JP2018134180A - Stem for artificial hip joint, and artificial hip joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stem for an artificial hip joint capable of preventing infection in the replacement of an artificial hip joint, and an artificial hip joint having the stem.SOLUTION: A stem 1A for an artificial hip joint includes a roughly rod-like body part 2, a hollow part located inside the body part 2, and a through-hole 4 penetrating between the hollow part and the periphery 21 of the body part 2. An artificial hip joint includes the stem 1A for an artificial hip joint, an artificial femoral head that engages with a neck part 6 of the stem 1A for an artificial hip joint, and a socket for slidably accommodating the artificial femoral head.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a stem for an artificial hip joint and an artificial hip joint including the stem.

  Conventionally, in order to recover the function of a hip joint that has been lowered due to a disease or an accident, an artificial hip joint replacement technique in which the hip joint is replaced with an artificial one has been performed. In artificial hip joint replacement, a stem for an artificial hip joint (hereinafter also referred to as “stem”) is used (see, for example, Non-Patent Document 1). It would be convenient if there was a stem that could prevent infection in hip replacement.

“M / L Taper Hip Prosthesis”, [online], Zimmer, [Search February 15, 2017], Internet <URL: http://www.zimmer.com/content/dam/zimmer-web/documents/ en-US / pdf / surgical-techniques / hip / zimmer-ml-taper-hip-prosthesis-surgical-technique.pdf>

  The subject of this invention is providing the stem for artificial hip joints which can prevent the infection in artificial hip joint replacement, and an artificial hip joint provided with the same.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found a solution means having the following constitution and have completed the present invention.
(1) An artificial hip joint comprising: a substantially rod-shaped main body portion; a hollow portion located inside the main body portion; and a through hole penetrating between the hollow portion and the outer peripheral portion of the main body portion. Stem.
(2) The artificial hip joint stem according to (1), wherein the medicine is accommodated in the hollow portion and the medicine is released to the outside through the through hole.
(3) The stem for an artificial hip joint according to (1) or (2), wherein each of the hollow portion and the through hole is cylindrical, and an inner diameter of the hollow portion is larger than an inner diameter of the through hole. .
(4) The artificial hip joint stem according to any one of (1) to (3), wherein the hollow portion extends along a central axis of the main body portion.
(5) The stem for an artificial hip joint according to any one of (1) to (4), wherein the through hole extends in a direction substantially perpendicular to the central axis of the main body.
(6) The stem for an artificial hip joint according to any one of (1) to (5), including a plurality of the through holes.
(7) The stem for an artificial hip joint according to (6), wherein the plurality of through holes are positioned at substantially equal intervals along the central axis of the main body.
(8) The artificial hip joint according to any one of (1) to (7), wherein the hollow portion is open to an outer peripheral portion of the main body portion, and further includes a cap that closes the opening portion of the hollow portion. Stem.
(9) The stem for an artificial hip joint according to (8), wherein the hollow portion is opened in each of outer peripheral portions on a proximal side and a distal side of the main body portion.
(10) The stem for an artificial hip joint according to (8), wherein the hollow portion opens in an outer peripheral portion on a proximal side of the main body portion.
(11) The stem for an artificial hip joint according to (9) or (10), wherein the hollow portion is configured so that a stem inserter can be attached thereto.
(12) The stem for an artificial hip joint according to (8), wherein the hollow portion opens in an outer peripheral portion on a distal side of the main body portion.
(13) The body part has a proximal part made of a metal material and a distal part made of a bone-resorbable material, and the hollow part is located in the distal part. For artificial hip joints.
(14) The artificial hip joint stem according to any one of (1) to (13), an artificial bone head fitted to a neck portion of the artificial hip joint stem, and a socket for slidably housing the artificial bone head And an artificial hip joint.

  ADVANTAGE OF THE INVENTION According to this invention, there exists an effect that the infection in artificial hip joint replacement can be prevented.

It is a front view which shows the stem for artificial hip joints concerning 1st Embodiment of this invention. It is the sectional view on the aa line of FIG. It is the bb line expanded sectional view of FIG. It is a figure which shows the stem for artificial hip joints concerning 2nd Embodiment of this invention, and is sectional drawing equivalent to FIG. It is a figure which shows the stem for artificial hip joints concerning 3rd Embodiment of this invention, and is sectional drawing equivalent to FIG. It is sectional drawing which shows the stem for artificial hip joints concerning 4th Embodiment of this invention. It is a figure which shows the stem for artificial hip joints concerning 5th Embodiment of this invention, and is sectional drawing equivalent to FIG. It is explanatory drawing which shows the artificial hip joint which concerns on one Embodiment of this invention. 1 to 8 show a state in which the stem is installed on the left foot, but when the stem is installed on the right foot, the left and right are symmetrical.

<Stem for artificial hip joint>
(First embodiment)
Hereinafter, a stem for an artificial hip joint according to a first embodiment of the present invention will be described in detail with reference to FIGS. In the following description, the case where the stem is installed on the left foot will be described as an example, but the stem can also be installed on the right foot.

  As shown in FIGS. 1 to 3, the stem 1 </ b> A of the present embodiment includes a main body portion 2, a hollow portion 3, and a through hole 4. The main body 2 has a substantially rod shape. The hollow part 3 is located inside the main body part 2 and functions as a part for accommodating a medicine. The through-hole 4 penetrates between the hollow part 3 and the outer peripheral part 21 of the main body part 2 and functions as a part for releasing the medicine to the outside of the stem 1A. According to the above-described configuration, since the medicine can be accommodated in the hollow portion 3 and the medicine can be released to the outside of the stem 1A via the through hole 4, infection in the hip replacement can be prevented.

  Examples of the drug include antibacterial drugs such as vancomycin or gentamicin. Examples of drug forms include powder, jelly, and liquid. The drug can be accommodated in the hollow portion 3 through the through hole 4, for example. When the jelly-like medicine is accommodated in the hollow portion 3, for example, a syringe or the like may be used. When the liquid medicine is accommodated in the hollow portion 3, for example, the stem 1A may be immersed in the medicine solution. The stem 1A includes a plurality of through holes 4 as will be described later. In the case of such a configuration, when the medicine is accommodated in the hollow portion 3, at least one of the plurality of through holes 4 may be sucked.

  In the present embodiment, both the hollow portion 3 and the through hole 4 are cylindrical. Further, the inner diameter of the hollow portion 3 is larger than the inner diameter of the through hole 4. According to these configurations, the medicine can be gradually released to the outside of the stem 1A through the through hole 4 having a relatively small inner diameter. The inner diameter of the hollow portion 3 is, for example, 2 to 10 mm. The inner diameter of the through hole 4 is, for example, 0.1 to 2 mm. In addition, each shape of the hollow part 3 and the through-hole 4 is not limited to a cylindrical shape. As a specific example, the through hole 4 may be, for example, a rectangular tube. Examples of the rectangular tube shape include a rectangular tube shape.

  The hollow portion 3 extends along the central axis S of the main body portion 2. As shown in FIG. 1, the central axis S is a bisector of an angle θ formed by the inner surface 22 and the outer surface 23 of the main body 2 in a front view. The front view is a state of the stem 1A when the human body with the stem 1A attached to the left foot or the right foot is viewed from the front side. In front view, the inner side surface 22 is located inside the main body 2, and the outer side surface 23 is located outside the main body 2. The inner side is located closer to the center line of the human body than the comparison target. The outside means being located on the side farther from the center line of the human body than the comparison target. For example, the angle θ is greater than 0 ° and equal to or less than 10 °. As shown in FIG. 2, the central axis S also has a configuration in which the middle point in the thickness direction A of the main body 2 is continuously obtained along the longitudinal direction B of the main body 2.

  The through hole 4 extends in a direction substantially perpendicular to the central axis S of the main body 2. The through hole 4 only needs to extend in a direction substantially perpendicular to the central axis S. The substantially vertical direction of the present embodiment includes a range of 90 ° ± 5 °.

  The stem 1A includes a plurality of through holes 4. According to such a configuration, the medicine can be released to the outside of the stem 1A with a good balance. When a plurality of through holes 4 are provided, the number of through holes 4 is, for example, 2 to 38. The configuration of each of the plurality of through holes 4 may be the same or different. In the present embodiment, the configurations of the plurality of through holes 4 are the same as each other.

  The plurality of through holes 4 are located at substantially equal intervals along the central axis S of the main body 2. According to such a configuration, the medicine can be released to the outside of the stem 1A with a good balance. Note that the plurality of through holes 4 are not limited to the configuration positioned at substantially equal intervals, and may be positioned at unequal intervals.

  As shown in FIG. 3, the through hole 4 opens on the outer surface 23, the front surface 24, and the rear surface 25 of the main body 2. The front surface 24 is located on the front side of the main body 2, and the rear surface 25 is located on the rear side of the main body 2. The front side is a direction side in which the face of the human body is facing when the stem 1A is attached to the human body. The rear side is a direction side in which the back portion of the human body is facing when the stem 1A is attached to the human body. The position where the through hole 4 opens is not limited to the position described above. The through hole 4 may be open on the inner side surface 22, for example.

  The stem 1A of the present embodiment further includes a neck portion 6 as shown in FIG. As shown in FIG. 8 to be described later, the neck portion 6 is a portion to which the artificial bone head 11 is fitted.

  The length of the stem 1A is, for example, 50 to 200 mm. Examples of the constituent material of the stem 1A include a metal material. Examples of the metal material include a titanium alloy or a cobalt-chromium alloy. As a manufacturing method of the stem 1A, for example, a cutting process or an additive manufacturing method may be used.

(Second Embodiment)
Next, an artificial hip joint stem according to a second embodiment of the present invention will be described in detail with reference to FIG. In FIG. 4, the same components as those in FIGS. 1 to 3 described above may be denoted by the same reference numerals and description thereof may be omitted.

  As shown in FIG. 4, in the stem 1 </ b> B of the present embodiment, the hollow portion 3 is open to the outer peripheral portion 21 of the main body portion 2. Specifically, the hollow portion 3 opens in the outer peripheral portions 21 on the proximal 2 a side and the distal 2 b side of the main body portion 2. The stem 1 </ b> B further includes a cap 5 that closes the opening 31 of the hollow portion 3. According to these configurations, since the medicine can be accommodated in the hollow portion 3 and released from the stem 1B through the through-hole 4 as in the above-described embodiment, infection in hip replacement surgery is possible. Can be prevented. Further, since the medicine can be accommodated in the hollow portion 3 through the opening 31, the workability when the medicine is accommodated in the hollow portion 3 can be improved.

  The proximal 2a of the main body 2 is located closer to the head of the human body than the comparison target. The distal 2b of the main body 2 is located on the side farther from the head of the human body than the comparison target. In other words, the distal 2b is located closer to the toe of the human body than the comparison target.

  The cap 5 is a member that prevents the medicine from leaking out of the hollow portion 3. Examples of the constituent material of the cap 5 include a metal material or a resin material. Examples of the metal material include a titanium alloy or a cobalt-chromium alloy. Examples of the resin material include polyethylene resin, polypropylene resin, or polyether ether ketone (PEEK) resin. The cap 5 for closing the opening 31 on the proximal 2a side and the cap 5 for closing the opening 2 on the distal 2b side may be the same or different from each other.

The cap 5 may have a hole that penetrates the cap 5 in the thickness direction. According to such a configuration, the medicine accommodated in the hollow portion 3 can be released from the cap 5 in addition to the through hole 4.
Since other configurations are the same as those of the stem 1A according to the first embodiment described above, the description thereof is omitted.

(Third embodiment)
Next, a stem for an artificial hip joint according to a third embodiment of the present invention will be described in detail with reference to FIG. In FIG. 5, the same components as those in FIGS. 1 to 4 described above may be denoted by the same reference numerals and description thereof may be omitted.

As shown in FIG. 5, in the stem 1 </ b> C of the present embodiment, the hollow portion 3 opens to the outer peripheral portion 21 on the proximal 2 a side of the main body portion 2. According to such a configuration, as in the above-described embodiment, the medicine can be accommodated in the hollow portion 3 and the medicine can be released to the outside of the stem 1C through the through hole 4. Infection can be prevented. Further, since the medicine can be accommodated in the hollow portion 3 through the opening 31, the workability when the medicine is accommodated in the hollow portion 3 can be improved.
Since other configurations are the same as those of the stems 1A and 1B according to the first and second embodiments described above, description thereof is omitted.

(Fourth embodiment)
Next, an artificial hip joint stem according to a fourth embodiment of the present invention will be described in detail with reference to FIG. In FIG. 6, the same components as those in FIGS. 1 to 5 described above may be denoted by the same reference numerals and description thereof may be omitted.

  As shown in FIG. 6, in the stem 1 </ b> D of the present embodiment, the hollow portion 3 opens in the outer peripheral portion 21 on the proximal 2 a side of the main body portion 2. According to such a configuration, similarly to the above-described embodiment, the medicine can be accommodated in the hollow portion 3 and the medicine can be released to the outside of the stem 1D through the through hole 4. Infection can be prevented. Further, since the medicine can be accommodated in the hollow portion 3 through the opening 31, the workability when the medicine is accommodated in the hollow portion 3 can be improved.

  In the stem 1D, the hollow portion 3 is configured so that a stem inserter can be attached thereto. Specifically, the stem inserter is a substantially columnar member used when the stem 1D is embedded in the femur 100 shown in FIG. 8 or when the stem 1D is removed from the femur 100. The stem inserter has a male screw portion at the tip. The hollow portion 3 has a female screw portion 32 that can be screwed with the male screw portion of the stem inserter. Therefore, in the stem 1D, the hollow portion 3 functions as a part to which the stem inserter can be attached, in addition to the function as a part for accommodating the medicine.

The hollow portion 3 may open to the outer peripheral portion 21 on the distal 2b side of the main body 2 in addition to the outer peripheral portion 21 on the proximal 2a side of the main body 2.
Since other configurations are the same as those of the stems 1A to 1C according to the first to third embodiments described above, the description thereof is omitted.

(Fifth embodiment)
Next, an artificial hip joint stem according to a fifth embodiment of the present invention will be described in detail with reference to FIG. In FIG. 7, the same components as those in FIGS. 1 to 6 described above may be denoted by the same reference numerals and description thereof may be omitted.

  As shown in FIG. 7, in the stem 1 </ b> E of the present embodiment, the hollow portion 3 opens in the outer peripheral portion 21 on the distal 2 b side of the main body portion 2. According to such a configuration, as in the above-described embodiment, the medicine can be accommodated in the hollow portion 3 and the medicine can be released to the outside of the stem 1E through the through-hole 4. Infection can be prevented. Further, since the medicine can be accommodated in the hollow portion 3 through the opening 31, the workability when the medicine is accommodated in the hollow portion 3 can be improved.

  In the stem 1E, the main body 2 has a proximal portion 26 and a distal portion 27. The proximal part 26 is a part located on the proximal 2a side of the main body part 2, and is made of a metal material. The distal portion 27 is a portion located on the distal 2b side of the main body portion 2, and is made of a bone resorbable material that is absorbed into the patient's bone over time. The hollow part 3 is located at the distal part 27. According to these configurations, the following effects can be obtained.

  When the stem 1E is inserted into the femur 100, the distal portion 27 can function as a guide, so that the stem 1E can be smoothly inserted along the medullary cavity of the femur 100. Further, until the stem 1E is embedded in the femur 100 and the proximal portion 26 is joined to the bone, the distal portion 27 can maintain the contact area with the bone and disperse the load. It can be avoided. After the coupling between the proximal portion 26 and the bone is completed, the distal portion 27 is absorbed into the bone over time, so that the stem 1E is substantially composed of the proximal portion 26 and has a small length. become. As a result, it is possible to suppress the occurrence of stress shielding (stress shielding) in a wide range due to the transmission of the load at the distal portion 27 after the operation. Further, since the hollow portion 3 is not located in the proximal portion 26, the strength of the stem 1E can be secured by the proximal portion 26 made of a metal material after the distal portion 27 disappears.

  Examples of the bone resorbable material include hydroxyapatite (HA), β-tricalcium phosphate (β-TCP), polylactic acid (PLA), poly-L-lactic acid (PLLA), or a complex thereof. It is done.

  The bone resorbable material is preferably absorbed into the patient's bone within 3 years, more preferably 1 to 3 years, and even more preferably 6 to 12 months. Confirmation that the distal portion 27 made of the bone resorbable material is absorbed by the bone of the patient can be performed by, for example, X-ray imaging. The distal portion 27 may be absorbed by the patient's bone to such an extent that it loses its function, and may not be completely absorbed by the patient's bone.

  The bending elastic modulus of the distal portion 27 is preferably 0.1 to 80 GPa, more preferably 1 to 40 GPa, and further preferably 5 to 20 GPa. According to such a configuration, since the strength of the distal portion 27 becomes similar to the strength of the human cortical bone, it is considered that it contributes to suppression of thigh pain (Thigh Pain) or stress shielding. It is done. The flexural modulus is a value measured according to JIS K 7171 or JIS R 1601.

A method for fixing the proximal portion 26 and the distal portion 27 to each other is not particularly limited. For example, a proximal member 26 and a distal portion 27 may be secured together using a securing member such as an adhesive.
Since other configurations are the same as those of the stems 1A to 1D according to the first to fourth embodiments described above, the description thereof is omitted.

<Artificial hip joint>
Next, an artificial hip joint according to an embodiment of the present invention will be described in detail with reference to FIG. 8, taking as an example the case of including the stem 1A according to the first embodiment described above.

  As shown in FIG. 8, the artificial hip joint 10 of this embodiment includes a stem 1A, an artificial bone head 11 that fits into the neck portion 6 of the stem 1A, and a socket 12 that slidably accommodates the artificial bone head 11. .

  According to the artificial hip joint 10 of the present embodiment, since the stem 1A is provided, the medicine can be accommodated in the hollow portion 3, and the medicine can be released to the outside of the stem 1A through the through hole 4. Infection in hip replacement can be prevented.

  The artificial bone head 11 is a substantially spherical member, and has a bottomed cylindrical recess 111 located at the center of the bottom surface thereof. The artificial bone head 11 is fitted to the neck portion 6 of the stem 1 </ b> A via the recess 111. Examples of the constituent material of the artificial bone head 11 include metal materials and ceramics. Examples of the metal material include a cobalt-chromium alloy. Examples of ceramics include alumina and zirconia.

  The socket 12 is a substantially cup-shaped member and has a substantially hemispherical recess 121 located at the center of the bottom surface thereof. The socket 12 slidably accommodates the artificial bone head 11 in the recess 121. The socket 12 is fixed to the acetabulum 102 of the hipbone 101. Examples of the constituent material of the socket 12 include a resin material. Examples of the resin material include polyethylene resin.

  In the present embodiment, the case where the stem 1A is used has been described as an example. However, even if the stems 1B to 1E are used instead of the stem 1A, an artificial hip joint having the same effect can be obtained.

  The embodiment according to the present invention has been illustrated above, but the present invention is not limited to the above-described embodiment, and it is needless to say that the embodiment can be arbitrarily set without departing from the gist of the present invention.

  For example, the stems according to the other embodiments may be configured by combining the components of the stems 1A to 1E according to the first to fifth embodiments.

DESCRIPTION OF SYMBOLS 1A ... Artificial hip joint stem 1B ... Artificial hip joint stem 1C ... Artificial hip joint stem 1D ... Artificial hip joint stem 1E ... Artificial hip joint stem 2 ... Main part 2a ... Proximal 2b ... Distal 21 ... Outer peripheral part 22 ... Inner side 23 ... Outer side 24 ... Front side 25 ... Rear side 26 ... Proximal part 27 ... Distal part DESCRIPTION OF SYMBOLS 3 ... Hollow part 31 ... Opening part 32 ... Female thread part 4 ... Through-hole 5 ... Cap 6 ... Neck part 10 ... Artificial hip joint 11 ... Artificial bone head 111- .... Recess 12 ... Socket 121 ... Recess 100 ... Femur 101 ... Hipbone 102 ... Acetabulum

Claims (14)

A substantially rod-shaped body,
A hollow portion located inside the body portion;
A stem for an artificial hip joint, comprising: a through hole penetrating between the hollow portion and an outer peripheral portion of the main body portion.   The stem for an artificial hip joint according to claim 1, wherein a drug is accommodated in the hollow portion and the drug is released to the outside through the through hole. Both the hollow part and the through hole are cylindrical,
The artificial hip joint stem according to claim 1, wherein an inner diameter of the hollow portion is larger than an inner diameter of the through hole.   The artificial hip joint stem according to claim 1, wherein the hollow portion extends along a central axis of the main body portion.   The artificial hip joint stem according to any one of claims 1 to 4, wherein the through hole extends in a direction substantially perpendicular to a central axis of the main body.   The stem for an artificial hip joint according to any one of claims 1 to 5, comprising a plurality of the through holes.   The stem for an artificial hip joint according to claim 6, wherein the plurality of through holes are located at substantially equal intervals along a central axis of the main body portion. The hollow portion is open to the outer peripheral portion of the main body portion,
The stem for an artificial hip joint according to any one of claims 1 to 7, further comprising a cap that closes the opening of the hollow portion.   The artificial hip joint stem according to claim 8, wherein the hollow portion is opened in each of outer peripheral portions on a proximal side and a distal side of the main body portion.   The artificial hip joint stem according to claim 8, wherein the hollow portion opens in an outer peripheral portion on a proximal side of the main body portion.   The stem for an artificial hip joint according to claim 9 or 10, wherein the hollow portion is configured so that a stem inserter can be attached thereto.   The prosthetic hip joint stem according to claim 8, wherein the hollow portion opens in an outer peripheral portion on a distal side of the main body portion. The body portion has a proximal portion made of a metal material and a distal portion made of a bone resorbable material;
The artificial hip joint stem according to claim 12, wherein the hollow portion is located at the distal portion. A stem for an artificial hip joint according to any one of claims 1 to 13,
An artificial bone head that fits into the neck of the stem for the artificial hip joint;
A hip joint comprising a socket for slidably housing the artificial bone head.

Images