Patent ID: 12257156

MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of an animal knee joint implant that reflects anatomical structure of an animal according to the present disclosure will be described in detail with reference to the accompanying drawings. In the following description of the present disclosure, when it is determined that a detailed description of a known function or configuration may unnecessarily make the subject matter of the present disclosure unclear, the detailed description will be omitted. Unless otherwise defined, all terms used herein have the same meaning as the general meaning of the terms understood by a person ordinarily skilled in the art to which this disclosure belongs, and when the general meaning conflicts with the meaning of the terms used herein, the meaning of the terms follows the definition used in the specification. Herein, it is noted that the drawings show an implant inserted in a left leg of an animal and a description thereof is described in order to help understanding.

FIG.2is a perspective view illustrating an animal knee joint implant according to an embodiment of the present disclosure, andFIG.3is an exploded perspective view ofFIG.2. Referring toFIGS.2and3, an animal knee joint implant1of the present disclosure refers to an artificial prosthesis that reflects the anatomical structure of an animal, and that is inserted into a knee joint of the animal so as to replace an anatomical knee joint of the animal damaged by various causes. The term “animal” may be considered to have a broad sense that covers all animals except a human being, such as a dog and a cat. The animal knee joint implant1is capable of being used for diseases, which are accompanied by bone loss, damage to surrounding muscles, ligaments, and the like, and are thus more complex than general knee joint diseases such as rheumatoid arthritis and degenerative arthritis. The animal knee joint implant is configured to be capable of reinforcing stability against varus and valgus as well as stability against flexion and extension, and capable of easily complementing gaps that may occur when the bones of a joint are cut. The animal knee joint implant1includes a tibia element10, a bearing element30, a femur element50, and a connecting element70.

The tibia element10is a component to be inserted into a tibia of an animal, and provides a space in which the bearing element30to be described later is capable of being seated and supports the bearing element30to be brought into contact with the femur element50. The tibia element10is horizontally resected by a surgeon in the process of knee joint replacement surgery and placed on the flat proximal portion of an animal's tibia. A portion of the tibia element10enters the inside of the animal's cancellous bone so as to allow the tibia element10to be stably fixed on the tibia. The tibia element10is not limited to a specific concept with respect to the material thereof, but may be preferably made of a cobalt chromium material.FIG.4is a view illustrating the tibia element according to an embodiment of the present disclosure,FIG.5is a rear view ofFIG.4, andFIG.6is a side view ofFIG.4. Referring toFIGS.4to6, the tibia element10includes a seating surface11, a post13, a tibia contact surface15, a tibia stem17, and a tibia spike19.

The seating surface11is a configuration that provides a space in which the bearing element30, which will be described later, is capable of being seated, and may preferably be configured to be inclined by reflecting the anatomical structure of an animal. Biologically, an animal's tibia has a medial height higher than a lateral height, and the seating surface11is preferably configured to be inclined laterally in order to reflect this anatomical structure of an animal. As illustrated inFIGS.4and5, an artificial tibia may be configured to have a medial height H2relatively higher than a lateral height H1by configuring the seating surface11to be inclined laterally. In addition, unlike biped humans, animals generally perform quadrupedalism. Thus, the distal portion of a femur is not located substantially vertically on the proximal portion of a tibia, but the distal portion of the femur is inclined somewhat posteriorly from the proximal portion of the tibia so as to perform joint motion. Accordingly, as illustrated inFIG.6, the seating surface11may be preferably configured to be inclined laterally and further to be inclined posteriorly. The seating surface11is preferably configured as a smooth flat surface such that, when a tibia element contact surface of the bearing element30to be described later is supported thereon, the bearing element30placed on the seating surface11is capable of rotating within a predetermined range.

The post13refers to a configuration protruding to be perpendicular to the seating surface11. The post13is not limited to a specific concept with respect to the specific shape thereof, but may preferably have a cylindrical shape, as illustrated inFIGS.4to6. According to the foregoing, the seating surface11is configured to be inclined laterally and posteriorly in order to reflect the anatomical structure of an animal. When the post13protrudes vertically on the seating surface11, the post13is also configured to be inclined laterally and posteriorly.

The post13may be inserted into a post-receiving hole35in the bearing element30to be described later. The separation of the bearing element30from the tibia element10is capable of being prevented through the post13, and the bearing element30to be described later is capable of rotating about the post13on the seating surface11of the tibia element10.

In addition, the post13may be inserted into a post-receiving hole713in the yoke unit71to be described later. In the yoke unit71to be described later, a coupling pin-receiving hole711is formed in the transverse direction, and the coupling pin73is seated in the coupling pin-receiving hole711. A gripping groove731is formed on the seated coupling pin73. When the post13is inserted into the post-receiving hole713after the coupling pin73is inserted into the coupling pin-receiving hole711, a portion of the post13is engaged in the gripping groove731in the coupling pin73so that it is possible to prevent separation of the coupling pin73.

The tibia contact surface15refers to a portion of the tibia element10that directly comes into contact with the tibia. In knee joint replacement surgery, a process of horizontally resecting the proximal portion of a problematic tibia is performed. In order for the tibia element10to be stably seated on the horizontally resected proximal portion of the tibia, the tibia contact surface15is preferably configured to have a shape complementary to the surface of the horizontally resected proximal portion of the tibia, as illustrated inFIG.6.

The tibia stem17refers to a configuration protruding distally from the tibia contact surface15. In the process of seating the tibia element10on the resected proximal portion of the tibia, it is necessary not only to position the tibia element at a predetermined point, but also to stably fix the tibia element10on the proximal portion of the tibia so as to prevent the tibia element10from deviating from the corresponding position. Therefore, the tibia stem17is inserted into the tibia and functions to firmly fix the tibia element10to the tibia. Preferably, the tibia stem17may be configured to be inclined posteriorly along the anatomical tibia shape of the animal such that the tibia step17is capable of being inserted into the cancellous bone of the tibia, which has relatively weak strength. The tibia stem17is not limited to any specific concept with respect to the specific shape thereof, but may have a substantially cylindrical shape, as illustrated inFIG.6.

The tibia spike19refers to a configuration that protrudes distally at a point of the tibia contact surface15that does not interfere with the tibia stem17in order to secure the force of fixing the tibia element10. When it is difficult to secure a sufficient fixation force between the tibia element10and the tibia only with the tibia stem17, the tibia spike19is configured on the tibia contact surface15so as to increase the structural stability of the tibia element10inserted into the proximal portion of the tibia. The tibia spike19is not limited to any specific concept with respect to the shape thereof, but preferably, as illustrated inFIG.6, the distal end thereof may be configured in a sharp cone shape. In addition, a plurality of tibia spikes19may be provided in a portion having weak structural stability. In addition, the tibia stem17is configured to be inclined posteriorly so as to conform to the anatomical structure of an animal. However, the tibia spike19complements the fixation force of the tibia stem17, and the degree of protrusion of the tibia spike19from the tibia contact surface15is shorter than that of the tibia stem17. Thus, the tibia spike19may be formed to protrude vertically from the tibia contact surface15without being inclined.

FIG.7is a view illustrating a bearing element according to an embodiment of the present disclosure,FIG.8is a side view ofFIG.7,FIG.9is a plan view ofFIG.7, andFIG.10is a view illustrating the bearing element seated on the tibia element. Hereinafter, reference will be made toFIGS.7to10.

The bearing element30refers to a configuration that is seated on the tibia element10and supports the femur element50to be described later. On the bearing element30, a medial condyle511and a lateral condyle513of the femur element50, which will be described later, are seated to perform knee joint motion. The bearing element30is not limited to a specific concept with respect to the material thereof, but may be preferably made of a polyethylene material. When the bones of a joint are cut, gaps may occur, and these gaps may have various shapes. The bearing element may be provided in various forms according to the gaps, and through this, the gaps may be easily complemented. The bearing element30includes a joint facet31, a tibia element contact surface33, and a post-receiving hole35.

The joint facet31is a portion that is in contact with the medial condyle511and the lateral condyle513of the femur element50, and is configured to have a concave shape so as to receive the condyles of the femur element50having a convex shape. The joint facet31is divided into a medial joint facet311configured to receive the medial condyle511of the femur element50and a lateral joint facet311configured to receive the lateral condyle513of the femur element50. Preferably, the medial joint facet311and the lateral joint facet313may be symmetrical to each other.

The tibia element contact surface33refers to a portion of the bearing element30that is in contact with the seating surface of the tibia element10. As described above, the seating surface11is configured as a smooth flat surface in order to facilitate the support of the bearing element30and rotation of the bearing element30about the post13. Preferably, the tibia element contact surface33is also configured as a smooth flat surface.

The post-receiving hole35is configured to receive the post13of the tibia element10, and refers to a hole penetrating from the joint facet31to the tibia element contact surface33. The bearing element30is prevented from deviating from the seating surface11of the tibia element10by the post13inserted into the post-receiving hole35, and the bearing element30is capable of rotating about the post13, as illustrated inFIG.10. The post-receiving hole35is preferably configured such that the hole axis351thereof is perpendicular to the tibia element contact surface33so as to accommodate the post13protruding vertically from the seating surface11.

FIG.11is a view illustrating a femur element according to an embodiment of the present disclosure,FIG.12is a front view ofFIG.11,FIG.13is a rear view ofFIG.11, andFIG.14is a side view ofFIG.11. Hereinafter, reference will be made toFIGS.11to14.

The femur element50is configured to be inserted into a femur of an animal, and is preferably coupled to the distal end of the femur. The femur element50is in contact with the joint facet31of the bearing element30so as to perform joint motion. The femur element50is not limited to a specific concept with respect to the material thereof, but may be preferably made of a cobalt chromium material. The femur element50includes condyles51, a pulley portion53, a femur contact surface55, a femur stem57, and a femur spike59.

The condyles51are portions having a convex shape on the lower side of the femur element50, and are configured to perform joint motion while being in contact with the joint facet31of the bearing element30having a concave shape. The condyles51are divided into a medial condyle511and a lateral condyle513while forming a separation space S therebetween. The medial condyle511and the lateral condyle513are seated on the medial joint facet311and the lateral joint facet313, respectively, so as to perform joint motion. Preferably, the medial condyle511and the lateral condyle513may be configured to be symmetrical to each other.

In each condyle51, a hole may be configured to penetrate the condyle51from the medial surface to the lateral surface of the condyle51. The hole penetrating the medial condyle511from the medial surface to the lateral surface of the medial condyle511is referred to as a medial coupling pin-seating hole5111, and the hole penetrating the lateral condyle513from the medial surface to the lateral surface of the lateral condyle513is referred to as a lateral coupling pin-seating hole5131. The medial coupling pin-seating hole5111and the lateral coupling pin-seating hole5131receive a coupling pin73to be described later so that the femur element50is rotatable about the coupling pin73.

The pulley portion53is formed on the anterior side of the femur element50and configured to be in contact with a patella of an animal for knee joint replacement surgery.

The femur contact surface55refers to a surface of the femur element50that is in contact with the femur, and may preferably be formed on the rear surface of the pulley portion50.

The femur stem57refers to a configuration that protrudes proximally from the femur contact surface55. The femur stem57is not limited to any specific concept with respect to the specific shape thereof, but may preferably have a substantially cylindrical shape. The femur stem57is inserted into the femur such that the femur element50is capable of being firmly fixed to the femur of the animal while having structural stability. Preferably, the femoral stem57may be configured to be inclined medially to reflect the anatomical structure of an animal.

The connecting element70refers to a configuration that enables joint motion between the femur element50and the bearing element30. Specifically, the connecting element70is connected to the medial condyle member511and the lateral condyle513of the femur element50so as to designate the center of rotation of the condyles51, and receives the post13of the tibia element10that penetrates the element30so as to connect the bearing element30. As a result, the connecting element70is capable of connecting the tibia element10and the femur element50to each other while preventing the bearing element30interposed between the tibia element10and the femur element50from deviating from the bearing element30so as to allow the femur element50to stably perform joint motion on the joint surface31of the bearing element30.FIG.15is a view illustrating a connecting element according to an embodiment of the present disclosure. Referring toFIG.15, the connecting element70includes a yoke unit71, a coupling pin73, and a bushing unit75.

FIG.16is a view illustrating a yoke unit according to an embodiment of the present disclosure,FIG.17is a side view ofFIG.16, andFIG.18is a bottom view ofFIG.16. Hereinafter, reference will be made toFIGS.16to18.

The yoke unit71is a configuration that is inserted into a separation space S between the medial condyle511and the lateral condyle513of the femur element50, and may be preferably configured to have a shape complementary to the medial space shape of the separation space S. The yoke unit71is configured to receive the post13of the tibia element10and to receive a coupling pin73to be described later. The post13may be received through the lower surface of the yoke part71, and the coupling pin73may be received through the medial and lateral surfaces of the yoke unit71. As will be described later, a gripping groove731is formed on the coupling pin73so that the post13is engaged in the gripping groove731. For this purpose, the yoke unit71preferably receives the post13after receiving the coupling pin73therein. The yoke unit71is not limited with respect to the material thereof, but may be made of a biometallic material in order to secure the strength of the connecting portion. The yoke unit71includes a coupling pin-receiving hole711and a post-receiving hole713.

The coupling pin-receiving hole711is configured to receive the coupling pin73to be described later, and may have a shape that penetrates the yoke unit71from the medial surface to the lateral surface, as illustrated inFIG.17. In addition, the coupling pin-receiving hole711is preferably configured to have a shape complementary to the outer circumferential shape of the coupling pin73for easy seating of the coupling pin73. The coupling pin-receiving hole711may communicate with the post-receiving hole713to be described later. As a result, the coupling pin73received in the coupling pin-receiving hole711is capable of being engaged with the post13received in the post-receiving hole713.

The post-receiving hole713is configured to receive the post13of the tibia element10, and may have a shape that penetrates the yoke unit71from the bottom surface to the top surface, as illustrated inFIG.18. For easy insertion of the post into the post-receiving hole713, the post-receiving hole713may be configured to have a shape complementary to the outer circumferential shape of the post13. However, as described above, when the tibia element10and the yoke unit71are made of a metal material, metals come into contact with each other. Thus, since a lower bushing755to be described later may be interposed between the post-receiving hole713and the post13, it is more preferable to configure the inner space of the post-receiving hole713in a shape complementary to the outer circumferential shape formed by fitting the lower bushing755on the post13. In this case, as illustrated inFIG.18, the post-receiving hole713may have a stepped portion7131on which one end of the lower bushing755is seated.

The coupling pin73is configured to penetrate and connect the medial condyle511, the lateral condyle513, and the yoke unit of the femur element50, and functions as the center axis of rotation of the femur element50to perform joint motion on the joint facet31of the bearing element30. The coupling pin73is not limited to a specific concept with respect to the shape thereof, but may preferably be configured in a cylindrical shape having a circular cross section in order to induce smooth joint motion.FIG.19is a view illustrating a coupling pin according to an embodiment of the present disclosure. Referring toFIG.19, the coupling pin73includes a gripping groove731.

The gripping groove731is configured to grip the post13of the tibia element10, and refers to a portion recessed on the coupling pin73while having a shape complementary to the outer circumferential surface of the post13. The coupling pin73passes through the medial coupling pin-seating hole5111of the medial condyle511and the lateral coupling pin-seating hole5131of the lateral condyle513. When there is no separate means for fixing the coupling pin73, the coupling pin73may be separated from the predetermined position through the medial coupling pin-seating hole5111or the lateral coupling pin-seating hole5131. Therefore, in order to prevent such a problem, by configuring the gripping groove731on the coupling pin73so that the post13is seated in the gripping groove731, it is possible to prevent the coupling pin73from deviating medially or laterally.

FIG.20is a view illustrating the post and the coupling pin inserted into the yoke unit, andFIGS.21and22are views illustrating the state in which the post and the coupling pin ofFIG.20are coupled. Referring toFIGS.20to22, as described above, it can be seen that a portion of the post13of the tibia element10enters the gripping groove731in the coupling pin73and the position of the coupling pin73is fixed by the post13. In this way, since the yoke unit71receives the coupling pin73in the transverse direction and the post13in the longitudinal direction, and the coupling pin73and the post13are fastened in the yoke unit71, it is possible to further reinforce stability against varus and valgus as well as stability against flexion and extension.

The bushing unit75refers to a configuration of a nonmetal material interposed between components, each made of a metal material, to prevent direct contact between the metal materials. Each of the tibia element10, the femur element50, the yoke unit71, and the coupling pin73may be made of a biometallic material to express predetermined strength. The medial bushing751may be inserted into the medial coupling pin-seating hole5111in the medial condyle511, the lateral bushing753may be inserted into the lateral coupling pin-seating hole5131in the lateral condyle513, and the lower bushing755may be inserted into the post-receiving hole713in the yoke unit71.

FIG.23is a view illustrating the usage state of an animal knee joint implant according to an embodiment of the present disclosure. Referring toFIG.23, the tibia element10may be inserted into the proximal portion of an animal's tibia T, the bearing element30may be seated on the inclined seating surface11of the tibia element10to be rotatable, and the femur element50may be inserted into the distal portion of the femur F of the animal so that the condyles51of the femur element50are capable of performing joint motion while being in contact with the joint facet31of the bearing element30. Therefore, it is possible to restore the original anatomical motion of an animal with a damaged knee joint.

The foregoing detailed description is illustrative of the present disclosure. In addition, the foregoing description is intended to illustrate and explain embodiments of the present disclosure, and the present disclosure may be used in various other combinations, modifications, and environments. That is, changes or modifications can be made within the scope of the concept of the present disclosure disclosed herein, the scope equivalent to the content described above, and/or the scope of the skill or knowledge of the art. The embodiments described above are intended to illustrate the best mode for carrying out the technical idea of the present disclosure, and various modifications required for specific application fields and uses of the present disclosure are also possible. Therefore, the foregoing detailed description of the present disclosure is not intended to limit the present disclosure to the disclosed embodiments. In addition, the appended claims should be interpreted as including other embodiments.