to achieve a secure and stable anchoring of the implant relative to the articular surface. In certain embodiments, the implant system can have a configuration in which the anchoring element can extend into the talus at an angle and / or spaced from the lateral ridge. Such a configuration can provide a reliable anchoring of the implant and / or the talus may be peeled off due to the reduced strength of the talus caused by the anchoring element extending along the side adjacent to the pulley surface. And / or it can be prevented from breaking. Various additional and / or alternative forms can also be employed.

  With reference to FIGS. 8 and 9, another embodiment of an implant 200 is shown. The illustrated implant 200 is generally configured to replace at least a portion of the articular surface of the patella. Similar to the previously described embodiments, the implant 200 may generally include an implant body 202 having a load bearing surface 204. The load bearing surface 204 of the illustrated implant 200 can have a contour and / or geometry that can suitably replace at least a portion of the articular surface of the patella. The implant 200 may also include a post 206 that can be coupled to an anchoring element (not shown) for anchoring the implant 200 to the articular surface and / or underlying bone. In addition to or in place of the post, various other mechanisms can be employed to couple the implant 200 to the anchoring element. Furthermore, embodiments of the implant can be provided as including an integral anchoring element. In such embodiments, the mechanism for coupling to the fusing element can optionally be eliminated.

  Similar to the previous embodiment, the load bearing surface 204 of the implant 200 can be defined by a first curved chord line 208 and a second curved chord line 210. The contour and / or geometric shape of the load bearing surface 204 can be provided as the first curved chord line 208 drawn to scale on the second curved chord line 210 and / or vice versa. is there. As described above, a load bearing surface 204 that is lofted can be achieved by moving the first curved chord line 208 along the second curved chord line 210. In other embodiments, the load bearing surface of the implant can be provided using an averaging algorithm to provide a shaping surface between the first curved chord line and the second curved chord line.

  Yet another embodiment of the implant 300 is shown in FIGS. The illustrated implant 300 may be capable of replacing at least a portion of a pulley-like joint surface, such as a human pulley-like joint surface. Similar to the embodiments described above, the implant 300 may generally include an implant body 302 having a load bearing surface 304. The load bearing surface 304 may be defined by a first curved chord line 306 and a second curved chord line 308. The load bearing surface 304 can be provided by moving the second curved chord line 308 along the first curved chord line 306 in connection with the design method described above. In addition, the load bearing surface can also be provided as a faired surface defined by first and second intersecting curved chords.

  Referring to FIG. 12, a typical articulating surface is shown as including an implant that can replace at least a portion of a pulley-like surface. The implant shown in FIG. 12 may be generally consistent with the embodiment described in connection with FIGS. The load bearing surface of the implant (recognizable in the sample photograph) may generally have a contour and / or geometry that can generally accommodate a portion of the articular surface that is replaced by the implant. In such embodiments, the implant can provide a smooth interaction with cooperating articulating surfaces as shown in FIG. As described above, in certain embodiments, the implantation site can be formed on the articular surface using a rotary cutting instrument. The rotary excision instrument can provide a circular cutting path that can project into the articular surface and / or the underlying cartilage. The shape of the implant may generally correspond to the intersection of the circular cutting path and the articular surface in such embodiments.

  In summary, according to certain aspects, an implant can be provided to replace a portion of the articular surface. The implant has a contour defined by a first curved chord line based on an articulating surface contour in a first plane and by a second curved chord line based on an articulating surface contour in a second plane. A load bearing surface may be included. The first and second planes may be planes that intersect each other. The implant may further include a bone abutting surface.

  According to other aspects, the present disclosure may provide an implant system for replacing a portion of an articular surface. The implant system may include an implant having a load bearing surface defined by first and second curved chords. The first curved chord line may be based on the contour of the joint surface in the first plane, and the second curved chord line is based on the contour of the joint surface in the second plane. There may be. The first and second planes may intersect each other. The implant system may also include an anchoring element that can engage the bone and be coupled to the implant.

  According to yet another aspect, the present disclosure can provide a method for forming an implant. The method may include measuring a contour of the joint surface in a first plane and measuring a contour of the joint surface in a second plane (where the first and second planes). Is an intersecting plane). The method may further include providing an implant body having a load bearing surface. The load bearing surface of the implant body may have a contour defined by a contour of the joint surface in the first plane and a contour of the joint surface in the second plane.

  While embodiments of an implant system have been provided in connection with implants configured to replace at least a portion of the talus, patella, and human pulley, implants related to the present disclosure may include various other joints of the implant body. It may be sized and shaped to replace at least a portion of the surface. Thus, in connection with the present disclosure, an implant system can be provided to replace at least a portion of various articular surfaces in addition to a portion of the articular surface of the talus. For example, the implant can be suitably employed to replace a portion of an articular surface such as a knee joint, a hip joint, a shoulder joint. Accordingly, the above examples should not be construed as limitations on the use of the implant in connection with the present disclosure.

1 is an exploded perspective view of one embodiment of an implant system including an implant consistent with the present disclosure and an anchoring system usable with the implant. FIG. FIG. 2 is a perspective view of the embodiment of the implant system of FIG. 1 showing the implant assembled to the anchoring element. FIG. 7 is a perspective view of another embodiment of an implant system consistent with the present disclosure, including an implant and an anchoring element. It is a figure which sees and sees the implant system shown in FIG. 3 from another viewpoint. FIG. 6 illustrates an ankle joint including a talus implant consistent with the present disclosure. FIG. 6 illustrates an ankle joint including a talus implant consistent with the present disclosure. FIG. 6 illustrates an ankle joint including a talus implant consistent with the present disclosure. FIG. 6 is a perspective view of another implant consistent with the present disclosure. It is a figure which sees and shows the implant shown in FIG. 8 from another viewpoint. FIG. 6 is a perspective view of yet another implant consistent with the present disclosure. It is a figure which sees and shows the implant shown in FIG. 10 from another viewpoint. FIG. 6 shows a pulley-like implant consistent with the present disclosure.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Implant system 102 Articular surface implant 104 Anchoring element 106 Implant body 108 Load bearing surface 110 Bone contact area 112 Post 114 Opening 116 1st curved chord line 118 2nd curved chord line 120 Cut edge 200 Implant 202 Implant body 204 Load bearing surface 206 Post 208 First curved chord line 210 Second curved chord line 300 Implant 302 Implant body 304 Load bearing surface 306 First curved chord line 308 Second curved chord line

Claims (20)

An implant for replacing a part of the joint surface,
A load having a contour defined by a first curved chord line based on the contour of the joint surface in a first plane and a second curved chord line based on the contour of the joint surface in a second plane. A load bearing surface that is a support surface, wherein the first and second planes are in an intersecting state;
A bone contact surface;
An implant comprising:   The implant according to claim 1, wherein the first plane and the second plane are orthogonal to each other.   The implant of claim 1, wherein the load bearing surface contour comprises a contour defined by the second curved chord line drawn to scale along the second curved chord line.   The implant according to claim 1, wherein the first curved chord line is based on a plurality of measurements of the joint surface in a first plane.   The implant according to claim 1, wherein the second curved chord line is based on a plurality of measurements of the joint surface in a second plane.   The implant of claim 1, further comprising an attachment mechanism that can be coupled to either the anchoring element or the implantation site.   The implant according to claim 6, wherein the attachment mechanism comprises a tapered post engageable with the anchoring element.   The implant according to claim 1, wherein the load supporting surface is cut so as to surround at least a part of the periphery of the load supporting surface. An implant system for replacing part of the joint surface,
A load supporting surface formed by a first curved chord line based on the contour of the joint surface in a first plane and a second curved chord line based on the contour of the joint surface in a second plane; An implant having the first and second planes in an intersecting state; and
An anchoring element engageable with bone and connectable to the implant;
An implant system comprising:   The system of claim 9, wherein the first plane and the second plane are orthogonal.   The system of claim 9, wherein the contour of the load bearing surface comprises a contour defined by the second curved chord line drawn to full size along the second curved chord line.   The system of claim 9, wherein the anchoring element comprises a threaded portion engageable with a bone.   The anchoring element comprises an opening, and the implant comprises a protrusion that can be at least partially received within the opening for coupling the implant and the anchoring element. The system according to claim 9.   10. The system of claim 9, wherein the first curved chord line is based on a plurality of measurements of the articulating surface in a first plane.   The system of claim 9, wherein the second curved chord line is based on a plurality of measurements of the articulating surface in a second plane. A method for manufacturing an implant comprising:
Measuring the contour of the joint surface in the first plane;
Measuring the contour of the joint surface in a second plane intersecting the first plane;
Providing an implant body having a load bearing surface;
The load bearing surface has a contour defined by a contour of the first joint surface in the first plane and a contour of the joint surface in the second plane. A method for manufacturing an implant.   The method of claim 16, wherein the first plane and the second plane are orthogonal.   The method according to claim 16, wherein the implant body further comprises a bone contact surface.   The contour of the load bearing surface is defined by the contour of the joint surface in the second plane drawn to the full size along the contour of the joint surface in the first plane. The method of claim 16.   Measuring the contour of the articulating surface within one of the first plane and the second plane comprises one of direct contact contour mapping and radiographic imaging. The method of claim 16.

Images