KR100904088B1 - A femoral stem for artificial hip-joint - Google Patents

Abstract

A femoral stem for artificial hip-joint is provided, which maintains the limit diameter to secure the intensity of the cervix of the femoral stem and maximizes the range of motion of the femoral stem. A femoral stem for artificial hip-joint comprises: a stem body(11) including a proximal part(111) and a pars distalis(113) extended downward from the proximal part; a cervix(13) which is extended upward to be inclined from the proximal part; and a truncated cone part(15) formed in the end part of cervix. The proximal part comprises the wire hole(1111) in which the respective wire can pass the inner side and outer side. The pars distalis comprises a rotation prevention groove(1131) formed in the front and rear in the longitudinal direction.

Description

Femoral Stem for Artificial Hip-joint

The present invention includes a stem body including a proximal portion and a distal portion extending downwardly from the proximal portion, an artificial hip joint including a cervical portion extending upwardly inclined at a predetermined angle from the proximal portion, and a truncated cone formed at an end of the cervical portion. More specifically, the femoral stem, and more particularly, the neck portion is formed by cutting inclined upwardly and downwardly on both sides of the outer circle, respectively, to form a chamfered surface, and between the chamfered surface and the chamfered surface and the outer circle, respectively, The chamfered surface is formed to be in contact with an imaginary inner circle forming the same center as the outer circle, the inclination angle of the chamfered surface is formed 20 to 30 ° from the vertical center axis of the outer circle, the chamfered surface is the same as the outer circle Rounded along the inner circle contacting the chamfered surface while forming a center and the surface between the chamfered surface and the outer circle The rounding process is performed along the circumference of the imaginary circle having a radius of 2 mm to 4 mm in contact with the surface and the outer circle at the same time, thereby minimizing the cross-sectional area to be deleted and maximizing the movement range. The present invention relates to a femoral stem for artificial hip joint, which can join large and small electrons of a fractured femur by including a wire hole.

The hip joint is the joint between the femur and pelvis of the human body, and it is the joint that plays the most important role in sitting or standing, and can be damaged by various pathological causes and traumas. Artificial hip joint may be applied.

Typically, the hip joint is composed of an acetabular cup (3) fixed to the acetabular pelvis and a femoral stem (1) inserted into and fixed to the femur, as shown in FIG. 1, the femoral stem (1) and the acetabular cup (3), for example. For example, it is made of titanium alloy, which is harmless to human body. An artificial head 5 formed of ceramic or metal material is fixed to the end of the femoral stem 1, and a corresponding hemisphere 7 is accommodated in the acetabular cup 3 to accommodate and rotate the artificial head 5. The corresponding hemispheres 7 are made of ceramic material or polymer polyethylene. The artificial hip joint configured as described above allows the artificial head 5 to rotate in response to the movement of the femur and femoral stem 1.

On the other hand, the most important thing in the artificial hip joint as described above is whether or not it is possible to perform a rotational movement having a range of joint movement closest to the hip joint of the human body, such joint movement is shown in Figure 1 femur relative to the pelvis This forward moving flexion and the opposite extension moving, adduction moving the femur inward with respect to the pelvis and abduction moving in the opposite direction as shown in FIG. As shown in FIG. 3, the internal rotation is rotated inward with respect to the pelvis, and the external rotation is rotated in the opposite direction.

Therefore, since the range of motion of the artificial hip joint is determined by the range of rotational motion of the femoral stem 1, that is, the rotation angle, it is necessary to minimize the interference with the corresponding hemisphere 7 when manufacturing the femoral stem 1, Since the part contacting the corresponding hemisphere 7 becomes the neck portion 13 of the femoral stem 1, the smaller the diameter of the neck portion 13 is, the larger the rotational movement range of the femoral stem 1 becomes. If too small, there is a limit to breakage.

Figure 4 is a cross-sectional view showing the cross-sectional structure of the neck of the conventional femoral stem and Figure 5 is a cross-sectional view showing a state that interferes with the corresponding hemisphere during the joint movement of the femoral stem according to Figure 4, referring to Figure 4 conventional femoral stem The cross section of the neck portion a has a cut face a1 symmetrically formed perpendicular to both sides of the outer circle formed in a circular shape having a limit diameter. In other words, while the marginal diameter of the neck (a) is maintained as it is, only the part contacted with the corresponding hemisphere faced and scraped off to compensate for the cut-off part, the movement range of the femoral stem relative to the corresponding hemisphere is expanded. In fact, since the acetabular cup 3 is inserted at an angle of about 40 to 50 degrees when the artificial hip is inserted, the part contacting the corresponding hemisphere 7 during joint movement is shown in FIG. 5. There is a problem that the increase in the movement range is too weak compared to the cross-sectional area actually deleted by the interference portion (a2) rather than the cut surface (a1).

In addition, even if the corner (a2) is simply rounded, the thickness of the corners must be maintained in order to secure a cross-sectional area to prevent the femoral stem from breaking.

That is, in the past, various attempts to maximize the range of motion of the femoral stem did not provide a solution for maximizing the range of motion while minimizing the cross-sectional area.

In addition, when the femur of the human body is fractured by trauma, etc., there are many cases in which the fracture of the femur and the femur are crushed together.In this case, the fractured electrifier and the small electron are inserted into the femur while performing an artificial hip joint. There were many problems with the procedure for joining the femur together with the femoral stem.

In addition, there is an urgent need for improved solutions for stability, rotation prevention, and pain reduction of the femoral stem inserted into the femur.

The present invention has been made to solve the above problems,

SUMMARY OF THE INVENTION An object of the present invention is to provide an artificial hip joint femoral stem having a cross-sectional shape of the neck which can maximize the range of motion of the femoral stem while maintaining the limit diameter for securing the strength of the neck of the femoral stem and eliminating the cross-sectional area. will be.

Another object of the present invention is to minimize the portion of the femoral stem interfering with and in contact with the corresponding hemisphere of the acetabular cup during joint movement of the artificial hip for artificial hip joint that can prevent wear or damage of the corresponding hemisphere, dislocation of the femoral stem, etc. To provide a femoral stem.

Still another object of the present invention is to provide an artificial hip joint femoral stem which can be easily joined to the femur together with the femur or the small electron of the fractured femur.

Still another object of the present invention is to provide an artificial hip joint femoral stem capable of maximizing rotation prevention and stability of the femoral stem inserted into the femur.

Still another object of the present invention is to provide an artificial hip joint femoral stem which can minimize the pain caused from the femoral stem inserted into the femur.

Artificial hip joint femoral stem for achieving the above object of the present invention includes the following configuration.

According to an embodiment of the present invention, the artificial hip joint femoral stem according to the present invention includes a stem body including a proximal portion and a distal portion extending downward from the proximal portion, and upwardly inclined at a predetermined angle from the proximal portion. And a truncated cone formed at an end of the neck, wherein the neck is chamfered upwardly and downwardly from the left and right sides of the outer circle to form a chamfered surface, and as the chamfered surface is formed, the left, The corners formed between the chamfered surfaces of the right side and the chamfered surfaces and the outer circles of the upper and lower portions of the outer circle are rounded, thereby maximizing the movement range while maintaining the maximum cross-sectional area.

According to another embodiment of the present invention, in the femoral stem for artificial hip joint according to the present invention, the chamfered surface is formed to be in contact with a virtual inner circle forming the same center as the outer circle.

According to another embodiment of the present invention, the inclination angle of the chamfered surface in the artificial hip joint femoral stem according to the present invention is characterized in that it is formed from 20 to 30 degrees from the vertical center axis of the outer circle.

According to another embodiment of the present invention, in the femoral stem for artificial hip joint according to the present invention, the chamfered surface between the left and right portions of the outer circle is rounded along an inner circle contacting the chamfered surface while forming the same center as the outer circle. It is characterized by.

According to another embodiment of the present invention, in the femoral stem for artificial hip joint according to the present invention, the inner circle is formed with a radius of 4 mm to 5.5 mm, and the chamfered surface between the chamfered surface and the upper and lower portions of the outer circle is chamfered. It is characterized by being rounded along the circumference of an imaginary circle having a radius of 2 mm to 4 mm in contact with the surface and the outer circle at the same time.

According to another embodiment of the present invention, in the femoral stem for artificial hip joint according to the present invention is characterized in that the outer diameter of the neck portion is formed of 10mm ~ 13mm.

According to another embodiment of the present invention, in the artificial hip joint femoral stem according to the present invention, the proximal portion includes a wire hole through which wires can pass through the inside and the outside, respectively, so that the fractured femoral or small electrons of the femur It can be joined.

According to another embodiment of the present invention, in the artificial hip joint femoral stem according to the present invention, the proximal side is tapered with an inclination of 8 ° to 12 ° in the direction of the winch, and the side of the distal part has a constant thickness. It is characterized in that formed in a straight line.

According to another embodiment of the present invention, the distal portion in the artificial hip joint femoral stem according to the invention is characterized in that it comprises a rotation preventing groove formed in the longitudinal direction on the front and rear.

According to another embodiment of the present invention, in the femoral stem for artificial hip according to the present invention, the distal portion is characterized in that it comprises a slot formed through both sides.

According to another embodiment of the present invention, the proximal portion of the artificial hip joint femoral stem according to the present invention is characterized in that it comprises a plurality of recessed grooves in the front and rear.

The present invention can obtain the following effects by the configuration, combination, and use relationship described above with the present embodiment.

The present invention provides an artificial hip joint femoral stem having a cross-sectional shape of the neck that can maximize the range of motion of the femoral stem while minimizing the cross-sectional area that is maintained and the marginal diameter for securing the strength of the neck of the femoral stem.

The present invention is to minimize the portion of the femoral stem interfering with the contact hemisphere of the acetabular cup during joint movement of the artificial hip joint artificial femoral stem that can prevent wear or damage of the hemisphere, dislocation of the femoral stem to provide.

The present invention provides an artificial hip joint femoral stem that can be easily bonded to the femur with the femur or the small electrons of the fractured femur.

The present invention provides an artificial hip joint femoral stem that can maximize the rotation prevention and stability of the femoral stem inserted into the femur.

The present invention provides an artificial hip joint femoral stem that can minimize the pain caused from the femoral stem inserted into the femur.

Hereinafter, with reference to the accompanying drawings, a preferred embodiment of the artificial hip joint femoral stem according to the present invention will be described in detail.

Figure 6 is a perspective view of the artificial hip joint femoral stem according to an embodiment of the present invention, Figure 7 is a front view of the artificial hip joint femoral stem according to an embodiment of the present invention, Figure 8 is an embodiment of the present invention 9 is a side view of the artificial hip joint femoral stem, Figure 9 is a cross-sectional view showing a cross-sectional structure of the neck portion of the artificial hip joint femoral stem according to one embodiment of the present invention.

6 to 9, the artificial hip joint femoral stem according to an embodiment of the present invention includes a proximal portion 111 and a distal portion 113 extending vertically downward from the proximal portion 111. And a neck 13 extending upwardly at an angle from the proximal portion 111 and a truncated cone portion 15 formed at an end of the neck 13, wherein the neck 13 is The chamfered surface 133 is formed by inclining upwardly and downwardly from the left and right sides of the outer circle 131 to form the chamfered surface 133, and as the chamfered surface 133 is formed, the chamfered surface of the left and right sides of the outer circle 131 ( Corners formed between the chamfered surface 133 and the outer circle 131 between the 133 and the upper and lower portions of the outer circle 131 are rounded, respectively, to maximize the range of motion while maintaining the maximum cross-sectional area. It features.

The stem body 11, the neck portion 13 and the truncated cone portion 15 is a general component of the artificial hip joint, the stem body 11 is inserted into the femur of the human body, the stem body 11 The frustoconical part 15 formed at the end of the neck portion 13 which is inclined at a predetermined angle from the upper part 13 is covered with an artificial head and inserted into a corresponding hemisphere of the acetabular cup inserted into the pelvis.

Hereinafter, the cross-sectional structure of the neck portion 13 which can maximize the range of motion of the femoral stem while maintaining the limit diameter for securing the strength of the neck portion 13 which is one of the core technical features of the present invention and minimizing the cross-sectional area that is deleted. Learn more about.

As shown in Figure 9, the cross section of the neck portion 13 of the femoral stem for artificial hip joint according to an embodiment of the present invention, the upper portion of the upper portion, the upper portion of the femoral stem in the longitudinal direction of the vertical axis (Y) When the lower portion, the left portion along the horizontal center axis (X) orthogonal to the vertical center axis (Y), the left portion and the right portion of the right side, the upper and lower portions of the left and right sides of the outer circle 131, respectively Chamfering inclined to form a chamfering surface 133, in which case the chamfering surface 133 may be formed symmetrically around a vertical center axis (Y) and a horizontal center axis (X), respectively, the outer circle 131 It may be formed to contact the virtual circle 135 forming the same center (O). In this case, the cutting depth of the chamfered surface 133 is changed according to the change of the radius R2 of the inner circle 135, and the radius R2 of the inner circle 135 is the radius R1 and the neck portion of the outer circle 131. It is determined in consideration of the cross-sectional area, etc. to secure the strength of 13), considering that the outer radius (R1) of the generally used femoral stem neck is 5 ~ 6.5mm the radius (R2) of the inner circle 135 is It is preferable to form about 4 ~ 5.5mm.

The angle of inclination α of the chamfering surface 133 is also determined in consideration of the cross-sectional area for securing the strength of the neck portion 13 and the range of motion of the femoral stem. In order to maximize both, the vertical center of the outer circle 131 is maximized. It is preferable to form about 20 to 30 degrees from the axis Y, and it is more effective to form around 25 degrees especially. This is a value in consideration of the compensation angle for the site where the neck portion 13 actually interferes and contacts during joint motion with respect to the corresponding hemisphere of the acetabular cup inserted into the pelvis at an inclination of approximately 45 °.

In FIG. 9, the cross section of the neck portion 13 is divided into a horizontal center axis (X) and a vertical center axis (Y). The quadrants are divided into one quadrant F1, two quadrants F2, three quadrants F3, and four quadrants. Referring to (F4), the rounding process between the chamfering surface 133 and the chamfering surface 133 and the outer circle 131 based on the first quadrant F1 will be described in detail.

The chamfering surface 133a formed in the first quadrant F1 and the chamfering surface 133b formed in the fourth quadrant F4 are rounded to minimize interference with the corresponding hemisphere, and the strength of the neck portion 13 is increased. In order to maximize the cross-sectional area to secure and at the same time to increase the ease of processing in the manufacturing process, the chamfering surface 133a and the chamfering surface 133b form the same center (O) as the outer circle 131 and the chamfering surfaces ( It may be rounded along the inner circle 135 in contact with 133a, 133b. That is, when the chamfered surfaces 133a and 133b are formed by chamfering upwardly and downwardly from the vertical center axis Y in the right and lower portions of the outer circle 131, the chamfering surfaces 133a and 133b, respectively, the chamfering surfaces 133a Silver forms an outer circle 131 and the edge (e2) in the upper portion, and forms an edge (e1) on the chamfering surface (133b) and the horizontal center axis (X) at the right side, to remove the edge (e1) For example, the contacts P1 and P2 contacting the inner circumference 135 and the chamfering surfaces 133a and 133b simultaneously contact the chamfering surfaces 133a and 133b, respectively, the contacts P1 and P2. ) Is rounded along the inner circle 135 in contact with the chamfering surfaces 133a and 133b while forming the same center (O) as the outer circle 131. In this case, the cross section of the neck portion 13 is shorter in length (between P3 and O) than the length between the upper and lower lengths (between P6 and O), thereby preventing interference with the corresponding hemisphere during joint movement. Will be minimized.

In addition, the chamfering surface 133a formed in the first quadrant F1 and the outer circle 131 are also rounded to minimize interference with the corresponding hemisphere, maximizing the cross-sectional area for securing the strength of the neck portion 13. At the same time, between the chamfered surface 133a and the outer circle 131, a radius R3 of 2 mm to 4 mm in contact with the chamfered surface 133a and the outer circle 131 at the same time, in order to increase the processing convenience in the manufacturing process. It can be rounded along the circumference of the circle d. That is, to remove the edge e2, the virtual circle d in contact with the chamfering surface 133a and the outer circle 131 at the same time and the contact point between the chamfering surface 133a and the outer circle 131 are respectively 'P4'. ',' P5 'of the virtual circle (d) of the radius (R3) 2mm ~ 4mm that the contact between the contact (P4) and the contact (P5) is in contact with the chamfering surface 133a and the outer circle 131 at the same time It is rounded along the circumference.

Therefore, when looking at the external shape of the cross section of the neck portion 13 formed in the first quadrant F1 from the vertical center axis Y to the horizontal center axis X as a whole, 'P5' to 'P5' which meets the vertical center axis Y Is formed along the circumference of the outer circle 131, from 'P5' to 'P4' is rounded along the circumference of the imaginary circle (d) having a radius of 2mm to 4mm, and from 'P4' to 'P1' It is formed along the chamfering surface 133a, and rounds along the inner circle 135 contacting the chamfering surfaces 133a and 133b while forming the same center O as the outer circle 131 from 'P1' to 'P3'. As a result, the distance from the center (O) to the outer surface gradually decreases from 'P6' to 'P3'.

When the chamfering surface 133a of the first quadrant and the rounding process of the corners thereof are applied to the second quadrant F2 to the fourth quadrant F4 in the same manner, the cross section of the neck portion 13 of the femoral stem for artificial hip joint of the present invention The shape will be formed.

The cross-sectional shape of the neck portion 13 of the artificial hip joint femoral stem of the present invention formed as described above has a similar cross-sectional area as compared to the cross-sectional shape of the neck portion of the conventional femoral stem shown in FIG. Frequently occurring cross-section H and H1 of the cross section of the conventional femoral stem shown in Figure 10 is significantly reduced than the cross-section (H2) of the cross section of the neck, maintaining a constant strength of the femoral stem and joint motion The range can be maximized.

Hereinafter will be described the joint motion range improvement and strength maintenance effect of the artificial hip joint femoral stem according to the present invention through a comparative test for the artificial hip joint femoral stem.

Test 1. Femoral stem  Exercise range comparison experiment

1. Purpose of the test: Comparison of range of motion of the joints between the artificial hip joint femoral stem and the conventional artificial hip joint femoral stem according to the present invention.

2. Test Material:

As shown in the figure below, Test Example 1 is a cross-sectional shape rounded around the circumference of the circle 12 mm, the inner circle 10.2 mm, the inclination angle of the chamfered surface 25 °, between the chamfered surface and the outer circle 3 mm radius (cross-section 96.14 Femoral stem for artificial hip according to the present invention having a neck of 2 mm 2)

[Test Example 1]

As can be seen in the figure below, Comparative Example 1 has a diameter of 12 mm, a width of 9 mm between the cut surface, and a 3 mm radius between the cut surface and the outer circle. Femoral stem for conventional artificial hip

Comparative Example 1

Test Example 2 is an artificial hip joint femoral stem according to the present invention having a neck having a cross-sectional shape (cross section 104.85 mm 2) formed of the same element as the Test Example 1, the outer circle 13mm, the inner circle 10.4mm.

Comparative Example 2 is a conventional artificial hip joint femoral stem having the same cross-sectional shape (section area 95.52 mm 2) formed with the same element and having an outer circumference of 13 mm.

3. Test method: Measure the range of motion such as flexion, extension, adduction, abduction, internal rotation, external rotation by angle under the same conditions for each test example and comparative example

4. Test Result:

Test Example 1 Comparative Example 1 Test Example 2 Comparative Example 2 Flexion 124˚ 123˚ 122˚ 121˚ Extension 68˚ 66˚ 67˚ 65˚ Flexion + Temple (sum) 192˚ 189˚ 189˚ 186˚ Adduction 57˚ 56˚ 56˚ 55˚ Abduction 70˚ 70˚ 68˚ 68˚ Civil War + Abduction (sum) 127˚ 126˚ 124˚ 123˚ Inner rotation (int.rotat.) 142˚ 141˚ 140˚ 138˚ Outer rotation (ext.rotat.) 78˚ 77˚ 77˚ 74˚ Inner rotation + outer rotation (sum) 220˚ 218˚ 217˚ 212˚

As can be seen in the test results table, Test Example 1, Test Example 2, each compared with Comparative Example 1, Comparative Example 2 having a similar cross-sectional area, 1 ~ 2˚ in flexion, extension, adduction, abduction, internal rotation, external rotation, etc. It can be seen that the degree of movement is improved and the effect of maximizing the range of motion is 6 to 9˚. This is a significant improvement compared to the conventional femoral stem, considering that the improvement of the motion angle of about 1˚ can significantly affect the wear and damage of the artificial hip and improve the convenience of the patient's daily life. It can be said.

Test 2. Femoral stem  Strength comparison

1. Purpose of the test: The stability of the human hip joint according to the present invention and the conventional hip joint femoral stem by comparing the strength that can withstand the load on the human body to examine the stability

2. Test Material: Test carried out for Test Examples 1 and 2 and Comparative Examples 1 and 2 above.

3. Test method: The moment of inertia and the moment of inertia, which are values indicating the degree to which the current state with respect to the bending load and the torsional load are to be maintained for the test examples 1 and 2 and the comparative examples 1 and 2, respectively. polar moment of inertia) (the values are proportional to the intensity, the greater the intensity).

For reference, the formula for calculating the moment of inertia is I _X = ∫ y ² dA, and the formula for calculating the moment of inertia is J _Z = ∫ (x ² + y ² ) dA ( Where x is the distance from the y axis and y is the distance from the x axis).

4. Test Result:

Test Example 1 Comparative Example 1 Test Example 2 Comparative Example 2 Moment of inertia 1052.86 1039.55 1258.16 1242.80 Polar moment of inertia 1500.68 1511.77 1881.33 1814.29

(Unit is mm ⁴ )

As can be seen from the test result table, the test example 1 and the comparative example 1 has a similar cross-sectional area, respectively, it can be confirmed that the moment of inertia and the moment of inertia measured similarly obtained similar results, and the test example 2 and As Comparative Example 2 also has a similar cross-sectional area, it can be seen that the measured moments of inertia and extreme moments of inertia also yield similar results. That is, it can be seen that the artificial hip joint femoral stem according to the present invention can maximize the range of motion while maintaining strength or stability as compared to the conventional femoral stem having a similar cross-sectional area.

According to another embodiment of the present invention, the outer circle 131 of the neck portion 13 may have a diameter of 10 mm to 13 mm, the conventional femoral stem is usually a truncated cone part to maintain the strength of the neck portion Compared to maintaining the outer diameter of the neck connecting the stem body with the diameter of the truncated cone, the diameter of the neck 13 and the outer circle 131 is 10 mm to 13 mm as in the present invention. If the diameter is reduced to (15), the area that interferes with the corresponding hemisphere can be reduced so that the range of motion of the femoral stem can be improved.

6 to 8, the artificial hip joint femoral stem according to another embodiment of the present invention has a wire hole 1111 and a front surface through which the wire c can pass through the proximal portion 111 and the inner side, respectively. And a plurality of recessed grooves 1113 at the rear and rear side, and the side of the proximal portion 111 is tapered in an inclination of 8 ° to 12 ° toward the winch part 113 and the side of the distal part 113 is tapered. Is formed in a straight line with a predetermined thickness, the distal portion 113 may include a rotation preventing groove 1131 formed in the longitudinal direction on the front and rear and a slot 1133 formed through both sides.

The proximal portion 111 and the distal portion 113 form upper and lower portions of the stem body 11, respectively, and the proximal portion 111 is tapered toward the lower portion, that is, toward the distal portion 113, and the width decreases. In addition, the distal portion 113 is formed to extend downward from the lower portion of the proximal portion 111 may also form a slightly tapered shape. This is to cause the wedge effect so that the femoral stem 1 inserted into the femur can be stably fixed in the femur. Further, according to the present invention, the side surface of the proximal portion 111 is also tapered toward the lower portion, that is, the distal portion 113 to form a shape that decreases in width, which causes a wedge effect and load is not transmitted to the proximal portion 111. Instead, the load is transmitted only to the distal portion 113 to ultimately prevent stress shielding, in which bone loss occurs in the proximal portion 111 and pain occurs in the distal portion 113.

The wire hole 1111 is a through hole formed in the inner and outer sides of the proximal portion 111 and does not affect the strength of the femoral stem. It becomes a portion corresponding to the location where the small electron is located, which utilizes the wire hole 1111 of the femoral stem (1) is inserted into the femur when the femur is fractured fracture and the charge and the small electron are separated from the femur This is for the purpose of easily bonding the charged and small electrons to the femur respectively. That is, as shown in FIG. 11, the fractured large electrons b1 and small electrons b2 are bundled using wires c to bond to the original positions of the femurs b, respectively, and the wires c are By passing through the wire hole 1111, the large electrons b1 and the small electrons b2 can be easily bundled, respectively, and thus, the large electrons b1 and the small electrons fixed using the wire c are formed. b2) can be completely bonded to the femur (b) after a certain period of time.

A plurality of grooves 1113 are formed in each of the front and rear surfaces of the proximal portion 111, and the grooves 1113 serve to add axial fixation force and stability to the femoral stem 1.

The anti-rotation groove 1131 is formed in the front and rear of the distal portion 113 in the longitudinal direction, respectively, the anti-rotation groove 1131 prevents the rotation of the femoral stem (1) to the initial fixed strength and stability It will play the role of adding.

The slot 1133 is a portion formed by cutting through both sides of the distal portion 113, and the distal portion 113 has a fluidity by the slot 1133, which is distal end portion 113 Because it serves to properly distribute the concentrated load to the distal portion 113 can reduce the pain of the femur caused by the load concentrated on the distal end.

In the above, the Applicant has described preferred embodiments of the present invention, but these embodiments are merely one embodiment for implementing the technical idea of the present invention, and any changes or modifications may be made as long as the technical idea of the present invention is implemented. Should be interpreted as being within the scope.

1 is a perspective view showing the flexion and extension of the artificial hip joint.

Figure 2 is a perspective view showing the adduction and abduction movement of the artificial hip joint.

Figure 3 is a perspective view showing the internal and external rotation of the artificial hip joint.

Figure 4 is a cross-sectional view showing a cross-sectional structure of the neck portion of a conventional femoral stem

5 is a cross-sectional view showing a state that interferes with the corresponding hemisphere during the joint movement of the femoral stem according to FIG.

Figure 6 is a perspective view of the femoral stem for artificial hip joint according to an embodiment of the present invention

7 is a front view of the artificial hip joint femoral stem according to one embodiment of the present invention

Figure 8 is a side view of the femoral stem for artificial hip joint according to an embodiment of the present invention

9 is a cross-sectional view showing a cross-sectional structure of the neck portion of the artificial hip joint femoral stem according to an embodiment of the present invention

10 is a cross-sectional view showing a cross-sectional structure of the neck portion of a conventional femoral stem

11 is a front view showing a state in which the crushed fracture of the charging and bonding the small electrons

* Explanation of the main symbols used in the drawings

1: thigh stem 3: acetabular cup 5: artificial head 7: corresponding hemisphere

11: stem body 13: neck 15: frustoconical

111: proximal 113: distal

131: outside 133: chamfering 135: visit

1111: wire hole 1113: groove

1131: anti-rotation groove 1133: slot

a: neck a1: cutting surface a2: corner

b: femur b1: great trochanter b2: small trochanter

c: wire α: inclination angle X: horizontal center axis Y: vertical center axis

Claims (11)

A stem body 11 including a proximal portion 111 and a distal portion 113 extending downward from the proximal portion, a neck portion 13 extending obliquely upward from the proximal portion, and a truncated cone portion formed at an end of the neck portion ( 15), The neck is chamfered upwardly and downwardly from the left and right sides of the outer circle 131 to form a chamfered surface 133, and as the chamfered surface is formed, between the chamfered surfaces of the left and right sides of the outer circle and the outer circle. The corners formed between the chamfered surface and the upper and lower portions of the upper and lower portions are rounded, so that the range of motion can be maximized while maximizing the range of motion of the artificial hip joint. The method of claim 1, wherein the chamfered surface 133 Femoral stem for artificial hip joint, characterized in that it is formed to have a center and the same center as the center of the outer circle (131) having a radius smaller than the radius of the outer circle (135). According to claim 2, wherein the inclination angle of the chamfered surface is femoral stem for artificial hips, characterized in that formed from 20 to 30 degrees from the vertical center axis of the outer circle. The femoral stem for artificial hip joint according to claim 3, wherein the chamfered surfaces of the left and right portions of the outer circle are rounded along the circumference of the inner circle contacting the chamfered surface while forming the same center as the outer circle. According to claim 4, wherein the inner circle is formed with a radius of 4mm to 5.5mm, and between the upper and lower chamfered surface and the outer circle of the outer circle is a virtual 2mm ~ 4mm radius of the contact with the chamfered surface and the outer circle simultaneously Femoral stem for artificial hips, characterized in that the rounding process along the circumference of the circle. The femoral stem for artificial hip joint according to any one of claims 1 to 5, wherein an outer diameter of the neck portion is 10 mm to 13 mm. The femoral stem for artificial hip joint according to claim 1, wherein the proximal portion includes a wire hole through which wires can pass through the inner and outer sides, respectively, to join the large and small electrons of the fractured femur. 8. The artificial hip joint according to claim 1 or 7, wherein the proximal side is tapered in an inclination of 8 ° to 12 ° in the distal direction, and the side of the distal part is formed in a straight line with a predetermined thickness. Thigh stem. The femoral stem for artificial hip joint according to claim 1 or 7, wherein the distal portion includes a rotation preventing groove formed in a longitudinal direction on the front and rear surfaces thereof. 8. The femoral stem for artificial hip according to claim 1 or 7, wherein the distal portion includes a slot formed through both sides. 8. The femoral stem for artificial hips according to claim 1 or 7, wherein the proximal portion includes a plurality of recessed grooves in the front and the rear.

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