JP3185273U - Stem extractor - Google Patents

Abstract

A stem extractor capable of extracting a stem without invading the proximal portion of a preserved femur is provided.
A main body portion 10 of a stem extractor G has a through hole 13, a male screw 14, and a long hole from one end side portion 11, and a nut member 20 is screwed to the male screw 14. The rod-shaped connecting member 30 has an obtuse bent portion 32. With the neck portion S2 of the stem S inserted through the through hole 13 of the main body portion 10, one end of the connecting member 30 inserted through the long hole is inserted into the screw hole S3 and screwed toward the through hole 13 side. The member 20 is constrained so that the connecting member 30 is not displaced. Thereby, the main body 10 and the connecting member 30 are fixed to the stem S. It is possible to remove the stem S from the femur by attaching the impact applying means 4 to the main body 10. In the bone-sparing artificial hip joint operation, it is possible to eliminate the need to remove the proximal part of the preserved femur.
[Selection] Figure 6A

Description

  The present invention relates to a stem removal tool for removing a stem installed on a femur in a hip prosthesis, and particularly, when performing a bone-preserving hip prosthesis, it invades the proximal portion of the preserved femur. The present invention relates to a stem extractor that can extract a stem without adding any other. In addition, a proximal part means the side near the adhesion part with a trunk.

  In general, the artificial hip joint is provided continuously to a stem S inserted into the bone marrow cavity H of the femur D as shown in FIG. 7 and an end of the insertion part S1 inserted into the bone marrow cavity H of the stem S. It comprises a bone head ball (not shown) fitted to the neck portion S2 and a socket member (not shown) fitted into the acetabulum. After the stem S is placed on the femur D, it may be necessary to remove the stem S from the femur D for some reason. One conventional means for removing the stem S is disclosed in Patent Document 1.

  The device described in Patent Document 1 is for removing a stem fixed to a femur using bone cement, and transmits ultrasonic vibrations to the stem so that a living bone tissue and bone cement and stem are The stem is pulled out by dissociating the fixed state.

  In an artificial hip joint operation that does not use bone cement, an extraction tool 1 called a stem inserter / extractor as shown in FIG. 8 is used. The extractor 1 is used for both an inserter (inserter) for inserting the stem S into the femur D and an extractor (extractor) for extracting the stem S from the femur D. Part 2 and a connecting rod 3 attached to one end of grip 2, and a male screw that is screwed into a screw hole S 3 provided in advance at a predetermined position of stem S is provided at the tip of connecting rod 3. . When inserting the stem S into the femur D, with the tip of the connecting rod 3 screwed into the screw hole S3 of the stem S, the other end of the grip 2 is struck with a hammer or the like, and the stem S is inserted into the femur. Insert into the bone marrow cavity H of D.

  When the stem S is pulled out from the femur D, the grip portion 2 is pulled manually with the connecting rod 3 screwed into the screw hole S3 of the stem S. Alternatively, as shown in FIG. 8, an impact applying means 4 called a slide hammer is attached to the other end of the grip portion 2, and an impact in the pulling direction of the stem S is applied thereby to pull out. The slide hammer is configured such that a straight rod-shaped guide shaft 5 is inserted into a weight 6 that is large enough to be gripped by a person, and the weight 6 is movable along the guide shaft 5. By connecting one end of the guide shaft 5 to the other end of the grip portion 2 and causing the weight 6 to collide with a locking portion 7 provided at the other end of the guide shaft 5, an impact force in the extraction direction is applied to the stem S. The stem S can be extracted from the femur D.

JP 7-47094 A

  Since the apparatus of Patent Document 1 uses ultrasonic vibration, the configuration is large. Further, this is not necessary for a type of artificial hip joint that does not use bone cement.

  The conventional extraction tool 1 shown in FIG. 8 is used for the bone-sparing artificial hip joint surgery that has been widely used recently, because the connecting rod 3 interferes with the proximal part of the preserved femur. May be difficult. In the conventional artificial hip joint treatment that is not a bone-sparing type, the living bone above the screw hole S3 provided in the stem S has been excised at the time of surgery. Even when the bone-sparing artificial hip joint operation is adopted, when it is necessary to remove the stem S once installed from the femur D, it is necessary to take measures such as excising the normal bone tissue that has been preserved, The invasion to the patient is increased and the operation time is increased.

  An object of the present invention is to provide a stem extractor that can withdraw a stem once installed on a femur during an artificial hip joint operation and that is less invasive to a patient.

The present invention has an insertion part that is inserted into the bone marrow cavity on the proximal side near the attachment part with the trunk of the femur, and a neck part that is connected to the insertion part and to which a head ball is attached. A stem removal tool for extracting a stem for artificial hip joint formation in which a recess is formed in the vicinity of the neck portion of the insertion portion from the femur,
A main body having a bent portion that is formed in a longitudinal shape and bends so that the axis of the one end side portion and the axis of the other end portion intersect at an obtuse angle in one plane,
A through hole through which the neck portion is inserted is provided on one end side,
On the other end side, it has an attachment part to which an impact applying means for applying an impact force in the direction of extracting the stem to the main body part is attached,
On the outer peripheral surface between the bent portion and the through hole, a male screw is formed,
In the portion where the male screw is formed, a main body portion in which a long hole penetrating in the same direction as the through hole is formed,
A nut member screwed onto the male screw;
A rod-shaped connecting member, including a connecting member inserted into the elongated hole in a state in which one end is fitted in the recess, and the other end protrudes from the elongated hole,
The stem extractor according to claim 1, wherein the displacement of the connecting member is restrained by the nut member by screwing the nut member in a direction close to the through hole.

  Further, according to the present invention, the connecting member has an obtuse bent portion, and the dimension from the bent portion to the one end fitted into the concave portion is 17 mm or more and 30 mm or less depending on the type of the stem. It is characterized by including a plurality of types different in the range.

  Further, the present invention is characterized in that a cylindrical synthetic resin guide tube into which the neck portion can be inserted is mounted in the through hole of the main body portion.

  According to the present invention, with the neck portion of the stem installed in the femur inserted into the through hole of the main body portion having the bent portion, one end portion is inserted into the concave portion of the stem, and the long hole of the main body portion is inserted. The main body portion and the connecting member are fixed to the stem by restraining the connecting member, which is inserted and protruded at the other end, from being displaced with a nut screwed in a direction close to the through hole. Then, it is possible to remove the stem from the femur by attaching impact applying means to the other end side of the main body and applying an impact force in the direction of extracting the stem to the main body. Since the stem extractor according to the present invention is fixed to the stem by the main body portion attached to the neck portion and the connecting member inserted into the recess, the stem is firmly held to facilitate the stem removal. Therefore, the operation time can be shortened. Further, in the bone-sparing artificial hip joint operation, it is possible to eliminate the need to remove the proximal part (great trochanter part) of the preserved femur, thereby preventing extra surgical invasion from being given to the patient. Since a conventional slide hammer can be used as the impact applying means, an increase in cost can be suppressed.

  Further, according to the present invention, the connecting member has an obtuse bent portion, and the dimension from the bent portion to the one end fitted into the concave portion depends on the type such as the size and shape of the stem. Since a plurality of different types are included in the range of 17 mm or more and 30 mm or less, appropriate treatment according to the patient can be performed.

  According to the present invention, since the cylindrical synthetic resin guide tube through which the neck portion can be inserted is mounted in the through hole of the main body portion, the operation of inserting the neck portion into the through hole is facilitated.

It is a side view which decomposes | disassembles and shows the structural member of the stem extraction tool G which concerns on one Embodiment of this invention. It is a perspective view which decomposes | disassembles and shows the structural member of the stem extraction tool G which concerns on one Embodiment of this invention. It is a perspective view which shows the state which assembled | attached the structural member of the stem extraction tool G which concerns on one Embodiment of this invention. It is a side view which shows the stem extraction tool G which concerns on one Embodiment of this invention, and the stem S of extraction object. It is a perspective view which shows the stem extraction tool G which concerns on one Embodiment of this invention, and the stem S of extraction object. It is a perspective view in the state where neck part S2 was inserted in guide cylinder 40 installed in penetration hole 13 of main part 10 of stem extraction tool G concerning one embodiment of the present invention. The neck portion S2 is inserted through the guide tube 40 installed in the through hole 13 of the main body portion 10 of the stem extractor G according to the embodiment of the present invention, and the one end portion 31 of the connecting member 30 is connected to the screw hole of the stem S. It is a perspective view which shows the state inserted in S3. It is a perspective view which shows the state which pushed the one end part 31 of the connection member 30 of the stem extraction tool G which concerns on one Embodiment of this invention in the screw hole S3 of the stem S. FIG. It is a side view which shows the state which pushed the one end part 31 of the connection member 30 of the stem extraction tool G which concerns on one Embodiment of this invention in the screw hole S3 of the stem S. FIG. It is a side view which shows the state which screwed the nut member 20 of the stem extraction tool G which concerns on one Embodiment of this invention, and is pressing the connection member 30. FIG. It is a side view which shows the state which attached the impact provision means 4 to the other end side part 17 of the main-body part 10 of the stem extraction tool G which concerns on one Embodiment of this invention. It is a side view which shows the state which fixed the stem extraction tool G which concerns on one Embodiment of this invention to stem S (A) with a small dimension. It is a side view which shows the state which fixed the stem extraction tool G which concerns on one Embodiment of this invention to the stem S (B) with a big dimension. 3 is a cross-sectional view showing a state where a stem S is installed on a femur D. FIG. It is a perspective view which shows the conventional stem extraction tool G.

  Hereinafter, an embodiment of a stem extractor G according to the present invention will be described with reference to the drawings. 1A to 1C relate to an embodiment of the present invention, FIG. 1A is an exploded side view showing components of the stem extractor G, and FIG. 1B is an exploded perspective view showing components. FIG. 1C is a perspective view showing a state in which the constituent members are assembled.

  The stem extractor G according to the present invention includes a main body 10, a nut member 20, a connecting member 30, and a guide tube 40.

  The main body portion 10 is formed in a longitudinal shape, and has a bent portion 16 that bends so that the axis L1 of the one end portion 11 and the axis L2 of the other end portion 17 intersect at an obtuse angle in one plane. The one end side portion 11 has a through hole 13 through which the neck portion S2 is inserted, and the other end side portion 17 is provided with an impact applying means 4 for applying an impact force in the direction of extracting the stem S to the main body portion 10. It has the attaching part 18 to which it is attached.

  The attachment portion 18 is realized, for example, as a screw hole forming portion in which an internal screw is formed. A male screw 14 is formed on the outer peripheral surface between the bent portion 16 and the through hole 13, and a long hole 15 penetrating in the same direction as the through hole 13 is formed in a portion where the male screw 14 is formed.

  The nut member 20 is screwed into a portion of the main body portion 10 where the male screw 14 is formed.

  The connecting member 30 is a rod-shaped member, and has a bent portion 32 that is bent at an obtuse angle between the one end portion 31 and the other end portion 35. Between the one end portion 31 and the bent portion 32 is a first intermediate portion 33, and between the bent portion 32 and the other end portion 35 is a second intermediate portion 34. In the present embodiment, the other end portion 35 is formed wider than the second intermediate portion 34 so as to be larger than the width dimension of the long hole 15. The one end 31 is fitted into a recess S3 (hereinafter, may be referred to as “screw hole”) of the main body 10. The second intermediate part 34 is inserted through the long hole 15 of the main body part 10.

  The guide tube 40 is a tube made of synthetic resin, has an inner diameter larger than the outer diameter of the neck portion S <b> 2, and is provided in the through hole 13 of the main body portion 10. For example, a slit 41 is formed in the guide tube 40 so that the outer diameter can be elastically expanded and contracted.

  In use, the stem extractor G is assembled as shown in FIG. 1C. The nut member 20 is screwed onto the male screw 14 of the main body 10 and rotated to be positioned near the bent portion 16. In this state, the connecting member 30 is inserted through the long hole 15 of the main body 10 from the one end 31 side. The guide tube 40 is mounted in the through hole 13 of the main body 10.

  Next, an operation procedure for extracting the stem S from the femur D using the stem extractor G will be described with reference to FIGS. 2A to 5B. 2A is a side view showing the stem extractor G and the stem S to be extracted, FIG. 2B is a perspective view showing the stem extractor G and the stem S to be extracted, and FIG. 3A is a main body of the stem extractor G FIG. 3B is a perspective view of a state in which the neck portion S2 is inserted through the through hole 13 of the portion 10, and FIG. 3B is a diagram illustrating that the neck portion S2 is inserted into the through hole 13 of the main body portion 10 of the stem removal tool G 4A is a perspective view showing a state where one end 31 is inserted into the screw hole S3 of the stem S. FIG. 4A shows a state where the one end 31 of the connecting member 30 of the stem removal tool G is pushed into the screw hole S3 of the stem S. 4B is a side view showing a state in which one end portion 31 of the connecting member 30 of the stem extractor G is pushed into the screw hole S3 of the stem S, and FIG. 5A is a screw view of the nut member 20 of the stem extractor G. The state where the connecting member 30 is pressed is shown Rear view, FIG. 5B, the other end portion 17 of the main body portion 10 of the stem extractor G, is a side view showing a state of attaching the impact application means 4.

  In the present embodiment, the screw hole for connecting the extraction tool 1 (refer to FIG. 8) called a conventional stem inserter / extractor to the recess S3 of the stem S into which the one end 31 of the connecting member 30 is fitted. Although S3 is used, a hole in which no screw is formed may be used.

  First, as shown in FIG. 2A and FIG. 2B, a stem extractor G assembled with each constituent member is prepared. Then, as shown in FIG. 3A, the neck portion S <b> 2 is inserted through the through hole 13 of the main body portion 10. With this state maintained, the one end 31 of the connecting member 30 is fitted into the screw hole S3 of the stem S as shown in FIG. Subsequently, as shown in FIGS. 4A and 4B, the one end 31 of the connecting member 30 is pushed into the back of the screw hole S3. At this time, the connecting member 30 moves in the long hole 15 from the bent portion 16 side to the through hole 13 side.

  Subsequently, as shown in FIG. 5A, the nut member 20 is screwed to the through hole 13 side, and the second intermediate portion 34 of the connecting member 30 is pressed to the through hole 13 side. This restrains both the displacement of the main body portion 10 in the direction of exiting from the neck portion S2 and the displacement of the connecting member 30 in the direction of exiting from the screw hole S3, so that the stem removal tool G does not detach from the stem S. To be fixed.

  Finally, the impact applying means 4 such as a slide hammer (see FIG. 8) is attached to the attachment portion 18 provided at the other end portion 17 of the main body portion 10, and the stem S is extracted from the main body portion 10 by using this. The stem S can be extracted from the femur D by applying a direction impact force.

  In the present embodiment, since the main body 10 and the connecting member 30 are both bent at an obtuse angle, when it becomes necessary to remove the stem in the bone-sparing artificial hip joint operation, the main body 10 and the connecting member 30 are rolled over to the proximal part of the femur. Even if the child part or the like is preserved, the stem removal tool G can be fixed to the stem S and the stem S can be pulled out without interfering with the preserved part. Therefore, the invasion to the patient can be reduced.

  6A is a side view showing a state in which the stem extractor G is fixed to the stem S (A) having a small size, and FIG. 6B is a state in which the stem extractor G is fixed to the stem S (B) having a large size. FIG. Even when the stems S (A) and S (B) having different sizes are extracted as in the present embodiment, the common stem extractor G can be used. In this case, when fixing the stem S (B) having a larger size than when fixing to the stem S (A) having a smaller size, the connecting member 30 is positioned closer to the bent portion 16 in the long hole 15 ( The displacement is constrained by the nut member 20 at a position far from the through hole 13).

(Other embodiments)
If the connecting members 30 having different lengths are prepared, it is possible to use the stem extractor G with the main body 10 common to the stem S having a larger dimensional difference.

  In addition, this invention can be suitably changed according to the implementation condition.

G Stem removal tool S Stem S1 Insertion part S2 Neck part S3 Recess 4 Impact applying means (slide hammer)
DESCRIPTION OF SYMBOLS 10 Main body part 11 One end side part 12 Through-hole part 13 Through-hole 14 Male screw part 15 Long hole 16 Bending part 17 Other end side part 20 Nut member 30 Connecting member 31 One end part 32 Bending part 33 Intermediate part 34 Intermediate part 35 Other end part 40 guide tube

Claims (3)

An insertion portion that is inserted into the bone marrow cavity on the proximal side near the attachment portion with the trunk of the femur, and a neck portion that is connected to the insertion portion and on which a head ball is attached, A stem extraction tool for extracting a stem for artificial hip joint formation in which a recess is formed in the vicinity of the neck portion from the femur,
A main body having a bent portion that is formed in a longitudinal shape and bends so that the axis of the one end side portion and the axis of the other end portion intersect at an obtuse angle in one plane,
A through hole through which the neck portion is inserted is provided on one end side,
On the other end side, it has an attachment part to which an impact applying means for applying an impact force in the direction of extracting the stem to the main body part is attached,
On the outer peripheral surface between the bent portion and the through hole, a male screw is formed,
In the portion where the male screw is formed, a main body portion in which a long hole penetrating in the same direction as the through hole is formed,
A nut member screwed onto the male screw;
A rod-shaped connecting member, including a connecting member inserted into the elongated hole in a state in which one end is fitted in the recess, and the other end protrudes from the elongated hole,
A stem extractor, wherein the displacement of the connecting member is restrained by the nut member by screwing the nut member in a direction close to the through hole.   The connecting member has an obtuse bent part, and the dimensions from the bent part to the one end fitted into the concave part are different in a range of 17 mm or more and 30 mm or less depending on the kind of the stem. The stem extractor according to claim 1, comprising:   3. The stem extractor according to claim 1, wherein a cylindrical synthetic resin guide tube into which the neck portion can be inserted is attached to the through hole of the main body portion.

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