JP5009562B2 - Intramedullary nail and orthopedic surgical instrument set - Google Patents

Description

  The present invention relates to an intramedullary nail and an orthopedic surgical instrument set, and more particularly to a structure of an intramedullary nail that is introduced into a medullary cavity of a long bone, for example, a radius or an ulna for internal fixation.

In general, an intramedullary nail introduced into the medullary cavity of a bone is sometimes used in orthopedic surgery for treating fractures of long bones such as the forearm bones, humerus bones, femurs, and tibias such as the radius and ulna. is there. As such an intramedullary nail, for example, a relatively straight intramedullary nail configured to be drilled in a bone end portion of a long bone with a drill or the like and introduced into the intramedullary cavity from the bone end portion is used. Used in sites that are difficult to introduce from the epiphysis, such as ribs and tibia, but use intramedullary nails designed to be introduced obliquely into the medullary cavity from the outer surface of the bone There is a case. In addition, a fixing hole for inserting and engaging a fixing screw screwed into the cortex of the long bone may be provided in the proximal end portion of these intramedullary nails (see, for example, Patent Documents 1 and 2 below) ). This type of intramedullary nail has a thin plate-like plate portion (base end portion) disposed on the outer surface of the bone, and a nail portion (insertion portion) introduced into the medullary cavity. It is known that a screw hole is provided in the part and a step part is provided between the plate part and the nail part.
JP 2003-265494 A JP-A-9-299384

  However, in the aforementioned intramedullary nail, when the intramedullary nail is introduced obliquely with respect to the bone axis from the outer surface of the bone, it has a cylindrical inner surface outside the opening formed by drilling the cortex. Since the concave groove is formed, the base end portion may not be stably installed. In order to avoid this, since the insertion portion must be inserted at a large angle with respect to the outer surface of the bone by increasing the inclination angle in the drilling direction, a step portion is provided between the proximal end portion and the insertion portion. There is a problem that it becomes difficult to insert the intramedullary nail because it is necessary or the degree of bending of the insertion portion must be increased.

  In addition, in the conventional intramedullary nail of this type, a curved tip is used so that it can be introduced into the medullary cavity from the outer surface of the bone, or in order to exert a predetermined reduction force in the medullary cavity. Part or insertion part. Therefore, when the insertion portion of the intramedullary nail is inserted into the medullary structure, the intramedullary nail rotates due to the insertion resistance of the long bone, and may not be inserted into the medullary cavity in a desired posture. For example, as shown in FIG. 6 of Patent Document 1 and Patent Document 2, since the plate portion, which is a conventional base end, is thin, even if the base end is gripped and inserted, deformation occurs in the base end. In some cases, the rotation of the insertion portion cannot be completely prevented, and when a cylindrical base end portion is provided as shown in FIG. 1 of Patent Document 2, the base end portion is gripped. It is conceivable that the proximal end slips due to insertion resistance and the entire intramedullary nail rotates.

Therefore, the present invention solves the above problems, and the problem is that when the intramedullary nail is inserted into the medullary cavity obliquely from the outer surface of the long bone, the proximal end portion of the long bone is stably stabilized. An object of the present invention is to provide an intramedullary nail that can be installed on the outer side surface and can easily and reliably insert the insertion portion into the medullary cavity in a predetermined posture.

In view of such circumstances, the intramedullary nail of the present invention includes a proximal end portion disposed on the outer surface side of the long bone, and an insertion portion that extends from the proximal end portion and is inserted into the medullary cavity of the long bone. comprising the in intramedullary nail for performing internal fixation of a long bone, the proximal end, wherein with comprises a cylindrical surface of the back surface which is formed along the axis, a flattened shape than back surface A surface formed along the axis from the edge opposite to the insertion portion of the base end portion , and an annular shape that receives the head of the fixing screw on the inner surface on the side of the surface penetrating from the surface to the back surface A first region provided at an end portion having a fixing hole formed with an engagement receiving surface, and extending linearly along the axis toward the insertion portion with respect to the first region, A cylindrical second region that is integrally connected coaxially with the back surface of one region and has an outer diameter smaller than the outer diameter of the back surface of the first region; Characterized in that it contains.

According to this invention, the back surface of the proximal end portion of the intramedullary nail is formed in a cylindrical surface shape along the axis, so that the outer surface of the long bone is drilled obliquely with respect to the bone axis toward the medullary cavity. In this way, the back surface of the base end can be stably aligned with the cylindrical groove formed on the outer surface, so that the head of the fixing screw can be used as an annular engagement receiving surface. By engaging, the proximal end can be reliably fixed on the outer surface of the bone using the fixing hole. Further, by making beyond the back surface of the cylindrical surface providing a planarized surface, since the base end portion while preventing the deformation to secure the rigidity of the base end portion is easy to grip to prevent rotation, Rotation during insertion of the intramedullary nail can be prevented, and the insertion portion can be easily and reliably introduced into the medullary cavity in a predetermined posture. Further, since the front surface is flattened from the back surface, it is possible to eliminate or reduce the amount of the proximal end portion protruding from the outer surface of the long bone.

  In this invention, it is preferable that the notch part is provided in the opening edge of the said fixing hole. According to this, since the cutout portion is provided at the opening edge of the fixing hole, the opening edge of the fixing hole can be elastically deformed, so that the head of the fixing member such as the fixing screw is elastically held. It is possible to increase the degree of freedom of the insertion angle of the fixing member with respect to the bone. It is also possible to grasp the head of the fixing member through the notch and remove the fixing member forcibly at the time of removing the fixing member.

  In the present invention, it is desirable that the opening edge is provided with a pair of notches at opposite positions with the fixing hole as a center. According to this, by providing the pair of notches, it is possible to cause the fixing hole to be more easily elastically deformed, and to hold the head of the fixing member sandwiched from both sides. Therefore, the extraction work can be performed more easily.

  In the present invention, it is desirable that the notch is configured in a slit shape extending along the axis. According to this, since the notch is configured in a slit shape along the axis, the opening edge of the fixing hole can be more easily elastically deformed.

Next, the orthopedic surgical instrument set of the present invention includes a proximal end portion disposed on the outer surface of the long bone, and an insertion portion extending from the proximal end portion and inserted into the medullary cavity of the long bone. An orthopedic surgical instrument set comprising: an intramedullary nail for performing internal fixation of a long bone; and an insertion instrument attached to the proximal end of the intramedullary nail. A cylindrical surface-shaped back surface formed along the surface, a surface flattened from the back surface, and a surface formed along the axis from the edge of the base end portion opposite to the insertion portion , and A first region provided at an end portion having a fixing hole formed with an annular engagement receiving surface formed on the inner surface on the surface side through the front surface and receiving the head of a fixing screw; It extends linearly along the axis on the side of the insertion portion with respect to one region, and is coaxial with the back surface of the first region A column-shaped second region connected to a body and having an outer diameter smaller than the outer diameter of the back surface of the first region, and the insertion instrument is engaged about the axis with respect to the back surface and the surface. It is characterized by having a mating engagement structure.

  In the present invention, it is preferable that the insertion instrument further includes a fixing unit that engages and fixes the fixing hole in a state where the engaging structure is engaged with the base end portion. According to this, since the insertion instrument can be fixed by the fixing means using the fixing hole in the base end portion, the insertion operation can be performed more easily.

In the present invention, together with out portion Ri pair of switching to the opposite position is provided around the fixing hole in the opening edge of the fixing hole, with engagable head is inserted into the fixing holes fixing An extraction device having a screw and a pair of hook portions that can be inserted into the pair of notches, and inserting the pair of hook portions into the notches to grip the head of the fixing screw. It is preferable to further comprise. According to this, since the pair of hook portions of the extraction tool can be inserted through the cutout portions and the head portion of the fixing screw can be sandwiched and gripped, the fixing screw can be forcibly extracted.

  According to the intramedullary nail of the present invention, the proximal end portion can be stably installed with respect to the long bone, and rotation around the axis during insertion can be prevented, and the insertion portion can be easily and reliably secured in a predetermined posture. An excellent effect of being able to be introduced into the cavity can be obtained.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view (a) and a side view (b) of an intramedullary nail 10 according to an embodiment of the present invention, and FIGS. 2 (a) and 2 (b) show an insertion portion 12 of the intramedullary nail 10 as a long bone (FIG. 2 (c), a side perspective view and a plan perspective view showing that the proximal end portion 11 is fixed on the outer surface of the long bone 1 by a fixing screw 13; ) Is an enlarged plan view showing a part of the base end portion 11 in an enlarged manner, FIG. 2D is an enlarged vertical sectional view, and FIG. 2E is an enlarged sectional view of the insertion portion 12.

  The intramedullary nail 10 includes a proximal end portion 11 and an insertion portion 12 that is integrally connected to the axial end portion of the proximal end portion 11 and extends from the connection portion. The intramedullary nail 10 is made of stainless steel, pure titanium, titanium alloy or the like. The base end portion 11 includes a first region 11A provided with a fixing hole 11a, and a second region 11B that is integrally connected to the first region 11A and formed narrower than the first region 11A. The second region 11B is integrally connected to the insertion portion.

A fixing hole 11a passes through the first region 11A provided at the end of the intramedullary nail 10 in the thickness direction. A front surface 11b and a back surface 11c are provided on both sides in the thickness direction of the first region 11A, the front surface 11b faces away from the long bone (rib in the illustrated example) 1, and the back surface 11c is configured to contact the long bone 1. Yes. The front surface 11b is configured to be flat along the axis 11x from the end edge, and the back surface 11c is configured to be a cylindrical surface centering on the axis 11x of the base end portion 11. Note that the front surface 11b does not need to be a completely flat surface, and may have a planar shape (such as a surface having a curvature smaller than the curvature of the back surface) that is flatter than the back surface.

  The fixing hole 11a opens to the surface 11b. The fixing hole 11a has a substantially circular opening shape, and notches 11s and 11t are provided at the opening edge in a direction along the axis 11x of the base end part 11 (longitudinal direction of the base end part 11). . The notches 11s and 11t are provided at positions facing each other across the fixing hole 11a. The notches 11s and 11t are each configured as a concave groove communicating with the opening range of the fixing hole 11a on the surface 11b. The notches 11s and 11t are each formed in parallel to the direction of the axis 11x of the base end 11 (longitudinal direction of the base end 11), and further formed into a slit shape (linear) extending parallel to the axis 11x. Has been. The notches 11s and 11t do not need to have a concave groove shape (that is, a shape that has an inner bottom and does not penetrate) as shown in the illustrated example. You may have the structure penetrated in the thickness direction of 1 area | region 11A. In this way, the opening shape of the fixing hole 11a is easily elastically deformed.

As shown in FIGS. 2C and 2D, an annular engagement receiving surface 11n that receives the head 13a of the fixing screw 13 is formed on the inner surface of the fixing hole 11a. In the present embodiment, the inner diameter of the opening edge of the fixing hole 11a is formed smaller than the head 13a. Then, by pressing the head 13a against the opening edge, the opening temporarily increases due to the elastic deformation by the notches 11s and 11t, so that the head 13a can be fitted into the fixed hole 11a. It has become. In this way, it is possible to prevent the head 13a from protruding from the intramedullary nail 10 when the screw portion 13b of the fixing screw 13 screwed into the cortex of the long bone 1 is loosened. Unlike the above structure, the fixing hole 11a is configured such that the opening portion on the surface 11b side can pass through the head 13a as it is, and the head 13a is simply received by the engagement receiving surface 11n. May be.

  The second region 11B is formed in a cylindrical shape centered on the axis 11x. That is, the base end portion 11 extends linearly along the axis 11x, and the back surface 11c of the first region 11A and the surface of the second region 11B are configured in a coaxial cylindrical surface. However, the diameter of the cylindrical surface of the back surface 11c is configured to be larger than the diameter of the cylindrical surface of the surface of the second region 11B.

  The insertion portion 12 is configured as a rod that can be elastically deformed as a whole. The connecting portion 12s connected to the base end portion 11 is bent so that the insertion portion 12 extends from the axis 11x. As shown in FIG. 2 (e), a plurality of concave grooves 12a are provided on the outer surface of the insertion portion 12, and convex ridges 12b are formed therebetween. That is, the cross section of the insertion portion 12 is a star shape (in the illustrated example, the number of the concave grooves 12a and the convex stripes 12b is four, but the number is not particularly limited). As a result, the insertion portion 12 can easily bite into the cancellous bone, so that the rotation of the fracture portion can be prevented and the fixing force can be increased. The distal end portion 12c of the insertion portion 12 is curved in the same direction as the inclination direction of the base end portion 11, and the thickness seen in the inclination direction is reduced, and is formed in a tongue shape (a spatula shape) as a whole. As a result, the distal end portion 12c of the insertion portion 12 is guided along the shape of the medullary cavity at the time of insertion, and the rotational resistance of the insertion portion 12 can be increased, so that the tissue can be stably and smoothly damaged without being damaged. Thus, the insertion portion 12 can be introduced into the medullary cavity.

  The extension shape seen in the longitudinal direction of the insertion portion 12 preferably has a three-dimensionally curved shape (anatomical shape) for generating an internal fixation action in the medullary cavity of the long bone 1. The inserted insertion portion 12 has a function of holding the long bone 1 in a reduced state from the inside by an elastic restoring force in the medullary cavity. In addition, although the extended shape of the insertion part 12 of the example of illustration is a shape corresponding to a radius, this is set suitably according to the shape of a medullary cavity.

  The intramedullary nail 10 having the structure described above is used as follows. First, as shown in FIG. 7, an entry hole (cortical opening of the long bone 1) 1a is formed obliquely toward the opposite end on the outer surface near the end of the long bone 1 shown in FIG. The entry hole 1a is formed by using a drilling tool (Owl, drill, reamer, etc.) having a two-stage drilling blade structure having a small-diameter distal-side perforated portion and a proximal-side perforated portion larger in diameter than the distal end portion. . The entry hole 1a is formed by applying a drilling instrument along an axis of 15 to 25 degrees, preferably 20 degrees with respect to the bone axis. By this processing, an entry hole 1 a which is an elliptical opening communicating with the medullary cavity is formed on the outer surface of the long bone 1, and this becomes the insertion point of the intramedullary nail 10. In the case of the rib, the insertion point is set at the distal side, and is set at a proximal side by 7 mm or more from the distal joint surface.

  Further, in front of the entry point of the entry hole 1a, concave grooves 1b and 1c having a cylindrical inner surface are formed, which are the back surface 11c and the first surface 11c of the first region 11A of the proximal end portion 11 of the intramedullary nail 10. The drilling diameter of the drilling device is selected in advance so as to match the two regions 11B. Specifically, the processing diameter (inner diameter of the concave groove 1b) of the front end side perforation part of the perforation instrument is identical to the outer diameter of the second region 11B of the base end part 11, and the processing diameter of the base end side perforation part of the perforation instrument (Inner diameter of the concave groove 1c) is set so as to coincide with the outer diameter of the back surface 11c of the first region 11A of the base end portion 11.

  Next, the insertion portion 12 of the intramedullary nail 10 is inserted into the medullary cavity from the entry hole 1a using the insertion instrument 20 shown in FIG. The insertion instrument 20 includes a mounting portion 21 provided at the distal end and a flexible shaft connected to the mounting portion 21 (for example, a thin strip material wound into a shaft shape). A shaft portion 22, a grip portion 23 having a flat portion 23 a connected to the shaft portion 22, and a tool engaging portion 24 connected to the grip portion 23 are sequentially provided along the axis. . In addition, the tool engaging part 24 is provided with the connection screw hole 24a for engaging with the slide hammer 50 shown in FIG.4 (c).

  As shown in FIG. 4A, the attachment portion 21 of the insertion instrument 20 is provided with an engagement hole 21a configured to allow insertion of the proximal end portion 11 (the first region 11A thereof) of the intramedullary nail 10. The engagement hole 21 a is open on the end surface of the attachment portion 21. The engagement hole 21a has an opening cross section corresponding to the cross-sectional shape of the first region 11A, a flat inner surface corresponding to the front surface 11b of the first region 11A, and a cylinder corresponding to the inner surface and corresponding to the rear surface 11c. And a planar inner surface portion. Thereby, when the base end part 11 is inserted in the engagement hole 21a, the intramedullary nail 10 is connected to the insertion instrument 20 in a manner in which the rotation around the axis is restricted. That is, the engagement hole 21a corresponds to the above-described engagement structure.

The attachment portion 21 is provided with a screw hole 21b that opens to the top thereof and communicates with the engagement hole 21a. A set screw 21c (see FIG. 4B) is screwed into the screw hole 21b, and the distal end of the set screw 21c is engaged with the fixing hole 11a, whereby the intramedullary nail 10 is connected and fixed to the insertion instrument 20. be able to. The engagement holes 21a and set screw 21 c correspond to the fixing means.

  Next, as shown in FIGS. 4B and 4C, the insertion portion 12 of the intramedullary nail 10 is inserted into the medullary cavity of the long bone 1 from the entry hole 1 a using the insertion tool 20. At this time, since the insertion instrument 20 is fixed around the axis with respect to the intramedullary nail 10, rotation of the intramedullary nail 10 during insertion can be prevented. In particular, since the first region 11A connected to the insertion instrument 20 at the time of insertion is formed thick, it has sufficient rigidity, and furthermore, the torsional rigidity around the axis of the second region 11B is also high. The rotation of the insertion portion 12 does not occur due to the deformation of the end portion 11 or the like. In addition, a measurement wire is inserted from the entry hole 1a to measure the depth of the medullary cavity, and the length of the long bone 1 is confirmed by a fluoroscopic image such as an X-ray image by superimposing the long bone 1 and the template. It is preferable to obtain the optimal length of the intramedullary nail 10 in advance by a method such as, and to select and use the intramedullary nail 10 having the optimal length.

  When the proximal end portion 11 of the intramedullary nail 10 approaches the entry hole 1a and is placed on the outer surface of the long bone 1, the insertion instrument 20 is removed from the intramedullary nail 10 and shown in FIG. 3 (c). Using the step impactor 40, the base end portion 11 is aligned with the concave grooves 1b and 1c in front of the entry hole 1a. The step impactor 40 includes a tip pressurizing part 41 configured to fit into the fixed hole 11a, a grip part 42 provided with a flat part 42a, and tool engaging parts 43 and 44. . The tool engaging portions 43 and 44 are configured so that the slide hammer 50 can be connected.

  As shown in FIG. 5, the distal end pressing portion 41 is configured to fit into the fixing hole 11 a in the proximal end portion 11 of the intramedullary nail 10 and engage with the opening edge thereof, and the side surface of the step impactor 40. The intramedullary nail 10 can be driven completely by applying an impact to the tool engaging portion 43 provided in the above with a manual hammer (not shown), the slide hammer 50 or the like. When the insertion of the intramedullary nail 10 into the long bone 1 is completed, the proximal end portion 11 of the intramedullary nail 10 is brought into a state of being fitted into the concave grooves 1b and 1c formed in front (outside) of the entry hole 1a. .

  In this state, as shown in FIG. 7, the back surface 11c of the first region 11A is closely fitted in the large-diameter groove 1c on the opposite side of the entry hole 1a, and the back surface of the second region 11B is the entry hole 1a. It closely fits into the small-diameter groove 1b formed on the side. In this case, the axis of the grooves 1b and 1c formed on the outside of the entry hole 1a (which coincides with the axis 11x of the base end 11) is inclined with respect to the bone axis, so the entry hole 1a side The groove 1b is deep and the groove 1c spaced from the entry hole 1a is shallow, but the groove 1b has a small diameter and the groove 1c has a large diameter. The part 11 can be reliably fitted. Moreover, since the surface 11b of the first region 11A is configured to be flat, it does not protrude significantly from the outer surface around the long bone 1.

  Then, a screw hole is formed in the cortex of the long bone 1 through a fixing hole 11a of the base end portion 11 with a drilling tool such as a drill (not shown), and the fixing screw 13 shown in FIG. When the fixing screw 13 is firmly screwed into the cortex, the seating surface of the head 13a comes into close contact with the engagement receiving surface 11n in the fixing hole 11a, and fixes the proximal end portion 11 on the outer surface of the long bone 1.

  FIG. 6 shows a procedure for removing the intramedullary nail 10 mounted as described above. In the case of removing the intramedullary nail 10 after the fracture has been fused, the intramedullary nail 10 is removed after removing the fixing screw 13 contrary to the above. The fixing screw 13 may be removed with a normal tool such as a wrench or a screwdriver. However, the fixing screw 13 is fixed when the fixing screw 13 is firmly fixed to the long bone 1 by a callus formation or the bone quality is soft. When the screw portion 13b of the screw 13 is idle and cannot be loosened, the removal tool 30 shown in FIG. 3 is used. The extraction device 30 has a pair of hook portions 31 a and 31 a at the engagement portion 31 at the tip, and these hook portions 31 a and 31 a are opened and closed by rotating the rotation operation portion 32 with respect to the grip portion 33. It is configured to be possible. The grip portion 33 is provided with a flat portion 33a.

  The hook portions 31a and 31a are configured to be able to be introduced into the notches 11s and 11t provided in the base end portion 11, respectively. Therefore, with the pair of hook portions 31a and 31a opened, the hook portions 31a and 31a are inserted into the notches 11s and 11t as shown in FIGS. By closing the portions 31a and 31a, the head portion 13 of the fixing screw 13 can be firmly held by the hook portions 31a and 31a. Then, the union with the bone is released by applying an impact using a manual hammer (not shown) or a slide hammer 50 (not shown) according to the degree of callus formation, and the fixing screw 13 as shown in FIG. 6 (c). To remove. Thereafter, the intramedullary nail 10 is pulled out from the long bone 1 using the step impactor 40 and the insertion instrument 20 in a procedure reverse to the above installation procedure.

  The intramedullary nail of the present invention is not limited to the above-described illustrated examples, and various changes can be made without departing from the scope of the present invention.

The top view (a) and side view (b) of embodiment of an intramedullary nail. Side view (a) and plan view (b) showing the attachment state of the intramedullary nail to the long bone, enlarged plan view (c), enlarged sectional view (d) and sectional view of the insertion part c). Plan view, side view and rear view (a) of insertion instrument used for orthopedic surgery using intramedullary nail, plan view, side view and rear view (b) of extraction instrument, and plan view and side view of step impactor Figure and rear view (c). The exploded perspective view (a) which shows the connection part of an insertion instrument and an intramedullary nail, the top view (b) at the time of insertion, and the side view (c) at the time of insertion. Work explanatory drawing which shows the mode of work using a step impactor. The expanded fragmentary sectional view (a) and side view (b) which show the mounting state of the extraction instrument, and the operation explanatory view (c) which shows the mode at the time of extraction operation. The expanded partial sectional view which shows the attachment state to the bone of the intramedullary nail.

DESCRIPTION OF SYMBOLS 10 ... Intramedullary nail, 11 ... Base end part, 11A ... 1st area | region, 11a ... Fixing hole, 11b ... Front surface, 11c ... Back surface, 11n ... Engagement receiving surface, 11s, 11t ... Notch part, 11x ... Axis line, 11B ... 2nd area | region, 11C ... 3rd area | region, 12 ... Insertion part, 12a ... Concave groove, 12b ... Convex strip, 1 ... Long bone (rib), 1a ... Entry hole, 1b, 1c ... Concave groove

Claims (7)

Intramedullary for internal fixation of a long bone, comprising a proximal end portion arranged on the outer surface of the long bone and an insertion portion extending from the proximal end and inserted into the medullary cavity of the long bone In the nail,
The base end portion has a cylindrical surface-like back surface formed along the axis, a shape flattened from the back surface, and an end edge of the base end portion opposite to the insertion portion from the edge to the axis line. And a fixing hole having an annular engagement receiving surface formed on the inner surface on the side of the surface penetrating from the surface to the back surface. The first region, and the first region extends linearly along the axis toward the insertion portion, and is integrally connected to the back surface of the first region, and is integrally connected to the first region. An intramedullary nail comprising a columnar second region having an outer diameter smaller than the outer diameter of the back surface.   The intramedullary nail according to claim 1, wherein a notch is provided at an opening edge of the fixing hole.   The intramedullary nail according to claim 2, wherein the opening edge is provided with a pair of notches at opposite positions with the fixing hole as a center.   The intramedullary nail according to claim 2 or 3, wherein the notch is formed in a slit shape extending along the axis. Intramedullary for internal fixation of a long bone, comprising a proximal end portion arranged on the outer surface of the long bone and an insertion portion extending from the proximal end and inserted into the medullary cavity of the long bone An orthopedic surgical instrument set comprising a nail and an insertion instrument attached to the proximal end of the intramedullary nail,
The base end portion has a cylindrical surface-like back surface formed along the axis, a shape flattened from the back surface, and extends along the axis from an edge of the base end portion opposite to the insertion portion. And a fixing hole in which an annular engagement receiving surface that receives the head of the fixing screw is formed on the inner surface on the surface side that penetrates from the surface to the back surface. A first region, linearly extending along the axis toward the insertion portion with respect to the first region, and integrally connected coaxially with the back surface of the first region, the back surface of the first region A cylindrical second region having an outer diameter smaller than the outer diameter of
The orthopedic surgical instrument set, wherein the insertion instrument has an engagement structure that engages with the base end portion around the axis.   The orthopedic surgical operation according to claim 5, wherein the insertion instrument further includes a fixing means for engaging and fixing the engaging structure with the fixing hole in a state in which the engaging structure is engaged with the base end portion. Instrument set.   The opening edge of the fixing hole is provided with a pair of notches at opposite positions with the fixing hole as a center, and a fixing screw having a head that is inserted through the fixing hole and can be engaged, and the pair And a pair of hook parts that can be inserted into the notch parts, and further comprising an extraction device that can insert the pair of hook parts into the notch parts and grip the head of the fixing screw. The orthopedic surgical instrument set according to claim 5 or 6.

Images