JP2018038713A - Implant system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an implant system capable of performing a cartilage deficiency treatment method which allows a patient to use a joint soon after an operation and does not leave foreign matters in the body.SOLUTION: An implant system 10 comprises an implant 12 and a tool 14. The implant 12 includes a bone fixation part 16, a joint contact part 18, an implant side engaging part 20, and a flange 22. The tool 14 includes a tool side engaging part 28 capable of engaging with the implant side engaging part 20. The outer diameter of the tool side engaging part 28 is equal to or smaller than that of the flange 22.SELECTED DRAWING: Figure 1

Description

  The present invention relates to an implant system used for the treatment of cartilage defects.

  Currently, several treatment methods are applied to joints damaged by illness or trauma. In the osteochondral transplantation method (mosaic practice), an osteochondral column is collected from an unloaded portion of cartilage and transplanted to a cartilage damaged portion. In the bone marrow stimulation method (drilling), a hole is made in the lower bone of the cartilage, the bone marrow fluid (cells and nutrient factors) is leached and a repair tissue is generated, thereby replacing the cartilage in the cartilage damaged part.

  On the other hand, in recent years, it has been desired to perform a less invasive treatment according to the patient's condition (age, degree of joint damage, etc.). For this reason, a treatment method has been proposed in which an implant is applied to compensate for a cartilage defect.

  The bioabsorbable cartilage repair system of Patent Document 1 includes a bioabsorbable delivery unit (support unit) configured to be attachable to a cartilage removal site, and a bioabsorbable insert (porous) supported by the bioabsorbable delivery unit. Insert). The cartilage repair plug of Patent Document 2 is configured to fill a damaged or excised cartilage space alone or in plural.

Japanese Patent Laid-Open No. 2005-246072 Special table 2004-520855 gazette

  In Patent Document 1, since both the support unit and the porous insert are made of a bioabsorbable material, there is an advantage that foreign matter does not remain in the body, but the bone to which the implant is fixed and the joint contact portion are on the same surface. Therefore, the patient cannot walk immediately after the operation because the bone to which the implant is fixed comes into contact with the portion facing the bone. In Patent Document 2, a single or a plurality of wounds or excised cartilage spaces are filled so that the patient can walk immediately after the operation, but is not made of a bioabsorbable material. End up.

  The present invention has been made in view of such problems, and provides an implant system that allows a patient to use a joint immediately after surgery and to perform a method for treating a cartilage defect without leaving a foreign body in the body. The purpose is to do.

  To achieve the above object, the present invention provides an implant system comprising an implant configured to be inserted into a living bone, and a jig for removing the implant from the bone, The implant includes a bone fixing unit configured to be inserted into and fixed to the bone, a joint contact unit configured to contact a portion of the joint facing the bone to which the implant is fixed, An implant-side engaging portion provided between the bone fixing portion and the joint contact portion and configured to be able to engage with the implant in order to remove the implant by the jig; and the bone fixing portion and the implant A flange portion that is provided between the side engaging portion, protrudes outward from the bone fixing portion and the implant side engaging portion, and comes into contact with the bone. A cylindrical jig-side engagement portion that can be engaged with the implant-side engagement portion in a state of covering the implant-side engagement portion in order to remove the implant, and an outer diameter of the jig-side engagement portion Is less than or equal to the outer diameter of the flange portion.

  According to the implant system of the present invention configured as described above, a hole is formed in the bone located in the cartilage defect portion, the bone fixing portion of the implant is embedded in the hole, and the space between the inner surface of the hole and the implant Bone marrow fluid can be leached to form a repaired tissue. Then, after the repair tissue is formed, the implant is extracted using a jig, and the bone marrow fluid is leached into the extracted portion (extraction hole), so that the repair tissue can be formed in the extraction hole. Therefore, the patient can use the joint immediately after the operation and can treat the cartilage defect without leaving a foreign body in the body. If the cartilage defect is treated at the knee joint, the patient can walk immediately. In addition, since the outer diameter of the jig side engaging portion is equal to or smaller than the outer diameter of the flange portion, the repaired tissue removed by the jig when the implant is removed may be reduced as much as possible. it can.

  The implant system further includes a notch forming device having an annular blade portion configured to form a notch for inserting the jig side engaging portion into a repaired tissue formed in a cartilage defect portion. Also good.

  With this configuration, it is possible to make a cut in advance in the repaired tissue surrounding the joint contact portion and the implant-side engagement portion. For this reason, when covering an implant side engaging part with a jig side engaging part in order to extract an implant, it can suppress that a repaired tissue destroys (crushes).

  In the above-described implant system, the notch forming device may include a positioning mechanism that performs center alignment between the blade portion and the flange portion by contacting the joint contact portion.

  With this configuration, since the center position of the blade portion of the notch forming device and the flange portion of the implant is aligned, the notch can be accurately formed in the repaired tissue.

  In the above-described implant system, a screw thread is provided on an outer peripheral portion of the bone fixing portion, and the jig-side engagement portion uses the jig to remove the implant from the bone. When applying a torque to the implant-side engagement portion, a protrusion may be provided so as not to be detached from the implant-side engagement portion.

  With this configuration, when the implant is removed from the bone, the implant can be rotated while being pulled, so that it is possible to suppress damage to the bone tissue due to the screw thread in the portion where the bone fixing portion is embedded. Or, even if the implant is rotated to remove the implant from the bone, the screw thread on the inner periphery of the part where the bone anchoring part is embedded by the thread of the bone anchoring part (the screw thread on the bone side) When collapsed, the implant can be reliably removed from the bone by rotating while pulling the implant.

  The present invention also includes a bone fixing unit configured to be inserted into and fixed to a bone, and a joint contact unit configured to contact a portion facing the bone in which the implant is fixed in the joint. A method for treating a cartilage defect using the provided implant, the hole forming step for forming a hole in the bone located in the cartilage defect part, and the exposed part of the inner surface of the hole through the hole An embedding step of embedding the bone fixing portion of the implant in a bone, and a first tissue that forms a repair tissue around the joint contact portion in the cartilage defect portion by leaching bone marrow fluid from the inner surface of the hole A forming step; an extraction step of extracting the implant from the bone after the repair tissue is formed; and a bone marrow fluid leached from the bone into an extraction hole formed by extracting the implant. , Characterized in that it comprises a second tissue formation step of forming a repair tissue to the removal hole.

  In the method for treating a cartilage defect, in the hole forming step, when the bone fixing portion is embedded in the bone in the embedding step, the inner peripheral surface of the hole and the inner peripheral surface are opposed to each other. The hole may be formed so that a space communicating with the cartilage defect is formed between the outer periphery of the implant.

  In the above method for treating a cartilage defect, the implant has a flange portion that is provided between the bone fixing portion and the joint contact portion and protrudes outward from the bone fixing portion and the joint contact portion. In the hole forming step, when the bone fixing portion is embedded in the bone in the embedding step, the end surface of the flange portion on the joint contact portion side is deeper than the opening position of the hole. You may form the said hole so that it may be located in the side.

  In the above-described method for treating a cartilage defect, the extraction step partially destroys the repaired tissue formed in the first tissue formation step with a jig, and includes the bone fixing portion and the joint contact portion. A jig connecting step for covering the implant-side engaging portion provided therebetween with a cylindrical jig-side engaging portion provided in the jig, and a force for removal via the jig. And a jig operation step for operating the jig so as to act.

  In the above-described method for treating a cartilage defect, the implant includes a flange portion provided between the bone fixing portion and the joint contact portion and protruding outward from the implant-side engagement portion. The outer diameter of the tool side engaging portion may be equal to or smaller than the outer diameter of the flange portion.

  In the method for treating a cartilage defect, the first tissue formation step is formed between the first tissue formation step and the removal step by an annular blade provided in a notch formation device. A notch forming step for forming a notch in the repair tissue may be provided, and the jig side engaging portion may be inserted into the notch in the jig connecting step.

  In the above method for treating a cartilage defect, the implant has a flange portion that is provided between the bone fixing portion and the joint contact portion and protrudes outward from the implant side engagement portion. In the forming step, center alignment between the blade portion and the flange portion may be performed by a positioning mechanism provided in the notch forming device.

  In the above-described method for treating a cartilage defect, a screw thread is provided on an outer peripheral portion of the bone fixing portion, and the jig side engagement portion has the jig for removing the implant from the bone. In the extraction step, torque is applied to the implant by the jig to extract the implant from the bone, and the protrusion is connected to the side of the implant. You may pull the said jig | tool in the state hooked on the joint part.

  ADVANTAGE OF THE INVENTION According to this invention, the treatment method of the cartilage defect which a patient can use a joint immediately after an operation, and does not leave a foreign material in the body can be performed.

1 is a perspective view of an implant system according to a first embodiment of the present invention. It is a side view of an implant. FIG. 3A is an explanatory view showing a cartilage defect, and FIG. 3B is an explanatory view of a hole forming step. 4A is an explanatory diagram of the embedding step, and FIG. 4B is an explanatory diagram of an initial stage of the first tissue formation step. FIG. 5A is an explanatory diagram of the final stage of the first tissue formation step, and FIG. 5B is an explanatory diagram of the extraction step. FIG. 6A is an explanatory diagram of an initial stage of the second tissue formation step, and FIG. 6B is an explanatory diagram of a final stage of the second tissue formation step. It is a 1st figure explaining the dimensional relationship between an implant and a hole. It is a 2nd figure explaining the dimensional relationship between an implant and a hole. It is a 3rd figure explaining the dimensional relationship between an implant and a hole. 10A is an explanatory diagram of a hole forming step according to a modification, and FIG. 10B is an explanatory diagram of an embedding step subsequent to the hole forming step of FIG. 10A. It is explanatory drawing of a notch formation device. It is explanatory drawing of the notch formation step which forms an incision in repair tissue using the notch formation device shown in FIG. It is a schematic explanatory drawing of the implant system which concerns on 2nd Embodiment of this invention.

  Hereinafter, preferred embodiments and modifications of the implant system according to the present invention will be described with reference to the accompanying drawings. In the modified example and the second embodiment, the same or similar elements as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

  An implant system 10 according to the first embodiment shown in FIG. 1 is used to treat a cartilage defect (for example, a cartilage defect of a knee joint) of a patient (living body). The implant system 10 includes an implant 12 configured to be inserted into a living bone 32 (see FIG. 3A and the like), and a jig 14 for embedding the implant 12 in the bone 32 and removing it from the bone 32. Prepare.

  As shown in FIGS. 1 and 2, the implant 12 includes a bone fixing portion 16, a joint contact portion 18, an implant side engagement portion 20, and a flange portion 22. The bone fixing part 16 is configured to be inserted into and fixed to the bone 32. The bone fixing part 16 is set to a length that can be sufficiently inserted into the cancellous material through the periosteum and dense material of the bone 32 to be fixed. Specifically, the bone fixing portion 16 includes a linear shaft portion 16a along the axial direction of the implant 12, and a screw thread 16b spirally provided on the outer peripheral surface of the shaft portion 16a. The tip of the screw thread 16b is a self-tapping screw. In addition, even if it is not a self-tap screw, when there is no hindrance to the bone 32, a self-tap screw may not be provided. A conical portion 16c having a reduced diameter toward the distal end and a sharp tip is provided at the distal end of the shaft portion 16a. If there is no hindrance to the bone 32 without the cone portion 16c, the cone portion 16c may not be provided.

  The constituent material of the implant 12 is not particularly limited, but a material having rigidity capable of being firmly fixed to the bone 32 and having little influence on the living body is preferable. Examples of the constituent material of the implant 12 include metal materials such as titanium, titanium alloys, titanium / nickel alloys, zirconium (zirconia), resin materials such as PEEK resin and PSU resin, other ceramics, and hydroxyapatite. .

  The joint contact portion 18 is configured to contact a portion (bone 38 and cartilage 40) facing the bone 32 to which the implant 12 is fixed in the joint. The joint contact portion 18 has a function of receiving a load from an opposite site in the joint in a state where the implant 12 is installed on the bone.

  In the first embodiment, the joint contact portion 18 has a circular shape when viewed from the axial direction. The joint contact portion 18 may have a non-circular shape (for example, an elliptical shape or a polygonal shape) when viewed from the axial direction. As shown in FIG. 2, the top surface 18 a of the joint contact portion 18 has an arc shape (dome shape) that bulges in a direction opposite to the bone fixing portion 16 in a side view.

  The implant-side engagement portion 20 is used to embed (screw) the implant 12 into the bone 32 and when the implant 12 is removed from the bone 32 (the jig-side engagement portion 28 described later). Is the part that engages. The implant side engaging portion 20 is provided between the bone fixing portion 16 and the joint contact portion 18 (specifically, a position adjacent to the joint contact portion 18).

  The implant side engaging portion 20 protrudes outward in the radial direction from the joint contact portion 18. That is, the implant-side engagement portion 20 is configured to have a larger diameter than the joint contact portion 18. A plurality of engagement grooves 20 a are provided on the outer peripheral portion of the implant-side engagement portion 20 at intervals in the circumferential direction. The plurality of engaging grooves 20a are arranged at equal intervals in the circumferential direction. Each engagement groove 20 a extends along the axial direction of the implant 12.

  The flange portion 22 is provided between the bone fixing portion 16 and the implant side engaging portion 20, and protrudes outward from the bone fixing portion 16 and the implant side engaging portion 20. That is, the flange portion 22 is configured to have a larger diameter than the bone fixing portion 16 and the implant side engaging portion 20. The flange portion 22 is formed in an annular shape and is disposed concentrically with the bone fixing portion 16, the joint contact portion 18, and the implant side engagement portion 20.

  The jig 14 shown in FIG. 1 has both a function of an embedding device for embedding the implant 12 in the bone 32 and a function of an extraction device for extracting the embedded implant 12 from the bone 32. In FIG. 1, the jig 14 partially shows only the tip, but the jig 14 has an elongated bar shape as a whole. A hub for the operator (user) to hold may be provided at the proximal end of the jig 14.

  The jig 14 includes a rod-shaped shaft portion 26 (jig body portion) and a cylindrical jig-side engagement portion 28 provided at the tip portion of the shaft portion 26. The jig side engaging portion 28 is configured to be able to engage with the implant side engaging portion 20 in a state of covering the implant side engaging portion 20 in order to extract the implant 12 from the bone 32. Specifically, the jig-side engagement portion 28 includes a hollow cylindrical tube portion 28a and a plurality of engagement ribs 28b provided on the inner peripheral surface of the tube portion 28a at intervals in the circumferential direction.

  An opening 29 that opens in the distal direction is provided at the distal end of the cylindrical portion 28a. The cylindrical portion 28 a is configured to cover the joint contact portion 18 and the implant-side engagement portion 20 of the implant 12 through the opening 29. The outer diameter D2 of the cylindrical portion 28a (the jig side engaging portion 28) is set to be equal to or smaller than the outer diameter D1 (see FIG. 2) of the flange portion 22 of the implant 12. In the first embodiment, the outer diameter D2 of the cylindrical portion 28a and the outer diameter D1 of the flange portion 22 are set to be substantially the same.

  The plurality of engagement ribs 28b are arranged at equal intervals in the circumferential direction. Each engaging rib 28b protrudes inward in the radial direction of the cylindrical portion 28a and extends along the axial direction of the cylindrical portion 28a. The plurality of engagement ribs 28 b can be engaged with a plurality of engagement grooves 20 a provided in the implant-side engagement portion 20.

  Next, an example of a method for treating a cartilage defect using the implant system 10 will be described.

  In FIG. 3A, the cartilage 30 of the patient's joint (for example, knee joint) has a region (cartilage defect portion 30a) where the cartilage 30 is lost. In the cartilage defect portion 30a, a treatment (dissection) for exposing the mother bed portion (the surface 32a of the bone 32) by removing the cartilage tissue that has been peeled off is performed under an arthroscope, if necessary. . The bone 32 is, for example, a femur. The hole forming step, the embedding step, and the extracting step described below are performed under an arthroscope.

  As shown in FIG. 3B, the operator forms a hole 34 in the surface 32a of the bone 32 (exposed surface of the bone 32) located in the cartilage defect 30a (hole forming step). In this case, when the bone fixing part 16 is embedded in the bone 32 in an embedding step (see FIG. 4A) described later, the surgeon sets the inner peripheral surface of the hole 34 and the implant 12 facing the inner peripheral surface. A hole 34 is formed so that a space P communicating with the cartilage defect 30a is formed between the outer periphery.

  In this example, in order to describe a case where a plurality (specifically, three) of implants 12 are embedded, as shown in FIG. 3B, a plurality (three) of holes 34 are formed in the hole forming step. . The number of implants 12 embedded in the bone 32 may be one. In this case, one hole 34 is formed.

  The hole 34 is formed using, for example, a drill. In the first embodiment, the hole 34 has a T-shaped cross section. That is, the hole 34 includes a first hole 34A formed in the surface layer of the bone 32, and a second hole 34B extending linearly from the center of the first hole 34A toward the deep side of the bone 32. It consists of. When viewed from the side of the cartilage 30 (the side of the cartilage defect 30a), the first hole 34A and the second hole 34B have a circular shape.

  In FIG. 3B, the inner diameter D3 of the first hole portion 34A is larger than the outer diameter D1 (see FIG. 2) of the flange portion 22 of the implant 12. The second hole 34B is thinner than the first hole 34A. The inner diameter D4 of the second hole portion 34B is smaller than the outer diameter D5 (see FIG. 2) of the bone fixing portion 16, and is constant along the axial direction of the second hole portion 34B. The inner diameter D4 of the second hole portion 34B may decrease toward the deeper side of the bone 32. The length L2 of the second hole portion 34B is longer than the length L1 (see FIG. 2) of the bone fixing portion 16 of the implant 12. The length L2 of the second hole portion 34B may be shorter than the length L1 of the bone fixing portion 16.

  Next, as shown in FIG. 4A, the surgeon implants the bone fixing portion 16 of the implant 12 into the bone 32 through the hole 34 so as to leave an exposed portion of the inner surface of the hole 34 (embedding step). In this example, a plurality (three) of implants 12 are embedded. A jig 14 (see FIG. 1) is used for embedding the implant 12.

  In the embedding step, specifically, the joint contact portion 18 and the implant side engagement portion 20 of the implant 12 are inserted into the jig side engagement portion 28 of the jig 14. Then, the surgeon rotates the implant 14 by rotating the jig 14 to screw the implant 12 (the bone fixing portion 16 provided with the screw thread 16b) into the bone 32 (the second hole portion 34B). Get in. In this case, torque is satisfactorily transmitted from the jig 14 to the implant 12 under the engagement action of the plurality of engagement grooves 20a and the plurality of engagement ribs 28b (see FIG. 1).

  As shown in FIG. 4A, the implant 12 is screwed to a position where the distal end surface of the flange portion 22 contacts the bottom surface of the first hole portion 34A. Thus, since the flange part 22 contacts the bottom surface of the first hole part 34A, the implant 12 can be embedded in the bone 32 with a desired embedding depth (screwing depth). Accordingly, it is possible to prevent the implant 12 from being excessively embedded in the bone 32. As shown in FIG. 4A, the top surface 18a of the joint contact portion 18 and the top surface 30b (surface) of the cartilage 30 are preferably at the same height in a state where the implant 12 is embedded in the bone 32.

  There is a space between the implant 12 (specifically, the portion closer to the joint contact portion 18 than the bone fixing portion 16) and the inner surface of the hole 34 (specifically, the inner peripheral surface of the first hole portion 34A). P is formed. As will be described later, the space P functions as a flow path for circulating the bone marrow fluid M.

  As shown in FIG. 7, the end surface 22a on the joint contact portion 18 side of the flange portion 22 is located on the deeper side of the bone 32 than the opening of the hole 34 (opening of the first hole portion 34A). The depth T2 of the first hole portion 34A is larger than the thickness T1 of the flange portion 22. In the hole forming step described above, such a hole 34 is formed.

  That is, in the hole forming step, when the bone fixing portion 16 is embedded in the bone 32 in the embedding step (FIG. 4A), the end surface 22a on the joint contact portion 18 side of the flange portion 22 is more than the opening position of the hole 34. The hole 34 is formed so as to be located on the deep side of the bone 32. As described above, since the inner diameter D3 (see FIG. 3B) of the first hole portion 34A is larger than the outer diameter D1 (see FIG. 2) of the flange portion 22, the space P is formed between the outer peripheral surface of the flange portion 22 and the first outer surface. It includes a space P1 formed between the inner peripheral surface of the hole 34A.

  As shown in FIG. 8, the inner diameter of the first hole portion 34 </ b> A may be substantially the same as the outer diameter of the flange portion 22. In this case, it is necessary to expose the inner peripheral surface of the first hole portion 34A so that the space P appropriately exhibits the function as the flow path of the bone marrow fluid M. For this reason, the distance L3 (depth of the space P) between the opening of the first hole portion 34A and the base end surface of the flange portion 22 (end surface 22a on the implant side engagement portion 20 side) is, for example, 0.3 to 5 mm. Is set, preferably 1 to 3 mm. Moreover, the distance W1 (width of the space P) between the inner peripheral surface of the first hole portion 34A and the outer peripheral surface of the implant-side engagement portion 20 is set to, for example, 0.3 to 5 mm, preferably 1 to 2 mm. Is set.

  Alternatively, as shown in FIG. 9, the implant 12 may not have the flange portion 22. In this case, the distance L4 (depth of the space P) between the opening of the first hole portion 34A and the most distal position of the implant side engaging portion 20 may be set to be equal to or greater than the distance L3 (FIG. 8) described above. In addition, the distance W2 (the width of the space P) between the inner peripheral surface of the first hole portion 34A and the outer peripheral surface of the implant-side engagement portion 20 may be set to be equal to or greater than the above-described distance W1.

  Reference is again made to FIG. 4A. As shown in FIG. 4A, in the cartilage defect portion 30a, adjacent implants 12 (implant-side engagement portions 20) are separated by a distance S (interval). Accordingly, a space R1 is formed between adjacent implants 12 in the cartilage defect 30a. The space R1 is a part of the space R around the implant 12 in the cartilage defect 30a. The space R1 communicates with a space P formed between the inner peripheral surface of the first hole 34A and the outer peripheral surface of the implant 12.

  When the implant 12 is embedded in the bone 32 in this manner, the operator closes the incision portion of the patient and finishes the procedure for the implantation. Then, the implant 12 is placed in the bone 32 for a predetermined period. While the implant 12 is placed in the bone 32, as shown in FIG. 4B, the joint contact portion 18 receives a load F from a portion (bone 38 and cartilage 40) facing the bone 32 in which the implant 12 is embedded. Thereby, since the bone 38 and the cartilage 40 which oppose the bone 32 do not contact, a patient can operate a daily life using a joint. In particular, when the application site of the implant 12 is a knee joint, the patient can walk immediately after the operation.

  On the other hand, during indwelling, as shown in FIG. 4B, the bone marrow fluid M (cells and nutrient factors) leaches out from the inner surface of the hole 34 (the inner peripheral surface of the first hole 34A). The bone marrow fluid M flows in the space P between the inner peripheral surface of the first hole 34A and the outer peripheral surface of the implant 12, and the space R around the implant 12 in the cartilage defect 30a. For this reason, the repair tissue 42 is formed in these spaces P and R as shown in FIG. 5A (first tissue formation step). In this case, the surface 42 a of the repair tissue 42 is flush with the top surface 18 a of the joint contact portion 18. The predetermined period during which the implant 12 is placed is longer than the period necessary for the exuded bone marrow fluid M to become a repaired tissue 42 stabilized as a tissue.

  After the implant 12 is placed in the bone 32 for a predetermined period, the operator removes the implant 12 from the bone 32 (extraction step). Specifically, as shown in FIG. 5B, the surgeon covers the joint contact portion 18 and the implant side engagement portion 20 of the implant 12 with a jig side engagement portion 28 provided at the distal end portion of the jig 14. (Jig connection step). Thereby, a plurality of engagement ribs 28b (see FIG. 1) provided in the jig-side engagement portion 28 are inserted into a plurality of engagement grooves 20a (see FIG. 1) provided in the implant-side engagement portion 20. It will be in the state. Further, when the jig side engaging portion 28 is put on the joint contact portion 18 and the implant side engaging portion 20, the jig side engaging portion 28 is inserted into the repair tissue 42.

  Next, the surgeon operates the jig 14 so that a force for removal is applied to the implant 12 via the jig 14 (jig operation step). Specifically, the jig 14 is rotated and rotated in the direction opposite to that when the implant 12 is screwed into the bone 32. As a result, the implant 12 is extracted from the bone 32, and an extraction hole 44 (implant embedment mark) is formed in the bone 32 and the repair tissue 42 as shown in FIG. 6A.

  In this case, as the implant 12 is removed using the jig 14, the repaired tissue 42 is partially destroyed by the jig 14. That is, as shown in FIG. 6A, a hole 44 a having an inner diameter substantially equal to the outer diameter of the flange portion 22 of the implant 12 is formed in the repair tissue 42. The hole 44 a constitutes a part of the extraction hole 44. When the implant 12 is removed from the bone 32 in this manner, the operator closes the patient's incision and finishes the procedure for removal.

  In the initial stage after the implant 12 is removed from the bone 32, as shown in FIG. 6A, the repaired tissue 42 receives a load F from the opposite site (bone 38 and cartilage 40) side. Since the repaired tissue 42 is stabilized as a tissue and has an appropriate strength, the load F can be favorably supported even in the absence of the implant 12, and the patient does not feel discomfort such as pain.

  In addition, after the implant 12 is removed from the bone 32, the bone marrow fluid M is leached from the bone 32 into the removal hole 44 as shown in FIG. 6A. As a result, the tissue of the bone marrow fluid M is eventually stabilized, and a repaired tissue 46 is formed in the extraction hole 44 as shown in FIG. 6B (second tissue formation step). As described above, the repaired tissues 42 and 46 are sequentially formed in the cartilage defect portion 30a, whereby the treatment of the cartilage defect is completed.

  As described above, according to the implant system 10, the hole 34 is formed in the bone 32 located in the cartilage defect portion 30 a, the bone fixing portion 16 of the implant 12 is embedded in the hole 34, and the inner surface of the hole 34 and the implant 12 are formed. The bone marrow fluid M can be leached into the space P between the two and the repaired tissue 42 can be formed in the cartilage defect 30a. Then, after the repair tissue 42 is formed, the implant 12 is extracted using the jig 14, and the bone marrow fluid M is leached into the extracted portion (extraction hole 44), thereby forming the repair tissue 42 in the extraction hole 44. be able to. Therefore, the patient can use the joint immediately after the operation and can treat the cartilage defect without leaving a foreign body in the body. In particular, when the treatment site for the cartilage defect is the knee joint, the patient can walk immediately. Further, since the outer diameter of the jig side engaging portion 28 is equal to or smaller than the outer diameter of the flange portion 22, the repair tissue 42 that is removed when the implant 12 is removed can be reduced as much as possible.

  In the hole forming step described above, the hole 34 having a T-shaped cross section is formed. However, the bone tissue is relatively soft, and there is no problem in screwing the implant 12 even without a pilot hole for screwing. In some cases, as shown in FIG. 10A, the hole 48 may be formed only in the surface layer portion of the bone 32. The hole 48 in this case is formed in the same shape and size as the first hole portion 34A of the hole 34 having a T-shaped cross section shown in FIG. 3B. In the embedding step, the implant 12 is screwed directly from the bottom surface of the hole 48 as shown in FIG. 10B. Thereby, the implant 12 can be embedded in the bone 32.

  The implant system 10 may further include a notch forming device 50 shown in FIG. The notch forming device 50 has an annular blade 52 at the tip. The blade portion 52 is configured to form a cut 62 (see FIG. 12) for inserting the jig side engaging portion 28 into the repair tissue 42 formed in the cartilage defect portion 30a. In FIG. 11, the blade part 52 is comprised by the annular | circular shape. The outer diameter of the blade part 52 is set to be substantially the same as the outer diameter of the jig side engaging part 28.

  The notch forming device 50 further includes a body 54 and a positioning mechanism 56. The blade 52 described above extends from the tip of the body 54 in the tip direction (downward in FIG. 11). The body 54 is a hollow body, and a positioning mechanism 56 is disposed inside the body 54. The positioning mechanism 56 is configured to align the center of the blade portion 52 and the flange portion 22 of the implant 12 by contacting the joint contact portion 18.

  Specifically, the positioning mechanism 56 includes a positioning member 58 that is provided with a recess 58a that conforms to (corresponds to) the curved shape of the top surface 18a of the joint contact portion 18, and that can slide in the axial direction with respect to the body 54. And an urging member 60 that elastically urges 58 in the distal direction. Although not shown in detail, the positioning member 58 is prevented from coming off from the body 54 in the distal direction by the retaining structure.

  The positioning member 58 is supported by the inner peripheral surface of the body 54. In the initial state of the notch forming device 50 shown in FIG. 11, the distal end of the positioning member 58 is positioned in the distal direction relative to the blade portion 52.

  The urging member 60 is disposed between the positioning member 58 and a surface 54 a facing the base end surface 58 b of the positioning member 58 inside the body 54. In FIG. 11, the urging member 60 has a form of a coil spring. The urging member 60 only needs to have a function of elastically urging the positioning member 58 in the distal direction, and is not limited to the form of a coil spring. The biasing member 60 may be a member made of an elastic material such as a rubber material, or may have a form of an air spring.

  The notch forming device 50 configured in this way can be used between the first tissue forming step described above and the removal step using the jig 14. In this case, specifically, the operator uses the annular blade portion 52 provided in the incision forming device 50 between the first tissue forming step and the removal step, as shown in FIG. A cut is formed in the repaired tissue 42 formed in the forming step (cut forming step).

  By performing the notch forming step, the notch 62 can be made in advance in the repaired tissue 42 surrounding the joint contact portion 18 and the implant side engaging portion 20. For this reason, when covering the implant side engaging part 20 with the jig side engaging part 28 in order to extract the implant 12, the jig side engaging part 28 is inserted into the repair tissue 42 along the cut 62. . Thereby, it can suppress that the repair structure | tissue 42 destroys (crushes).

  In this case, the notch forming device 50 is provided with a positioning mechanism 56. For this reason, when the positioning member 58 comes into contact with the joint contact portion 18, the blade portion 52 is caused by the engagement between the top surface 18 a having the curved shape of the joint contact portion 18 and the concave portion 58 a provided in the positioning member 58. Then, center alignment with the flange portion 22 of the implant 12 is performed. Then, in a state where this center alignment is performed, the blade portion 52 is inserted into the repair tissue 42, and a cut 62 is formed. At this time, the positioning member 58 is displaced in the proximal direction within the body 54 against the elastic biasing force of the biasing member 60.

  Such a positioning mechanism 56 makes it possible to accurately form a cut in the repaired tissue 42.

  An implant system 10a according to the second embodiment shown in FIG. 13 includes an implant 12a and a jig 14a. The implant-side engagement portion 20 is provided with a locking recess 20b that is recessed in the circumferential direction. The locking recess 20b is provided in each of the plurality of engaging grooves 20a. Each locking recess 20 b communicates with the engagement groove 20 a and is recessed in a direction in which the implant 12 a is rotated in order to remove the implant 12 a from the bone 32.

  Each locking recess 20b is provided at an end portion (position adjacent to the flange portion 22) of the implant side engaging portion 20 on the flange portion 22 side. In addition, each latching recessed part 20b may be provided in the axial direction intermediate position in the implant side engaging part 20 (position spaced apart from the flange part 22 to the joint contact part 18 side). The structure of the other part of the implant 12a is the same as that of the implant 12 of 1st Embodiment mentioned above.

  The jig-side engaging portion 28 of the jig 14a is provided with a protruding portion 28c that protrudes in the direction in which the jig 14a is rotated in order to remove the implant 12 from the bone 32. The protrusion 28c is provided on each of the plurality of engagement ribs 28b (see also FIG. 1). That is, a plurality of protruding portions 28c are provided at intervals in the circumferential direction. The plurality of protrusions 28c can be inserted into the plurality of locking recesses 20b, respectively. The width of the engagement rib 28b is set so that the engagement rib 28b can move in the circumferential direction within the engagement groove 20a because the protrusion 28c is detached from the locking recess 20b in the circumferential direction.

  In FIG. 13, each protrusion 28c is provided at the tip of each engagement rib 28b. In addition, when each latching recessed part 20b is provided in the axial direction intermediate position in the implant side engaging part 20, each protrusion 28c is provided in the axial direction intermediate position of each engaging rib 28b. The other parts of the jig 14a are configured in the same manner as the jig 14 of the first embodiment described above.

  When treating the cartilage defect using the implant system 10a according to the second embodiment configured as described above, the surgeon performs the procedure from the hole formation step in the same manner as the implant system 10 according to the first embodiment described above. Each step up to two tissue formation steps can be performed. In this case, in the removal step, the operator applies torque to the implant 12a by the jig 14a in order to remove the implant 12a from the bone 32, and the protrusion 28c to the implant-side engagement portion 20 (locking recess 20b). The jig 14a is pulled in the proximal direction in the hooked state (the state shown in FIG. 13).

  Thereby, when extracting the implant 12a from the bone 32, since the implant 12a can be rotated while being pulled, damage to the bone tissue due to the screw thread 16b can be suppressed. Alternatively, although the implant 12a is rotated to remove the implant 12a from the bone 32, the screw thread (bone) of the inner peripheral portion of the portion where the bone fixing portion 16 is embedded by the screw 16b of the bone fixing portion 16 When the screw thread 32 on the side 32 is broken, the implant 12a can be reliably removed from the bone 32 by rotating the implant 12a while pulling.

  In addition, about the part which is common in 1st Embodiment among 2nd Embodiment, the same or similar operation | movement and effect as 1st Embodiment are acquired.

  The present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 10, 10a ... Implant system 12, 12a ... Implant 14, 14a ... Jig 16 ... Bone fixing part 18 ... Joint contact part 20 ... Implant side engaging part 20a ... Engaging groove 20b ... Locking recessed part 22 ... Flange part 28 ... Jig side engaging portion 28b ... engaging rib 28c ... projecting portion 50 ... notch forming device 56 ... positioning mechanism

Claims (12)

An implant system comprising an implant configured to be inserted into a bone of a living body, and a jig for removing the implant from the bone,
The implant is
A bone anchor configured to be inserted and secured to the bone;
A joint contact portion configured to contact a portion of the joint facing the bone to which the implant is fixed;
An implant-side engaging portion that is provided between the bone fixing portion and the joint contact portion and configured to be able to engage with the implant in order to remove the implant by the jig;
A flange portion provided between the bone fixing portion and the implant side engaging portion, projecting outward from the bone fixing portion and the implant side engaging portion, and contacting the bone;
The jig has a cylindrical jig side engaging portion that can be engaged with the implant side engaging portion in a state of covering the implant side engaging portion in order to remove the implant.
The outer diameter of the jig side engaging portion is equal to or smaller than the outer diameter of the flange portion.
An implant system characterized by that. The implant system according to claim 1.
Further comprising an incision forming device having an annular blade portion configured to form an incision for inserting the jig side engaging portion in a repair tissue formed in a cartilage defect portion;
An implant system characterized by that. The implant system according to claim 2, wherein
The notch forming device has a positioning mechanism that performs center alignment of the blade portion and the flange portion by contacting the joint contact portion.
An implant system characterized by that. The implant system according to any one of claims 1 to 3,
A screw thread is provided on the outer peripheral portion of the bone fixing portion,
In the jig side engaging portion, the implant side engaging portion is configured not to be detached from the implant side engaging portion when torque is applied to the implant by the jig to remove the implant from the bone. Protrusions that are hooked on are provided,
An implant system characterized by that. An implant including a bone fixing unit configured to be inserted into and fixed to a bone and a joint contact unit configured to contact a portion facing the bone in which the implant is fixed in a joint is used. A method for treating cartilage defects,
A hole forming step for forming a hole in the bone located in the cartilage defect;
Implanting the bone anchoring portion of the implant into the bone through the hole to leave an exposed portion of the inner surface of the hole;
A first tissue formation step of leaching bone marrow fluid from the inner surface of the hole to form a repaired tissue around the joint contact portion in the cartilage defect;
An extraction step of removing the implant from the bone after the repair tissue is formed;
A second tissue formation step of leaching bone marrow fluid from the bone into an extraction hole formed by extracting the implant to form a repaired tissue in the extraction hole, and
A method for treating cartilage defects characterized by the above. The method for treating a cartilage defect according to claim 5,
In the hole forming step, when the bone fixing portion is embedded in the bone in the embedding step, between the inner peripheral surface of the hole and the outer peripheral portion of the implant facing the inner peripheral surface, Forming the hole so that a space communicating with the cartilage defect is formed;
A method for treating cartilage defects characterized by the above. The method for treating a cartilage defect according to claim 5,
The implant has a flange portion provided between the bone fixing portion and the joint contact portion and projecting outward from the bone fixing portion and the joint contact portion,
In the hole forming step, when the bone fixing portion is embedded in the bone in the embedding step, the end surface on the joint contact portion side of the flange portion is deeper than the opening position of the hole. Forming the hole so as to be located in the
A method for treating cartilage defects characterized by the above. The method for treating a cartilage defect according to claim 5,
The extraction step includes
The repaired tissue formed in the first tissue formation step is partially destroyed with a jig, and the implant side engaging portion provided between the bone fixing portion and the joint contact portion is treated with the healing. A jig connecting step that is covered by a cylindrical jig side engaging portion provided on the tool;
A jig operation step for operating the jig so that a force for removal is applied to the implant through the jig,
A method for treating cartilage defects characterized by the above. The method for treating a cartilage defect according to claim 8,
The implant has a flange portion that is provided between the bone fixing portion and the joint contact portion and protrudes outward from the implant side engagement portion,
The outer diameter of the jig side engaging portion is equal to or smaller than the outer diameter of the flange portion.
A method for treating cartilage defects characterized by the above. The method for treating a cartilage defect according to claim 8,
Incision formation that forms an incision in the repaired tissue formed in the first tissue formation step by an annular blade provided in the incision formation device between the first tissue formation step and the extraction step Has steps,
In the jig connecting step, the jig side engaging portion is inserted into the cut.
A method for treating cartilage defects characterized by the above. The method for treating a cartilage defect according to claim 10,
The implant has a flange portion that is provided between the bone fixing portion and the joint contact portion and protrudes outward from the implant side engagement portion,
In the notch forming step, the positioning of the blade part and the flange part is performed by a positioning mechanism provided in the notch forming device.
A method for treating cartilage defects characterized by the above. The method for treating a cartilage defect according to claim 9,
A screw thread is provided on the outer peripheral portion of the bone fixing portion,
The jig side engaging portion is provided with a protruding portion that protrudes in a direction in which the jig is rotated to remove the implant from the bone,
In the extraction step, torque is applied to the implant by the jig in order to extract the implant from the bone, and the jig is pulled in a state where the protrusion is hooked on the implant side engagement part.
A method for treating cartilage defects characterized by the above.

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