Pelvic orthopedic devices

Abstract

To provide a pelvic orthosis for stably covering the bone head of the femur.SOLUTION: A pelvic orthosis comprises a plurality of screw members 10 and 10A-10C. In each of the plurality of screw members 10 and 10A-10C, a fixing part for being fixed by being inserted into the pelvis B1 is formed at one end, and an auxiliary part protruding from the pelvis B1 is formed at the other end. In a state in which the fixing part of each of the plurality of screw members 10 and 10A-10C is fixed to the pelvis, the auxiliary part of each of the plurality of screw members 10 and 10A-10C forms a part of a surface that is extended from the pelvis B1.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] This invention relates to a pelvic orthosis used in the treatment of hip osteoarthritis. [Background technology]

[0002] The hip joint is the joint that connects the pelvis and femur. The hip joint consists of the acetabulum formed in the pelvis and the femoral head at the tip of the femur, with cartilage positioned between the acetabulum and the femur. In a normal hip joint, the acetabulum surrounds approximately four-fifths of the femoral head, stabilizing the joint, but the hip joint is also entirely covered by muscles and tendons to support the forces applied to it.

[0003] There is a known congenital disease in which the acetabulum is born underdeveloped, called acetabular dysplasia. Patients with this condition may develop osteoarthritis of the hip, which causes pain and impaired mobility due to friction between the femoral head and the acetabulum as the cartilage wears away over the years due to weight bearing.

[0004] A procedure called shelf plasty may be performed on patients with acetabular dysplasia. This procedure involves transplanting bone to the pelvis to extend the acetabulum, creating a shelf to expand the area of the acetabulum. This prevents localized load bearing on the femoral head through load distribution. For example, shelf plasty is described in JP 2020-530313.

[0005] However, because the femoral head is spherical, it is difficult to graft bone of a suitable shape onto the femur. The width of the bone grafted in shelf arthroplasty is about 2-3 cm, making it difficult to completely cover the femoral head. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Special Publication No. 2020-530313 Summary of the Invention [Problem to be solved by the invention]

[0007] One object of the present invention is to provide a pelvic orthosis that provides stable coverage of the femoral head. [Means for solving the problem]

[0008] According to one aspect of the present invention, the pelvic orthosis device is a pelvic orthosis device made up of a plurality of rod members, each of which has a fixed portion formed at one end to be inserted into and fixed to the pelvis, and an auxiliary portion formed at the other end to protrude from the pelvis, and when the fixed portion of each of the plurality of rod members is fixed to the pelvis, the auxiliary portion of each of the plurality of rod members protrudes from the pelvis. Lateral to the acetabulum Forms part of an extending surface.

[0009] According to this aspect, when the fixing portion of each of the plurality of rod members is fixed to the pelvis, the auxiliary portion of each of the plurality of rod members forms a part of the surface extending from the pelvis. Therefore, the plurality of rod members receive a part of the force received from the femoral head. Therefore, the force received by the acetabulum from the femoral head can be reduced. As a result, a pelvic orthopedic device that stably covers the femoral head can be provided. Preferably, the auxiliary portion is located above the labrum.

[0014] According to another aspect of the present invention, a pelvic orthosis device is a pelvic orthosis device made up of a plurality of rod members, each of which has a fixed portion formed at one end thereof to be inserted into and fixed to the pelvis, and an auxiliary portion formed at the other end thereof to protrude from the pelvis, and when the fixed portion of each of the plurality of rod members is fixed to the pelvis, the auxiliary portion of each of the plurality of rod members forms a part of a surface extending from the pelvis, The auxiliary part is made of a material softer than the fixed part.

[0015] According to this aspect, the auxiliary part is formed of a material softer than the fixed part, so that the auxiliary part elastically deforms due to the pressure received from the femoral head, thereby reducing the force applied to the femoral head.

[0016] According to another aspect of the present invention, a pelvic orthosis device is a pelvic orthosis device made up of a plurality of rod members, each of which has a fixed portion formed at one end thereof to be inserted into and fixed to the pelvis, and an auxiliary portion formed at the other end thereof to protrude from the pelvis, and when the fixed portion of each of the plurality of rod members is fixed to the pelvis, the auxiliary portion of each of the plurality of rod members forms a part of a surface extending from the pelvis, The device further includes a support member that is disposed between the auxiliary portion and the pelvis and supports the auxiliary portion from above.

[0017] According to this aspect, since a support member that supports the auxiliary part from above is disposed between the auxiliary part and the pelvis, when the auxiliary part is subjected to pressure from the femoral head, the force acting between the fixing part and the pelvis can be dispersed, thereby reducing the force acting on the pelvis per unit area and minimizing deformation of the auxiliary part. A plurality of rods may be placed in the pelvis along the edge of the acetabulum. According to this aspect, it is possible to reduce the variation in the distance between the plurality of rods and the femoral head. The fastening portion may be blasted and / or treated with hydroxyapatite. According to this aspect, the fixing part is subjected to blast processing, thereby improving the bonding strength between the fixing part and the pelvis, and the fixing part is subjected to hydroxyapatite processing, thereby improving the affinity with the pelvis. [Brief explanation of the drawings]

[0018] [Figure 1] 1 is an external perspective view of a screw member according to an embodiment of the present invention; [Figure 2] FIG. [Figure 3] FIG. 1 is a diagram showing the skeleton including the left and right hip joints. [Figure 4] This is an enlarged view of the left hip joint. [Figure 5] FIG. 1 is a perspective view showing an example of how a pelvic orthosis device is attached to a pelvis. [Figure 6] FIG. 1 is a left side view of the left hip joint. [Figure 7] This is a cross-sectional view of the left hip joint in the XZ plane. [Figure 8] This is a cross-sectional view of the left hip joint in the XY plane. [Figure 9] FIG. 10 is a side view of a screw member according to a first modified example. [Figure 10] FIG. 10 is a cross-sectional view of a screw member according to a first modified example. [Figure 11] FIG. 10 is a diagram schematically showing the state of the left hip joint to which the pelvic orthopedic device according to the second modified example is attached. DETAILED DESCRIPTION OF THE INVENTION

[0019] Hereinafter, a pelvic orthosis device according to an embodiment of the present invention will be described with reference to the drawings. In the following description, the same components are designated by the same reference numerals. Their names and functions are also the same. Therefore, detailed description thereof will not be repeated.

[0020] A pelvic orthopedic device 1 in this embodiment includes multiple screw members 10. Here, an example in which the pelvic orthopedic device 1 includes four screw members 10 will be described. FIG. 1 is an external perspective view of a screw member according to one embodiment of the present invention, and FIG. 2 is a side view of the screw member of FIG. 1. Referring to FIGS. 1 and 2, the screw member 10 is a cylindrical rod and includes a fixed portion 11 and an auxiliary portion 13. The fixed portion 11 is formed at one end of the screw member 10 and is a portion that is inserted into and fixed to the pelvis. A screw thread is formed on the fixed portion 11. The auxiliary portion 13 is formed at the other end of the screw member 10 and is a portion that protrudes from the pelvis. A groove 13a into which a surgical tool is inserted is formed on the end surface of the auxiliary portion 13. With the tool engaged with the groove 13a, the screw member 10 rotates about the rotation center axis as the tool rotates. This causes the fixed portion 11 of the screw member 10 to be screwed into the pelvis.

[0021] The screw member 10 is preferably made of a material that has a high affinity with bone. The screw member 10 is made of, but is not limited to, a composite material such as a carbon fiber reinforced composite material, or a bioactive artificial bone. Examples of artificial bone include hydroxyapatite and β-tricalcium phosphate (β-TCP). The screw member 10 may also be made of other materials such as metal or resin.

[0022] The fixing portion 11 is preferably subjected to a blasting process in order to improve the fixing force to the bone.

[0023] The length of the screw member 10 is 8.5 to 15 mm, the length of the fixing portion 11 is 3.5 to 5 mm, and the length of the auxiliary portion 13 is 3.5 to 5 mm.

[0024] Here, the hip joint and its surrounding area will be described. Figure 3 shows a skeleton including left and right hip joints. Figure 4 is an enlarged view of a left hip joint. As shown in Figure 3, the left hip joint J1 is located between the pelvis B1 and the left femur B2, and the right hip joint J2 is located between the pelvis B1 and the right femur B3. Below, the left hip joint J1 will be described as a representative example.

[0025] As shown in Figure 4, the left hip joint J1 is composed of the acetabulum B11 of the pelvis B1 and the femoral head B21 of the left femur B2. A labrum 31 is located on the edge of the acetabulum B11. Various other tissues, such as cartilage 33, are present within the left hip joint J1. The left hip joint J1 is enclosed by a joint capsule 35.

[0026] Fig. 5 is a perspective view showing an example of how a pelvic orthopedic device is attached to a pelvis. Fig. 5 is a view of the area around the left hip joint J1 of the pelvis as seen from diagonally forward and diagonally upward to the left. In Fig. 5, four screw members 10 are positioned on the left side surface of the pelvis B1 on the side of the left hip joint J1, and the direction of embedding is indicated by arrows. Four holes 14, 14A to 14C are formed in the pelvis B1, and the screw members 10, 10A to 10C are screwed into the four formed holes 14, 14A to 14C, respectively, using a tool, thereby embedding each of the screw members 10, 10A to 10C into the pelvis B1. With each of the screw members 10, 10A to 10C embedded in the pelvis B1, the fixing portion 11 is fixed to the pelvis B1. When the screw members 10, 10A to 10C are embedded in the pelvis B1, the auxiliary portion 13 of each of the screw members 10, 10A to 10C forms a part of a surface extending from the pelvis B1.

[0027] Hereinafter, the front-to-back direction of a person will be referred to as the Y direction, the left-to-right direction of a person as the X direction, and the up-to-down direction of a person as the Z direction. We will also define the Y axis parallel to the Y direction, the X axis parallel to the X direction, and the Z axis parallel to the Z direction. The X axis, Y axis, and Z axis are perpendicular to each other.

[0028] 6 to 8 are diagrams showing the area around the left hip joint when a pelvic orthopedic device is attached to the pelvis. Fig. 6 is a left side view of the left hip joint J1, Fig. 7 is a cross-sectional view of the left hip joint J1 in the XZ plane, and Fig. 8 is a cross-sectional view of the left hip joint J1 in the XY plane. The XZ plane is a plane parallel to the X-axis and Z-axis. The XY plane is a plane parallel to the X-axis and Y-axis.

[0029] 6 and 8, the four screw members 10, 10A to 10C are arranged at intervals from the front. The intervals at which the four screw members 10, 10A to 10C are arranged are, for example, 5 mm to 10 mm. The intervals at which the four screw members 10, 10A to 10C are arranged may also be equal.

[0030] The four screw members 10, 10A to 10C are arranged along the end of the acetabulum B11 of the pelvis B1. A specific description will be given below.

[0031] As shown in FIG. 6, the end of the acetabulum B11 of the pelvis B1 has an upwardly convex curve in the YZ plane. Therefore, the four screw members 10, 10A-10C are arranged at different positions in the Y direction but at different positions in the Z direction. Specifically, screw member 10 is arranged below screw member 10A, which is arranged below screw member 10B, and screw member 10B is arranged above screw member 10C. Because the femoral head B21 of the left femur B2 has an upwardly convex curve in the YZ plane, the four screw members 10, 10A-10C are arranged so that the distances from the femoral head B21 of the left femur B2 to each of the four screw members 10, 10A-10C are approximately the same in the YZ plane. Therefore, variation in the distance between the plurality of screw members 10, 10A-10C and the femoral head B21 can be reduced.

[0032] As shown in Figure 7, the screw member 10 is embedded in the pelvis B1 obliquely upward. In other words, the screw member 10 is embedded in the pelvis B1 so that the end of the screw member 10 on the fixed portion 11 side is positioned higher than the end of the screw member 10 on the auxiliary portion 13 side. Therefore, the auxiliary portion 13 of the screw member 10 is oriented in the XZ plane substantially parallel to a line tangent to the curve of the acetabulum B11 at the end of the acetabulum B11 of the pelvis B1. Because the femoral head B21 of the left femur B2 has an upwardly convex curve in the XZ plane, by embedding the screw member 10 obliquely upward in the pelvis B1, the distance between the end of the auxiliary portion 13 of the screw member 10 opposite the fixed portion 11 and the femoral head B21 of the left femur B2 can be made as small as possible.

[0033] As shown in FIG. 8, in the XY plane, the end of the acetabulum B11 of the pelvis B1 forms a concave curve to the right. The four screw members 10, 10A to 10C are arranged perpendicular to the pelvis B1. Therefore, the contact area between the embedded fixing portion 11 and the pelvis B1 is larger in each of the screw members 10, 10A to 10C than when the screw members 10, 10A to 10C are embedded in the pelvis B1 at an angle. Therefore, each of the screw members 10, 10A to 10C can be more reliably fixed to the pelvis B1. Note that each of the screw members 10, 10A to 10C may be arranged in the pelvis B1 so as to be parallel to the X direction in the XY plane.

[0034] Area S indicated by a dotted line in Fig. 8 is a surface that comes into contact with the screw members 10, 10A to 10C and extends from the pelvis B1. As shown in Fig. 7, a force that pushes the femoral head B21 of the left femur B2 upward is applied to the acetabulum B11 of the pelvis B1 and area S. Area S comes into contact with the screw members 10, 10A to 10C above.

[0035] Between the screw members 10, 10A to 10C and the femoral head B21 of the left femur B2, there are the glenoid labrum 31 and the joint capsule 35. Therefore, the force applied to the region S from the femoral head B21 of the left femur B2 is applied to the screw members 10, 10A to 10C via the glenoid labrum 31 and the joint capsule 35, or via the joint capsule 35. Therefore, part of the force pushing the femoral head B21 of the left femur B2 upward is applied to the screw members 10, 10A to 10C.

[0036] Therefore, when the screw members 10, 10A to 10C are attached to the pelvis B1, a force pushing the femoral head B21 upward is applied to the acetabulum B11 and the region S, so the force applied to the acetabulum B11 is smaller than when the screw members 10, 10A to 10C are not attached, and therefore damage to the cartilage 33 between the acetabulum B11 and the femoral head B21 is reduced.

[0037] <First Modification> The pelvic orthopedic device 1 in the first modified example has a modified screw member 10. FIG. 9 is a side view of the screw member in the first modified example. FIG. 10 is a cross-sectional view of the screw member in the first modified example. With reference to FIGS. 9 and 10, the screw member 10 in the first modified example includes a threaded portion 21 and a covering member 23. The covering member 23 has a hollow cylindrical shape. The inner diameter of the covering member 23 is the same as or slightly larger than the diameter of the threaded portion 21. When the threaded portion 21 penetrates the covering member 23, the threaded portion 21 and the covering member 23 are coupled and integrated. The portion of the threaded portion 21 that is covered by the covering member 23 is the auxiliary portion 13, and the portion of the threaded portion 21 that is not covered by the covering member 23 is the fixed portion 11.

[0038] The diameter of the screw head of the screw portion 21 is larger over a predetermined length from the end on the side where the groove 13a is formed than the diameter of the remaining portion. As a result, when the fixing portion 11 of the screw portion 21 is fixed to the pelvis B1, one end of the covering member 23 abuts against the pelvis B1 and the other end abuts against the screw head, and the covering member 23 is sandwiched between the pelvis B1 and the screw head of the screw portion 21. This restricts relative movement between the covering member 23 and the screw portion 21.

[0039] The material of the screw portion 21 is metal. The covering member 23 is formed of a composite material such as a carbon fiber reinforced composite material, or artificial bone. Examples of artificial bone include hydroxyapatite and β-tricalcium phosphate (β-TCP).

[0040] For this reason, the covering member 23 is made of a material softer than the threaded portion 21. Therefore, the covering member 23 elastically deforms due to the pressure received from the femoral head B21 of the left femur B2, and the force applied to the femoral head B21 can be reduced.

[0041] The fixing portion 11 of the screw portion 21 has a thread formed thereon. The fixing portion 11 of the screw portion 21 is preferably subjected to a blasting treatment to improve the fixing force to the bone. The fixing portion 11 of the screw portion 21 may also be subjected to a hydroxyapatite treatment to improve affinity with the bone.

[0042] Instead of passing the threaded portion 21 through the covering member 23, the screw member 10A may be formed so that the covering member 23 is integrated with the threaded portion 21 by being processed to cover the threaded portion 21.

[0043] <Second Modification> Pelvic orthopedic device 1 in the second modification has support members 15 that support four screw members 10, 10A to 10C. Here, support members 15 that support screw members 10 will be described.

[0044] FIG. 11 is a schematic diagram showing the state of a left hip joint to which a pelvic orthopedic device according to the second modified example is attached. FIG. 11 is a cross-sectional view of the left hip joint J1 in the XZ plane. As shown in FIG. 11, a support member 15 is disposed so as to contact the side of the screw member 10 opposite the acetabulum B11. The support member 15 is a triangular flat plate, and is disposed so that one side contacts the screw member 10 and the other side contacts the pelvis B1. The support member 15 may be fitted to the screw member 10 or may be formed integrally with the screw member 10. The support member 15 is positioned above the screw member 10, and therefore supports the screw member 10 from above. This prevents the screw member 10 from tilting upward when a force is applied to the screw member 10 from below.

[0045] As described above, the pelvic orthopedic device 1 in this embodiment is comprised of a plurality of screw members 10, 10A to 10C. Each of the plurality of screw members 10, 10A to 10C has a fixing portion 11 at one end that is inserted into and fixed to the pelvis B1, and an auxiliary portion 13 that protrudes from the pelvis B1 at the other end. When the fixing portion 11 of each of the plurality of screw members 10, 10A to 10C is fixed to the pelvis B1, the auxiliary portion 13 of each of the plurality of screw members 10, 10A to 10C forms a part of a surface extending from the pelvis B1. Therefore, when the fixing portion 11 of each of the plurality of screw members 10, 10A to 10C is fixed to the pelvis B1, the auxiliary portion 13 of each of the plurality of screw members 10, 10A to 10C forms a part of a surface extending from the pelvis B1. Therefore, in addition to the acetabulum B11, the plurality of screw members 10, 10A to 10C receive a portion of the pressure from the femoral head B21. Therefore, the force that the acetabulum B11 receives from the femoral head B21 can be reduced.

[0046] Furthermore, the plurality of screw members 10, 10A to 10C may be disposed in the pelvis B1 along the end of the acetabulum B11, thereby making it possible to reduce variations in the distance between the plurality of screw members 10, 10A to 10C and the femoral head B21.

[0047] Furthermore, the fixing part 11 may be subjected to a blasting treatment and / or a hydroxyapatite treatment. The bonding strength between the fixing part 11 that has been subjected to a blasting treatment and the pelvis can be improved. Furthermore, the affinity between the fixing part 11 that has been subjected to a hydroxyapatite treatment and the pelvis can be improved.

[0048] The auxiliary part 13 in the first modified example is formed of a material softer than the fixed part 11. Therefore, the auxiliary part 13 is elastically deformed by the pressure received from the femoral head B21, and the force applied to the femoral head B21 can be reduced.

[0049] The pelvic orthopedic device 1 in the second modification includes a support member 15 that is disposed between the surface of the auxiliary part 13 opposite the acetabulum B11 and the pelvis B1 and supports the auxiliary part 13. This makes it possible to distribute the force acting between the fixing part 11 and the pelvis B1 when the auxiliary part 13 receives pressure from the femoral head B21. This reduces the force acting per unit area on the pelvis B1 and also reduces deformation of the auxiliary part 13.

[0050] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is defined by the claims, not by the above description, and is intended to include all modifications within the meaning and scope of the claims. [Explanation of symbols]

[0051] 1 Pelvic orthopedic device, 10, 10A to 10C screw member, 11 fixing part, 13 auxiliary part, 13a groove, 14 hole, 15 support member, 21 screw member, 23 covering member, 31 labrum, 33 cartilage, 35 joint capsule, B1 pelvis, B11 acetabulum, B2 left femur, B21 femoral head, B3 right femur, J1 left hip joint, J2 right hip joint, S region.

Claims

1. A pelvic orthosis device consisting of a plurality of rods, Each of the plurality of rods has a fixing portion formed at one end to be inserted into and fixed to the pelvis, and an auxiliary portion formed at the other end to protrude from the pelvis, A pelvic orthosis device, wherein when the fixed portion of each of the plurality of rod members is fixed to the pelvis, the auxiliary portion of each of the plurality of rod members forms part of a surface extending outward from the pelvis to the acetabulum.

2. A pelvic orthopedic device as described in claim 1, wherein the auxiliary part is located above the labrum.

3. A pelvic orthosis device consisting of a plurality of rods, Each of the plurality of rods has a fixing portion formed at one end to be inserted into and fixed to the pelvis, and an auxiliary portion formed at the other end to protrude from the pelvis, When the fixed portion of each of the plurality of rod members is fixed to the pelvis, the auxiliary portion of each of the plurality of rod members forms a part of a surface extending from the pelvis, A pelvic orthosis device, wherein the auxiliary part is formed of a material softer than the fixed part.

4. A pelvic orthosis device consisting of a plurality of rods, Each of the plurality of rods has a fixing portion formed at one end to be inserted into and fixed to the pelvis, and an auxiliary portion formed at the other end to protrude from the pelvis, When the fixed portion of each of the plurality of rod members is fixed to the pelvis, the auxiliary portion of each of the plurality of rod members forms a part of a surface extending from the pelvis. The pelvic orthosis device further comprises a support member disposed between the auxiliary part and the pelvis, and supporting the auxiliary part from above.

5. The pelvic orthosis of any one of claims 1 to 4, wherein the plurality of rods are positioned in the pelvis along the edge of the acetabulum.

6. The pelvic orthosis device according to any one of claims 1 to 5, wherein the fixing portion is subjected to a blast treatment and / or a hydroxyapatite treatment.

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