KR20150077235A - Artificial Shoulder Joint - Google Patents

Abstract

The present invention relates to an artificial shoulder joint replacing a damaged shoulder joint, and especially, to an artificial shoulder joint which prevents an imperfect combination as a post of a humeral head is exactly inserted into the inside of the recess by which concave portions are arranged on the external circumferential surface of the post thereof at regular intervals, convex portions are provided inside a recess of a stem, the concave portions of the head are coupled to the convex portions of the recess, thus an eccentric location of the head can be adjusted. The present invention comprises: a humeral head including an upper portion having a joint surface, and including a lower portion having the post located on a rear side; and a stem which the humeral head is inserted thereinto and fixed thereto. The post comprises: a location setting portion having a central shaft eccentric from a central shaft of the upper portion, and setting a location for the stem; and a combination portion fixed to the stem. The stem comprises: a protrusion portion for setting a location of the humeral head which interacts with the location setting portion; and the recess for fixing the head into the stem by containing the combination portion.

Description

Artificial Shoulder Joint

The present invention relates to an artificial shoulder joint replacing a damaged shoulder joint. More particularly, the present invention relates to an artificial shoulder joint replacing a damaged shoulder joint by arranging concave portions at regular intervals on an outer circumferential surface of a post of a head of a humerus and placing a convex portion in the recess of the stem, The present invention relates to an artificial shoulder joint for preventing an imperfect coupling from occurring by inserting a post into a recess precisely so that an eccentric position of the head can be adjusted by engaging a protrusion of the stem.

Artificial shoulder joints are a type of artificial prosthesis that replaces the human shoulder joints. They are largely composed of a glenoid that is attached to the scapula, a humeral head that moves in contact with the joint surface of the glnoid, and a humeral stem which is implanted in a humerus and into which the head of the humerus is inserted.

However, the position and structure where the head of the humerus is joined to the shoulder bone of each person are different from each other anatomically, so that when the artificial shoulder joint is performed, it is necessary to reflect such anatomical structure well. Therefore, artificial shoulder joints are needed for the artificial shoulder joint treatment, which reflects the anatomical coupling structure of the shoulder bone and the humerus in patients requiring shoulder joint treatment.

As shown above, the artificial shoulder joint is made by inserting and fixing the glinoid into the shoulder bone, inserting the stem into the upper bone, fixing the head of the upper arm to the recess of the stem, It is practiced to induce curved contact to achieve natural shoulder motion. Therefore, if the human anatomical structure of the patient is not reflected, the joint surfaces between the glnoids inserted in the shoulder bone and the inserted upper and lower humerus heads in the stem are displaced from each other or have an unnatural curved surface contact, Which causes discomfort. Therefore, it is necessary to provide an artificial shoulder joint that allows the surgeon to adjust the positional relationship between the glnoid and the head in accordance with the surgical situation during the surgical procedure.

The following prior art documents relate to conventional artificial shoulder joints, but it is difficult to adjust the position of the head with respect to the stem, which leads to the problems of the prior art.

U.S. Patent No. 5,658,340

SUMMARY OF THE INVENTION The present invention has been conceived to solve the problems of the prior art as described above, and it is an object of the present invention to provide a method and apparatus for positioning an upper shaft of a head of a humerus by eccentrically positioning a post- The artificial shoulder joint is provided to allow the position of the face to be eccentrically adjusted.

Another object of the present invention is to provide an artificial shoulder joint which allows positioning of the post of the upper arm head and addition of a latching portion in the recess of the stem such that the articular surface of the upper arm head can be positioned at a predetermined position with respect to the stem will be.

It is a further object of the present invention to provide an apparatus and a method for controlling the position of a post such that the positioning portion of the post includes a concave portion arranged along the circumference on the outer circumferential surface of the post and the engaging portion of the stem includes the convex portion, The present invention provides an artificial shoulder joint capable of eccentrically adjusting a position of a joint surface of a head by fixing a position by an engagement and further rotating a head to select a concave portion to be coupled to the engagement portion.

Another object of the present invention is to reduce the possibility that the central angle of the concave portion of the post is larger than the central angle of the convex portion of the post so that the convex portion of the post is aligned with the convex portion of the stem and even if it is aligned, So that the concave portion of the post can be easily aligned and engaged with the convex portion of the stem by allowing the convex portion of the stem to quickly find the alignment state.

It is a further object of the present invention to provide an apparatus and a method for controlling the position of the head by uniformly adjusting the position of the head by arranging eight concave portions located around the post and arranging them at an equal angle, And to prevent the unstable coupling between the first and second protrusions by allowing the first protrusions and the protrusions of the protrusions to be easily coupled to each other.

It is a further object of the present invention to provide a method of forming a recess of a head, wherein the recess of the stem is constituted by a first recess and a second recess such that the positioning portion of the head is positioned at the first recess, The artificial shoulder joint is provided so that the position setting and the coupling of the head can be simultaneously performed.

It is a further object of the present invention to provide a method of forming a male morse taper in a second recess of a stem and a male morse taper in a joining portion of a post of the head, So that the head can be easily and firmly engaged and fixed to the stem.

       The present invention is embodied by the following embodiments in order to achieve the above object.

According to an embodiment of the present invention, the present invention includes a humeral head having an upper portion having a curved surface and a lower portion having a post positioned on a rear surface thereof, and a stem to which the upper arm head is inserted and fixed The post having a central axis eccentric in the central axis of the upper portion and having a positioning portion for establishing a position with respect to the stem and a coupling portion fixed to the stem, A latch for setting the position of the head of the upper arm, and a recess for receiving the engaging portion and fixing the head to the stem.

According to another embodiment of the present invention, the positioning portion of the post of the present invention includes a plurality of recesses arranged along the circumference on the outer circumferential surface of the post.

According to another embodiment of the present invention, the recess is formed in the center axis direction of the post.

According to another embodiment of the present invention, the present invention is characterized in that the plurality of recesses are each divided and arranged at an equal angle.

According to another embodiment of the present invention, the present invention is characterized in that the post includes a convex portion between the adjacent concave portion and the concave portion.

According to another embodiment of the present invention, the present invention is characterized in that the concave portion and the convex portion are arranged on a concentric circle having the same central axis.

According to another embodiment of the present invention, the present invention is characterized in that the central angle? 1 of the concave portion is larger than the central angle? 2 of the convex portion.

 According to another embodiment of the present invention, the present invention is characterized in that the coupling portion has a male morse taper structure.

According to another embodiment of the present invention, there is provided a surgical instrument, wherein the locking part includes a convex part protruding toward the recess, the convex part being coupled to the concave part of the positioning part to position the head of the humeral head on the stem .

According to another embodiment of the present invention, the present invention is characterized in that the recess of the stem includes a first recess in which the positioning portion is located and a second recess in which the coupling portion is located.

According to another embodiment of the present invention, the post further includes a guide portion between the positioning portion and the engaging portion, and the guide portion is inclined at the lower end of the positioning portion to lead to the upper end of the engaging portion, Is easily inserted into the recess of the stem.

According to another embodiment of the present invention, the concave portion is formed to extend to the guide portion.

According to another embodiment of the present invention, in the present invention, the first recess has a concave portion recessed outward on both sides of the convex portion, and the convex portion and the concave portion of the first recess are connected to each other by a curved surface, As shown in Fig.

According to another embodiment of the present invention, the second recess has a female Morse taper structure, which engages with the male thread of the engagement part of the post, .

According to another embodiment of the present invention, the distance r3 from the recess central axis of the stem to the apex p3 of the convex portion of the stem is greater than the distance r2 from the central axis of the post's head to the apex p2 of the convex portion of the post But is larger than the distance r1 from the central axis of the post to the vertex p1 of the concave portion of the post.

The present invention has the following effects.

SUMMARY OF THE INVENTION The present invention has been conceived to solve the problems of the prior art as described above, and it is an object of the present invention to provide a method and apparatus for positioning an upper shaft of a head of a humerus by eccentrically positioning a post- So that the position of the surface can be eccentrically adjusted.

The present invention can provide an effect that the position setting unit is added to the post of the upper arm bone head and the latching part is inserted in the recess of the stem so that the joint plane of the upper arm bone head can be positioned at a predetermined position with respect to the stem.

The present invention is characterized in that the positioning portion of the post includes a concave portion arranged on the outer circumferential surface of the post along the circumference of the post and the engaging portion of the stem includes the convex portion so that the concave portion of the positioning portion and the convex portion of the engaging portion are engaged So that the position of the joint surface of the head can be eccentrically adjusted by making it possible to select the concave portion coupled to the engaging portion by rotating the head.

The present invention reduces the possibility that the convex portion of the post is larger than the central angle of the convex portion of the post so that the convex portion of the post is aligned with the convex portion of the stem, So that the concave portion of the post can be easily aligned and engaged with the convex portion of the stem.

In the present invention, eight concave portions located on the periphery of the post are arranged at equal angles so that the position of the head can be uniformly adjusted. When the head is fixed to the stem after rotation of the head, It is possible to easily combine the convex part and the convex part so that the unstable coupling between them can be prevented.

The present invention is characterized in that the recess of the stem is constituted by the first recess and the second recess so that the positioning portion of the head is positioned at the first recess and the engagement portion of the post is positioned at the second recess, So that it is possible to simultaneously perform an engagement and an engagement of the link member.

In the present invention, a female morse taper is formed in the second recess of the stem, and a male morse taper is formed in the joining portion of the head post, so that the post of the head is inserted into the second recess of the stem So that the head can be easily and firmly engaged with and fixed to the stem.

1 is a perspective view of an artificial shoulder joint according to an embodiment of the present invention;
FIG. 2 is a reference view showing the artificial shoulder joint shown in FIG. 1; FIG.
3 is an exploded perspective view of the artificial shoulder joint shown in Fig.
FIG. 4 is a perspective view of an upper arm head of the artificial shoulder joint shown in FIG. 1; FIG.
5 is a side view of the upper arm bone head shown in Fig.
FIG. 6 is a bottom view of the upper arm bone head shown in FIG. 4;
7 is a perspective view of the stem of artificial shoulder joint shown in Fig.
8 is an enlarged perspective view of the recess of the stem shown in Fig.
FIG. 9 is a cross-sectional view taken along the line AA in FIG. 2 with the upper arm head coupled to the stem;
Fig. 10 is an enlarged view of a portion B in Fig. 2, taken along the line xx in Fig. 9. Fig.
FIG. 11 is a view showing a state in which the position of the stem is adjusted by rotating the head of the upper arm in view of the head viewed from the stem direction.

Applicants will now describe the embodiments with reference to the accompanying drawings.

The artificial shoulder joint 1 of the present invention includes a glenoid 6, a humeral head 2, a humeral stem 4, Mixed).

As shown in FIG. 2, the glyonide 6 is generally made of polyethylene (PE), preferably ultra high molecular weight polyethylene (UHMWPE), and has a joint surface 61 on one side And an engaging portion 63 which engages with a scapula on the other side. The engaging portion 63 may be formed into a threaded shape as shown or may be formed in various other shapes, though it is not shown. Such a glennoid is described in detail in U.S. Patent No. 6406495 and the like, so that further explanation will be omitted.

Referring to FIG. 4, the upper arm bone head 2 includes an upper portion 22 and a lower portion 24, and is usually made of a metal material, preferably cobalt chromium.

The upper portion 22 has a hemispherical shape as a whole and is formed with a joint surface 221 having a curved surface so as to be in contact with the joint surface of the glnoid 6 at the front. 225 are formed and are embedded at a certain depth inward to form a flat back surface 223. Here, the hemispherical shape is not limited to the hemisphere exactly, and it should be understood that the joint surface forms a curved surface.

The lower portion 24 includes a post projecting rearward from the rear surface 223 of the upper portion 22 and the post has a center axis cx2 at a position spaced apart from the center axis cx1 of the head by a distance d 4 and Fig. 6). That is, the post is eccentrically positioned by the distance d from the center of the head. The eccentricity of the post is intended to allow the head to be rotated relative to the stem and to be locked in place so as to be suitable for other human anatomy, as will be described later.

The post is protruded backward by a predetermined length from the rear surface 223 of the upper portion 22 and has a circular cross section. The post has a positioning portion 241 formed on the back surface and formed below the positioning portion 241, And a coupling portion 243.

The position setting unit 241 is vertically protruded from the back surface 223 and includes a plurality of concave portions 241a and convex portions 241b along the circumference.

The concave portion 241a is formed as a groove recessed inward in the longitudinal direction, and the inner side surface of the groove forms a curved surface and is connected to a neighboring convex portion 243. 6, each of the concave portions 241a has the same radius r1 from the center axis cx2 to the point p1 of the concave portion, and is formed in the same shape.

The convex portion 241b is formed along the circumference on a concentric circle having a radius r2 and sharing the center axis cx2, which is formed continuously at the end of the concave portion.

The number of concave and convex portions affects the procedure and the result of the operation of the head and the stem. The concave portion is arranged at a uniform angle? 1 and a convex portion at an angle? 2 with the center axis cx2 as a center. An angle? 1 +? 2 formed by one concave portion and convex portion becomes a unit of one rotation of the head. For example, if the angle of the concave portion and the convex portion is 15 degrees, 24 concave portions and convex portions are formed centering on the central axis cx2, and the unit of one rotation of the head is 15 degrees. The rotational angle, that is, the rotational position, can be adjusted. If the angle is 30 degrees, 12 concave portions and convex portions are formed, and the unit of one rotation of the head is 30 degrees, so that the rotational angle, that is, the rotational position, of the head is adjusted 12 times with respect to the stem. When the angle is 45 degrees, eight recesses and convex portions are formed, and the unit of one rotation of the head is 45 degrees, so that the rotation angle of the head can be adjusted eight times with respect to the stem. As described above, the smaller the unit of rotation, the greater the number of concave and convex portions. On the contrary, the larger the number of concave and convex portions, the smaller the number of concave and convex portions. In terms of precise positioning, the angle of the unit of rotation becomes smaller as the number increases, so that the position of the head can be set more precisely with respect to the stem 4. However, when the number of units is decreased, , The precision of the position adjustment becomes poor.

The engaging part 243 is formed on the lower side of the positioning part, and the outer surface of the engaging part 243 has a male morse taper structure. The detailed description of the morphotropic structure is omitted. Therefore, the coupling portion has a conical structure that becomes narrower toward the lower side. The engaging portion is coupled to the recess of the stem to be described later so as to be coupled to the stem, thereby facilitating the operation and convenience of the operation.

According to another embodiment of the present invention, a guide portion 245 may be additionally provided between the positioning portion and the engaging portion.

As shown in FIGS. 4 and 5, the guide portion 245 is inclined at a predetermined angle to a portion formed by inclining a certain portion of the positioning portion. When the head is inserted into the stem 4, the guide portion 245 serves to guide the port so that the port can be easily inserted into the recess of the stem. Therefore, the concave portion and the convex portion are also chamfered together to form the shape shown in Fig. 5, since the concave portion 241a and the convex portion 241b are formed by chamfering the lower end portion of the positioning portion .

7 is a perspective view of the stem. Referring to FIG. 7, the stem 4 includes a top 42 formed in a conical shape at a proximal end and a distal end 42 formed in a cylindrical shape at a distal end, (44).

The upper portion 42 has a front surface 421 formed perpendicular to the center axis cx3, and the front surface 421 has a flat surface. In addition, the upper portion 42 includes recesses 423, 425 embedded along the central axis at the front face 421. 8, the recesses 423 and 425 may include a first recess 423 embedded in the front surface 421 at a predetermined depth and a second recessed portion 423 formed at the end of the first recess, And a recess 425.

The first recess 423 is a space in which the positioning part of the post of the head is positioned as a recessed space embedded in the front surface 421 and has a convex portion 424 protruding in the radial direction toward the center axis cx3 And an insertion recess 323b having a radius r5 (see Fig. 9).

The locking recess 423a is a space defined by the convex portion 424 having the distance r3 at the vertex p3 and the concave portion 427 having the distance r4 to the vertex p4. The convex portion 424 has a vertical distance r3 from the central axis cx3 to the vertex p3, and the inner surface 424a has a curved surface, which is a portion protruding from the first recess in the direction of the central axis cx3. The concave portion 427 has a vertical distance r4 from the central axis cx3 to the vertex p4 and is formed by the inner surface 424a of the convex portion 424a As shown in Fig.

The convex portion 424 is engaged with the concave portion 241a of the post to prevent the rotation of the head. The concave portion 427 of the stem has a convex portion 241b of the post at the time of inserting the post of the head, So that it can be easily inserted into the first recess without being caught by the stem.

The insertion recess 423b is a space formed by a circle having a radius r5 on the center axis cx3 and has an inner surface 423b-1 formed continuously with the inner surface 424a of the locking sheath, The position setting portion of the post is inserted and positioned. The distance r5 is equal to or greater than the radius r2 of the convex portion of the post.

Here, the relation between the radii r1 and r2 and the distances r3, r4 and r5 is r4> r5? R2> r3> r1. 9, although the radius r2 of the convex portion of the post is smaller than or equal to the distance r5 of the first recess, the insertion may not be easy due to various foreign substances (body fluids, tissues, etc.) 2 is pulled toward the concave portion 427 of the stem 4 and inserted, the position can be easily adjusted or inserted. The concave portion 427 functions as described above.

The second recess 425 is formed as a reduced diameter by a step 426 formed on the lower side of the first recess, and its inner surface has a female morse taper structure. It is a space to combine. Therefore, when the positioning between the positioning part of the head and the first recess of the stem is performed, the head is inserted deeply into the stem so that the coupling part of the head is inserted into the second recess of the stem, .

The Applicant will now look at the working relationship of the present invention.

Referring to FIG. 10, which illustrates the process of positioning the head of the present invention relative to the stem,

11 shows an example in which twelve concave portions and convex portions are formed on the post of the stem, and one rotation unit, that is, one rotation angle? Is 30 degrees. As shown in the figure, a virtual point p5 is set on the articulating surface 221 , And the movement of the point p5 according to the rotation of the head is examined. First, as shown in Fig. 11 (1), the head is aligned with the stem so that the center axis cx2 of the post, which is the lower part of the head 2, coincides with the center axis cx3 of the recess of the stem. Then, the head is rotated by a desired angle to position it, and then the concave portion 241a of the post of the head is aligned with the convex portion 424 of the first recess of the stem, and the head is pressed in the stem direction, The engaging portion 243 is inserted into the second recess 425 of the stem 4 so that the head is engaged and fixed to the stem. 11 (2) shows a state in which the head 2 is rotated by one rotation unit (rotation angle 30 degrees) in the counterclockwise direction in (1), and it can be confirmed that the position of the virtual point p5 has been changed. 11 (3) shows a state in which the unit of rotation is further rotated by one rotation unit in the counterclockwise direction in (2), and it can be confirmed that the point p5 of the assumption is changed at the position of (2). 11 (4) shows the position of the head when it is rotated by 6 rotation units (i.e., 180 degrees rotation), and it can be confirmed that the virtual point p5 is located at a position opposite to the position of (1) in FIG. As described above, the rotational position of the head can be adjusted through the process of joining the concave portion of the post of the head and the convex portion of the stem.

12 shows a process in which incomplete coupling between the head and the stem is blocked and complete coupling is induced.

12 (1), when the concave portion 241a of the head post is aligned with the convex portion 424 of the first recess 423 of the stem 4, the concave portion 241a of the concave portion 241a The convex portion 424 of the stem is surrounded by the convex portions 241b on both sides because the convex portion 241b is located on both sides. In this state, the distance to the apex p3 of the convex portion 424 of the first recess r3 is larger than the distance r1 to the apex p1 of the concave portion 241a and smaller than the distance r2 to the vertex of the convex portion 241b of the post. Therefore, when the head is pressed in the stem direction in this state, The setting portion 241 can enter the first recess 423 and the joining portion 243 of the post can respectively enter the second recess 425 so that the head is positioned on the stem and simultaneously, Thereby being fixedly coupled.

12 (2), in the course of rotating the head, the concave portion 241a of the post of the head is not aligned with the convex portion 424 of the first recess 423 of the stem 4, When the convex portion 241b is aligned with the convex portion 424 of the first recess 423 of the stem 4, the distance r2 of the block portion of the post is smaller than the distance r3 of the block portion 424 of the first recess The head of the head 2 can not enter the recess of the stem 4 even if the head is pressed against the stem in this state so that the head can not be engaged with the stem. If the concave portion of the head and the convex portion of the stem are not aligned as described above, the coupling is not performed. Thus, a medical accident that the operation is completed in a state where the head is not coupled to the stem during the operation is prevented.

According to another embodiment of the present invention, as shown in Fig. 6, the angle? 1 formed by each concave portion may be larger than the angle? 2 formed by each convex portion. This is because when the head 2 is rotated relative to the stem 4, the concave portion 241a of the head is moved to the convex portion of the stem 424, and even if the convex portion of the head is aligned with the convex portion of the stem, the concave portion of the post and the convex portion of the stem can quickly find the alignment state even if it is rotated a little to the left or right, The portion 241b is not aligned with the convex portion 424 of the stem and is not inserted and coupled, and the process of re-aligning is repeated, thereby unnecessarily lengthening the operation time or making the surgical procedure difficult. Furthermore, it is possible to more effectively prevent the risk of medical accidents completing the surgery despite the imperfect bonding state.

The applicant of the present invention has been described above with reference to the embodiments of the present invention. However, the present invention is not limited to the above embodiments, and various changes and modifications may be made.

1: shoulder joint prosthesis
2: Upper head,
22: upper portion, 221: joint surface, 223: back surface, 225: flange
24: Lower part, 241: Position setting part, 241a: Concave part, 241b:
243: coupling portion, r1: groove radius, r2: projection radius
4: stem, 42: upper portion, 44: lower portion
423b-1: inner surface 425: second recess 425a: third inner surface 426: step 424: convex portion 423: first recess 423a: locking recess 423b: 424a: inner surface 427: concave portion, 427a: inner surface 6:

Claims (15)

A humeral head having an upper portion having a curved surface and a lower portion having a post positioned on a rear surface thereof, and a stem to which the upper head is inserted and fixed,
The post having a central axis eccentric to the central axis of the upper portion and configured to position with respect to the stem, and a coupling portion fixed to the stem,
Wherein the stem includes a latch portion for setting a position of the upper arm bone head that interacts with the position setting portion, and a recess for receiving the coupling portion and fixing the head to the stem. The artificial shoulder joint according to claim 1, wherein the positioning portion of the post includes a plurality of recesses arranged along a circumference on an outer circumferential surface of the post. 3. The artificial shoulder joint according to claim 2, wherein the concave portion is formed in the center axis direction of the post. The artificial shoulder joint according to claim 2, wherein the plurality of recesses are arranged at equal angles. The artificial shoulder joint according to any one of claims 1 to 4, wherein the post includes a convex portion between the adjacent concave portion and the concave portion. 6. The artificial shoulder joint according to claim 5, wherein the concave portion and the convex portion are arranged concentrically with the same central axis. The artificial shoulder joint according to claim 6, wherein the central angle &thetas; 1 of the concave portion is larger than the central angle &thetas; 2 of the convex portion. The artificial shoulder joint according to claim 1, wherein the joint portion has a male morse taper structure. The connector according to any one of claims 2 to 4 or 6 to 8, wherein the engaging portion includes a convex portion protruding toward the recess, and the convex portion is formed on the concave portion of the positioning portion Wherein the upper arm is positioned to the stem. 10. The device of claim 9, wherein the recess of the stem includes a first recess in which the locating portion is located and a second recess in which the engaging portion is located, the recess having a central axis coinciding with the central axis of the post Features artificial shoulder joints. 10. The method of claim 9, wherein the post further comprises a guide between the positioning portion and the engagement portion, the guide portion is inclined at a lower end of the positioning portion and is led to an upper end of the engagement portion, So as to be easily inserted into and coupled with the artificial shoulder joint. The artificial shoulder joint according to claim 11, wherein the concave portion extends to the guide portion. 11. The connector according to claim 10, wherein the first recess has a concave portion recessed outward on both sides of the convex portion, and the convex portion and the concave portion of the first recess are connected to each other by a curved surface to form an inner surface of the first recess Features artificial shoulder joints. 11. The method of claim 10, wherein the second recess has a female morse taper structure to engage the male portion of the engagement portion of the post to couple the head of the humeral head to the recess of the stem Artificial shoulder joints. 14. The method of claim 13, wherein the distance r3 from the recess central axis of the stem to the apex p3 of the convex portion of the stem is less than the distance r2 from the central axis of the post's post to apex p2 of the convex portion of the post, Is greater than the distance (r1) to the apex (p1) of the concave portion of the post.

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