WO2017042914A1

WO2017042914A1 - Bone drill reamer

Info

Publication number: WO2017042914A1
Application number: PCT/JP2015/075621
Authority: WO
Inventors: 雅規水上; 信夫松崎; 竜太福豊; 康文椙本
Original assignee: プロスパー株式会社; ケイ・エヌ・メディカル株式会社
Priority date: 2015-09-09
Filing date: 2015-09-09
Publication date: 2017-03-16
Also published as: JPWO2017042914A1; JP6474906B2

Abstract

One example of this bone drill reamer is a reamer 1 which is provided with a drill section 2 and a shaft 3. A main body 19 of the shaft 3 has no slit formed on the outer circumferential surface thereof and bends in response to an external force due to the elasticity of a material thereof. The drill section 2 comprises a cutting edge section 4 and a tubular cutting edge-side connection section 5 integrally joined to the cutting edge section 4. The cutting edge-side connection section 5 is provided with projections 10 on the inner circumferential surface in the vicinity of an opening of a cutting edge section through hole 6. The projections 10 mate with a spiral groove formed on the shaft 3.

Description

Bone drilling reamer

The present invention relates to a bone drilling reamer. More specifically, the present invention relates to a bone drilling reamer having excellent handling properties and sufficient strength.

Traditionally, bone joints that combine intramedullary nails with lag screws and fixing pins have been used in the field of fracture treatment. The intramedullary nail is inserted along the longitudinal direction of the bone to be treated, and is used particularly for the treatment of femoral and tibial fractures.

When the intramedullary nail is used on the bone to be treated, a hole for inserting the intramedullary nail into the longitudinal direction of the bone tissue is formed as a pretreatment. This hole is opened by a reamer having a drill-like cutting edge provided at the tip and an electric tool (or airway tool) (hereinafter referred to as “rotary tool”) for applying a rotational force to the reamer.

Since the reamer used for the femur and tibia has a curved shape of the bone to be perforated, a flexible reamer having an elastic shaft is generally used.

Even if the user of the rotary tool cannot directly face the bone to be drilled, this flexible reamer is able to place the blade tip against the bone even if the user stands diagonally or laterally. Drilling is possible. That is, a degree of freedom is given to the posture and standing position during the treatment.

As the structure of the flexible reamer, for example, the structure described in Non-Patent Document 1 exists.

The flexible reamer described in Non-Patent Document 1 has a drill-like cutting edge at the tip and is connected to a rotary tool. In addition, a plurality of cuts are formed on the outer peripheral surface of the shaft to impart elasticity to the shaft.

The structure of the conventional flexible reamer is shown in more detail in FIG. In the flexible reamer 100 shown in FIG. 6, the cut 102 is continuously formed in the shaft 101. Due to the cut 102, the shaft 101 receives an external force and bends flexibly.

Further, a convex portion 103 is formed at the end portion of the shaft 101, and a concave portion 105 is formed at the end portion of the blade edge 104. The shaft 101 and the blade edge 104 are connected by fitting the convex portion 103 and the concave portion 105 in a fixed direction and sliding and fitting them. The size of the cutting edge 104 can be changed according to the hole to be drilled.

In addition, a through-hole is formed in the shaft 101 and the blade edge 104 in the longitudinal direction, and a rod-shaped rod that guides the reamer when in use can be inserted. Moreover, the edge part 106 on the opposite side to the convex part 103 of the flexible reamer 100 is a part fixed by fitting with a rotary tool (not shown).

However, in the flexible reamer described in Non-Patent Document 1 and FIG. 6, the cutting edge is fixed to the shaft only by fitting the concavo-convex portion, and the fixing force is insufficient. There is a possibility that the cutting edge may fall during use, and in that case, it becomes necessary to prepare a new sterilized cutting edge.

Also, since the shaft and the cutting edge are made of a material such as surgical stainless steel and each member is expensive, it is not realistic to prepare a plurality of spare members.

Also, considering the firm fixation of the blade edge, it is conceivable to adopt a screw structure. However, the screw structure may cause a strong bite, and it may be difficult to remove the blade edge. In addition, unless the structure can be easily detached to some extent, it becomes an obstacle to quick work.

In the flexible reamer shown in FIG. 6, the shaft is bent more flexibly than necessary due to the continuous cut of the shaft. Since the shaft bends greatly with respect to external force, the position of the cutting edge may not be stable during use, and the excavation location may shift. If the bone perforation site is shifted, the insertion position of the intramedullary nail is shifted as a result, and the fixation with the bone connector becomes insufficient.

Also, when the shaft bends greatly, external force concentrates on the connecting part between the rotating tool and the end of the shaft, and the shaft may break at the same part.

Furthermore, in use, there is a present situation in which a bone tissue or the like excavated is clogged in the cut portion of the shaft, and the cleaning work after use becomes a heavy burden.

The present invention has been made in view of the above points, and an object of the present invention is to provide a bone excavation reamer having excellent handleability and sufficient strength.

In order to achieve the above object, a bone excavation reamer according to the present invention is a first cylindrical body in which a first through hole is formed, and has a shaft having elasticity and one end side of the shaft. And a second connecting body formed with a second through-hole communicating with the first through-hole, a first connecting portion that can be fixed to a predetermined rotary tool, and the other end of the shaft A second tubular portion having a third cylindrical hole formed on the outer peripheral surface and having a third through hole formed on the side and in communication with the first through hole; and A fourth cylindrical body formed with a fourth through-hole capable of being installed while the second connecting portion is screwed together, and an end of the fourth cylindrical body opposite to the second connecting portion; And a fifth cylindrical body in which a fifth through-hole that can communicate with the third through-hole is formed and having a protruding piece on the outer peripheral surface. And a part.

Here, since the shaft is the first cylindrical body in which the first through hole is formed, a member having a diameter smaller than the diameter of the first through hole can be inserted into the shaft. That is, for example, a rod-like reamer guide rod for guiding the bone reamer movement can be inserted.

Also, the elastic shaft makes it possible to use the bone digging reamer while bending it against an external force.

Further, since the first connecting portion is a second cylindrical body in which a second through hole communicating with the first through hole is formed, the second through hole is formed inside the first connecting portion. It becomes possible to insert a member having a smaller diameter. Further, the member inserted into the first through hole can be inserted into the second through hole side. That is, for example, a rod-shaped reamer guide rod for guiding the movement of the bone digging reamer can be inserted.

Also, the shaft can be connected to the rotary tool by the first connecting portion which is located on one end side of the shaft and can be fixed to the predetermined rotary tool. The predetermined rotary tool here means an instrument capable of rotating the shaft in the forward and reverse directions by the driving force of the motor.

Further, since the second connecting portion is a third cylindrical body in which a third through hole communicating with the first through hole is formed, the third through hole is formed inside the second connecting portion. It becomes possible to insert a member having a smaller diameter. Moreover, the member inserted through the third through hole can be inserted into the second through hole. That is, for example, a rod-shaped reamer guide rod for guiding the movement of the bone digging reamer can be inserted.

In addition, a second connection portion that is located on the other end side of the shaft and has a spiral groove formed on the outer peripheral surface, and a fourth through-hole that can be installed while the second connection portion is screwed are formed. The fourth tubular body can connect the fourth tubular body to the shaft. Moreover, since it fits in the part of a spiral groove, a connection state can fully be hold | maintained with respect to the rotation to a fixed direction. Moreover, it becomes a structure which can be rotated and removed easily.

In addition, the fifth cylindrical body in which the fifth through-hole capable of communicating with the third through-hole is formed, and the drill portion having the protruding piece on the outer peripheral surface enables excavation of bone tissue. . That is, the drill portion is rotated by the rotational force applied from the rotary tool, and the protruding piece excavates the bone tissue.

Moreover, when the number of grooves is 3 or less in a side view from the short direction side of the second connecting portion, the fourth cylindrical body can be detached from the shaft with a small number of rotations. it can. That is, it becomes easier to attach or remove the blade to or from the shaft, and the handleability is improved.

The fourth cylindrical body has two protrusions that can be fitted into the spiral groove on the inner peripheral surface of the fourth through-hole, and the spiral groove is located at the end of the second connection portion. In the case where the notch is used as the start point, the fourth cylindrical body can be connected to the shaft by fitting the two protruding portions into the spiral groove from the two notches. Further, the connection state between the fourth cylindrical body and the shaft can be further stabilized.

Further, the shaft has a large diameter portion formed with a diameter larger than the diameter of the fourth through hole at a position adjacent to the end point of the spiral groove of the second connection portion, and the drill portion side of the fourth through hole When a part of is formed with a diameter smaller than the diameter of the second connecting portion, the fourth cylindrical body can be more easily attached to the shaft. That is, when the attachment is performed through the spiral groove, the tip of the fourth cylindrical body comes into contact with the large diameter portion of the second connection portion and stops. Further, the tip of the second connection portion comes into contact with a part of the fourth through hole on the drill portion side and stops. Since the movement of fitting the fourth cylindrical body into the spiral groove stops at a predetermined position, the connection state can be easily confirmed and a stable structure can be obtained.

Also, when the outer peripheral surface of the shaft is formed without breaks, the maintainability of the bone drilling reamer can be improved. That is, for example, the excavated bone tissue can be made difficult to adhere to the outer peripheral surface of the shaft during use.

Further, when the shaft is formed of a super elastic body, sufficient strength and bending with respect to external force can be imparted to the bone drilling reamer. The superelastic body here means, for example, one containing an alloy of titanium and nickel (Nitinol), an iron-manganese-silicon alloy, or the like.

In the case where the protruding portions are positioned to face each other on the inner peripheral surface of the fourth through hole and the notches are formed at positions facing each other on the outer peripheral surface of the second connecting portion, the fourth cylinder It becomes easier to attach the shaped body to the shaft. Further, the connection state between the fourth cylindrical body and the shaft can be further stabilized.

The bone digging reamer according to the present invention has excellent handleability and has sufficient strength.

It is the schematic of the reamer for bone excavation which concerns on embodiment of this invention. It is the schematic sectional drawing (a) which looked at the schematic sectional drawing (a) of a drill part, and the drill part from the blade edge | side side connection part side. It is the schematic (b) which looked at the schematic (a) of the shaft side connection part, and the shaft from the shaft side connection part side. It is the schematic (a) before the connection of a blade edge side connection part and a shaft side connection part, and the schematic diagram (b) after connection. It is the schematic sectional drawing (a) which shows the state which inserted the reamer guide rod in the shaft, and the schematic sectional drawing (b) which shows the state which the rod head stopped in the middle of the blade edge part through-hole. It is the schematic (a) which shows the conventional flexible reamer, and the schematic (b) which shows the connection part of a shaft and a blade edge | tip.

Hereinafter, embodiments of the present invention will be described with reference to the drawings to facilitate understanding of the present invention.
FIG. 1 is a schematic view of a bone excavation reamer according to an embodiment of the present invention. In addition, the structure of this invention is not limited to the content shown below, It can change suitably.

As shown in FIG. 1, a reamer 1 as an example of a bone drilling reamer to which the present invention is applied includes a drill portion 2 and a shaft 3.

The drill part 2 is a part that is pierced through the bone tissue of the bone to be treated by a rotational force applied by a rotary tool (not shown) to which the reamer 1 is attached. The drill portion 2 has a plurality of sizes having different blade diameters, for example, in increments of 1 mm in accordance with the size of the bone, and can be exchanged for one shaft. Further, the diameter of the blade may be different in steps of 0.5 mm.

Also, the drill part 2 is formed of stainless steel that can pierce bone tissue and can be used for surgery.

The shaft 3 is an elastic cylindrical body in which a shaft through hole 9 is formed at the center in the longitudinal direction. Further, the shaft 3 is bent and deformed with respect to an external force during use, and returns to its original shape when the external force is no longer applied. More specifically, the shaft 3 is formed of a titanium-nickel alloy commonly called Nitinol, and exhibits properties of superelasticity and a shape memory effect.

Further, the outer peripheral surface of the main body portion 19 of the shaft 3 is not formed with a cut, and is bent with respect to the external force by the elasticity of the material.

A tool connecting portion 24 is provided at the end of the shaft 3 opposite to the drill portion 2. The tool connection part 24 is a part which connects the rotary tool which drives a motor and produces rotational motion, and the shaft 3, and a rotary tool fixes. A tool connection part through hole 25 communicating with the shaft through hole 9 is formed inside the tool connection part 24.

Here, a known rotary tool can be used, and a tool that fits into a notch provided in the tool connecting portion 24 of the shaft 3 and can fix or separate the tool connecting portion 24 with a lock mechanism is used. It is preferable.

Also, the rotary tool is a member that rotates the fixed shaft 3 with high torque clockwise or counterclockwise. Normally, when using a bone digging reamer, excavation is performed by rotation in only one direction, and rotation in the opposite direction is not used.

Here, the size and shape of the drill part 2 are not particularly limited, and can be appropriately changed according to the size of the bone to be drilled and the bone joint to be used.

Further, the drill part 2 does not necessarily need to be formed of stainless steel, and any material that has a strength capable of drilling a hole in bone tissue and can be used for surgery is sufficient.

Further, the shaft 3 is not necessarily formed of nitinol, and a material exhibiting properties of superelasticity and a shape memory effect can be adopted.

The drill part 2 includes a cutting edge part 4 and a cylindrical cutting edge side connecting part 5 joined integrally with the cutting edge part 4. The blade edge portion 4 has a plurality of blades positioned at regular intervals on the outer peripheral surface of the cylindrical body, and each blade is formed to be slightly curved along the longitudinal direction of the drill portion 2.

As shown in FIG. 2 (a), a blade edge portion through hole 6 is formed in the blade edge portion 4 along the longitudinal direction. The blade edge portion through hole 6 communicates with a through hole formed inside the blade edge side connection portion 5 and can communicate with the shaft through hole 9 of the shaft 3.

Further, inside the blade edge side connection portion 5, a small diameter through hole 7 having a diameter similar to the diameter of the blade edge portion through hole 6 and a large diameter through hole 8 having a diameter larger than the small diameter through hole 7 communicate with each other. Is formed. The large diameter through hole 8 and the shaft through hole 9 of the shaft 3 have the same diameter. Moreover, the blade edge part through hole 6 and the small diameter through hole 7 are formed to be slightly smaller than the diameter of the head of the reamer guide rod described later.

Further, the cutting edge side connecting portion 5 is provided with a protruding portion 10 on the inner peripheral surface in the vicinity of the opening portion of the cutting edge portion through hole 6. The protrusion 10 is a portion that fits into a spiral groove provided on the shaft 3 side described later.

Here, the small-diameter through hole 7 and the large-diameter through hole 8 having different diameters do not necessarily have to be formed inside the cutting edge side connecting portion 5, and any through hole into which the reamer guide rod can be inserted is sufficient. It is. However, as will be described later, when the shaft 3 and the drill portion 2 are connected, the tip of the shaft side connecting portion stops at the position of the boundary where the diameters are different, and the connection structure and the point that makes it easy to understand that the connection is completed From the viewpoint of stability, it is preferable that the small-diameter through hole 7 and the large-diameter through hole 8 having different diameters are formed inside the cutting edge side connecting portion 5.

In addition, the blade tip portion through-hole 6 does not necessarily have to have the same diameter as the small-diameter through-hole 7 inside the blade tip portion 4, and any through-hole into which the reamer guide rod can be inserted is sufficient. is there.

Also, the blade tip through hole 6 and the small diameter through hole 7 do not necessarily need to be formed slightly smaller than the diameter of the head of the reamer guide rod. However, as will be described later, since the head of the reamer guide rod inserted into the reamer 1 is stopped at the position of the cutting edge part through hole 6 of the drill part 2, the cutting edge part penetration is prevented. It is preferable that the hole 6 and the small-diameter through-hole 7 are formed to be slightly smaller than the diameter of the head of the reamer guide rod.

Further, FIG. 2B is a view of the drill 2 as viewed from the cutting edge side connecting portion 5 side, but the protruding portion 10 is provided at a position facing the circumference of the large diameter through hole 8. That is, the two protrusions 10 are provided at 180 degrees on the circumference when viewed from one side.

Here, the protrusions 10 do not necessarily have to be provided at positions facing each other on the circumference of the large-diameter through-hole 8, and any one that can be fitted into the spiral groove of the shaft 3 is sufficient. However, it is preferable that the protruding portion 10 is provided at a position facing the circumference of the large-diameter through-hole 8 from the viewpoint of easy connection and removal.

As shown in FIG. 3A, the end of the shaft 3 opposite to the tool connecting portion 24 is a shaft-side connecting portion 11. The shaft side connection portion 11 is a portion that fits with the blade edge side connection portion 5. That is, it becomes a part for attaching the drill part 2 to the shaft 3.

The shaft side connecting portion 11 has a spiral groove 12 formed on the outer peripheral surface on the tip side. The spiral groove 12 is fitted to the protruding portion 10 of the above-described cutting edge side connection portion 5 and guides the cutting edge side connection portion 5 toward the shaft 3 along the groove. Further, in the region where the spiral groove 12 is formed, the cutting edge side connecting portion 5 and the shaft side connecting portion 11 are overlapped and connected.

The spiral groove 12 is formed with a groove width of about 2 mm. Further, the spiral groove 12 is formed with a groove depth of about 0.5 mm with respect to the thickness of the outer peripheral surface of the shaft-side connecting portion 11 of about 1.0 mm. Further, the region sandwiched between the spiral grooves 12 of the shaft side connecting portion 11, that is, the region where the groove processing between the grooves is not performed is about 2.5 mm in width, which is slightly larger than the width of the spiral groove 12. It has become.

Here, the groove width of the spiral groove 12, the depth of the groove, and the thickness of the outer peripheral surface of the shaft side connection portion 11 are not limited, and the blade edge side connection portion 5 and the shaft side connection portion 11 can be overlapped and connected. If it is, it is enough.

Also, the region sandwiched between the spiral grooves 12 of the shaft side connecting portion 11 does not necessarily have to have a width slightly larger than the groove width of the spiral grooves 12. However, the contact area between the inner peripheral surface of the blade-side connecting portion 5 and the outer peripheral surface of the shaft-side connecting portion 11 is widened, and the connected state is stabilized, so that the spiral groove 12 of the shaft-side connecting portion 11 is stabilized. It is preferable that the sandwiched region has a width slightly larger than the width of the spiral groove 12.

The shaft 3 has a stopper portion 13 having a diameter larger than that of the region adjacent to the region where the spiral groove 12 is formed. The stopper portion 13 is provided from the vicinity of the end point 14 of the spiral groove.

The spiral groove 12 is a spiral groove formed on the outer peripheral surface of the shaft-side connecting portion 11 from the end of the shaft-side connecting portion 11 to the end point 14 until the end point 14. Further, as shown in FIG. 3A, when the spiral groove 12 is viewed from the side surface, the length is formed from the start point 15 to the end point 14 so that the number of grooves is three or less. Here, the term “three or less” means the approximate number of appearances, and there are positions where the number of grooves is two depending on the part to be seen.

Here, when the spiral groove 12 is viewed from the side of the shaft 3, the spiral groove 12 is necessarily formed with such a length that the number of grooves is three or less from the start point 15 to the end point 14. There may be a shape in which the number of grooves increases. However, since it becomes easy to attach or remove the drill portion 2 to the shaft 3 and the handleability is improved, when the spiral groove 12 is viewed from the side of the shaft 3, the start point 15 to the end point 14. By the time, it is preferable that the number of grooves be 3 or less.

FIG. 3B is a view of the shaft 3 as viewed from the shaft-side connecting portion 11 side. The starting point 15 of the spiral groove 12 is formed as two notches 16 on the outer peripheral surface of the shaft-side connecting portion 11. It is visible. Further, the two notches 16 are provided at positions facing each other on the circumference of the shaft through hole 9 of the shaft side connecting portion 11. That is, the two notches 16 are provided at 180 degrees on the circumference when viewed from one side.

Further, the length of the region where the spiral groove 12 of the shaft side connecting portion 11 is provided is about 1.0 cm, and the length of the cutting edge side connecting portion 5 is about 1.3 to 80%. ing.

Here, the notch 16 does not necessarily have to be provided at a position facing the circumference of the shaft through hole 9 of the shaft side connecting portion 11, as long as it can be fitted to the protruding portion 10 of the drill portion 2. It is enough. However, it is preferable that the notch 16 is provided at a position facing the circumference of the shaft through hole 9 of the shaft side connecting portion 11 from the viewpoint of easy connection and removal.

Further, the length of the region where the spiral groove 12 of the shaft side connection portion 11 is provided is not necessarily about 70 to 80% of the length of the cutting edge side connection portion 5. However, the area where the inner peripheral surface of the cutting edge side connecting portion 5 and the outer peripheral surface of the shaft side connecting portion 11 come into contact with each other becomes longer, and the spiral groove 12 of the shaft side connecting portion 11 becomes stable because the connected state is stabilized. The length of the provided region is preferably about 80% of the length of the cutting edge side connecting portion 5.

When attaching the cutting edge side connection part 5 of the drill part 2 to the shaft side connection part 11 of the shaft 3, the two protruding parts 10 are respectively fitted with the two notches 16 to be connected. .

Further, a state where the cutting edge side connecting portion 5 is completely fitted to the shaft side connecting portion 11, that is, a state where the protruding portion 10 reaches the position of the end point 14 of the spiral groove 12 is a state where the connection is completed. As shown in FIGS. 4A and 4B, at this time, the end portion 17 of the cutting edge side connection portion 5 is in contact with the stopper portion 13 of the shaft side connection portion 11.

Further, in the state where the connection of the drill portion 2 to the shaft 3 is completed, the end portion 18 of the shaft side connection portion 11 is a boundary portion between the small diameter through hole 7 and the large diameter through hole 8 inside the cutting edge side connection portion 5. It has a structure that touches.

The structure when the reamer guide rod 20 is inserted into each through hole of the reamer 1 will be described with reference to FIG.

The reamer guide rod 20 is a rod-shaped member for guiding the movement of the reamer 1 in the advancing / retreating direction when the reamer 1 excavates bone tissue. As shown to Fig.5 (a), it is comprised from the rod main body 21 which can be inserted in the through-hole inside each member which comprises the reamer 1, and the spherical rod head 22 provided in the end of the rod main body 21. Yes.

The total length of the reamer guide rod 20 in the longitudinal direction is formed to be longer than the total length of the reamer 1 in the longitudinal direction. Moreover, the end 23 opposite to the rod head 22 of the reamer guide rod 20 is inserted into the blade tip through-hole 6, and the small-diameter through-hole 7, the large-diameter through-hole 8, the shaft through-hole 9, and the tool connection portion. It progresses to the through-hole 25 and comes out of the shaft 3.

As shown in FIG. 5 (b), the rod head 22 has a structure that is caught in the middle part of the blade tip through hole 6. More specifically, the diameter of the rod head 22 is formed to be slightly larger than the diameter of the blade tip through hole 6.

Since the diameter of the lot head 22 and the diameter of the cutting edge side through hole 6 have the above-described structure, the drill portion 2 rotates in a direction away from the shaft side connection portion 11, and the drill portion 2 and the shaft 3 are rotated. Even when separated, the drill portion 2 is caught by the rod head 22 and supported by the reamer guide rod 20.

That is, even if the connection state of the drill part 2 and the shaft 3 is released, the drill part 2 is not dropped off, and the trouble that the drill part 2 is placed in the bone can be avoided. Further, for example, when the shaft and the blade edge are anastomosed, the blade edge is less likely to fall when handed directly from the assistant (nurse) to the operator.

The following explains the procedure for using the reamer described above.

First, the separated drill part 2 and shaft 3 are connected. The two protrusions 10 of the cutting edge side connection portion 5 of the drill portion 2 are aligned with the positions of the two notches 16 of the spiral groove 12 of the shaft side connection portion 11.

Then, the drill portion 2 is rotated until the protruding portion 10 reaches the end point 14 of the spiral groove 12. At this time, the protrusion 10 rotates about one turn along the spiral groove 12 and reaches from the start point 15 to the end point 14. The drill part 2 can be separated from the shaft 3 by rotating the drill part 2 in the reverse direction.

Since the connection between the drill part 2 and the shaft 3 is a simple operation that only rotates the drill part 2 about one rotation, the user during the operation can easily prepare the reamer 1.

Subsequently, the reamer guide rod 20 is inserted into each through hole inside the reamer 1. The reamer guide rod 20 is inserted into the blade tip through hole 6 of the drill portion 2 at the end 23 side of the rod. The reamer guide rod 20 is sequentially inserted into the small diameter through hole 7, the large diameter through hole 8, the shaft through hole 9, and the tool connection portion through hole 25.

Further, at this time, the drill portion 2 is caught in the head 22 of the reamer guide rod 20 in the middle of the cutting edge through hole 6 so that the reamer 1 cannot enter further beyond the head 22.

Then, the tool connection portion 24 of the reamer 1 is combined with the fitting portion of the rotary tool, and the tool connection portion 24 is fixed to the rotary tool by the lock mechanism of the rotary tool. At this point, the preparation of the bone drilling reamer is completed.

When excavating the bone tissue of the target bone, rotate the rotary tool in one direction. The rotary tool rotates at a high torque, and the rotational force is transmitted to the drill part 2 via the shaft 3, and the plurality of blades of the blade edge part 4 of the drill part 2 excavate the bone tissue. In addition, the rotation direction of the rotary tool is a rotation direction opposite to the rotation direction for separating the drill portion 2 from the shaft 3.

Also, if the user accidentally rotates the rotary tool in the rotational direction for separating the drill portion 2 from the shaft 3 and the drill portion 2 is separated from the shaft 3, the rod head 22 of the reamer guide rod 20. However, it is possible to prevent the drill portion 2 from falling off by being caught at a position where the diameter of the blade tip portion through-hole 6 becomes small.

Since the main body portion 19 of the shaft 3 of the reamer 1 is formed of a titanium-nickel alloy having super elasticity, it can bend appropriately between the bone excavation site and the rotary tool and perform stable excavation. it can. That is, unlike the conventional flexible reamer, the shaft is not greatly bent, and the blade of the drill portion 2 can be firmly applied to the target position of the target bone.

By drilling the bone tissue with the blade of the drill part 2, a hole for inserting a bone connector such as an intramedullary nail can be drilled. Since the main body portion of the shaft 3 after excavation is not cut, the excavated bone tissue hardly adheres to the shaft, and the cleaning operation after use can be facilitated.

As described above, the bone excavation reamer of the present invention is excellent in handleability and has sufficient strength.

DESCRIPTION OF SYMBOLS 1 Reamer 2 Drill part 3 Shaft 4 Cutting edge part 5 Cutting edge side connection part 6 Cutting edge part through hole 7 Small diameter through hole 8 Large diameter through hole 9 Shaft through hole 10 Projection part 11 Shaft side connection part 12 Spiral groove 13 Stopper part 14 End point DESCRIPTION OF SYMBOLS 15 Start point 16 Notch 17 End part 18 End part 19 Main body part 20 Reamer guide rod 21 Rod main body 22 Rod head 23 End part 24 Tool connection part 25 Tool connection part through-hole

Claims

A first cylindrical body having a first through hole and a shaft having elasticity;
A first connecting portion that is located on one end side of the shaft and is a second cylindrical body in which a second through hole communicating with the first through hole is formed and can be fixed to a predetermined rotary tool When,
A second cylindrical body located on the other end side of the shaft and having a third through hole communicating with the first through hole and having a spiral groove formed on the outer peripheral surface; A connection,
A fourth cylindrical body formed with a fourth through-hole capable of being installed while the second connection portion is screwed;
A fifth cylindrical body in which a fifth through hole is formed which is located at an end of the fourth cylindrical body opposite to the second connection portion and which can communicate with the third through hole. And a drill part having a projecting piece on the outer peripheral surface.
2. The bone digging reamer according to claim 1, wherein the spiral groove has three or less grooves in a side view from the lateral direction side of the second connection portion.
The fourth cylindrical body has two protrusions that can be fitted into the spiral groove on the inner peripheral surface of the fourth through-hole,
3. The bone excavation reamer according to claim 1, wherein the spiral groove starts from two notches located at an end of the second connection portion.
The shaft has a large-diameter portion formed with a diameter larger than the diameter of the fourth through hole at a position adjacent to the end point of the spiral groove of the second connection portion.
4. The bone drilling reamer according to claim 1, wherein a part of the fourth through hole on the drill part side is formed with a diameter smaller than a diameter of the second connection part.
The bone digging reamer according to claim 1, 2, 3, or 4, wherein the outer peripheral surface of the shaft is formed without a break.
The bone excavation reamer according to claim 1, 2, 3, 4, or 5, wherein the shaft is formed of a superelastic body.
The protrusions are located opposite to each other on the inner peripheral surface of the fourth through hole;
The bone digging reamer according to claim 3, wherein the notches are formed at positions facing each other on an outer peripheral surface of the second connecting portion.