KR102443253B1 - Patient-Specific Pin Guide for Total Knee Arthroplasty for Minimally Invasive Total Knee Arthroplasty - Google Patents

Abstract

The present invention relates to a patient-specific pin guide that can be easily seated in the tibia region without interference with the patellar tendon and soft tissue during total arthroplasty of an artificial knee joint using a minimally invasive surgical method. A patient-specific pin guide for a minimally invasive total arthroplasty procedure of an artificial knee joint according to the present invention comprises: a functional body portion with a pin insertion portion formed on one side of the outer surface; an inner plateau contact portion connected to the functional body and contacting the inner plateau portion of the tibia; a protuberance inner contact portion formed to protrude from one side of the inner surface of the functional body portion to a certain thickness so that a portion of the functional body portion is located on the edge, and in contact with the inner region from the upper protuberance of the tibia; an inner spur contact portion formed to extend to one side of the protuberance inner contact portion while having a thinner thickness than the protuberance inner contact portion, in contact with the spur located in the inner front of the tibia in the form of surrounding the spur, and having a separate space, through which soft tissue can pass, formed between the outer surface and the inner surface of the functional body; and an alignment shaft insertion portion which is formed on the outer surface of the functional body portion and into which an alignment shaft is inserted to check the mechanical axis of the tibia.

Description

Patient-Specific Pin Guide for Total Knee Arthroplasty for Minimally Invasive Total Knee Arthroplasty

The present invention relates to a patient-customized pin guide used in total knee arthroplasty, and more particularly, to be easily seated on the tibia without interference with the patellar tendon and soft tissues during total knee arthroplasty to which minimally invasive surgery is applied. It relates to a patient-specific pin guide for a minimally invasive total knee arthroplasty that can be performed.

Total knee arthroplasty is a surgical procedure that started in earnest in the early 1970s. When the knee joint is no longer able to carry out normal daily activities due to various diseases or trauma, and does not respond to drug therapy or physical therapy as the disability worsens. By replacing artificial joints made of special alloys and polymer materials for patients who cannot be resolved by other treatment methods, normal gait is possible and pain is relieved, while at the same time gaining stability and correcting deformity of the deformed knee joint enables daily life surgery that makes

Such total knee arthroplasty is being actively performed for patients who have difficulty in daily life due to worn-out knee joints. During surgery, damaged parts of the femur, tibia, and patella that form the knee joint are removed, and an artificial joint is replaced to enable normal gait and daily life without pain.

Meanwhile, in recent total knee arthroplasty, minimally invasive surgery that minimizes the patient's surgical incision site, reduces postoperative pain and complications, and enables rapid recovery according to the patient's early behavior has been widely applied.

In other words, Minimal-Invasive Surgery (MIS) is a surgical method that leaves minimal scars on the human body by reducing the incision area during surgery. It has advantages such as quick recovery, short hospital stay, and less blood loss.

However, when performing total knee arthroplasty by applying minimally invasive surgery (MIS), there are many difficulties when the operation is performed using the existing patient-specific instrument (PSI). In other words, it is difficult to perform surgery by abducting the patella due to the small skin incision following minimally invasive surgery. difficult.

In addition, in the process of seating the patient-specific surgical instrument (PSI) on the tibia, interference with the patella tendon and surrounding soft and skin tissues may occur, and the surgical field of view may be narrowed due to a small skin incision. Several obstacles can make it difficult to settle in.

For this reason, the area of the contact part of the patient-customized surgical instrument in contact with the tibia is very limited, and it is unstablely seated on the bone surface, so there is a problem with many difficulties in implementing its function.

Korean Patent Registration No. 10-2143842 (2020.08.06)

The present invention has been devised to solve the above problems, and the technical problem to be solved in the present invention is that when total knee arthroplasty is performed using minimally invasive surgery, the operation can be performed without abduction of the patella, and the patella The purpose of this invention is to provide a patient-specific pin guide for minimally invasive total knee arthroplasty that can be stably seated on the tibia without interference with tendons and skin tissue, etc.

A patient-tailored pin guide for a minimally invasive total knee arthroplasty procedure according to the present invention for solving the above technical problem includes: a functional body portion having a pin insertion portion formed on one side of the outer surface; an inner high flat portion contacting portion connected to the functional body portion and contacting the inner flat portion of the tibia; a protruding inner contact part protruding to a predetermined thickness on one inner surface of the functional body so that a portion of the functional body part is located outside the upper part of the tibia and contacting the inner region from the upper part of the tibia; While having a thinner thickness than the inner contact portion of the raised protrusion, it is extended to one side of the inner contact portion of the raised bone to contact the bone spur located in front of the inner side of the tibia. a medial osteophyte contact; It is formed on the outer surface of the functional body portion and the alignment shaft insertion portion for confirming the mechanical axis of the tibia is inserted; characterized in that it comprises a.

Here, the functional body portion located outside the raised upper inner contact portion may be formed to have a distance of 10 mm or more from the surface of the tibia.

In addition, an intaglio for cutting in the form of an intaglio may be formed on one side of the contacting part of the inner high flat part.

In this case, the intaglio for cutting may be cut using an osteotomy instrument when the patient-customized pin guide is removed.

In addition, a plurality of contact protrusions protruding downwardly and contacting the cortical bone of the medial plateau of the tibia may be formed in the contact portion of the inner plateau.

In this case, the contact protrusion may have a conical shape and be positioned at a portion where the cartilage defect of the inner plateau is generated to be in point contact with the cortical bone of the inner plateau of the tibia.

In addition, the medial osteophyte contact portion is formed to extend to the lower region of the osteophyte located in the inner front of the tibia, and may be inserted between the surface of the tibia and soft tissue to be in contact with the surface of the tibia.

And, the alignment shaft insertion portion may be formed to protrude from the outer surface of the functional body portion positioned on the ridge of the tibia.

In this case, an opening may be formed at the front side of the alignment shaft insertion part.

According to the patient-specific pin guide structure for the minimally invasive total knee arthroplasty procedure of the present invention, when performing total knee arthroplasty using the minimally invasive surgical method, the treatment can be performed without abduction of the patella. There is an advantage in that it can be operated without interference with the patellar tendon or surrounding skin and soft tissues, and can be easily operated by being seated in a stable structure on the tibia to be treated.

In addition, by configuring the alignment shaft insertion part to check the alignment state on the front side of the pin guide, after the pin guide is seated in the tibia, the alignment shaft is inserted into the insertion part to easily check the alignment state of the pin guide with the naked eye. There is this.

In addition, since the front side of the alignment shaft insertion unit is formed in an open structure, even when the alignment shaft is repeatedly inserted into the alignment shaft insertion unit, it is possible to prevent the alignment shaft insertion unit from being easily damaged.

In addition, in the case of the existing pin guide, it was possible to check the alignment state of the pin guide using two mechanisms, an alignment handle and an alignment shaft, but the present invention provides convenience to check the mechanical axis of the tibia using only one alignment axis. There is an advantage that

In addition, by forming an intaglio for cutting that can separate the contact part of the tibial plateau and the functional body part, after fixing the pin using a pin guide to the tibia, when removing the pin guide, the intaglio for cutting part is osteotomy ( Since it can be easily separated by cutting it using a tool for osteotomy, it has the advantage of making it very easy to remove the pin guide even in a narrow space.

In addition, by forming a plurality of conical contact protrusions that protrude downward as much as the thickness of the cartilage in the contact portion of the inner plateau of the tibia and make point contact with the surface of the inner flat portion of the tibia, the contact protrusion is compensated for as much as the thickness of the cartilage lost in the tibial plateau. Even if there is no connection defect, the contact protrusion digs as much as the thickness of the cartilage and is supported by making point contact with the cortical bone.

In addition, by forming the thickness and width of the medial osteophyte contact part of the pin guide to have a shape that gradually becomes thinner toward the lower side and the medial direction of the tibia, the medial osteophyte contact part naturally penetrates into the space between the bone and the skin tissue and is applied to the surface of the medial side surface of the tibia. It has the advantage of being easily mounted.

In addition, by forming the end of the medial bone spine contact portion of the pin guide facing in the medial direction of the tibia not to exceed the point of curvature inflection point (about 90 degrees in the medial direction with respect to the anterior cruciate ligament) at which the outer surface curvature of the tibia is changed to the maximum, the pin guide It is possible to prevent the problem that the removal of the pin guide is difficult because the medial bone spur contact part is caught at the inflection point of curvature when removing can do.

1 is a comparative view showing a comparison between the incision according to the conventional method and the minimally invasive surgical method of the present invention during total knee arthroplasty.
Figure 2 is a perspective view showing a patient-customized pin guide structure of the present invention used for minimally invasive surgery in total knee arthroplasty.
Figure 3 is a plan view of the pin guide of Figure 2 viewed from the top.
Figure 4 is a perspective view of the pin guide of Figure 2 viewed from the inside.
5 and 6 are exemplary views showing a state in which the pin guide of the present invention is inserted into the skin incision and seated on the tibia.
Figure 7 is a perspective view showing a comparison of the area in which the pin guide of the present invention and the pin guide of the present invention is in contact with the tibia.
8 is a plan view of the pin guide seated on the tibia as viewed from above.
9 is a cross-sectional view showing a state in which the pin guide is seated on the bone surface without interference with the patellar tendon and soft tissue through the separation space formed in the pin guide.
Figure 10 is an exemplary view for explaining the length of the raised medial contact portion and the medial osteophyte contact portion in contact with the tibial surface.
11 is a cross-sectional view showing a state in which the contact protrusion of the medial plateau contact portion is supported by making point contact with the medial plateau portion of the tibia in which the cartilage is lost.
Figure 12 is an exemplary view illustrating a state in which the height and the front and rear width of the contact portion of the medial high flat portion for preventing interference with the rear part of the femur are reduced.
13 is an exemplary view showing the state of cutting and separating the intaglio part for cutting through the instrument for osteotomy when the pin guide fixed to the tibia is separated.
14 and 15 are exemplary views showing the state of confirming the alignment state of the pin guide through the alignment shaft inserted into the alignment shaft insertion portion of the pin guide.

Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those of ordinary skill in the art can easily carry out the present invention.

However, the present invention may be implemented in several different forms and is not limited to the embodiments described herein. In addition, it is to be noted that throughout the detailed description, parts denoted by the same reference numerals mean the same components.

Hereinafter, a patient-specific pin guide structure for a minimally invasive total knee arthroplasty procedure according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

First, FIG. 1 shows a comparison of the skin incision by the conventional conventional method and the skin incision by the minimally invasive surgical method of the present invention during total knee arthroplasty.

As mentioned earlier, when performing knee arthroplasty by applying the Minimal-Invasive Surgery (MIS) method, the patient's recovery time is fast and the patient's recovery time is fast and hospitalization is The period is shortened and the blood loss is small.

In addition, since the operation is performed with only about 60 to 70% of the skin incision of the conventional conventional surgical method (Fig. ) is difficult, and interference with the patellar tendon 40 and soft tissue occurs a lot, and due to a small skin incision, the surgical field of view is narrowed because the high flat part of the tibia is not exposed to the outside, and the contact area of the pin guide Since the area is limited, there may be difficulties in implementing the proper function of the pin guide.

In order to overcome various surgical difficulties due to the application of such minimally invasive surgery, the present invention devised a patient-specific pin guide suitable for minimally invasive surgery (MIS).

Hereinafter, an embodiment of the structure of the patient-customized pin guide 100 of the present invention that can be applied to minimally invasive surgery (MIS) will be described in detail.

2 to 4 specifically show the patient-specific pin guide structure of the present invention that can be used in minimally invasive surgery in total knee arthroplasty.

For reference, in the following description, the 'medial direction' refers to the medial (inner) direction of the knee, and the 'lateral direction' refers to the lateral (outer) direction of the knee where the arm is located.

2 to 4, the patient-customized pin guide 100 of the present invention used in minimally invasive surgery in total knee arthroplasty is a functional body part 110, an inner high-flat contact part 120, and an inner protrusion. The contact portion 130 , the inner bone pole contact portion 140 , and the alignment shaft insertion portion 150 are formed in the form of a single structure integrally connected to each other.

The functional body part 110 is a basic body part in the patient-customized pin guide 100 of the present invention, and a pair of insertion holes 123 and 125 into which a pin (not shown) can be inserted into one side of the outer surface. Pin inserts 124 and 126 are formed. The functional body part 110 is disposed at a position spaced apart from the surface of the tibia 20 by a certain distance without direct contact with the surface of the tibia 20 .

The inner plateau contact portion 120 is connected to the upper side of the functional body portion 110 in the form of a leg, and is in direct contact with the medial tibial plateau portion of the tibia 20 .

That is, the medial plateau contact part 120 is formed to extend toward the upper side of the functional body part 110 to make point contact with the cartilage defect occurring in the medial tibial plateau. To this end, a plurality of contact protrusions 122 that protrude downward for a predetermined distance and come into contact with the cortical bone of the medial plateau of the tibia may be formed in the inner plateau contact portion 120 .

In this case, the contact protrusion 122 may have a downwardly pointed cone shape and be formed so as to be in point contact with the cortical bone portion of the inner plateau of the tibia 20 . It is preferable that the contact protrusion 122 is designed to focus on a portion in which cartilage loss occurs relatively a lot in the inner high-flat contact portion 120 .

The raised inner contact portion 130 is a portion connected to the inner surface of the functional body portion 110 , and is a portion in direct contact with the surface of the tibia 20 . The protruding inner contact portion 130 has a predetermined thickness from one side of the inner surface of the functional body 110 and protrudes from the upper portion of the protrusion of the tibia 20 to the inner condyle region.

Here, the thickness D1 of the raised inner contact part 130 is formed to be larger than the thickness of the functional body part 110 , and the left and right widths (inner and outer direction widths) of the raised inner contact part 130 are the functional body part 110 . It is formed smaller than the left and right width. Accordingly, a portion of the functional body portion 110 has a shape structure partially drawn out in the outer direction of the tibia 20 with respect to the raised inner contact portion 130 .

Accordingly, a spaced space (SP1) surrounded by the raised inner contact portion 130 and the functional body portion 110 may be formed on the periphery of the raised inner contact part 130 . This separation space (SP1) is a space provided on the inside of the functional body part 110 with a size corresponding to the width D1 of the thickness D1 of the raised inner contact part 130, and the pin guide 100 is to be seated on the tibia 20. In this case, a portion of the incised skin tissue can pass through the separation space SP1, so that the pin guide 100 can be stably seated on the tibia 20 without interfering with the skin tissue.

In this case, the spaced space SP1 can adjust the width of the protrusion of the inner contact part 130 in order not to interfere with the incised skin tissue to adjust the width of the spaced space SP1 in the front-rear direction (front-rear direction of the tibia). have.

Here, the protruding thickness of the raised inner contact part 130 protruding from the inner surface of the functional body part 110 corresponds to the separation distance from the functional body part 110 . Accordingly, as the protruding thickness of the protruding inner contact portion 130 increases, the distance between the functional body portion 110 and the bone surface increases.

At this time, when the separation distance of the functional body part 110 spaced apart from the bone surface is 10 mm or more, since it does not receive any interference with the skin and the patellar tendon, it is preferable to form the thickness of the raised inner contact part 130 to a thickness of 10 mm or more. do.

In this way, the inner surface of the functional body part 110 forms a spaced space SP1 so as to be separated by 10 mm or more from the surface of the tibia 20, and the skin and soft tissue are positioned between the spaced space SP1. (100) can be stably fixed without interference with the skin and soft tissue.

On the other hand, the medial bone spur contact portion 140 is a portion extending a certain distance in the inner direction of the tibia 20 from one side of the raised inner contact portion 130, and the thickness of the inner bone pole contact portion 140 is the raised inner contact portion 130. It is formed to have a thinner thickness.

The medial osteophyte contact portion 140 is in contact with the surface of the tibia 20 in the form of enclosing an osteophyte located in the inner anterior portion of the tibia 20, and the thickness and width of the medial bone spur contact portion 140 is the raised inner contact portion. Since the thickness of 130 is smaller than the width, a certain spaced space SP2 is formed between the inner bone pole contact portion 140 and the functional body portion 110 . That is, a spaced space SP2 is provided between the inner surface of the functional body part 110 and the outer surface of the inner osteophyte contact part 140 , and skin and soft tissues can pass through the spaced space SP2 .

Accordingly, when the pin guide 100 is seated on the tibia 20 , the inner osteophyte contact portion 140 may be inserted between the surface of the tibia 20 and the skin and soft tissue to be in contact with the surface of the tibia. The inner bone spur contact portion 140 may be formed to extend to the lower region of the bone spur located in front of the inner side of the tibia 20 .

In addition, when the pin guide 100 is seated on the tibia 20, the more the interference with the soft tissue occurs from the front side of the tibia 20 to the inward direction, the pin guide 100 of the present invention is the inner Since the osteophyte contact portion 140 is inserted between the bone surface and the soft tissue and comes into contact with the bone surface, stable seating is possible without any interference with the soft tissue.

In this case, it is preferable that the thickness of the medial osteophyte contacting part 140 is about 3 to 4 mm so that the medial bone spur contact part 140 can be easily inserted between the bone surface and soft tissue to be in stable contact with the bone surface. do.

On the other hand, the alignment axis insertion unit 150 is a configuration provided to confirm the patient's tibial mechanical axis, and a predetermined length forward to the portion adjacent to the pin insertion units 124 and 126 in the functional body unit 110 . It has a protruding structure.

Specifically, the alignment shaft insertion part 150 is located on the outer surface of the functional body part 110 located in the condyle part of the tibia, and the alignment shaft insertion part 150 is aligned to check the mechanical axis of the tibia. An insertion hole 152 having a vertically penetrating shape into which the axis AR is inserted is formed.

In this case, as shown in FIG. 15 to be described later, the lower end end of the alignment shaft AR inserted into the alignment shaft insertion unit 150 is attached to the second toe or the back of the foot of the patient's ankle joint 60 as shown in FIG. designed to be located.

In addition, an opening 154 is formed on the front side of the insertion hole 152 so that a part of the insertion hole 152 is opened to the front side. Due to the formation of the opening 154 as described above, when the alignment shaft AR is repeatedly inserted into the insertion hole 152 of the alignment shaft insertion part 150, it is possible to prevent the insertion part from being damaged.

At this time, in the embodiment of the present invention, as shown in FIG. 14 to be described later, the width of the alignment shaft insertion part 150 connected to the functional body part 110 is 12 mm, the height is formed to be 10 mm or more, and the opening 154 is The width was formed to be 3 mm or more.

In this way, by inserting the alignment axis (AR) into the alignment axis insertion unit 150 in a state where the pin guide 100 is seated on the tibia, it is determined whether the lower end of the alignment axis AR is positioned on the patient's second toe. By checking, it is possible to easily check with the naked eye whether the pin guide 100 is fixed in place.

In the case of the alignment shaft insertion part structure employed in the existing pin guide, there was a lot of trouble in the confirmation process of the alignment shaft because two mechanisms, an alignment handle and an alignment shaft, were required, but the present invention used for minimally invasive surgery In the structure of the pin guide 100, if there is only one alignment axis (AR) by reducing it by one step, it is convenient to check the mechanical axis of the tibia very easily.

On the other hand, after the pin guide 100 of the present invention is seated on the tibia 20, the pin P is inserted to fix the pin P to the tibia 20, and after bone cutting is performed, the pin guide 100 is removed. When separated from the tibia 20 again, since there is a rear inclination angle in the inner high flat portion contact portion 120, it may be difficult to separate the pin guide 100 by pulling it out in the direction of the pin.

For this reason, in the pin guide 100 of the present invention, when the pin guide 100 is removed from the tibia, an intaglio for cutting can be easily cut between the functional body portion 110 and the inner high flat portion contact portion 120 ( 160) is formed.

That is, an intaglio portion 160 for cutting processed in the form of an intaglio groove is formed on the inner high flat portion contact portion 120 that is a certain distance away from the connection point between the functional body portion 110 and the inner high flat portion contact portion 120 . By cutting the intaglio part 160 for cutting using a cutting tool, the inner high flat part contact part 120 can be separated from the functional body part 110 .

In this case, the intaglio portion 160 for cutting is the circumferential surface of the inner high flat portion contact portion 120 so that it can be easily cut using the blade of the instrument 170 for osteotomy as shown in FIG. 13 to be described later. It can be processed in the form of an intaglio groove of a certain depth formed along the .

Therefore, when removing the pin guide 100 seated on the tibia 20, the intaglio portion 160 for cutting is cut using the blade of the instrument for osteotomy 170 to cut the inner high flat portion contact portion 120. It can be easily separated from the functional body part 110, and the functional body part 110 part in a state in which the inner high flat part contact part 120 is separated is pulled out in the opposite direction to the pin (P) insertion direction from the tibia 20 can be easily separated.

Meanwhile, FIGS. 5 and 6 show a state in which the patient-specific pin guide of the present invention is inserted between the skin incised by minimally invasive surgery and is seated on the tibia. And, Figure 7 shows a comparison of the area in which each contact portion of the conventional pin guide and the pin guide of the present invention is in contact with the tibia surface. 8 is a view from the top of the pin guide seated on the tibia, and FIG. 9 shows the pin guide seated on the bone surface without interfering with the patellar tendon and soft tissue through the separation space formed in the pin guide. .

In total knee arthroplasty, the pin guide used in the conventional surgical method has a large and wide medial frontal contact area that comes into contact with the medial frontal surface of the tibia. There was a disadvantage that it was not suitable for the minimally invasive surgery (MIS) method, which had a lot of interference between the lateral plateau, the patella, and the patellar tendon, because the contact part that came into contact with the minor part was wide.

That is, the pin guide applied to the conventional conventional surgical method, as shown in FIG. It had a form of being seated on the tibia through the lower anterior medial bone spine (C) and the medial and lateral contact parts (L, E) of the plateau.

In contrast, the contact portion of the pin guide 100 of the present invention used for minimally invasive surgery (MIS) starts with the upper region (A) of the tibial ridge as shown in FIG. , because only the lower part of the anterior medial bone spur (C) and the medial side of the high plateau (D) are used as contact parts, interference of the patellar tendon starting from the tibial prominence, the soft tissue and skin on the outside of the anterior tibia are avoided, so that the tibia 20 is easy to use can be firmly established.

That is, the patient-customized pin guide 100 of the present invention has a structure in which the contact portion that comes into contact with the tibia outer high flat portion is removed from the existing pin guide structure, and only the inner high flat portion of the tibia is contacted through the inner high flat portion contact portion 120 . and a spaced space (SP1) surrounded by the functional body part 110 and the raised inner contact part 130, and a spaced space SP2 between the inner osteophyte contact part 140 and the functional body part 110, so that the skin and Since it is composed in a relatively free form against soft tissue interference, it is a very suitable structure for minimally invasive surgery with a small amount of skin incision.

And, since the alignment axis insertion part 150 for checking the alignment axis (AR) has a structure that protrudes toward the front side of the functional body part 110 in the form of a handle, the pin guide 100 is seated on the tibia 20 . It is possible to easily check the alignment state of the pin guide 100 through the alignment axis AR, and there is an advantage in that the operation can be performed more conveniently.

In addition, in the case of performing artificial knee joint surgery by the conventional palliative incision method, in Fig. 1 (a), abduction of the patella, which is performed in a state in which the patella 30 is tilted in the lateral direction of the tibia 20, is generally performed. There are many, in this case, the patellar tendon (40) is stretched can have a bad effect on joint movement.

However, the present invention uses the pin guide 100 of the present invention without abducting the patella 30 when the surgery is performed using the minimally invasive method (MIS), and the pin guide is properly seated on the tibia 20 without any difficulty. It can be implemented to have

On the other hand, in general, the area where the joints contact each other is covered with cartilage (Cartilage). The same is true for the femur and tibia in the knee joint. Cartilage is also present in the Tibial plateau portion of the tibia, and when a defect occurs in the cartilage in this portion, friction occurs between the bone and the bone, resulting in pain. However, due to the characteristics of computed tomography (CT) imaging, it is impossible to identify cartilage other than bone, and it is difficult to rebuild cartilage that is missing.

For this reason, in the pin guide 100 of the present invention, as shown in FIG. 11 , a plurality of contact protrusions 122 having a conical shape on the contact surface of the medial plateau contacting part 120 in contact with the cartilage portion of the medial plateau of the tibia are provided. It can be formed to compensate for the loss of cartilage in the medial plateau region.

In this case, the contact protrusion 122 formed on the contact surface of the inner plateau contacting part 120 is more than 2-3 mm, which is the statistical cartilage thickness of the human body from the medial plateau cortical bone in consideration of the cartilage thickness of the medial plateau region that cannot be reconstructed. It may be formed with a length (thickness) that is spaced apart from each other.

As such, the contact protrusion 122 digs as much as the thickness of the cartilage and makes point contact with the cortical bone even if there is no cartilage defect in the inner plateau portion, so the inner plateau contact portion 120 is located on the cortical bone portion regardless of whether the cartilage is defective or not. It can be stably supported by contact.

And, when skin incision is made using the minimally invasive method (MIS) during total knee arthroplasty, the range of motion (R.O.M) of the patient's knee is further reduced than the conventional skin incision method, which is due to the difference in the amount of skin incision and small skin incision. It is caused by soft tissue, skin and tendon interference, and posterior osteophyte impingement of the knee joint.

As described above, when the skin incision is made by the minimally invasive method, it is difficult to secure the visual field inside the skin and the gap is narrower than the conventional incision, so in the pin guide 100 of the present invention, as shown in FIG. By reducing the direction length L and the height of the upper inclined surface 124 to a minimum, it is possible to prevent collision with the posterior condyle of the femur and the osteophyte.

On the other hand, Figure 10 shows the contact range and thickness of the raised inner contact portion 130 and the inner bone pole contact portion 140 that are in direct contact with the tibial surface in the pin guide of the present invention.

As shown in (a) of FIG. 10 , when the raised medial contact part 130 and the medial bone spine contact part 140 in contact with the tibia 20 are viewed from the top, the contact surface leading from the raised medial contact part 130 to the medial bone spine contact part 140 The range is preferably designed to come within the range of about 90 ° in the medial direction of the tibia 20 with respect to the anterior cruciate ligament region (T).

In addition, as seen from the sagittal side as shown in FIG. 10 (b), the thickness of the raised medial contact part 130 and the medial osseous pole contact part 140, in particular, the medial osseous pole contact part 140, the thickness of the tibia 20 in the medial direction And the inner bone spur contact portion 140 can be easily inserted into the space between the skin tissue and the bone to be seated in a shape that gradually decreases in thickness in the lower direction.

In addition, as shown in FIG. 9, by forming the protuberance inner contact part 130, which is the thickest part, to have a thickness of 10 mm or more in order to avoid interference with the patellar tendon and surrounding skin tissues, the inner surface of the protrusion inner contact part 130 , The patellar tendon and the skin tissue are positioned between the spaced spaces SP1 and SP2 located in the lateral direction, so that the pin guide 100 can be stably seated on the tibia surface without unreasonableness.

On the other hand, in the process of removing the pin guide 100 again after the pin guide 100 is seated on the tibia 20 and fixed with a pin, it may be difficult to remove the pin guide 100 due to the rear inclination angle. In the case shown in FIG. 13, the intaglio part 160 for cutting that is cut in the form of an intaglio groove in the inner high flat part contact part 120 connected in the form of a leg to the upper side of the functional body part 110 of the pin guide is subjected to osteotomy (Osteotomy). ) If a force is applied using the blade of the instrument 170, the inner high-flat contact part 120 is easily separated from the functional body 110, and the pin guide 100 including the inner high-flat contact part 120 is removed from the tibia. It can be easily removed.

And, after the pin guide 100 of the present invention is seated on the tibia, as shown in FIGS. 14 and 15 , the alignment axis AR is inserted into the alignment axis insertion part 150 of the pin guide 100 to the patient's tibia. In this case, it is possible to check the mechanical axis of the patient's tibia by checking whether the lower end of the alignment axis AR falls on the second toe or the back of the foot of the ankle joint 60 . That is, when the end of the alignment axis AR is located at the second toe or the top of the foot of the ankle joint, it may be determined that the pin guide 100 is fixed in place.

Although preferred embodiments of the present invention have been described above, the scope of the present invention is not limited to these specific embodiments, and those skilled in the art will appropriately change within the scope described in the claims of the present invention. This will be possible.

10: femur 20: tibia
30: patella 40: patella tendon
100: patient-customized pin guide 110: functional body part
120: inner high flat portion contact portion 122: contact protrusion
124,126: pin insert 130: raised inner contact portion
140: medial bone spur contact 150: alignment shaft insertion part
154: opening 160: intaglio for cutting

Claims (9)

Functional body portion having a pin insertion portion formed on one side of the outer surface;
an inner high flat portion contacting portion connected to the functional body portion and in contact with the inner flat portion of the tibia;
a protrusion inner contact part protruding to a predetermined thickness on one inner surface side of the functional body part so that a part of the functional body part is located on the outside, and contacting from the upper ridge of the tibia to the medial condyle region inside the tibia;
While having a thinner thickness than the raised inner contact portion, it is extended on one side of the raised inner contact portion to contact the bone spur located in the inner anterior portion of the tibia, and is in contact with the outer surface and the inner surface of the functional body. a spaced medial osteophyte contact;
It is formed on the outer surface of the functional body part, the alignment shaft insertion part into which the alignment shaft for confirming the mechanical axis of the tibia is inserted; including,
The medial osteophyte contact portion is formed to extend to the lower region of the osteophytes located in the inner front of the tibia, and is inserted between the surface of the tibia and soft tissue to contact the surface of the tibia. Patient-specific pin guides for replacement surgery.
The patient-specific pin guide for minimally invasive total knee arthroplasty according to claim 1, wherein the functional body portion located outside the protruding inner contact portion has a separation distance of 10 mm or more from the surface of the tibia.
[2] The patient-specific pin guide for a minimally invasive total knee arthroplasty procedure according to claim 1, wherein an engraved engraving portion for cutting is formed on one side of the inner high flat portion contacting portion.
[Claim 4] The patient-specific pin guide for minimally invasive total knee arthroplasty according to claim 3, wherein the intaglio for cutting is cut using an osteotomy when the patient-customized pin guide is removed.
The patient-specific pin guide for minimally invasive total knee arthroplasty according to claim 1, wherein a plurality of contact protrusions protruding downward to contact the cortical bone of the medial plateau of the tibia are formed in the contact portion of the medial plateau. .
According to claim 5, wherein the contact protrusion has a conical shape, is located in the portion where the cartilage defect occurs in the medial plateau of the tibia, the minimally invasive artificial knee joint, characterized in that the point contact with the cortical bone of the medial plateau of the tibia. Patient-specific pin guides for replacement surgery.
delete The patient-specific pin guide for minimally invasive total knee arthroplasty according to claim 1, wherein the alignment shaft insertion part protrudes from the outer surface of the functional body located at the ridge of the tibia.
The patient-specific pin guide for a minimally invasive total knee arthroplasty procedure according to claim 8, wherein an opening is formed in the front side of the alignment shaft insertion part.

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