JP3912716B2

JP3912716B2 - Intramedullary nail attachment device

Info

Publication number: JP3912716B2
Application number: JP2000038417A
Authority: JP
Inventors: 修吾松本; 信二松井
Original assignee: Homs Engineering Inc
Current assignee: Homs Engineering Inc
Priority date: 2000-02-16
Filing date: 2000-02-16
Publication date: 2007-05-09
Anticipated expiration: 2020-02-16
Also published as: JP2001224600A

Description

【０００１】
【発明の属する技術分野】
本発明は髄内釘の取付装置に係り、特に、大腿骨の近位端から髄内へ導入される髄内釘の本体釘に対し交差するように挿通される交差ネジの固定作業を行う場合に好適な技術に関する。
【０００２】
【従来の技術】
一般に、大腿骨の頭部近傍の骨折を治療する場合、大腿骨の近位端に軸線方向に穴を穿設し、大腿骨の髄内に髄内釘を導入して骨折部を固定する方法が知られている。このように大腿骨頭部の骨折治療を行うための髄内釘としては、髄内に挿入され、基部寄りに形成された傾斜孔（交差孔）を有する本体釘と、この本体釘の傾斜孔に挿通するように形成されたラグスクリュウ（交差ネジ）とを備えたものが多く用いられている。
【０００３】
上記の髄内釘を体内に装着する場合には、以下のような作業を行う。まず、大腿骨の近位端から髄内へ向けて穴を穿設し、本体釘の基端をターゲットデバイスとよばれる取付装置に接続した状態で、本体釘を大腿骨の上記穴に挿入する。次に、本体釘の骨内の姿勢をＸ線撮影装置などにより確認し、必要に応じて本体釘の姿勢を修正する。そして、取付装置を用いてガイドワイヤを本体釘の傾斜孔の軸線方向に案内し、大腿骨に導入する。そして、取付装置に案内されたドリルなどをガイドワイヤに沿って移動させ、大腿骨に傾斜孔に沿った傾斜穴を穿設する。その後、穿設された傾斜穴に沿って取付装置に案内されたラグスクリュウをねじ込み、ラグスクリュウの先端を大腿骨の頭部内に導入する。そして、このラグスクリュウの骨内の姿勢を再びＸ線装置などを用いて確認し、必要に応じてその姿勢を修正する。
【０００４】
次に、上記取付装置を髄内釘から取り外した後、本体釘の基端（大腿骨の近位端側の端部）から上記傾斜孔にまで達する軸穴内にセットスクリュウをねじ込み、セットスクリュウの先端をラグスクリュウの外周面に形成された係合溝に係合させ、このセットスクリュウによって本体釘に対してラグスクリュウの回転止めを行い、必要に応じてラグスクリュウを軸線方向にも固定する。
【０００５】
【発明が解決しようとする課題】
ところで、上記髄内釘の装着作業においては、ラグスクリュウの外周面に形成された複数の係合溝における周回方向の位置を本体釘の軸穴と一致させ、本体釘の軸穴内にねじ込まれたセットスクリュウの先端を係合溝内に導入するようにして係合させる必要がある。しかし、通常、体内に導入されているラグスクリュウの回転方向の姿勢を、同様に体内にある本体釘の軸穴に対して直接視認しながら合わせることは不可能であるので、従来は医者の経験や感を頼りにラグスクリュウの回転姿勢を適宜に調整し、セットスクリュウをねじ込んでいた。このため、セットスクリュウをねじ込んでも、ラグスクリュウの係合溝にセットスクリュウの先端が確実に係合しているかどうかを確認することができず、ラグスクリュウと本体ネジとの係合不良によって整合されていた骨折部が外れてしまうなどの事故が生じていた。
【０００６】
また、従来、髄内釘の本体釘の基端部に接続したままでセットスクリュウを髄内釘の軸穴にねじ込むことができるように構成された取付装置も提案されている。このような取付装置においては、取付装置に案内されたドライバー等の回転工具をラグスクリュウに嵌合させ、ラグスクリュウをねじ込むとともに、回転工具や取付装置に設けた位置合わせマークを頼りにラグスクリュウの回転姿勢を合わせ、そのまま取付装置を接続した状態で、セットスクリュウをねじ込むことができる。しかしながら、このような取付装置においては、本体釘の基端部に対して接続可能な接続構造と、セットスクリュウを通過させることの可能な開口部との双方を接続端部に設ける必要があるため、接続端部や髄内釘の基端部をコンパクトに構成することが困難であり、構造も複雑になるため、加工が困難であり、製造コストの上昇が避けられないという問題点がある。
【０００７】
そこで本発明は上記問題点を解決するものであり、その課題は、視覚以外の感覚により確実に係合状態を感知できるようにすることによって、各部品の構造を複雑化することなく、髄内釘における本体釘の軸穴に対して交差ネジの係合溝を確実に合わせることができる取付装置を提供することにある。
【０００８】
【課題を解決するための手段】
上記課題を解決するために本発明の髄内釘の取付装置は、骨の髄内に挿入配置され、軸線方向に伸びる軸穴及び軸線方向と交差する方向に貫通した交差孔を備えた本体釘と、該本体釘の前記交差孔に挿通され、外周面に周回方向に複数の係合溝を有する交差ネジと、前記本体釘に前記交差孔に挿通された前記交差ネジを少なくとも回転方向に結合させるために前記軸穴内に導入されて前記交差孔に対する開口部から突出することにより前記係合溝に係合するように構成された係合部材とを有する髄内釘に対して、前記交差ネジを前記交差孔に通してねじ込むための髄内釘の取付装置であって、前記交差ネジに対して回転方向に係合可能に構成された回転工具と、前記交差ネジを前記交差孔に向けて案内するための案内部とを有し、前記回転工具には複数の前記係合溝に対応した位置に複数の係合部が設けられ、前記案内部には前記係合溝が前記軸穴に合致した状態で前記係合部に対して係合する被係合部が設けられ、前記係合部と前記被係合部のうち少なくともいずれか一方を他方に向けて付勢する付勢手段を備えていることを特徴とする。
【０００９】
この発明によれば、係合部と被係合部が付勢手段によって相互に付勢されていることによって、回転工具の係合部と案内部の被係合部との係脱状態に応じた感触が回転工具に伝わるので、この感触を頼りに係合部と被係合部とが係合した状態で回転工具の回転姿勢を確実に位置決めすることができるから、視覚に頼ることなく、交差ネジの係合溝を本体釘の軸穴に確実に合致させることができる。
【００１０】
ここで、前記案内部は取付装置の支持部に設けられた案内孔に挿入固定されたスリーブであることが好ましい。また、取付装置の支持部とスリーブとの回転方向の位置決めを行うマークが設けられていることが好ましい。
【００１１】
【発明の実施の形態】
次に、添付図面を参照して本発明に係る髄内釘の取付装置の実施形態について詳細に説明する。
【００１２】
［比較例］
図１には、比較例の髄内釘の調整方法に係る髄内釘１０と、髄内釘１０に接続してラグスクリュウや他の骨ネジ等をねじ込むときの案内を行う取付装置２０と、本比較例に係る調整具３０とを示す。
【００１３】
髄内釘１０は、大腿骨の髄内に沿って導入される本体釘１１と、大腿骨の頭部に向けてねじ込まれるラグスクリュウ（交差ネジ）１２とから構成される。本体釘１１は、基端部において開口した軸穴１１ａを備えている。また、本体釘１１の基端部寄り部分には、上記の軸穴１１ａと連通し、斜めに本体釘１１を貫通する大小２つの傾斜孔１１ｂ，１１ｃが形成されている。さらに、本体釘１１の先端寄りには、水平に本体釘１１を貫通する水平孔１１ｄと、本体釘１１の先端において開いたすり割部１１ｅとが形成されている。
【００１４】
軸穴１１ａには、後述する接続ネジ２４と螺合するための雌ネジと、セットスクリュウ１３の雄ネジ１３ａと螺合するための雌ネジとが形成されている。セットスクリュウ１３には、軸穴１１ａにねじ込んだとき、後述するラグスクリュウ１２の係合溝１２ｄと係合する係合端部１３ｂが設けられている。
【００１５】
ラグスクリュウ１２は、上記本体釘１１の傾斜孔１１ｂに挿通可能に構成されているとともに、後述するガイドワイヤを挿通可能な、軸線方向に貫通した軸孔１２ａを備えている。また、ラグスクリュウ１２には、骨内に切り込むとともに骨内で固定されるように構成されたタッピングネジ１２ｂと、タッピングネジ１２ｂの後方に伸びる軸部１２ｃと、軸部１２ｃの外周面上において周回方向に複数（図示の場合には４本）配列するように形成された軸線方向に伸びる係合溝１２ｄと、軸部１２ｃの基端部内側に設けられ、後述する回転工具２３に係合する例えば６角穴形状の係合異形部１２ｅとを有している。
【００１６】
取付装置２０は、髄内釘１０に接続したときに本体釘１１とほぼ平行に伸びる支持部２１と、この支持部２１の上端にて連結され、本体釘１１の基端部に接続されるアーム部２２とからなる。アーム部２２の先端部には開口部２２ａが形成され、この開口部に係合する接続ネジ２５を本体釘１１の軸穴１１ａの開口内縁部に形成された雌ネジに螺合させることによって、本体釘１１とアーム部２２とを接続固定できるように構成されている。
【００１７】
支持部２１の下部には図示一点鎖線で示すスリーブ２４を嵌合させる案内孔２１ａが形成されている。スリーブ２４は図示しない締め付け構造によって案内孔２１ａ内に挿通された状態でしっかりと固定され、案内孔２１ａによってスリーブ２４を介して回転工具２３が本体釘１１の傾斜孔１１ｂの軸線方向に案内されるように構成されている。案内孔２１ａ及びスリーブ２４は、回転工具２３だけではなく、後述するガイドワイヤ、ドリルやリーマ等の穿孔器具、ラグスクリュウ１２をもそれぞれ傾斜孔１１ｂに向けて案内するように構成されている。
【００１８】
本比較例では、後述する方法で調整具３０が用いられる。この調整具３０は、操作ハンドル３１と、操作ハンドルの中央部に接続された可撓性の軸部３２と、軸部３２の先端に接続された先端部３３とから構成される。軸部３２としては全体として緩やかに湾曲するが、十分な弾性を有し、折り曲げることのできない程度の強度を備えていることが好ましい。先端部３３はラグスクリュウ１２の上記係合溝１２ｄに対して、セットスクリュウ１３の係合端部１３ｂと同様に係合可能に構成された係合端部３３ａを備えている。また、先端部３３は、上記本体釘１１の軸穴１１ａに対して出し入れ自在に構成されている。
【００１９】
上記構造の髄内釘１０、取付装置２０及び調整具３０を用いた大腿骨の骨折部の固定方法を以下に説明する。まず、上記従来例と同様に、本体釘１１を取付装置２０に接続し、本体釘１１の大腿骨髄内への導入、ガイドワイヤの骨内及び傾斜孔１１ｂへの導入、傾斜孔１１ｂに沿った骨の穿孔を順次実施し、その後、図１に示すように回転工具２３を用いてラグスクリュウ１２のねじ込みを行う。ラグスクリュウ１２のねじ込みは、支持部２１に装着されたスリーブ２４に回転工具２３を挿通させ、この回転工具２３の先端部を、ラグスクリュウ１２の係合異形部１２ｅに対して係合させて回転させることにより行う。
【００２０】
ラグスクリュウ１２を回転させていくと、ラグスクリュウ１２は図示しない大腿骨の内部に進行し、傾斜孔１２ｂを通過して、大腿骨頭部内に進む。そして、所定深さまで進行したとき、図１に示す調整具３１を接続ネジ２５に形成された通孔を通して本体釘１１の軸穴１１ａ内に挿入し、傾斜孔１１ｂ内に導入されているラグスクリュウ１２の軸部１２ｃの表面に調整具３１の係合端部３３ａを突き当てる。このとき、回転工具２３の操作ハンドル２３ａを一方の手に把持して軸部３２をやや撓ませながら、軸部３２の弾性力に応じた圧力で係合端部３３ａをラグスクリュウ１２の軸部１２ｃに突き立てる一方、他方の手で回転工具２３を操作してラグスクリュウ１２を回転させ、調整具３０の操作ハンドル３１の感触を確認する。ラグスクリュウ１２が回転すると、調整具３０の係合端部３３ａが軸部１２ｃの表面に形成された係合溝１２ｄと係合したり、係合溝１２ｄから外れたりし、これによって軸穴１１ａに対して出し入れ自在に構成された先端部３３が軸穴１１ａにおける傾斜孔１１ｂに対する開口部から出没移動するので、調整具３０の軸部３２が軸線方向に移動し、操作ハンドル３１を把持している手にその感触が伝わるので、係合端部３３ａが係合溝１２ｄと係合したときのラグスクリュウ１２の回転姿勢を確実に知ることができる。
【００２１】
上記のようにして調整具３０の係合端部３３ａが係合溝１２ｄに係合したときにラグスクリュウ１２の回転を止め、その回転姿勢を維持する。その後、回転工具２３をラグスクリュウ１２から離反させるとともに、髄内釘の本体釘１１から取付装置２０を取り外す。そして、セットスクリュウ１３を軸穴１１ａ内に入れ、ねじ込むことによって、セットスクリュウ１３の係合端部１３ａをラグスクリュウ１２の係合溝１２ｄに係合させる。
【００２２】
本比較例では、ラグスクリュウ１２の係合溝１２ｄの位置を本体釘１１の軸穴１１ａの傾斜孔１１ｂに対する開口部と合致させるために、可撓性及び弾性を備えた軸部３２を有し、その先端部３３にラグスクリュウ１２の係合溝１２ｄに対して係合可能な係合端部３３ａを備えた調整具を用いていることにより、ラグスクリュウ１２の回転によって係合端部３３ａが係合溝１２ｄに対して係脱する様子を弾力のある軸部３２を介して感触によって確実に知ることができる。また、軸部３２が可撓性を有することによって、図示のように腰部の側方へ撓ませた状態で用いることができるので、操作性を向上させることができ、このように撓
ませた状態でも軸部３２の弾性によって、係合端部３３ａと係合溝１２ｄとの係合状態の変化の感触を支障なく得ることができる。
【００２３】
［実施形態］
次に、本発明に係る実施形態について図２を参照して説明する。この実施形態においては、上記比較例で説明したものと同一の髄内釘１０に対してガイドワイヤ、穿孔具、ラグスクリュウ１２等を案内するための、上記比較例とほぼ同様の取付装置４０である。この取付装置４０は、比較例と同じ支持部４１、アーム部４２を備えている。
【００２４】
支持部４１は上記と同様のスリーブ４４を本体釘１１の傾斜孔１１ｂに向けた姿勢に案内し、アーム部４２は上記と同様の接続ネジ４５によって本体釘１１の基端部に接続固定されるようになっている。本実施形態では、支持部４１の端部に位置合わせマーク４１ｅを有し、この位置合わせマーク４１ｅは、スリーブ４４の外面に形成された位置合わせマーク４４ｅに合わせるためのものである。スリーブ４４は、軸線方向に貫通するように形成された案内孔４４ａにより上記と同様にラグスクリュウ１２及びその図示しない係合異形部に係合した回転工具４３とを案内するようになっている。ラグスクリュウ１２及び回転工具４３はスリ
ーブ４４の内部に挿通され、ラグスクリュウ１２は上記傾斜孔１１ｂに向けてねじ込まれる。
【００２５】
スリーブ４４の基端部４４ｂの内部には、案内孔４４ａ内に出没可能に構成された係合ボール４４ｃが内蔵され、この係合ボール４４ｃをコイルバネ等からなる弾性部材４４ｄが案内孔４４ａ内に押し付けるようになっている。
【００２６】
一方、回転工具４３は、ガイドワイヤを挿通するための軸線方向に貫通した軸孔を備えていると共に、その基端部に操作ハンドル４３ａを有し、その先端部には、ラグスクリュウ１２の係合異形部に対して回転方向に嵌合する係合嵌合部４３ｂを備えている。また、操作ハンドル４３ａと係合嵌合部４３ｂとの間には軸線方向に伸びる円筒部４３ｃとなっており、この円筒部４３ｃの外面上には、ラグスクリュウ１２の係合溝１２ｄと等しい周期及び数で周回方向に配列形成された複数の係合溝４３ｄが形成されている。
【００２７】
ラグスクリュウ１２と、これに係合した回転工具４３とがスリーブ４４の軸孔内に挿入され、ラグスクリュウ１２が骨内に導入され、本体釘１１ｂを通過して所定位置の近くまでねじ込まれたとき、上記係合溝４３ｄはスリーブ４４の基端部４４ｂ内に導入され、係合溝４３ｄのうちの一つが上記係合ボール４４ｃに係合するようになる。このとき、係合ボール４４ｃが係合溝４３ｄに入り込み、係合しても、回転工具４３の回転が妨げられることはなく、弾性部材４４ｄの弾性力によってクリック感をもって回転工具４３を回転させることができる。そして、回転工具４３を回転させていくとき、上記クリック感によって、係合ボール４４ｃが係合溝４３ｄに係合しているか否かを感知することができるように構成されている。
【００２８】
本実施形態では、支持部４１とスリーブ４４とが位置合わせマーク４１ｅと４４ｅとを合わせるようにして取り付けられている場合において、回転工具４３に係合したラグスクリュウ１２の係合溝１２ｄが本体釘１１の軸穴１１ａの傾斜孔１１ｂに対する開口部と合致するとき、必ず回転工具４３の係合溝４３ｄが係合ボール４４ｃに係合しているように、係合溝１２ｄ、係合溝４３ｄ及び係合ボール４４ｃの間の、回転方向の位置が整合するように構成されている。したがって、回転工具４３を回転駆動して、ラグスクリュウ１２を骨内の適切な深さまでにねじ込み、上記のようにしてクリック感によって係合溝４３ｄと係合ボール４４ｄとが係合した位置で回転を止めると、ラグスクリュウ１２の係合溝１２ｄは軸穴１１ａの開口部に合致するので、その後、たとえ取付装置２０を髄内釘１０から取り外したとしても、上記比較例と同様に確実にセットスクリュウ１３をラグスクリュウ１２の係合溝１２ｄに係合させることができる。
【００２９】
尚、本発明の髄内釘の取付装置は、上述の図示例にのみ限定されるものではなく、本発明の要旨を逸脱しない範囲内において種々変更を加え得ることは勿論である。
【００３０】
【発明の効果】
以上、説明したように本発明によれば、交差ネジの係合溝と調整具の係合端部とが係合しているか否かを直接感覚によって感知できるから、視覚に頼ることなく、確実に交差ネジを本体釘に係合させることができるため、術者に安心感を与えることができ、交差ネジの係合不良を防止することができる。
【図面の簡単な説明】
【図１】比較例である髄内釘の調整具を、髄内釘及び取付装置とともに示す概略構成図である。
【図２】本発明に係る実施形態である髄内釘の取付装置を髄内釘とともに示す概略構成図である。
【符号の説明】
１０髄内釘
１１本体釘
１１ａ軸穴
１１ｂ傾斜孔
１２ラグスクリュウ
１２ｄ係合溝
１３セットスクリュウ
１３ａ係合端部
２０，４０取付装置
２３，４３回転工具
２４，４４スリーブ
３０調整具
３２軸部
３３先端部
３３ａ係合端部
４４ｃ係合ボール
４４ｄ弾性部材[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an intramedullary nail attachment device, and in particular, when fixing a cross screw inserted so as to intersect with a main body nail of an intramedullary nail introduced from the proximal end of a femur into the marrow. It relates to a technique suitable for the above.
[0002]
[Prior art]
In general, when treating a fracture near the head of the femur, a method of fixing a fracture by drilling a hole in the axial direction at the proximal end of the femur and introducing an intramedullary nail into the medullary of the femur It has been known. In this way, the intramedullary nail for treating the fracture of the femoral head includes a main body nail having an inclined hole (cross hole) inserted in the marrow and formed near the base, and an inclined hole of the main body nail. A thing provided with the lag screw (crossing screw) formed so that it may penetrate is often used.
[0003]
When mounting the above intramedullary nail in the body, the following work is performed. First, a hole is drilled from the proximal end of the femur into the medulla and the body nail is inserted into the hole in the femur with the proximal end of the body nail connected to an attachment device called a target device. . Next, the posture of the main body nail in the bone is confirmed by an X-ray imaging apparatus or the like, and the posture of the main body nail is corrected as necessary. Then, the guide wire is guided in the axial direction of the inclined hole of the main body nail using the attachment device, and is introduced into the femur. Then, a drill or the like guided by the attachment device is moved along the guide wire, and an inclined hole is formed in the femur along the inclined hole. Thereafter, the lug screw guided by the attachment device is screwed along the drilled hole, and the tip of the lug screw is introduced into the head of the femur. Then, the posture of the lag screw in the bone is confirmed again using an X-ray apparatus or the like, and the posture is corrected if necessary.
[0004]
Next, after removing the attachment device from the intramedullary nail, the set screw is screwed into the shaft hole reaching the inclined hole from the base end of the main body nail (the end on the proximal end side of the femur). The front end is engaged with an engaging groove formed on the outer peripheral surface of the lag screw, the set screw is used to stop the rotation of the lag screw relative to the main body nail, and the lag screw is also fixed in the axial direction as necessary.
[0005]
[Problems to be solved by the invention]
By the way, in the above-mentioned intramedullary nail mounting operation, the positions in the circumferential direction of the plurality of engaging grooves formed on the outer peripheral surface of the lug screw are aligned with the shaft hole of the main body nail and screwed into the shaft hole of the main body nail. It is necessary to engage the set screw by introducing the tip of the set screw into the engagement groove. However, since it is usually impossible to adjust the posture in the rotational direction of the lag screw introduced into the body while directly observing the axial hole of the body nail in the body, it is impossible for the doctor to experience it in the past. Relying on the feeling, the rotation posture of the lag screw was adjusted appropriately, and the set screw was screwed in. For this reason, even if the set screw is screwed in, it cannot be confirmed whether the tip of the set screw is securely engaged with the engagement groove of the lag screw, and alignment is caused by a poor engagement between the lag screw and the main body screw. Accidents occurred, such as the fractured part being removed.
[0006]
Conventionally, there has also been proposed an attachment device configured so that the set screw can be screwed into the shaft hole of the intramedullary nail while being connected to the proximal end portion of the body nail of the intramedullary nail. In such a mounting device, a rotary tool such as a screwdriver guided by the mounting device is fitted into the lag screw, the lag screw is screwed in, and the lag screw is relied on using the alignment mark provided on the rotary tool or the mounting device. The set screw can be screwed in a state where the rotation posture is matched and the mounting device is connected as it is. However, in such an attachment device, it is necessary to provide both the connection structure connectable to the base end portion of the main body nail and the opening portion through which the set screw can pass at the connection end portion. The connecting end and the base end of the intramedullary nail are difficult to configure in a compact manner, and the structure becomes complicated. Therefore, there is a problem that processing is difficult and an increase in manufacturing cost is inevitable.
[0007]
Therefore, the present invention solves the above-mentioned problems, and the problem is to make it possible to detect the engagement state with a sense other than vision without complicating the structure of each component. It is an object of the present invention to provide an attachment device capable of reliably aligning an engagement groove of a cross screw with a shaft hole of a main body nail in a nail.
[0008]
[Means for Solving the Problems]
In order to solve the above-mentioned problems, an intramedullary nail attachment device according to the present invention includes a body nail that is inserted into a bone marrow and includes an axial hole extending in an axial direction and a cross hole penetrating in a direction intersecting the axial direction. And a cross screw having a plurality of engaging grooves in a circumferential direction on the outer peripheral surface and a cross screw inserted in the cross hole into the main body nail at least in the rotational direction. An intramedullary nail having an engaging member configured to engage the engaging groove by being introduced into the shaft hole and projecting from an opening to the intersecting hole. An intramedullary nail attachment device for screwing a screw through the cross hole, the rotary tool being configured to be able to engage with the cross screw in a rotational direction, and the cross screw toward the cross hole A guide part for guiding, the rotating work Has a plurality of engaging portions at positions corresponding to the plurality of engaging grooves, and the guide portion engages with the engaging portions in a state where the engaging grooves are aligned with the shaft holes. An engaged portion is provided, and biasing means for biasing at least one of the engaging portion and the engaged portion toward the other is provided.
[0009]
According to the present invention, the engaging portion and the engaged portion are urged to each other by the urging means, so that the engagement portion of the rotary tool and the engaged portion of the guide portion are engaged / disengaged. Since the touch is transmitted to the rotary tool, the rotational posture of the rotary tool can be reliably positioned in a state where the engaging portion and the engaged portion are engaged based on this touch, so without relying on vision, The engagement groove of the cross screw can be surely aligned with the shaft hole of the main body nail.
[0010]
Here, it is preferable that the guide portion is a sleeve inserted and fixed in a guide hole provided in a support portion of the attachment device. Moreover, it is preferable that a mark for positioning the support portion of the attachment device and the sleeve in the rotational direction is provided.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
Next, an embodiment of an intramedullary nail attachment device according to the present invention will be described in detail with reference to the accompanying drawings.
[0012]
[Comparative example]
FIG. 1 shows an intramedullary nail 10 according to a comparative method for adjusting an intramedullary nail, an attachment device 20 for guiding a lag screw or other bone screw connected to the intramedullary nail 10, The adjustment tool 30 which concerns on this comparative example is shown.
[0013]
The intramedullary nail 10 includes a main body nail 11 that is introduced along the inside of the femur and a lag screw (cross screw) 12 that is screwed toward the head of the femur. The main body nail 11 is provided with a shaft hole 11a opened at the base end portion. Further, two large and small inclined holes 11b and 11c that are communicated with the shaft hole 11a and obliquely penetrate the main body nail 11 are formed near the base end portion of the main body nail 11. Further, a horizontal hole 11 d that penetrates the main body nail 11 horizontally and a slit portion 11 e that opens at the front end of the main body nail 11 are formed near the front end of the main body nail 11.
[0014]
The shaft hole 11 a is formed with a female screw for screwing with a connection screw 24 described later and a female screw for screwing with the male screw 13 a of the set screw 13. The set screw 13 is provided with an engagement end portion 13b that engages with an engagement groove 12d of the lug screw 12 described later when screwed into the shaft hole 11a.
[0015]
The lug screw 12 is configured to be able to be inserted into the inclined hole 11b of the main body nail 11, and includes an axial hole 12a penetrating in the axial direction through which a guide wire described later can be inserted. Further, the lug screw 12 has a tapping screw 12b configured to be cut into the bone and fixed in the bone, a shaft portion 12c extending rearward of the tapping screw 12b, and an orbit on the outer peripheral surface of the shaft portion 12c. A plurality of (four in the illustrated case) axially extending engaging grooves 12d formed in the direction and provided on the inner side of the base end portion of the shaft portion 12c and engaged with a rotary tool 23 described later. For example, it has a hexagonal hole-shaped engaging deformed portion 12e.
[0016]
The attachment device 20 includes a support portion 21 that extends substantially parallel to the main body nail 11 when connected to the intramedullary nail 10, and an arm that is connected to the upper end of the support portion 21 and connected to the base end portion of the main body nail 11. Part 22. An opening 22a is formed at the tip of the arm 22, and a connection screw 25 that engages with the opening is screwed into a female screw formed at the inner edge of the opening of the shaft hole 11a of the main body nail 11. The main body nail 11 and the arm part 22 can be connected and fixed.
[0017]
A guide hole 21 a is formed in the lower portion of the support portion 21 for fitting the sleeve 24 shown by a dashed line in the figure. The sleeve 24 is firmly fixed in a state where the sleeve 24 is inserted into the guide hole 21a by a fastening structure (not shown), and the rotary tool 23 is guided in the axial direction of the inclined hole 11b of the main body nail 11 through the sleeve 24 by the guide hole 21a. It is configured as follows. The guide hole 21a and the sleeve 24 are configured to guide not only the rotary tool 23 but also a guide wire, a drilling device such as a drill or a reamer, and the lag screw 12 described later toward the inclined hole 11b.
[0018]
In this comparative example, the adjustment tool 30 is used by a method described later. The adjustment tool 30 includes an operation handle 31, a flexible shaft portion 32 connected to the central portion of the operation handle, and a tip portion 33 connected to the tip of the shaft portion 32. The shaft portion 32 is gently curved as a whole, but preferably has sufficient elasticity and a strength that cannot be bent. The distal end portion 33 includes an engagement end portion 33 a configured to be engageable with the engagement groove 12 d of the lug screw 12 in the same manner as the engagement end portion 13 b of the set screw 13. Further, the distal end portion 33 is configured to be freely inserted into and removed from the shaft hole 11 a of the main body nail 11.
[0019]
A method for fixing a fractured portion of the femur using the intramedullary nail 10, the mounting device 20, and the adjusting tool 30 having the above structure will be described below. First, as in the above-described conventional example, the main body nail 11 is connected to the mounting device 20, and the main body nail 11 is introduced into the femoral bone marrow, the guide wire is introduced into the bone and the inclined hole 11b, and the inclined hole 11b is aligned Bone drilling is performed sequentially, and then the lag screw 12 is screwed in using the rotary tool 23 as shown in FIG. The screw of the lag screw 12 is rotated by inserting the rotary tool 23 through the sleeve 24 mounted on the support portion 21 and engaging the tip of the rotary tool 23 with the engaging deformed portion 12e of the lag screw 12. To do.
[0020]
As the lag screw 12 is rotated, the lag screw 12 advances into the femur (not shown), passes through the inclined hole 12b, and advances into the femoral head. 1 is inserted into the shaft hole 11a of the main body nail 11 through the through hole formed in the connection screw 25, and the lug screw introduced into the inclined hole 11b. The engaging end portion 33a of the adjustment tool 31 is abutted against the surface of the 12 shaft portions 12c. At this time, while holding the operation handle 23a of the rotary tool 23 with one hand and slightly bending the shaft portion 32, the engagement end portion 33a is moved to the shaft portion of the lug screw 12 with a pressure corresponding to the elastic force of the shaft portion 32. The lug screw 12 is rotated by operating the rotary tool 23 with the other hand, and the feel of the operation handle 31 of the adjustment tool 30 is confirmed. When the lug screw 12 rotates, the engagement end portion 33a of the adjustment tool 30 engages with or disengages from the engagement groove 12d formed on the surface of the shaft portion 12c, and thereby the shaft hole 11a. Since the tip 33 configured to be freely inserted into and retracted from the opening of the inclined hole 11b in the shaft hole 11a moves in and out, the shaft 32 of the adjustment tool 30 moves in the axial direction and grips the operation handle 31. Since the touch is transmitted to the holding hand, the rotation posture of the lug screw 12 when the engagement end portion 33a is engaged with the engagement groove 12d can be surely known.
[0021]
As described above, when the engagement end portion 33a of the adjustment tool 30 is engaged with the engagement groove 12d, the rotation of the lug screw 12 is stopped and the rotation posture is maintained. Thereafter, the rotary tool 23 is moved away from the lug screw 12 and the attachment device 20 is removed from the intramedullary nail 11. Then, the set screw 13 is inserted into the shaft hole 11 a and screwed to engage the engagement end portion 13 a of the set screw 13 with the engagement groove 12 d of the lug screw 12.
[0022]
In this comparative example, in order to make the position of the engagement groove 12d of the lug screw 12 coincide with the opening portion of the shaft hole 11a of the main body nail 11 with respect to the inclined hole 11b, the shaft portion 32 having flexibility and elasticity is provided. By using the adjustment tool provided with the engagement end portion 33a that can be engaged with the engagement groove 12d of the lug screw 12 at the distal end portion 33, the engagement end portion 33a is rotated by the rotation of the lug screw 12. The state of engagement / disengagement with respect to the engagement groove 12d can be surely known by touch through the elastic shaft portion 32. Further, since the shaft portion 32 has flexibility, it can be used in a state where it is bent to the side of the waist as shown in the figure, so that the operability can be improved, and the state where it is bent in this way However, due to the elasticity of the shaft portion 32, it is possible to obtain a feeling of change in the engagement state between the engagement end portion 33a and the engagement groove 12d without any trouble.
[0023]
[Embodiment]
Next, an embodiment according to the present invention will be described with reference to FIG. In this embodiment, the attachment device 40 is substantially the same as the comparative example for guiding the guide wire, the punch, the lug screw 12 and the like to the same intramedullary nail 10 as described in the comparative example. is there. This attachment device 40 includes the same support part 41 and arm part 42 as in the comparative example.
[0024]
The support portion 41 guides the sleeve 44 similar to the above to the posture toward the inclined hole 11b of the main body nail 11, and the arm portion 42 is connected and fixed to the base end portion of the main body nail 11 by the connection screw 45 similar to the above. It is like that. In the present embodiment, an alignment mark 41 e is provided at the end of the support portion 41, and this alignment mark 41 e is for alignment with the alignment mark 44 e formed on the outer surface of the sleeve 44. The sleeve 44 guides the lug screw 12 and the rotary tool 43 engaged with an engaging deformed portion (not shown) in the same manner as described above by a guide hole 44a formed so as to penetrate in the axial direction. The lag screw 12 and the rotary tool 43 are inserted into the sleeve 44, and the lag screw 12 is screwed toward the inclined hole 11b.
[0025]
An engagement ball 44c configured to be able to protrude and retract in the guide hole 44a is built in the base end portion 44b of the sleeve 44, and an elastic member 44d made of a coil spring or the like is placed in the guide hole 44a. It is designed to be pressed.
[0026]
On the other hand, the rotary tool 43 is provided with an axial hole penetrating in the axial direction for inserting a guide wire, and has an operation handle 43a at its base end, and the engagement of the lug screw 12 at its distal end. An engagement fitting portion 43b that fits in the rotational direction with respect to the deformed portion is provided. A cylindrical portion 43c extending in the axial direction is formed between the operation handle 43a and the engagement fitting portion 43b. On the outer surface of the cylindrical portion 43c, a period equal to that of the engagement groove 12d of the lug screw 12 is provided. A plurality of engaging grooves 43d arranged in the circumferential direction by the number are formed.
[0027]
The lag screw 12 and the rotating tool 43 engaged therewith were inserted into the shaft hole of the sleeve 44, the lag screw 12 was introduced into the bone, and passed through the main body nail 11b and screwed to near a predetermined position. At this time, the engagement groove 43d is introduced into the proximal end portion 44b of the sleeve 44, and one of the engagement grooves 43d is engaged with the engagement ball 44c. At this time, even if the engagement ball 44c enters and engages with the engagement groove 43d, the rotation of the rotary tool 43 is not hindered and the rotary tool 43 is rotated with a click feeling by the elastic force of the elastic member 44d. Can do. When the rotary tool 43 is rotated, it can be detected whether or not the engagement ball 44c is engaged with the engagement groove 43d by the click feeling.
[0028]
In the present embodiment, when the support portion 41 and the sleeve 44 are attached so that the alignment marks 41e and 44e are aligned, the engagement groove 12d of the lug screw 12 engaged with the rotary tool 43 is the main body nail. 11, the engagement groove 12 d, the engagement groove 43 d, and the engagement groove 43 d so that the engagement groove 43 d of the rotary tool 43 is always engaged with the engagement ball 44 c when the shaft hole 11 a matches the opening of the inclined hole 11 b. The engaging balls 44c are configured such that the positions in the rotational direction are aligned. Therefore, the rotary tool 43 is driven to rotate, the lug screw 12 is screwed to an appropriate depth in the bone, and is rotated at the position where the engagement groove 43d and the engagement ball 44d are engaged by a click feeling as described above. Since the engagement groove 12d of the lug screw 12 matches the opening of the shaft hole 11a, even if the attachment device 20 is removed from the intramedullary nail 10, it is securely set as in the comparative example. The screw 13 can be engaged with the engaging groove 12d of the lug screw 12.
[0029]
It should be noted that the intramedullary nail attachment device of the present invention is not limited to the illustrated example described above, and it is needless to say that various modifications can be made without departing from the gist of the present invention.
[0030]
【The invention's effect】
As described above, according to the present invention, whether or not the engagement groove of the cross screw and the engagement end of the adjustment tool are engaged can be directly sensed. Since the cross screw can be engaged with the main body nail, it is possible to give the operator a sense of security and prevent the cross screw from being poorly engaged.
[Brief description of the drawings]
FIG. 1 is a schematic configuration diagram showing an intramedullary nail adjustment tool as a comparative example together with an intramedullary nail and an attachment device.
FIG. 2 is a schematic configuration diagram showing an intramedullary nail attachment device according to an embodiment of the present invention together with an intramedullary nail.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 10 Intramedullary nail 11 Main body nail 11a Shaft hole 11b Inclined hole 12 Lug screw 12d Engaging groove 13 Set screw 13a Engaging end part 20 and 40 Mounting apparatus 23 and 43 Rotating tool 24 and 44 Sleeve 30 Adjuster 32 Shaft part 33 Tip Part 33a engaging end 44c engaging ball 44d elastic member

Claims

A body nail that is inserted and arranged in the bone marrow and has an axial hole extending in the axial direction and a cross hole penetrating in a direction intersecting the axial direction, and is inserted into the cross hole of the main body nail and is rotated around the outer circumferential surface. A cross screw having a plurality of engaging grooves and a cross screw inserted through the cross hole into the main body nail are introduced into the shaft hole to project at least in a rotational direction and project from an opening with respect to the cross hole. An intramedullary nail attachment device for screwing the cross screw through the cross hole with respect to an intramedullary nail having an engagement member configured to engage with the engagement groove. And
A rotating tool configured to be able to engage with the intersecting screw in a rotation direction; and a guide portion for guiding the intersecting screw toward the intersecting hole. A plurality of engaging portions are provided at positions corresponding to the mating grooves, and the guide portion is provided with an engaged portion that engages with the engaging portion in a state where the engaging groove is aligned with the shaft hole. And a biasing means for biasing at least one of the engaging portion and the engaged portion toward the other.