JP4953774B2

JP4953774B2 - Femoral component

Info

Publication number: JP4953774B2
Application number: JP2006303190A
Authority: JP
Inventors: 純彦前野
Original assignee: Kyocera Medical Corp
Current assignee: Kyocera Medical Corp
Priority date: 2006-11-08
Filing date: 2006-11-08
Publication date: 2012-06-13
Anticipated expiration: 2026-11-08
Also published as: JP2008119051A

Description

本発明は、人工股関節において大腿骨の近位部側に埋入されて用いられる大腿骨用コンポーネントに関する。 The present invention relates to a femoral component that is used by being implanted on the proximal side of a femur in an artificial hip joint.

従来より、大腿骨や股関節において骨折したりあるいは変形性股関節症やリウマチなどの疾患を患った患者に対して、人工股関節置換術が行われている。この人工股関節置換術では、骨盤側に配置されるコンポーネントと大腿骨側に配置される大腿骨用コンポーネントとで構成される人工股関節が用いられる。大体骨用コンポーネントは、人工股関節において大腿骨の近位部側に埋入されて用いられる。なお、以下の説明においては、人体において相対的に心臓に近い側に位置することを「近位」といい、遠い側に位置することを「遠位」という。また、人体の中心線に近い側を「内側」といい、遠い側を「外側」という。 Conventionally, artificial hip joint replacement has been performed on patients suffering from fractures in the femur and hip joint or suffering from diseases such as osteoarthritis of the hip and rheumatism. In this hip replacement, a hip prosthesis composed of components arranged on the pelvis side and components for the femur arranged on the femur side is used. The roughly bone component is used by being implanted on the proximal side of the femur in an artificial hip joint. In the following description, positioning on the side of the human body that is relatively close to the heart is referred to as “proximal”, and positioning on the far side is referred to as “distal”. The side closer to the center line of the human body is called “inside” and the far side is called “outside”.

上述のような大腿骨用コンポーネントとして、特許文献１および特許文献２に記載されたものが知られている。特許文献１に記載の大腿骨用コンポーネントは、頭部部材と軸部部材との２つの部材から構成され、これらの部材が結合されることで一体化されるモジュール式人工股関節である。特許文献２に記載の大腿骨用コンポーネントは、基部セグメントと末梢部セグメントと骨幹端セグメントとの３つの部材から構成されるモジュールヒップ補綴であり、これらの基部セグメントおよび末梢部セグメントがそれぞれ骨幹端セグメントに対して係合することで一体化される。 As the above-described components for the femur, those described in Patent Document 1 and Patent Document 2 are known. The femoral component described in Patent Document 1 is a modular artificial hip joint that is composed of two members, a head member and a shaft member, and is integrated by combining these members. The femoral component described in Patent Document 2 is a module hip prosthesis composed of three members, a base segment, a distal segment, and a metaphyseal segment, and these base segment and distal segment are respectively metaphyseal segments. To be integrated.

特表平１０−５０９０６４号公報Japanese National Patent Publication No. 10-509064 特表２００３−５２６４５４号公報Special table 2003-526454 gazette

特許文献１、２に記載された大腿骨用コンポーネントにおいては、大腿骨用コンポーネントが複数の部材で構成されているため、一体化される制約条件の下で各構成部材の形状および寸法をある程度変更して設計できるようになっている。しかしながら、特許文献１または特許文献２に記載された大腿骨用コンポーネントの場合、構成部材が一体化されるための制約条件が大きいため、各構成部材の設計を変更して得られる大腿骨用コンポーネント全体としての形態や寸法がかなり限定されてしまうことになる。手術を行う術者は、患者の骨形状や骨質、骨損失や疾患の状況等に応じてその患者に最適な形態や寸法の大腿骨用コンポーネントを選択して用いる必要があるが、上述のように、特許文献１または特許文献２に記載された大腿骨用コンポーネントのみでは、対応できる形態や寸法が限定されるため、患者の状況に応じた最適な大腿骨コンポーネントの選択にあたって限界がある。 In the femoral component described in Patent Documents 1 and 2, since the femoral component is composed of a plurality of members, the shape and dimensions of each component are changed to some extent under the constraints to be integrated. And can be designed. However, in the case of the femoral component described in Patent Document 1 or Patent Document 2, since the restrictive condition for integrating the constituent members is large, the femoral component obtained by changing the design of each constituent member The form and dimensions as a whole are considerably limited. The surgeon performing the operation needs to select and use the femoral component with the optimal shape and dimensions for the patient according to the patient's bone shape and quality, bone loss and disease status, etc. In addition, only the femoral component described in Patent Document 1 or Patent Document 2 has a limitation in selecting an optimal femoral component according to the patient's situation because the form and dimensions that can be handled are limited.

また、術者は、上述のように、患者の状況に応じて最適な形態や寸法の大腿骨用コンポーネントを選択して用いる必要があり、手術前のレントゲン写真やＣＴ画像から得られる情報に基づいて、その患者に最適な大腿骨用コンポーネントを判断して準備する。しかし、レントゲン写真やＣＴ画像からの情報だけでは、患者に最適な形態や寸法の大腿骨用コンポーネントを正確に判断することが難しい。このため、手術に際して、術者は、複数の形態や寸法の大腿骨用コンポーネントを準備しなければならない場合も多く、とくに手術前の判断が難しい場合には、非常に多くの種類の形態や寸法の大腿骨用コンポーネントを準備しなくてはならないことになる。また、場合によっては、手術前に準備した大腿骨用コンポーネントをその手術において使用することができない場合や、その手術において使用できてもまた再手術をして大腿骨用コンポーネントの取り換えを行うことが必要となる場合もある。 In addition, as described above, the operator needs to select and use a femoral component having an optimal form and size according to the patient's situation, and is based on information obtained from X-rays and CT images before surgery. Determine and prepare the femoral component that best fits the patient. However, it is difficult to accurately determine the femoral component having the optimal shape and dimensions for the patient only by information from X-ray images and CT images. For this reason, surgeons often have to prepare several femoral components in multiple forms and dimensions, especially when it is difficult to make judgments before surgery. The femoral component must be prepared. In some cases, the femoral component prepared before the operation cannot be used in the operation, or even if it can be used in the operation, the reoperation is performed to replace the femoral component. It may be necessary.

本発明は、上記実情に鑑みることにより、患者の骨形状や骨質、骨損失や疾患の状況等に応じてその患者に最適な形態や寸法の大腿骨用コンポーネントを選択するに際して柔軟に幅広く対応することができ、手術中であっても少ない部材点数で種々の形態や寸法に対応して構成することができる大腿骨用コンポーネントを提供することを目的とする。 In view of the above circumstances, the present invention can flexibly support a wide range of femoral components in the form and size optimal for the patient according to the bone shape, bone quality, bone loss, disease status, etc. of the patient. An object of the present invention is to provide a femoral component that can be configured corresponding to various forms and dimensions with a small number of members even during surgery.

Means and effects for solving the problems

本発明は、人工股関節において大腿骨の近位部側に埋入されて用いられる大腿骨用コンポーネントに関する。
そして、本発明の大腿骨用コンポーネントは、上記目的を達成するために以下のようないくつかの特徴を有している。即ち、本発明は、以下の特徴を単独で、若しくは、適宜組み合わせて備えている。 The present invention relates to a femoral component that is used by being implanted on the proximal side of a femur in an artificial hip joint.
And the component for femurs of this invention has the following some features in order to achieve the said objective. That is, the present invention comprises the following features alone or in appropriate combination.

上記目的を達成するための本発明に係る大腿骨用コンポーネントにおける第１の特徴は、人工股関節において用いられる骨頭ボールに嵌合する首部部材と、前記首部部材に対して嵌合可能であるとともに前記首部部材に嵌合する側に向かってテーパ状に広がるように形成され、表面の少なくとも一部に粗面化処理が施されているテーパ状部材と、前記首部部材に対して嵌合可能であるとともに前記テーパ状部材に対しても嵌合可能に設けられ、棒状に形成された棒状部材と、を備えていることである。 In order to achieve the above object, the first feature of the femoral component according to the present invention includes a neck member that fits a head ball used in an artificial hip joint, a neck member that can be fitted to the neck member, and the neck member. A taper-shaped member that is formed so as to expand in a tapered shape toward the side to be fitted to the neck member and is roughened on at least a part of the surface thereof, and can be fitted to the neck member. And a rod-shaped member that is provided so as to be fitted to the tapered member and is formed in a rod shape.

この構成によると、首部部材とテーパ状部材と棒状部材とを全て組み合わせることによって、または首部部材およびテーパ状部材を組み合わせることによって、あるいは首部部材および棒状部材を組み合わせることによって、それぞれ形態や寸法の異なる大腿骨用コンポーネントを形成することができる。このため、患者の骨形状や骨質、骨損失や疾患の状況等に応じてその患者に最適な形態や寸法の大腿骨用コンポーネントを高い自由度で選択することができる。そして、組み合わせ自由度の高い各構成部材を適宜組み合わせるだけで種々の形態や寸法の大腿骨用コンポーネントを極めて容易に形成することができる。さらに、首部部材、テーパ状部材、および棒状部材の各構成部材の形状や寸法を適宜変更することで幅広い形態と寸法に亘る大腿骨用コンポーネントを容易に設計することができる。また、手術に際しては、少ない部材点数の各構成部材を準備しておくだけで、手術中の患者の状況に応じその場で柔軟に最適な形態や寸法の大腿骨用コンポーネントを形成して対応することができる。
したがって、本発明によると、患者の骨形状や骨質、骨損失や疾患の状況等に応じてその患者に最適な形態や寸法の大腿骨用コンポーネントを選択するに際して柔軟に幅広く対応することができ、手術中であっても少ない部材点数で種々の形態や寸法に対応して構成することができる大腿骨用コンポーネントを提供することができる。 According to this configuration, the shape and dimensions are different by combining all of the neck member, the tapered member, and the rod-shaped member, or by combining the neck member and the tapered member, or by combining the neck member and the rod-shaped member. A femoral component can be formed. Therefore, it is possible to select a femoral component having a shape and size optimal for the patient according to the bone shape and quality of the patient, the bone loss, the state of the disease, and the like with a high degree of freedom. And the component for femurs of various forms and dimensions can be very easily formed only by combining each structural member with a high combination freedom degree suitably. Furthermore, the femoral component over a wide range of forms and dimensions can be easily designed by appropriately changing the shape and dimensions of each component member of the neck member, the tapered member, and the rod-like member. In addition, during the operation, it is possible to flexibly form the femoral component of the optimal shape and size on the spot according to the situation of the patient during the operation by preparing each component member with a small number of members. be able to.
Therefore, according to the present invention, according to the patient's bone shape and bone quality, bone loss or disease status, etc., it can be flexibly and widely used when selecting the femoral component of the optimal shape and size for the patient, It is possible to provide a femoral component that can be configured corresponding to various forms and dimensions with a small number of members even during surgery.

本発明に係る大腿骨用コンポーネントにおける第２の特徴は、前記首部部材における本体部分に対する前記骨頭ボールに嵌合する突出嵌合部の突出方向の角度と、前記突出嵌合部の前記本体部分からの突出長さ寸法と、のうちの少なくともいずれかが異なる複数の前記首部部材が備えられていることである。 The second feature of the femoral component according to the present invention is that the protrusion direction angle of the protrusion fitting portion that fits the head ball with respect to the main body portion of the neck member, and the main body portion of the protrusion fitting portion. A plurality of the neck members different from each other in at least one of the protruding length dimensions.

この構成によると、本体部分に対する突出嵌合部の突出方向の角度と、突出嵌合部の本体部分からの突出長さとのうちの少なくともいずれかが異なる複数の首部部材が備えられているため、手術の際に、かかる複数の首部部材のうちから患者の状況に最適な形状や寸法の首部部材を適宜選択することができる。したがって、形状や寸法のバリエーションをもたせた複数の首部部材を準備しておくだけで、部材点数を増加させることなく、さらに多くの種々の形態や寸法の大腿骨コンポーネントを容易に形成することができる。 According to this configuration, since the plurality of neck members having at least one of the angle in the protruding direction of the protruding fitting portion with respect to the main body portion and the protruding length from the main body portion of the protruding fitting portion are provided, At the time of surgery, a neck member having a shape and size optimal for the patient's situation can be appropriately selected from the plurality of neck members. Accordingly, it is possible to easily form femoral components of many different forms and dimensions without increasing the number of members simply by preparing a plurality of neck members having variations in shape and dimensions. .

本発明に係る大腿骨用コンポーネントにおける第３の特徴は、テーパ状に広がるように形成されている前記テーパ状部材における広がり部分の広がり方向の寸法と、前記テーパ状部材における前記広がり方向と直交する幅方向の寸法と、のうちの少なくともいずれかが異なる複数の前記テーパ状部材が備えられていることである。 The third feature of the femoral component according to the present invention is that the dimension of the expanding portion of the tapered member formed so as to expand in a tapered shape is orthogonal to the expanding direction of the tapered member. A plurality of the tapered members differing in at least one of the dimensions in the width direction are provided.

この構成によると、広がり部分の広がり方向の寸法と幅方向の寸法とのうちの少なくともいずれかが異なる複数のテーパ状部材が備えられているため、手術の際に、かかる複数のテーパ状部材のうちから患者の状況に最適な形状や寸法のテーパ状部材を適宜選択することができる。したがって、形状や寸法のバリエーションをもたせた複数のテーパ状部材を準備しておくだけで、部材点数を増加させることなく、さらに多くの種々の形態や寸法の大腿骨コンポーネントを容易に形成することができる。 According to this configuration, since the plurality of tapered members having at least one of the dimension in the spreading direction and the dimension in the width direction of the spreading portion are provided, the plurality of tapered members are provided during surgery. A tapered member having a shape and size optimal for the patient's situation can be selected as appropriate. Therefore, it is possible to easily form femoral components of many different forms and dimensions without increasing the number of members only by preparing a plurality of tapered members having variations in shape and dimensions. it can.

本発明に係る大腿骨用コンポーネントにおける第４の特徴は、前記棒状部材における長手方向の寸法と当該長手方向と直交する断面の径寸法とのうちの少なくともいずれかが異なる複数の前記棒状部材が備えられていることである。 A fourth feature of the femoral component according to the present invention is the provision of a plurality of the rod-like members in which at least one of a longitudinal dimension of the rod-like member and a cross-sectional diameter perpendicular to the longitudinal direction is different. It is being done.

この構成によると、長手方向の寸法と断面の径寸法とのうちの少なくともいずれかが異なる複数の棒状部材が備えられているため、手術の際に、かかる複数の棒状部材のうちから患者の状況に最適な形状や寸法の棒状部材を適宜選択することができる。したがって、形状や寸法のバリエーションをもたせた複数の棒状部材を準備しておくだけで、部材点数を増加させることなく、さらに多くの種々の形態や寸法の大腿骨コンポーネントを容易に形成することができる。 According to this configuration, since the plurality of rod-shaped members having at least one of the longitudinal dimension and the cross-sectional diameter dimension are different, the situation of the patient is selected from the plurality of rod-shaped members during the operation. It is possible to appropriately select a rod-shaped member having an optimal shape and size. Therefore, it is possible to easily form femoral components of many different forms and dimensions without increasing the number of members only by preparing a plurality of rod-shaped members having variations in shape and dimensions. .

本発明に係る大腿骨用コンポーネントにおける第５の特徴は、前記複数の棒状部材のうち前記長手方向の寸法が最も長い棒状部材において、その外周に前記長手方向に沿って形成された複数条の線状突起が形成されていることである。 A fifth feature of the femoral component according to the present invention is that, among the plurality of rod-shaped members, the rod-shaped member having the longest longitudinal dimension has a plurality of lines formed on the outer periphery thereof along the longitudinal direction. That is, a protrusion is formed.

この構成によると、複数の棒状部材のうち最も長い寸法の棒状部材と首部部材とを組み合わせて大腿骨用コンポーネントを形成するような場合においても、組み合わされる棒状部材にはその外周に複数条の線状突起が長手方向に沿って形成されているため、かかる線状突起によって大腿骨内に大腿骨用コンポーネントが容易にしっかりと固定されることになる。 According to this configuration, even in the case of forming the femoral component by combining the longest-sized rod-shaped member and the neck member among the plurality of rod-shaped members, the combined rod-shaped member has a plurality of lines on its outer periphery. Since the protuberance is formed along the longitudinal direction, the femoral component is easily and firmly fixed in the femur by the linear protrusion.

本発明に係る大腿骨用コンポーネントにおける第６の特徴は、嵌合した前記首部部材および前記テーパ状部材を連結可能であるとともに、嵌合した前記首部部材および前記棒状部材を連結可能であるネジ部材をさらに備え、前記首部部材は、前記ネジ部材の先端側が貫通する貫通孔が形成され、前記ネジ部材は、先端側に形成され、弾性変形することで前記テーパ状部材または前記棒状部材に形成された雌ネジ部よりも縮径して当該雌ネジ部に挿入される弾性変形部と、前記テーパ状部材または前記棒状部材において前記雌ネジ部よりも内部側に形成された空隙部分まで前記弾性変形部が挿入されて当該弾性変形部が弾性回復したときに、前記テーパ状部材または前記棒状部材に対して内部で係止する係止部と、前記係止部に対して前記弾性変形部の側とは反対側に形成され、前記雌ネジ部と螺合する雄ネジ部と、を有していることである。 A sixth feature of the femoral component according to the present invention is that the fitted neck portion and the tapered member can be coupled, and the fitted neck portion and the rod-shaped member can be coupled. The neck member is formed with a through-hole through which the distal end side of the screw member penetrates, and the screw member is formed on the distal end side, and is elastically deformed to form the tapered member or the rod-shaped member. The elastic deformation portion that has a diameter smaller than that of the female screw portion and is inserted into the female screw portion, and the elastic deformation to the gap portion formed on the inner side of the female screw portion in the tapered member or the rod-shaped member. When the elastic member is inserted and the elastically deforming portion recovers elastically, the locking portion that locks the taper-shaped member or the rod-shaped member inside, and the elasticity against the locking portion To the side of the shaped part is formed on the opposite side, it is that it has a male screw portion that is screwed with the female screw portion.

この構成によると、ネジ部材の雄ネジ部をテーパ状部材または棒状部材の雌ネジ部と螺合させながら、弾性変形部を雌ネジ部よりも縮径させてテーパ状部材または棒状部材の内部の空隙部分まで挿入すると、弾性変形部が弾性回復することでネジ部材の掛止部がテーパ状部材または棒状部材とその内部で掛止することになる。このため、ネジ部材の抜け止めが確実に図られることになり、首部部材およびテーパ状部材、または、首部部材および棒状部材が外れることを確実に防止できる連結構造を実現することができる。 According to this configuration, while the male screw portion of the screw member is screwed with the female screw portion of the taper-shaped member or the rod-shaped member, the elastic deformation portion is reduced in diameter than the female screw portion so that the inside of the taper-shaped member or the rod-shaped member. When the gap portion is inserted, the elastic deformation portion recovers elastically, so that the latching portion of the screw member is latched with the tapered member or the rod-shaped member inside thereof. For this reason, the screw member is surely prevented from coming off, and it is possible to realize a connection structure that can reliably prevent the neck member and the tapered member, or the neck member and the rod-like member from coming off.

本発明に係る大腿骨用コンポーネントにおける第７の特徴は、前記弾性変形部は、前記ネジ部材の先端側が可撓な二股構造として形成されることで設けられていることである。 A seventh feature of the femoral component according to the present invention is that the elastically deformable portion is provided by forming the distal end side of the screw member as a flexible bifurcated structure.

この構成によると、ネジ部材の先端側を可撓な二股構造に形成することで、ネジ部材の先端側に設けられる弾性変形部を簡易な構造で容易に形成することができる。 According to this structure, the elastic deformation part provided in the front end side of a screw member can be easily formed with a simple structure by forming the front end side of a screw member in a flexible forked structure.

以下、本発明を実施するための形態について図面を参照しつつ説明する。なお、本発明は、人工股関節において大腿骨の近位部側に埋入されて用いられる大腿骨用コンポーネントとして広く適用することができるものである。 Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The present invention can be widely applied as a femoral component that is used by being embedded in the proximal portion of the femur in an artificial hip joint.

（第１実施形態）
図１は、本発明の第１実施形態に係る大腿骨用コンポーネント１を示す図であって、組み合わされていない状態で各構成部材を上下に配置して示す正面図（図１（ｂ））、および図１（ｂ）の平面図（図１（ａ））を示したものである。また、図２は、構成部材が組み合わされた状態を例示する大腿骨用コンポーネント１の斜視図である。また、図３は、本実施形態の大腿骨用コンポーネント１が人工股関節において用いられた例を説明する模式図であって、左股関節に対して人工股関節置換術が行われた場合における人工股関節の配置を骨盤１００（二点鎖線で示す）および大腿骨１０１（断面図で示す）とともに示したものである。 (First embodiment)
FIG. 1 is a view showing a femoral component 1 according to the first embodiment of the present invention, and is a front view showing the constituent members arranged vertically in a state where they are not combined (FIG. 1 (b)). FIG. 1B is a plan view of FIG. 1B (FIG. 1A). FIG. 2 is a perspective view of the femoral component 1 illustrating a state in which the constituent members are combined. FIG. 3 is a schematic diagram for explaining an example in which the femoral component 1 of the present embodiment is used in an artificial hip joint. When the artificial hip joint replacement is performed on the left hip joint, FIG. The arrangement is shown with the pelvis 100 (shown with a two-dot chain line) and the femur 101 (shown with a cross-sectional view).

図３に示す人工股関節は、大腿骨用コンポーネント１と、球面の一部を構成するように形成された内面を有するカップ１０２と、このカップ１０２に対して可動自在に嵌め込まれる骨頭ボール１０３とを備えて構成されている（カップ１０２および骨頭ボール１０３は断面図で示している）。骨頭ボール１０３は大腿骨用コンポーネント１の近位部側に結合されている。そして、カップ１０２が骨盤１００側に配置されて大腿骨用コンポーネント１が大腿骨１０１の近位部側に埋入された状態で配置されて人工股関節が構成される。 The artificial hip joint shown in FIG. 3 includes a femoral component 1, a cup 102 having an inner surface formed so as to constitute a part of a spherical surface, and a head ball 103 that is movably fitted to the cup 102. The cup 102 and the head ball 103 are shown in cross-section. The head ball 103 is coupled to the proximal side of the femoral component 1. And the cup 102 is arrange | positioned at the pelvis 100 side, and the component 1 for femur is arrange | positioned in the state embedded by the proximal part side of the femur 101, and an artificial hip joint is comprised.

上述のように人工股関節の一要素として用いられる本実施形態の大腿骨用コンポーネント１について、さらに詳しく説明する。図１および図２に示すように、大腿骨用コンポーネント１は、首部部材１１とテーパ状部材１２と棒状部材１３とを備えて構成されている。これらの各構成部材（１１、１２、１３）は、例えば、チタン合金等により形成される。 The femoral component 1 of this embodiment used as an element of the artificial hip joint as described above will be described in more detail. As shown in FIGS. 1 and 2, the femoral component 1 includes a neck member 11, a tapered member 12, and a rod-like member 13. Each of these constituent members (11, 12, 13) is formed of, for example, a titanium alloy.

首部部材１１は、骨頭ボール１０３に嵌合する部材として設けられている。そして、この首部部材１１には、本体部分１１ａと、本体部分１１ａから突出するように形成されて骨頭ボール１０３に嵌合する（図３参照）突出嵌合部１１ｂと、テーパ状部材１２および棒状部材１３との嵌合用に本体部分１１ａから突出するように形成された嵌合凸部１１ｃと、が設けられている。 The neck member 11 is provided as a member fitted to the bone head ball 103. The neck member 11 has a main body portion 11a, a protruding fitting portion 11b that is formed so as to protrude from the main body portion 11a and engages with the head ball 103 (see FIG. 3), a tapered member 12, and a rod-like member. A fitting convex portion 11 c formed so as to protrude from the main body portion 11 a for fitting with the member 13 is provided.

テーパ状部材１２は、首部部材１１に対して嵌合可能であるとともに首部部材１１に嵌合する側に向かってテーパ状に広かるように形成されている。このテーパ状部材１２には、本体部分１２ａと、本体部分１２ａに対して両側にそれぞれテーパ状に広がるように形成されている広がり部分１２ｂおよび１２ｃと、嵌合凹部１２ｄと、嵌合凸部１２ｅと、が設けられている。 The tapered member 12 can be fitted to the neck member 11 and is formed so as to expand in a tapered shape toward the side fitted to the neck member 11. The tapered member 12 includes a main body portion 12a, wide portions 12b and 12c formed so as to expand in a tapered shape on both sides of the main body portion 12a, a fitting concave portion 12d, and a fitting convex portion 12e. And are provided.

テーパ状部材１２の本体部分１２ａおよび広がり部分１２ｂ・１２ｃは、ショットブラスト等の周知の方法により粗面化処理（ポーラス処理）が施されている。なお、かかる粗面化処理は、テーパ状部材１２の少なくとも一部に施されていればよい。また、大腿骨１０１において広がり部分１２ｂは近位部外側に配置されて広がり部分１２ｃは近位部内側に配置されるようになっており（図３参照）、図１に示す例では、近位部内側に配置される広がり部分１２ｃの方が広がり方向の寸法が大きくなっている。なお、広がり部分１２ｂ・１２ｃの広がり方向の寸法は適宜設定することができ、広がり部分１２ｂ・１２ｃのうちのいずれか一方が形成されていなくてもよい。 The main body portion 12a and the widened portions 12b and 12c of the tapered member 12 are subjected to roughening treatment (porous treatment) by a known method such as shot blasting. The roughening process may be performed on at least a part of the tapered member 12. Further, in the femur 101, the expanded portion 12b is disposed outside the proximal portion and the expanded portion 12c is disposed inside the proximal portion (see FIG. 3). In the example shown in FIG. The dimension of the spreading direction is larger in the spreading part 12c arranged inside the part. In addition, the dimension of the expansion direction of the expansion part 12b * 12c can be set suitably, and either one of the expansion part 12b * 12c does not need to be formed.

また、テーパ状部材１２の嵌合凹部１２ｄは、本体部分１２ａに対して凹み形成されており、首部部材１１の嵌合凸部１１ｃが嵌挿されて嵌合するようになっている。これより、首部部材１１とテーパ状部材１２とが嵌合されて結合されることになる。嵌合凹部１２ｄの内周面は、例えば凹み方向に向かって僅かに内側に傾斜するテーパ状の内周面として形成されており、嵌合凸部１１ｃの外周面も、同様に僅かに傾斜したテーパ状の外周面として形成され、嵌合凹部１２ｄと嵌合凸部１１ｃとが嵌合するときには、これらのテーパ状の内周面と外周面とが摺接することで、高い摩擦力が生じて強固に結合されるようになっている。この嵌合凹部１２ｄの凹み方向と垂直な断面と、嵌合凸部１１ｃの軸方向と垂直な断面とは、いずれも同心円状に形成されているため、軸周り方向における任意の角度で首部部材１１をテーパ状部材１２に対して嵌合可能になっている。なお、嵌合凸部１１ｃおよび嵌合凹部１２ｄの断面形状は必ずしも円形でなくてもよく、多角形等の形状であってもよい。また、テーパ状部材１２の嵌合凸部１２ｅは、棒状部材１３との嵌合用に本体部分１２ａから突出するように形成されている。そして、この嵌合凸部１２ｅは、首部部材１１の嵌合凸部１１ｃと外周面が同じ形状となるように形成されている。 Further, the fitting concave portion 12d of the tapered member 12 is formed to be recessed with respect to the main body portion 12a, and the fitting convex portion 11c of the neck member 11 is fitted and fitted therein. Thus, the neck member 11 and the tapered member 12 are fitted and coupled. The inner peripheral surface of the fitting recess 12d is formed as, for example, a tapered inner peripheral surface that is slightly inclined inward in the direction of the recess, and the outer peripheral surface of the fitting convex portion 11c is also slightly inclined similarly. When the fitting concave portion 12d and the fitting convex portion 11c are fitted with each other, the tapered inner peripheral surface and the outer peripheral surface are in sliding contact with each other, and a high frictional force is generated. It is designed to be tightly coupled. Since the cross section perpendicular to the recess direction of the fitting concave portion 12d and the cross section perpendicular to the axial direction of the fitting convex portion 11c are both formed concentrically, the neck member has an arbitrary angle in the direction around the axis. 11 can be fitted to the tapered member 12. In addition, the cross-sectional shape of the fitting convex part 11c and the fitting recessed part 12d does not necessarily need to be circular, and shapes, such as a polygon, may be sufficient. Further, the fitting convex portion 12 e of the tapered member 12 is formed so as to protrude from the main body portion 12 a for fitting with the rod-like member 13. And this fitting convex part 12e is formed so that the fitting convex part 11c of the neck member 11 and an outer peripheral surface may become the same shape.

棒状部材１３は、首部部材１１に対して嵌合可能であるとともにテーパ状部材１２に対しても嵌合可能に設けられており、棒状に形成されている。この棒状部材１３には、軸状の本体部分１３ａと、本体部分１３ａに対してその軸方向に凹み形成されている嵌合凹部１３ｂと、が設けられている。嵌合凹部１３ｂは、テーパ状部材１２の嵌合凹部１２ｄと内周面が同じ形状となるように形成されている。このため、嵌合凸部１３ｂは、首部部材１１の嵌合凸部１１ｃとテーパ状部材１２の嵌合凹部１２ｄとが嵌合するのと同様に、首部部材１１の嵌合凸部１１ｃおよびテーパ状部材１２の嵌合凸部１２ｅのいずれとも嵌合可能になっている。なお、図２では、首部部材１１、テーパ状部材１２、および棒状部材１３が嵌合により全て結合して組み合わされた状態を示している。 The rod-shaped member 13 can be fitted to the neck member 11 and can be fitted to the tapered member 12, and is formed in a rod shape. The rod-shaped member 13 is provided with a shaft-shaped main body portion 13a and a fitting concave portion 13b that is recessed with respect to the main body portion 13a in the axial direction. The fitting recess 13b is formed so that the fitting recess 12d of the tapered member 12 and the inner peripheral surface have the same shape. For this reason, the fitting convex part 13b is the same as the fitting convex part 11c of the neck member 11, and the fitting concave part 12d of the taper-shaped member 12, and the fitting convex part 11c of the neck member 11 and the taper. Any of the fitting protrusions 12e of the shaped member 12 can be fitted. FIG. 2 shows a state in which the neck member 11, the tapered member 12, and the rod-like member 13 are all joined and combined by fitting.

図４は、上述した大腿骨用コンポーネント１を各構成部材を組み合わせることで形成するパターンを説明する模式図である。図４（ａ）は、組み合わされる前の状態の各構成部材を示しており、図４（ｂ）乃至（ｄ）は、各構成部材が適宜組み合わされた各パターンを示している。患者の状況に応じた最適な大腿骨用コンポーネントの形態が確定していない状態であれば、手術に際しては、図４（ａ）に示すように、首部部材１１、テーパ状部材１２、および棒状部材１３とも準備される。そして、術者は、手術中において、患者の状況に応じて、構成部材を適宜組み合わせて図４（ｂ）乃至（ｄ）のいずれかのパターンの大腿骨用コンポーネントを形成し、大腿骨に埋入するように配置させることになる。 FIG. 4 is a schematic diagram for explaining a pattern formed by combining the constituent members for the femoral component 1 described above. FIG. 4A shows the constituent members in a state before being combined, and FIGS. 4B to 4D show patterns in which the constituent members are appropriately combined. If the optimal configuration of the femoral component according to the patient's condition has not been determined, the neck member 11, the tapered member 12, and the rod-like member are used during the operation as shown in FIG. 4 (a). 13 are also prepared. Then, during the operation, the surgeon forms the femoral component having any one of the patterns shown in FIGS. 4 (b) to (d) by appropriately combining the constituent members according to the patient's condition, and is embedded in the femur. It will be arranged to enter.

図４（ｂ）は、大腿骨用コンポーネント１の構成部材のうち首部部材１１およびテーパ状部材１２が組み合わされて大腿骨用コンポーネントが形成されたパターンを示したものである。このパターンの場合、術者は、首部部材１１の嵌合凸部１１ｃとテーパ状部材１２の嵌合凹部１２ｄとを嵌合させることのみで、大腿骨用コンポーネントを形成することになる。図４（ｃ）は、大腿骨用コンポーネント１の構成部材のうち首部部材１１および棒状部材１３が組み合わされて大腿骨用コンポーネントが形成されたパターンを示したものである。このパターンの場合、術者は、首部部材１１の嵌合凸部１１ｃと棒状部材１３の嵌合凹部１３ｂとを嵌合させることのみで、大腿骨用コンポーネントを形成することになる。図４（ｄ）は、大腿骨用コンポーネント１の構成部材全てが組み合わされて大腿骨用コンポーネントが形成されたパターンを示したものである。このパターンの場合、術者は、首部部材１１の嵌合凸部１１ｃとテーパ状部材１２の嵌合凹部１２ｄとを嵌合させ、テーパ状部材１２の嵌合凸部１２ｅと棒状部材１３の嵌合凹部１３ｂとを嵌合させることで、大腿骨用コンポーネントを形成することになる。なお、本実施形態では、首部部材１１に嵌合凸部１１ｃが設けられている場合を例にとって説明したが、この通りでなくてもよく、首部部材１１に嵌合凹部が設けられ、この嵌合凹部に嵌合する嵌合凸部がテーパ状部材１２および棒状部材１３に設けられているものであってもよい。 FIG. 4B shows a pattern in which the femoral component is formed by combining the neck member 11 and the tapered member 12 among the constituent members of the femoral component 1. In the case of this pattern, the operator forms the femoral component only by fitting the fitting convex portion 11 c of the neck member 11 and the fitting concave portion 12 d of the tapered member 12. FIG. 4C shows a pattern in which the femoral component is formed by combining the neck member 11 and the rod-shaped member 13 among the constituent members of the femoral component 1. In the case of this pattern, the operator forms the femoral component only by fitting the fitting convex portion 11 c of the neck member 11 and the fitting concave portion 13 b of the rod-like member 13. FIG. 4 (d) shows a pattern in which all components of the femoral component 1 are combined to form the femoral component. In the case of this pattern, the operator fits the fitting convex portion 11 c of the neck member 11 and the fitting concave portion 12 d of the tapered member 12, and fits the fitting convex portion 12 e of the tapered member 12 and the rod-like member 13. The femoral component is formed by fitting the joint recess 13b. In this embodiment, the case where the fitting protrusion 11c is provided on the neck member 11 has been described as an example. However, this need not be the case, and the fitting recess is provided on the neck member 11, and this fitting is not necessary. A fitting projection that fits into the fitting recess may be provided on the tapered member 12 and the rod-like member 13.

以上説明した大腿骨用コンポーネント１によると、首部部材１１とテーパ状部材１２と棒状部材１３とを全て組み合わせることによって、または首部部材１１およびテーパ状部材１２を組み合わせることによって、あるいは首部部材１１および棒状部材１３を組み合わせることによって、それぞれ形態や寸法の異なる大腿骨用コンポーネントを形成することができる。このため、患者の骨形状や骨質、骨損失や疾患の状況等に応じてその患者に最適な形態や寸法の大腿骨用コンポーネントを高い自由度で選択することができる。そして、組み合わせ自由度の高い各構成部材（１１、１２、１３）を適宜組み合わせるだけで種々の形態や寸法の大腿骨用コンポーネントを極めて容易に形成することができる。さらに、首部部材１１、テーパ状部材１２、および棒状部材１３の各構成部材の形状や寸法を適宜変更することで幅広い形態と寸法に亘る大腿骨用コンポーネントを容易に設計することができる。また、手術に際しては、少ない部材点数の各構成部材を準備しておくだけで、手術中の患者の状況に応じその場で柔軟に最適な形態や寸法の大腿骨用コンポーネントを形成して対応することができる。 According to the femoral component 1 described above, the neck member 11, the tapered member 12, and the rod-like member 13 are all combined, or the neck member 11 and the tapered member 12 are combined, or the neck member 11 and the rod-like member are combined. By combining the members 13, femoral components having different forms and dimensions can be formed. Therefore, it is possible to select a femoral component having a shape and size optimal for the patient in accordance with the bone shape and quality of the patient, the bone loss, the state of the disease, and the like with high flexibility. And the component for femurs of various forms and dimensions can be very easily formed only by combining each structural member (11, 12, 13) with a high combination freedom degree suitably. Furthermore, by appropriately changing the shapes and dimensions of the constituent members of the neck member 11, the tapered member 12, and the rod-shaped member 13, it is possible to easily design a femoral component over a wide range of shapes and dimensions. In addition, during the operation, it is possible to flexibly form the femoral component of the optimal shape and size on the spot according to the situation of the patient during the operation by preparing each component member with a small number of members. be able to.

したがって、大腿骨用コンポーネント１によると、患者の骨形状や骨質、骨損失や疾患の状況等に応じてその患者に最適な形態や寸法の大腿骨用コンポーネントを選択するに際して柔軟に幅広く対応することができ、手術中であっても少ない部材点数で種々の形態や寸法に対応して構成することができる大腿骨用コンポーネントを提供することができる。 Therefore, according to the femoral component 1, it is possible to respond flexibly and widely when selecting the femoral component having the optimum shape and size for the patient according to the bone shape and quality of the patient, the bone loss, the state of the disease, and the like. Therefore, it is possible to provide a femoral component that can be configured corresponding to various forms and dimensions with a small number of members even during surgery.

（第２実施形態）
図５は、本発明の第２実施形態に係る大腿骨用コンポーネント２を示す図であって、構成部材が組み合わされた状態を例示する正面図（図５（ｂ））、平面図（図５（ｂ））、および側面図（図５（ｃ））を示したものである。また、図６は、図５（ｃ）のVI−VI線矢視断面図である。第２実施形態に係る大腿骨用コンポーネント２も第１実施形態の大腿骨用コンポーネント１と同様に用いられる。そして、図５および図６に示すように、大腿骨用コンポーネント２は、首部部材２１、テーパ状部材２２、棒状部材２３、およびネジ部材２４を備えて構成されている。なお、以下の説明においては、第２実施形態における第１実施形態と同様の構成要素については、符号は異なるが同一の用語を用いて説明することで、適宜説明を割愛する。 (Second Embodiment)
FIG. 5 is a diagram showing a femoral component 2 according to the second embodiment of the present invention, and is a front view (FIG. 5 (b)) and a plan view (FIG. 5) illustrating a state in which constituent members are combined. (B)) and a side view (FIG.5 (c)) are shown. FIG. 6 is a cross-sectional view taken along the line VI-VI in FIG. The femoral component 2 according to the second embodiment is also used in the same manner as the femoral component 1 of the first embodiment. As shown in FIGS. 5 and 6, the femoral component 2 includes a neck member 21, a tapered member 22, a rod-like member 23, and a screw member 24. In the following description, components similar to those in the first embodiment in the second embodiment are described using the same terms although the reference numerals are different, and the description will be omitted as appropriate.

図５および図６に示す大腿骨用コンポーネント２は、第１実施形態に係る大腿骨用コンポーネント１と同様に、首部部材２１、テーパ状部材２２、棒状部材２３の各構成部材を適宜組み合わせることで、３つのパターンの大腿骨用コンポーネントを形成することができる。ただし、この大腿骨用コンポーネント２では、嵌合した首部部材２１およびテーパ状部材２２を連結可能であるとともに、嵌合した首部部材２１および棒状部材２３を連結可能であるネジ部材２４がさらに備えられている。 Similar to the femoral component 1 according to the first embodiment, the femoral component 2 shown in FIGS. 5 and 6 is obtained by appropriately combining the constituent members of the neck member 21, the tapered member 22, and the rod-shaped member 23. Three patterns of femoral components can be formed. However, the femoral component 2 further includes a screw member 24 that can connect the fitted neck member 21 and the tapered member 22 and can connect the fitted neck member 21 and the rod-like member 23. ing.

図５および図６に示すパターンは、首部部材２１、テーパ状部材２２、棒状部材２３の全ての構成部材を組み合わせたパターンであり、首部部材２１をテーパ状部材２２に嵌合し、テーパ状部材２２を棒状部材２３に嵌合することで、大腿骨用コンポーネントが形成される。このパターンの場合、首部部材２１の嵌合凸部２１ｃとテーパ状部材２２の嵌合凹部２２ｄとが嵌合し、テーパ状部材２２の嵌合凸部２２ｅと棒状部材２３の嵌合凹部２３ｂとが嵌合し、さらに、首部部材２１とテーパ状部材２２とがネジ部材２４により連結されている。なお、首部部材２１のテーパ状部材２２に対する嵌合角度は、第１実施形態と同様に、任意に調整することができる。図７および図８は、首部部材２１のテーパ状部材２２に対する嵌合角度を変更した例を示す斜視図であり、３つの嵌合角度について示したものである。なお、図７（ａ）および図８（ａ）、図７（ｂ）および図８（ｂ）、図７（ｃ）および図８（ｃ）が、それぞれ同一の角度の斜視図および平面図として対応している。 The pattern shown in FIGS. 5 and 6 is a pattern in which all the constituent members of the neck member 21, the tapered member 22, and the rod-like member 23 are combined, and the neck member 21 is fitted to the tapered member 22 to form the tapered member. By fitting 22 to the rod-like member 23, a femoral component is formed. In the case of this pattern, the fitting convex portion 21c of the neck member 21 and the fitting concave portion 22d of the tapered member 22 are fitted, and the fitting convex portion 22e of the tapered member 22 and the fitting concave portion 23b of the rod-like member 23 are fitted. Are fitted, and the neck member 21 and the tapered member 22 are connected by a screw member 24. In addition, the fitting angle with respect to the taper-shaped member 22 of the neck part member 21 can be arbitrarily adjusted similarly to 1st Embodiment. 7 and 8 are perspective views showing an example in which the fitting angle of the neck member 21 with respect to the tapered member 22 is changed, and shows three fitting angles. 7A and FIG. 8A, FIG. 7B and FIG. 8B, FIG. 7C and FIG. 8C are respectively a perspective view and a plan view at the same angle. It corresponds.

また、図９および図１０は、大腿骨用コンポーネント２における他の組み合わせパターンを示したものであり、その正面図（図９（ａ））、平面図（図９（ｂ））、側面図（図９（ｃ））、図９（ｃ）のX−X矢視断面図（図１０）である。この図９および図１０に示すパターンは、大腿骨用コンポーネント２の構成部材のうち首部部材２１および棒状部材２３が組み合わされたパターンであり、この場合、テーパ状部材２２を用いずに首部部材２１を棒状部材２３に嵌合することで、大腿骨用コンポーネントが形成される。このパターンの場合、首部部材２１の嵌合凸部２１ｃと棒状部材２３の嵌合凹部２３ｂとが嵌合し、首部部材２１と棒状部材２３とがネジ部材２４により連結されている。なお、図５・図６に示す組み合わせパターンおよび図９・図１０に示す組み合わせパターン以外のパターンとして、棒状部材２３を用いずに首部部材２１とテーパ状部材２２とを嵌合して組み合わせることで大腿骨用コンポーネントを形成することもできる。 FIGS. 9 and 10 show other combination patterns in the femoral component 2, and are a front view (FIG. 9A), a plan view (FIG. 9B), a side view ( FIG. 9 (c)) and FIG. 9 (c) are cross-sectional views taken along the line XX (FIG. 10). The pattern shown in FIG. 9 and FIG. 10 is a pattern in which the neck member 21 and the rod-shaped member 23 are combined among the constituent members of the femoral component 2. In this case, the neck member 21 is not used without using the tapered member 22. By fitting to the rod-shaped member 23, a femoral component is formed. In the case of this pattern, the fitting convex portion 21 c of the neck member 21 and the fitting concave portion 23 b of the rod-shaped member 23 are fitted, and the neck member 21 and the rod-shaped member 23 are connected by the screw member 24. As a combination pattern other than the combination pattern shown in FIGS. 5 and 6 and the combination pattern shown in FIGS. 9 and 10, the neck member 21 and the tapered member 22 are fitted and combined without using the rod-like member 23. A femoral component can also be formed.

次に、大腿骨用コンポーネント２の各構成部材（２１、２２、２３）およびネジ部材２４について、さらに詳しく説明する。 Next, each component member (21, 22, 23) and screw member 24 of the femoral component 2 will be described in more detail.

首部部材２１の斜視図である図１１および大腿骨用コンポーネント２の断面図である図６に示すように、首部部材２１は、第１実施形態と同様の本体部分２１ａと突出嵌合部２１ｂと嵌合凸部２１ｃとが設けられている。ただし、首部部材２１には、ネジ部材２４の先端側が貫通する貫通孔２１ｄが形成されている。また、この貫通孔２１ｄの中途には、貫通孔２１ｄに挿入されたネジ部材２４のネジ頭部と当接してネジ部材２４の貫通孔２１ｄへの挿入深度を規制する段部２１ｅも設けられている。 As shown in FIG. 11, which is a perspective view of the neck member 21, and FIG. 6, which is a cross-sectional view of the femoral component 2, the neck member 21 includes a main body portion 21 a and a protruding fitting portion 21 b similar to those in the first embodiment. The fitting convex part 21c is provided. However, the neck member 21 is formed with a through-hole 21d through which the distal end side of the screw member 24 passes. Further, in the middle of the through hole 21d, there is also provided a step portion 21e that contacts the screw head of the screw member 24 inserted into the through hole 21d and regulates the insertion depth of the screw member 24 into the through hole 21d. Yes.

また、大腿骨用コンポーネント２においては、首部部材２１が複数種類備えられている。図１２は、複数の首部部材２１を説明する模式図である。この図１２の模式図では、突出嵌合部２１の形状および寸法が異なった複数の首部部材２１を重ねて示している。この図１２に示すように、大腿骨用コンポーネント２においては、首部部材２１における本体部分２１ａに対する突出嵌合部２１ｂの突出方向の角度が１２５°、１３０°、１３５°と３種類に異なるものと、突出嵌合部２１ｂの本体部分２１ａからの突出長さ寸法がＬ１、Ｌ２と２種類に異なるものと、が備えられている。すなわち、大腿骨用コンポーネント２においては、突出嵌合部２１ｂの突出方向の角度が３種類でそれぞれの角度に対して突出寸法長さが２種類あり、合計で６個の首部部材２１が備えられている。なお、図１２で説明したものは例示であり、突出方向の角度および突出長さ寸法の選定の仕方や選定した個数については、適宜設定することができる。また、突出方向の角度および突出長さ寸法のうちいずれか一方のみが異なる首部部材２１が複数備えられているものであってもよい。 In the femoral component 2, a plurality of types of neck members 21 are provided. FIG. 12 is a schematic diagram illustrating a plurality of neck members 21. In the schematic diagram of FIG. 12, a plurality of neck members 21 having different shapes and dimensions of the protruding fitting portions 21 are shown in an overlapping manner. As shown in FIG. 12, in the femoral component 2, the angle of the protruding direction of the protruding fitting portion 21b with respect to the main body portion 21a of the neck member 21 is different from three types of 125 °, 130 °, and 135 °. The protrusion length dimension of the protrusion fitting portion 21b from the main body portion 21a is different from L1 and L2 in two types. That is, in the femoral component 2, there are three types of projection direction angles of the projecting fitting portion 21 b and two types of projecting dimension lengths for each angle, and a total of six neck members 21 are provided. ing. In addition, what was demonstrated in FIG. 12 is an illustration, and it can set suitably about the method of selection of the angle of a protrusion direction and a protrusion length dimension, and the selected number. Further, a plurality of neck members 21 that differ only in one of the angle in the protruding direction and the protruding length dimension may be provided.

また、テーパ状部材２２の斜視図である図１３および大腿骨用コンポーネント２の断面図である図６に示すように、テーパ状部材２２は、第１実施形態と同様の本体部分２２ａと広がり部分２２ｂ・２２ｃと嵌合凹部２２ｄと嵌合凸部２２ｅとが設けられている。ただし、テーパ状部材２２には、後述するネジ部材２４に設けられる雄ネジ部２４ｃと螺合する雌ネジ部２２ｆと、雌ネジ部２２ｆよりもテーパ状部材２２におけるさらに内部側に設けられる空隙部分２２ｇとが形成されている。 Moreover, as shown in FIG. 13 which is a perspective view of the taper-shaped member 22 and FIG. 6 which is a cross-sectional view of the femoral component 2, the taper-shaped member 22 has a main body portion 22a and a widened portion similar to those in the first embodiment. 22b and 22c, the fitting recessed part 22d, and the fitting convex part 22e are provided. However, the tapered member 22 has a female screw portion 22f that is screwed with a male screw portion 24c provided in a screw member 24 described later, and a gap portion provided further on the inner side of the tapered member 22 than the female screw portion 22f. 22g is formed.

また、大腿骨用コンポーネント２においては、テーパ状部材２２が複数備えられている。図１４は、複数のテーパ状部材２２を説明する模式図である。図１４（ａ）の模式図では、テーパ状に広がるように形成されているテーパ状部材２２の広がり部分２２ｂ・２２ｃの広がり方向の寸法が異なった複数のテーパ状部材２２を重ねて示している。一方、図１４（ｂ）の模式図では、テーパ状部材２２における広がり部分２２ｂ・２２ｃの広がり方向と直交する幅方向の寸法が異なった複数のテーパ状部材２２を重ねて示している。この図１４に示すように、大腿骨用コンポーネント２においては、広がり部分２２ｂ・２２ｃの広がり方向の寸法が長さＬ３とＬ４との間で５段階に異なるとともに、幅方向の寸法も幅長さＬ５とＬ６との間で５段階に異なるもの（広がり方向の寸法が１段階大きくなると幅方向の寸法も１段階大きくなるように対応した５種類のもの）が備えられている。なお、図１４では、広がり方向の寸法および幅方向の寸法が対応して段階的に変化するものを例にとって説明したが、それぞれ独立に段階的に変化する複数のテーパ状部材であってもよく、いずれか一方のみが異なるテーパ状部材であってもよい。また、広がり方向の寸法については、広がり部分２２ｂおよび２２ｃが独立に変化するように異なるものやいずれか一方のみが異なるものであってもよい。 Further, the femoral component 2 is provided with a plurality of tapered members 22. FIG. 14 is a schematic diagram illustrating a plurality of tapered members 22. In the schematic diagram of FIG. 14A, a plurality of tapered members 22 having different dimensions in the expanding direction of the expanded portions 22b and 22c of the tapered member 22 formed so as to expand in a tapered shape are shown in an overlapping manner. . On the other hand, in the schematic diagram of FIG. 14B, a plurality of tapered members 22 having different dimensions in the width direction perpendicular to the expanding direction of the expanded portions 22b and 22c in the tapered member 22 are shown superimposed. As shown in FIG. 14, in the femoral component 2, the dimension in the spreading direction of the spreading portions 22 b and 22 c is different in five stages between the lengths L3 and L4, and the dimension in the width direction is also the width length. There are five different levels between L5 and L6 (five types corresponding to the dimension in the width direction being increased by one step when the dimension in the spreading direction is increased by one step). In FIG. 14, the example in which the dimension in the spreading direction and the dimension in the width direction change correspondingly in a stepwise manner has been described as an example, but a plurality of tapered members that change independently in a stepwise manner may be used. The tapered member may be different only in one of them. Further, the dimension in the spreading direction may be different so that the spreading parts 22b and 22c change independently, or only one of them may be different.

また、大腿骨用コンポーネント２においては、棒状部材２３は複数備えられている。図１５（ａ）は、長手方向の寸法が異なる複数の棒状部材２３のうち長手方向の寸法が最も長いものの斜視図を示している。この図１５（ａ）および大腿骨用コンポーネント２の断面図である図６に示すように、棒状部材２３には、第１実施形態と同様の本体部分２３ａと嵌合凹部２３ｂとが設けられている。ただし、棒状部材２３には、後述するネジ部材２４に設けられる雄ネジ部２４ｃと螺合する雌ネジ部２３ｃと、雌ネジ部２３ｃよりも棒状部材２３におけるさらに内部側に設けられる空隙部分２３ｄとが形成されている。なお、図１５（ａ）およびこの図１５（ａ）のｂ−ｂ線矢視断面図である図１５（ｂ）に示すように、長手方向の長さが最も長い棒状部材２３においては、その外周に長手方向に沿って形成された複数条の線状突起が形成されている。 Further, the femoral component 2 includes a plurality of rod-like members 23. FIG. 15A shows a perspective view of the longest dimension in the longitudinal direction among the plurality of rod-shaped members 23 having different dimensions in the longitudinal direction. As shown in FIG. 15 (a) and FIG. 6 which is a sectional view of the femoral component 2, the rod-like member 23 is provided with a main body portion 23a and a fitting recess 23b similar to those in the first embodiment. Yes. However, the rod-shaped member 23 includes a female screw portion 23c that is screwed with a male screw portion 24c provided on a screw member 24 described later, and a gap portion 23d that is further provided on the inner side of the rod-shaped member 23 than the female screw portion 23c. Is formed. As shown in FIG. 15 (a) and FIG. 15 (b), which is a sectional view taken along line bb in FIG. 15 (a), in the rod-shaped member 23 having the longest length in the longitudinal direction, A plurality of linear protrusions formed along the longitudinal direction are formed on the outer periphery.

図１６は、複数の棒状部材２３を説明する模式図である。この図１６の模式図では、棒状部材２３の形状および寸法が異なった複数の棒状部材２３を重ねて示している。この図１６に示すように、大腿骨用コンポーネント２においては、棒状部材２３における長手方向の寸法が長さＬ７、Ｌ８、Ｌ９と３種類に異なるものと、長手方向と直交する断面の径寸法が各長さ寸法（Ｌ７、Ｌ８、Ｌ９）ごとにそれぞれ３種類に異なるものと、が備えられている。すなわち、大腿骨用コンポーネント２においては、長手方向の長さ寸法が３種類でそれぞれの長さ寸法に対して径寸法が３種類あり、合計で９種類の棒状部材２３が備えられている。なお、図１６で説明したものは例示であり、長さ寸法や径寸法の選定の仕方や選定の個数については、適宜設定することができる。また、長さ寸法および径寸法のうちいずれか一方のみが異なる棒状部材２３が複数備えられているものであってもよい。 FIG. 16 is a schematic diagram for explaining a plurality of rod-shaped members 23. In the schematic diagram of FIG. 16, a plurality of rod-like members 23 having different shapes and dimensions of the rod-like member 23 are shown in an overlapping manner. As shown in FIG. 16, in the femoral component 2, the longitudinal dimension of the rod-shaped member 23 is different in three types of lengths L7, L8, and L9, and the diameter dimension of the cross section perpendicular to the longitudinal direction is different. Three different types are provided for each length dimension (L7, L8, L9). That is, the femoral component 2 has three types of lengths in the longitudinal direction and three types of diameters with respect to each length, and a total of nine types of rod-like members 23 are provided. In addition, what was demonstrated in FIG. 16 is an illustration, and it can set suitably about the selection method of length dimension and a diameter dimension, and the number of selection. Further, a plurality of rod-like members 23 that differ only in one of the length dimension and the diameter dimension may be provided.

図１７は、ネジ部材２４の斜視図（図１７（ａ））と正面図（図１７（ｂ））とを示したものである。この図１７に示すように、ネジ部材２４には、軸部２４ｄと、弾性変形部２４ａと、掛止部２４ｂと、雄ネジ部２４ｄと、が設けられている。このネジ部材２４は、図６および図１０によく示すように、その先端側が、首部部材２１の貫通孔２１ｄを貫通するようにこの貫通孔２１ｄに挿入される。 FIG. 17 shows a perspective view (FIG. 17A) and a front view (FIG. 17B) of the screw member 24. As shown in FIG. 17, the screw member 24 is provided with a shaft portion 24d, an elastic deformation portion 24a, a latching portion 24b, and a male screw portion 24d. As shown well in FIGS. 6 and 10, the screw member 24 is inserted into the through hole 21 d so that the tip side thereof penetrates the through hole 21 d of the neck member 21.

ネジ部材２４の弾性変形部２４ａは、軸部２４ｄの先端側に形成されている。この弾性変形部２４ａは、ネジ部材２４の先端側が可撓な二股構造として形成されることで設けられている。そして、テーパ状部材２２に嵌合した首部部材２１の貫通孔２１ｄからネジ部材２４が挿入されていくと、弾性変形部２４ａは弾性変形することでテーパ状部材２２に形成された雌ネジ部２２ｆよりも縮径してその雌ネジ部２２ｆに挿入されるようになっている。同様に、棒状部材２３に嵌合した首部部材２１の貫通孔２１ｄからネジ部材２４が挿入されていった場合も、弾性変形部２４ａは弾性変形することで棒状部材２３に形成された雌ネジ部２３ｃよりも縮径してその雌ネジ部２３ｃに挿入されるようになっている。 The elastic deformation portion 24a of the screw member 24 is formed on the distal end side of the shaft portion 24d. The elastic deformation portion 24a is provided by forming the distal end side of the screw member 24 as a flexible bifurcated structure. Then, when the screw member 24 is inserted from the through hole 21d of the neck member 21 fitted to the tapered member 22, the elastic deformation portion 24a is elastically deformed so that the female screw portion 22f formed in the tapered member 22 is obtained. The diameter is further reduced, and it is inserted into the female screw portion 22f. Similarly, when the screw member 24 is inserted from the through hole 21d of the neck member 21 fitted to the rod-shaped member 23, the elastic deformation portion 24a is elastically deformed so that the female screw portion formed in the rod-shaped member 23 is formed. The diameter is smaller than that of 23c and is inserted into the female screw portion 23c.

また、ネジ部材２４の掛止部２４ｂは、弾性回復部２４ａに対して外方にテーパ状に広がった後に弾性回復部２４ａと反対側で段状に狭まった部分として形成されている。このため、掛止部２４ｂは、テーパ状部材２２において雌ネジ部２２ｆよりも内部側に形成された空隙部分２２ｇまで弾性変形部２４ａが挿入されてこの弾性変形部２４ａが弾性回復したときに、テーパ状部材２２に対してその内部で掛止する（すなわち、雌ネジ部２２ｆから空隙部分２２ｇに開口した部分における縁部で掛止する）ようになっている（図６参照）。同様に、棒状部材２３において雌ネジ部２３ｃよりも内部側に形成された空隙部分２３ｄまで弾性変形部２４ａが挿入されてこの弾性変形部２４ａが弾性回復した場合も、棒状部材２３に対してその内部で掛止する（すなわち、雌ネジ部２３ｃから空隙部分２３ｄに開口した部分における縁部で掛止する）ようになっている（図１０参照）。 Further, the latching portion 24b of the screw member 24 is formed as a portion narrowed in a step shape on the opposite side to the elastic recovery portion 24a after spreading outwardly with respect to the elastic recovery portion 24a. For this reason, when the elastic deformation part 24a is inserted into the gap 22g formed on the inner side of the female screw part 22f in the tapered member 22 and the elastic deformation part 24a is elastically recovered, The taper-shaped member 22 is hooked inside thereof (that is, hooked at an edge portion at a portion opened from the female screw portion 22f to the gap portion 22g) (see FIG. 6). Similarly, when the elastic deformation portion 24a is inserted to the gap portion 23d formed on the inner side of the female screw portion 23c in the rod-shaped member 23 and the elastic deformation portion 24a is elastically recovered, It is latched internally (that is, latched at the edge of the portion opened from the female screw portion 23c to the gap portion 23d) (see FIG. 10).

ネジ部材２４の雄ネジ部２４ｃは、掛止部２４ｂに対して弾性変形部２４ａの側とは反対側に形成され、テーパ状部材２２の雌ネジ部２２ｆまたは棒状部材２３の雌ネジ部２３ｃと螺合する。なお、この雌ネジ部２４ｃは、弾性変形部２４ａが設けられている二股構造の根元部分にも形成されていてもよい。 The male screw portion 24c of the screw member 24 is formed on the opposite side to the elastic deformation portion 24a side with respect to the latching portion 24b, and the female screw portion 22f of the tapered member 22 or the female screw portion 23c of the rod-like member 23 is formed. Screw together. The female screw portion 24c may also be formed at the root portion of the bifurcated structure where the elastic deformation portion 24a is provided.

なお、上述したように、大腿骨用コンポーネント２においては、首部部材２１が６種類、テーパ状部材２２が５種類、棒状部材２３が９種類備えられている。このため、首部部材２１およびテーパ状部材２２を組み合わせるパターンの大腿骨用コンポーネントが３０通り、首部部材２１および棒状部材２３を組み合わせるパターンの大腿骨用コンポーネントが５４通り、首部部材２１とテーパ状部材２２と棒状部材２３とを組み合わせるパターンの大腿骨用コンポーネントが２７０通り、合計で３５４通りの大腿骨用コンポーネントのうちから最適な形態及び寸法の大腿骨用コンポーネントを選択することができる。 As described above, the femoral component 2 includes six types of neck members 21, five types of tapered members 22, and nine types of rod-shaped members 23. For this reason, there are 30 femoral components in a pattern in which the neck member 21 and the tapered member 22 are combined, and 54 femoral components in a pattern in which the neck member 21 and the rod-shaped member 23 are combined, and the neck member 21 and the tapered member 22 are combined. There are 270 femoral components in a pattern combining the rod-like member 23 and the total of 354 femoral components, and the femoral component having the optimum shape and size can be selected from a total of 354 femoral components.

以上説明した第２実施形態に係る大腿骨用コンポーネント２によると、首部部材２１の本体部分２１ａに対する突出嵌合部２１ｂの突出方向の角度と、突出嵌合部２１ｂの本体部分２１ａからの突出長さとのうちの少なくともいずれかが異なる複数の首部部材２１が備えられているため、手術の際に、かかる複数の首部部材２１のうちから患者の状況に最適な形状や寸法の首部部材２１を適宜選択することができる。したがって、形状や寸法のバリエーションをもたせた複数の首部部材２１を準備しておくだけで、部材点数を増加させることなく、さらに多くの種々の形態や寸法の大腿骨コンポーネントを容易に形成することができる。 According to the femoral component 2 according to the second embodiment described above, the angle in the protruding direction of the protruding fitting portion 21b with respect to the main body portion 21a of the neck member 21, and the protruding length of the protruding fitting portion 21b from the main body portion 21a. Since a plurality of neck members 21 having at least one of the plurality of neck members 21 are provided, a neck member 21 having a shape and a size optimal for a patient's situation is appropriately selected from the plurality of neck members 21 during surgery. You can choose. Therefore, it is possible to easily form femoral components of many different forms and dimensions without increasing the number of members only by preparing a plurality of neck members 21 having variations in shape and dimensions. it can.

また、大腿骨用コンポーネント２によると、テーパ状部材２２における広がり部分２２ｂ・２２ｃの広がり方向の寸法と幅方向の寸法とのうちの少なくともいずれかが異なる複数のテーパ状部材２２が備えられているため、手術の際に、かかる複数のテーパ状部材２２のうちから患者の状況に最適な形状や寸法のテーパ状部材２２を適宜選択することができる。したがって、形状や寸法のバリエーションをもたせた複数のテーパ状部材２２を準備しておくだけで、部材点数を増加させることなく、さらに多くの種々の形態や寸法の大腿骨コンポーネントを容易に形成することができる。 Moreover, according to the component 2 for femurs, the taper-shaped member 22 is provided with the plurality of taper-shaped members 22 in which at least one of the dimension in the expanding direction and the dimension in the width direction of the expanding portions 22b and 22c is different. Therefore, the taper-shaped member 22 having the optimum shape and size for the patient's situation can be appropriately selected from the plurality of taper-shaped members 22 during the operation. Therefore, by simply preparing a plurality of tapered members 22 having variations in shape and size, it is possible to easily form femoral components of many different forms and sizes without increasing the number of members. Can do.

また、大腿骨用コンポーネント２によると、棒状部材２３における長手方向の寸法と断面の径寸法とのうちの少なくともいずれかが異なる複数の棒状部材２３が備えられているため、手術の際に、かかる複数の棒状部材２３のうちから患者の状況に最適な形状や寸法の棒状部材２３を適宜選択することができる。したがって、形状や寸法のバリエーションをもたせた複数の棒状部材２３を準備しておくだけで、部材点数を増加させることなく、さらに多くの種々の形態や寸法の大腿骨コンポーネントを容易に形成することができる。 Further, according to the femoral component 2, a plurality of rod-like members 23 in which at least one of the longitudinal dimension and the cross-sectional diameter of the rod-like member 23 are different are provided. From among the plurality of rod-shaped members 23, the rod-shaped member 23 having a shape and size optimal for the patient's situation can be selected as appropriate. Therefore, it is possible to easily form femoral components of many different forms and dimensions without increasing the number of members only by preparing a plurality of rod-shaped members 23 having variations in shape and dimensions. it can.

また、大腿骨用コンポーネント２によると、複数の棒状部材２３のうち最も長い寸法の棒状部材２３と首部部材２１とを組み合わせて大腿骨用コンポーネントを形成するような場合においても、組み合わされる棒状部材２３の外周には複数条の線状突起２３ｅが長手方向に沿って形成されているため、かかる線状突起２３ｅによって大腿骨内に大腿骨用コンポーネントが容易にしっかりと固定されることになる。 Further, according to the femoral component 2, even when the femoral component is formed by combining the longest-sized rod-shaped member 23 and the neck member 21 among the plurality of rod-shaped members 23, the combined rod-shaped member 23. Since a plurality of linear projections 23e are formed along the longitudinal direction on the outer circumference of the, the femoral component is easily and firmly fixed in the femur by the linear projections 23e.

また、大腿骨用コンポーネント２によると、ネジ部材２４の雄ネジ部２４ｃをテーパ状部材２２の雌ネジ部２２ｆまたは棒状部材２３の雌ネジ部２３ｃと螺合させながら、弾性変形部２４ａを雌ネジ部２２ｆまたは２３ｃよりも縮径させてテーパ状部材２２または棒状部材２３の内部の空隙部分２２ｇまたは２３ｄまで挿入すると、弾性変形部２４ａが弾性回復することでネジ部材２４の掛止部２４ｂがテーパ状部材２２または棒状部材２３とその内部で掛止することになる。このため、ネジ部材２４の抜け止めが確実に図られることになり、首部部材２１およびテーパ状部材２２、または、首部部材２１および棒状部材２３が外れることを確実に防止できる連結構造を実現することができる。 Further, according to the femoral component 2, the elastic deformation portion 24 a is screwed into the female screw while the male screw portion 24 c of the screw member 24 is screwed with the female screw portion 22 f of the tapered member 22 or the female screw portion 23 c of the rod-like member 23. When the diameter is smaller than that of the portion 22f or 23c and inserted into the gap portion 22g or 23d inside the tapered member 22 or the rod-like member 23, the elastic deformation portion 24a is elastically recovered, whereby the latching portion 24b of the screw member 24 is tapered. The hook-shaped member 22 or the rod-shaped member 23 is hooked inside. For this reason, the screw member 24 is surely prevented from coming off, and a connection structure that can reliably prevent the neck member 21 and the taper-shaped member 22 or the neck member 21 and the rod-shaped member 23 from coming off is realized. Can do.

以上、本発明の第１および第２実施形態について説明したが、本発明は上述の実施の形態に限られるものではなく、特許請求の範囲に記載した限りにおいて様々な変更が可能なものである。 Although the first and second embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. .

本発明は、人工股関節において大腿骨の近位部側に埋入されて用いられる大腿骨用コンポーネントとして広く適用することができるものである。 INDUSTRIAL APPLICABILITY The present invention can be widely applied as a femoral component used by being embedded in the proximal part of the femur in an artificial hip joint.

本発明の第１実施形態に係る大腿骨用コンポーネントを示す図であって、組み合わされていない状態で各構成部材を上下に配置して示す正面図およびその平面図である。It is a figure which shows the component for femurs which concerns on 1st Embodiment of this invention, Comprising: It is the front view which shows and arrange | positions each structural member up and down in the state which is not combined, and its top view. 図１に示す大腿骨用コンポーネントにおける構成部材が組み合わされた状態を例示する斜視図である。It is a perspective view which illustrates the state in which the structural member in the component for femurs shown in FIG. 1 was combined. 図２に示す大腿骨用コンポーネントが人工股関節において用いられた例を説明する模式図である。It is a schematic diagram explaining the example in which the component for femurs shown in FIG. 2 was used in the artificial hip joint. 図１に示す大腿骨用コンポーネントを各構成部材を組み合わせることで形成するパターンを説明する模式図である。It is a schematic diagram explaining the pattern which forms the component for femurs shown in FIG. 1 by combining each structural member. 本発明の第２実施形態に係る大腿骨用コンポーネントを示す図であって、構成部材が組み合わされた状態を例示する正面図、平面図、および側面図を示したものである。It is a figure which shows the component for femurs concerning 2nd Embodiment of this invention, Comprising: The front view which illustrates the state in which the structural member was combined, the top view, and the side view are shown. 図５におけるVI−VI線矢視断面図である。FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. 5. 図５に示す大腿骨用コンポーネントにおける首部部材のテーパ状部材に対する嵌合角度を変更した例を示す斜視図である。It is a perspective view which shows the example which changed the fitting angle with respect to the taper-shaped member of the neck member in the component for femurs shown in FIG. 図５に示す大腿骨用コンポーネントにおける首部部材のテーパ状部材に対する嵌合角度を変更した例を示す斜視図である。It is a perspective view which shows the example which changed the fitting angle with respect to the taper-shaped member of the neck member in the component for femurs shown in FIG. 図５に示す大腿骨用コンポーネントにおける構成部材の他の組み合わせパターンを示した正面図、平面図、および側面図である。It is the front view, top view, and side view which showed the other combination pattern of the structural member in the component for femurs shown in FIG. 図９のX−X線矢視断面図である。FIG. 10 is a cross-sectional view taken along line X-X in FIG. 9. 図５に示す大腿骨用コンポーネントにおける首部部材の斜視図である。FIG. 6 is a perspective view of a neck member in the femoral component shown in FIG. 5. 図１１に示す首部部材における複数の種類の首部部材を説明する模式図である。FIG. 12 is a schematic diagram illustrating a plurality of types of neck members in the neck member shown in FIG. 11. 図５に示す大腿骨用コンポーネントにおけるテーパ状部材の斜視図である。FIG. 6 is a perspective view of a tapered member in the femoral component shown in FIG. 5. 図１３に示すテーパ状部材における複数の種類のテーパ状部材を説明する模式図である。FIG. 14 is a schematic diagram illustrating a plurality of types of tapered members in the tapered member shown in FIG. 13. 図５に示す大腿骨用コンポーネントにおける棒状部材の斜視図である。It is a perspective view of the rod-shaped member in the component for femurs shown in FIG. 図１５に示す大腿骨用コンポーネントにおける複数の種類の棒状部材を説明する模式図である。FIG. 16 is a schematic diagram illustrating a plurality of types of rod-shaped members in the femoral component shown in FIG. 15. 図５に示す大腿骨用コンポーネントにおけるネジ部材の斜視図および正面図である。FIG. 6 is a perspective view and a front view of a screw member in the femoral component shown in FIG. 5.

Explanation of symbols

１大腿骨用コンポーネント
１１首部部材
１１ｃ首部部材の嵌合凸部
１２テーパ状部材
１２ｄテーパ状部材の嵌合凹部
１２ｅテーパ状部材の嵌合凸部
１３棒状部材
１３ｂ棒状部材の嵌合凹部 DESCRIPTION OF SYMBOLS 1 Femoral component 11 Neck member 11c Neck member fitting convex part 12 Tapered member 12d Tapered member fitting concave part 12e Tapered member fitting convex part 13 Bar-shaped member 13b Rod-shaped member fitting concave part

Claims

A femoral component used by being implanted in the proximal part of the femur in an artificial hip joint,
A neck member fitted to a head ball used in an artificial hip joint;
A tapered member formed so as to spread in a tapered shape toward the side to be fitted to the neck member with a matable to said neck member,
A rod-shaped member that can be fitted to the neck member and can be fitted to the tapered member, and is formed into a rod shape;
Equipped with a,
A pattern formed by combining the neck member and the taper member, a pattern formed by combining the neck member and the rod member, and a combination of the neck member, the taper member and the rod member. A femoral component having three formation patterns, i.e., a formed pattern .

At least one of an angle in a projecting direction of the projecting fitting portion that fits into the head ball with respect to the main body portion of the neck member and a projecting length dimension of the projecting fitting portion from the main body portion are different. The femoral component according to claim 1, wherein a plurality of the neck members are provided.

A plurality of dimensions in which at least one of the dimension in the expanding direction of the expanding portion of the tapered member formed so as to expand in a tapered shape and the dimension in the width direction orthogonal to the expanding direction in the tapered member are different. The femoral component according to claim 1, wherein the tapered member is provided.

4. The plurality of rod-shaped members, wherein at least one of a dimension in a longitudinal direction of the rod-shaped member and a diameter dimension of a cross section perpendicular to the longitudinal direction is provided. The femoral component according to claim 1.

The rod-shaped member having the longest longitudinal dimension among the plurality of rod-shaped members has a plurality of linear protrusions formed along the longitudinal direction on the outer periphery thereof. The femoral component described in 1.

A screw member capable of connecting the fitted neck portion and the tapered member, and capable of connecting the fitted neck portion and the rod-like member;
The neck member is formed with a through hole through which the tip side of the screw member passes,
The screw member is
An elastically deformable portion formed on the distal end side and elastically deformed so as to have a diameter smaller than that of the female screw portion formed on the tapered member or the rod-shaped member and inserted into the female screw portion;
When the elastic deformation portion is inserted into the gap portion formed on the inner side of the female screw portion in the taper-shaped member or the rod-shaped member and the elastic deformation portion recovers elastically, the taper-shaped member or the rod-shaped member A locking portion for locking the member internally,
A male screw part formed on the side opposite to the elastic deformation part side with respect to the locking part, and screwed with the female screw part;
The femoral component according to any one of claims 1 to 5, wherein the femoral component is provided.

The femoral component according to claim 6, wherein the elastic deformation portion is provided by forming a distal end side of the screw member as a flexible bifurcated structure.