WO2019240103A1

WO2019240103A1 - Bone surgery instrument

Info

Publication number: WO2019240103A1
Application number: PCT/JP2019/022995
Authority: WO
Inventors: 宏一黒田; 靖治横山; 知彦福原; 真樹新; 来鈴木; 原田　実; 宗久岩永; 光也浦田
Original assignee: オリンパステルモバイオマテリアル株式会社
Priority date: 2018-06-12
Filing date: 2019-06-10
Publication date: 2019-12-19
Also published as: JPWO2019240103A1; TWI705792B; TW202000140A; JP6960055B2

Abstract

In order to apply, with a simple means, suitable pressure between bone fragments opened by a osteotomy or fracture, without reducing the fixing force of the engaging part of a screw, without increasing dead space and without expanding the pilot hole, this bone surgery instrument 1 is provided with a fixed member 2 which is fixed to a bone B, a rotating body 5, and a rotating body housing member 4 which is attached to the fixed member 2 in a position different from where the fixed member is fixed to the bone B and which supports the rotating body 5 so as to enable rotation around a rotation axis that intersects with the surface of the bone B, wherein the rotating body 5 is provided with an anchor part 6 which can engage with the bone B on an eccentric axis decentered from the rotation axis.

Description

Bone surgery instrument

The present invention relates to a bone surgery instrument.

In osteoarthritis of the knee, for example, osteotomy is indicated when the articular cartilage of the patella and femur is damaged. In such an operation, the bone is incised (or fractured) to correct the bending of the bone and is fixed with an osteosynthesis plate until the bone is fused. If there is a large gap between the plate and the bone, the fixation may not be successful. In such a case, generally, a bone screw that is not engraved with a screw is applied to the plate, and the plate is pressed against the bone. An operation that puts pressure on the face is added.

In Patent Document 1, an elliptical screw hole is described, and the head portion has an unthreaded concave surface that can accept a spherical screw, and the head portion is conically shaped with a screw thread. It has a portion to which the screw can be fixed.

In Patent Document 2, when a screw whose head is threaded is inserted into an elliptical screw hole so as to pass through a position near the unthreaded edge of the screw hole, The part is shown moving and the screw is locked.

Patent Document 3 shows that the head of the bone screw is a gear, and the fracture surface that has been released can be shortened and compression force can be applied by moving the bone plate across the fractured part. Yes.

Japanese Patent No. 4162408 Japanese Patent No. 4997712 Japanese Patent No. 5198623

As a problem of the prior art, in

Patent Documents

1 and 2, the screw thread forming portion of the screw hole becomes partial, thereby increasing the risk of infection due to a decrease in fixing force, incorrect insertion in the screw insertion direction, and an increase in dead space. . In addition, a large compression screw must be inserted into the bone, and after removing the screw, a screw with a screw thread formed on the head of the bone screw is not necessary. There is concern about a decrease in bone strength due to expansion.

In Patent Document 3, the bone screw whose head is a gear does not contribute to the fixing force between the bone plate and the bone, and the reduction of the entire fixing force becomes a problem. Also, the moving direction cannot be adjusted.

A fixing member fixed to a bone, a rotating body, and the fixing member are attached to a position different from the fixing position to the bone, and the rotating body can be rotated around a rotation axis intersecting the surface of the bone. And a rotating body housing member to be supported, and the rotating body includes an anchor portion engageable with the bone on an eccentric axis that is eccentric with respect to the rotation axis.

According to the present invention, the fixing force of the engaging portion of the screw is not lowered, the dead space is not increased, the pilot hole is not expanded, and the bone pieces opened by osteotomy or fracture are simply used by simple means. There is an effect that it is possible to apply a large pressure.

It is a perspective view which shows the instrument for bone surgery which concerns on one Embodiment of this invention. FIG. 2 is an exploded longitudinal sectional view of the bone surgery instrument of FIG. 1. It is a longitudinal cross-sectional view which shows the state which attached the bone surgery instrument of FIG. 2 to the bone. FIG. 4 is a longitudinal sectional view showing a state in which torque is started to be applied to the rotating body of the bone surgery instrument of FIG. 3. It is a longitudinal cross-sectional view which shows the state which rotated the rotary body of FIG. 4 180 degree | times, stuck the osteotomy surface, and applied the compression force. It is a longitudinal cross-sectional view which shows the state which fastened the bone screw to the other screw hole in the state of FIG. It is a longitudinal cross-sectional view which shows the state which removed the rotary body accommodating member, the rotary body, and the anchor member from the bone plate in the state of FIG. It is a longitudinal cross-sectional view which shows the modification of the bone surgery instrument of FIG. It is a cross-sectional view which shows the modification of the rotary body of the bone surgery instrument of FIG. It is a longitudinal cross-sectional view which shows the other modification of the bone surgery instrument of FIG.

A bone surgery instrument 1 according to an embodiment of the present invention will be described below with reference to the drawings.
As shown in FIG. 1, the bone surgery instrument 1 according to the present embodiment includes a bone plate (plate member, fixing member) 2, a bone screw 3 that fixes the bone plate 2 to the bone B, and a bone plate 2. Rotating body housing member 4 that is detachably attached to the rotating body, rotating body 5, and anchor member (anchor portion) 6. The bone plate 2 is disposed across the fracture or osteotomy formed in the bone B, and is fixed to the bone B by a bone screw 3 on one side of the fracture or osteotomy.

The material of the bone plate 2 is preferably titanium, titanium alloy, stainless steel, cobalt chromium alloy, PEEK material, polymer material such as polylactic acid, and stainless steel. The bone plate 2 can function substantially as an implant. The reference thickness is desirably 1 mm to 5 mm, and more desirably 2 mm to 4.5 mm. Instead of the bone plate 2, another bridging member may be employed as the fixing member.

As shown in FIG. 2, the rotating body housing member 4 is a cylindrical member, and is a male screw portion that can be detachably fastened to a screw hole (through hole) 7 formed in the bone plate 2 at one end in the longitudinal direction. 8 is provided. The rotating body housing member 4 is provided with an inner hole 9 having a circular cross section that penetrates along the central axis.

The size of the inner hole 9 of the rotating body accommodating member 4 is preferably 2 mm to 10 mm, and more preferably 3 mm to 7 mm.
The rotating body housing member 4 may be a direction guide of a drill for drilling a pilot hole of the bone screw 3 attached to the bone plate 2.

The rotating body 5 includes a fitting outer surface 5a formed of a cylindrical surface that is rotatably fitted in the inner hole 9 of the rotating body housing member 4 at one end in the longitudinal direction, and a knob for applying a rotational force to the other end in the longitudinal direction. Part 10 is provided. Further, the rotating body 5 is provided with a hole 11 penetrating the rotating body 5 in the longitudinal direction at a position eccentric with respect to the rotation axis C that is the center line of the cylindrical surface.

With the fitting outer surface 5a of the rotator 5 fitted in the inner hole 9 of the rotator housing member 4, an anchor member 6 such as a guide pin or a thin bone screw is inserted into the hole 11 of the rotator 5 and rotated. It is arranged on an eccentric axis that is eccentric with respect to the axis C, and the tip of the anchor member 6 is inserted into the bone B. Thereby, the tip of the anchor member 6 is engaged with the bone B.

The knob portion 10 of the rotating body 5 is preferably cut out. This facilitates the supply of torque to the knob portion 10.
Further, the knob portion 10 of the rotating body 5 is provided with a convex portion that protrudes along the longitudinal direction. And the recessed part is provided in the other end of the rotary body accommodating member 4. FIG. The rotating body 5 is inserted into the inner hole 9 of the rotating body housing member 4, and the convex portion of the knob portion 10 is fitted into the recessed portion of the rotating body housing member 4, thereby constituting the rotation preventing structure 15. The rotation preventing structure 15 maintains the rotating body 5 in a state of pressing the rotating body 5 against the rotating body accommodating member 4 in a direction perpendicular to the rotation axis C in a state where the convex portion is fitted in the concave portion. The relative rotation about the rotation axis C with respect to the housing member 4 is restricted. Further, in a state where the convex portion is not fitted in the concave portion, the rotating body 5 can rotate around the rotation axis C with respect to the rotation housing member 4.

The operation method will be described.
Before rotating the rotator 5, the bone plate 2 straddling the fracture surface needs to be fixed to the bone B on the opposite side of the screw hole 7 to which the rotator accommodating member 4 is attached across the fracture surface. It is necessary to fix with anchor members 6 such as bone screws or guide pins.

As shown in FIG. 2, the male screw of the rotating member housing member 4 is inserted into one of the screw holes 7 arranged on the opposite side of the fracture hole with respect to the screw hole 7 fixing the bone plate 2 to the bone B. By fastening the part 8, the central axis of the rotating body housing member 4 is arranged in a direction intersecting the surface of the bone B. In this state, as shown in FIG. 3, the fitting outer surface 5 a of the rotating body 5 is fitted into the inner hole 9 of the rotating body housing member 4.

Then, the rotating body 5 is rotated around the rotation axis C with respect to the rotating body accommodating member 4, and the eccentric hole 11 is arranged at a desired phase position. In this state, as shown in FIG. 3, the anchor member 6 such as a thin bone screw or a guide pin is inserted into the hole 11 and the tip of the anchor member 6 is inserted into the bone B.

In this state, as shown in FIG. 4, torque is applied to the knob portion 10 of the rotating body 5 to rotate the rotating body 5 around the rotation axis C with respect to the rotating body housing member 4. Thereby, since the anchor member 6 moves in the direction orthogonal to the rotation axis C with respect to the rotating body housing member 4, a compression force can be applied to the bone B in a direction in which the interval between the fracture surfaces is shortened or expanded. FIG. 5 shows a case where the distance between the fracture surfaces is shortened.

Rotating operation of the rotating body 5 may require a large torque, and a driver, cap, or wrench that can apply a large torque to the rotating body 5 may be used. In this case, a torque-controlled screwdriver or wrench may be used to adjust the compression force.

After completion of the rotation operation, as shown in FIG. 6, a firm anchor such as a bone screw 3 or the like is fixed to the other screw hole 7 of the bone plate 2. As a result, as shown in FIG. 7, the rotating body 5, the rotating body accommodating member 4, and the temporary fixing anchor member 6 attached thereto can be removed. Before fixing a strong anchor such as the bone screw 3 or the like, there is a risk that the rotating body 5 will rotate spontaneously and return to its original position. Also good.

Further, when the initial insertion position of the anchor member 6 (the position of the hole 11 of the rotator 5) in the rotator housing member 4 is the position farthest from the fracture surface, if the rotator 5 is rotated by 180 °, it is separated. The amount of shortening and compression of the fractured surface is maximized. The maximum amount of movement is twice the amount of eccentricity of the hole 11 of the rotating body 5.
When adjusting the moving direction of the bone plate 2, the initial phase position of the anchor member 6 and the phase position after rotation may be adjusted.

Furthermore, as shown in FIG. 8, when the hole 11 provided at the eccentric position of the rotating body 5 is inclined with respect to the rotation axis C of the rotating body 5, the maximum amount of movement of the fractured surface that has been separated. Is larger than when parallel. When the inclination angle of the hole 11 of the rotating body 5 with respect to the rotation axis C is too large, the rotational torque of the rotating body 5 becomes too large to rotate. Furthermore, an excessive bending moment is applied to the anchor member 6, causing the instrument to be damaged and unrepairable.

Considering the necessary compression force and the rigidity of the material of the anchor member 6 when used for knee joint or ankle osteotomy, the diameter of the rotating member housing member 4 is preferably 3 mm to 10 mm, more preferably 4 mm. 6 mm. The outer diameter of the anchor member 6 is desirably 1.5 mm to 5.5 mm, and more desirably 2.0 mm to 3.0 mm. In this case, the inclination angle of the hole 11 provided at the eccentric position of the rotating body 5 is desirably 10 ° at the maximum. More preferably, it is 5 °.

Two or more sets of combinations of the rotator accommodating member 4, the rotator 5 and the anchor member 6 may be attached to the same bone plate 2. By simultaneously operating the two sets, the torque applied to each rotating body 5 can be reduced. Further, by operating two or more sets of the rotating body housing member 4, the rotating body 5, and the anchor member 6 in stages, the shortened amount and the compressed amount of the fractured surface that has been separated can be adjusted until a desired state is reached. It is.

Rotating body 5 may be formed like a washer. In that case, the rotating body 5 and the bone plate 2 may be embedded in the body. The anchor member 6 can also be a bone screw or bone pin that is implanted in the body. They can also be handled as surgical instruments.

In the present embodiment, the anchor member 6 penetrates the hole 11 formed through the rotating body 5. However, instead of this, as shown in FIG. Good. Moreover, the hole 11 that penetrates the anchor member 6 may be configured to be gradually tapered toward an end surface facing the surface of the bone B.

In addition, the anchor member 6 is allowed to pass through the hole 11 of the rotator 5, but as shown in FIG. 10, the anchor member 6 is located at a position protruding from the end surface of the rotator 5 facing the surface of the bone B. The rotating body 5 may be formed integrally.

Further, as the anti-rotation structure 15, the knob portion 10 is provided with a convex portion and the rotating body housing member 4 is provided with a concave portion at the other end, but is not limited thereto. For example, the knob portion 10 may be provided with a recess, and the rotating body housing member 4 may be provided with a protrusion on the other end.

1 Bone surgical instrument 2 Bone plate (plate member, fixing member)
3 Bone screw 4 Rotating body housing member 5 Rotating body 6 Anchor member (anchor part)
7 Screw hole (through hole)
9 Inner hole 11 Hole 12 Recess 15 Detent structure B Bone C Rotation axis

Claims

A fixing member fixed to the bone;
A rotating body,
A rotating body containing member that is attached to the fixing member at a position different from the position fixed to the bone, and supports the rotating body so as to be rotatable around a rotation axis that intersects the surface of the bone;
An instrument for bone surgery, wherein the rotating body includes an anchor portion engageable with the bone on an eccentric axis that is eccentric with respect to the rotation axis.
The bone surgical instrument according to claim 1, wherein the fixing member is a plate member disposed at a position across the fractured portion.
The bone surgery instrument according to claim 1 or 2, wherein one or more of the rotating body housing member, the rotating body, and the anchor portion are detachable.
The anchor is a round bar,
The bone surgery instrument according to any one of claims 1 to 3, wherein the rotating body has a hole or a recess into which the anchor portion is detachably fitted on the eccentric axis.
The rotating body housing member includes an inner hole for rotatably housing the rotating body,
The bone surgery instrument according to claim 4, wherein the rotation axis of the rotating body is inclined with respect to a central axis of the inner hole of the rotating body housing member.
The bone surgery instrument according to any one of claims 1 to 5, comprising two or more sets of the rotating body housing member, the rotating body, and the anchor portion.
The fixing member includes a through-hole for detachably attaching the rotating body housing member;
The bone surgery instrument according to any one of claims 3 to 6, wherein a bone screw having a diameter larger than that of the anchor portion can be fixed to the through-hole after the rotary member housing member is removed.
The bone surgery instrument according to any one of claims 1 to 7, further comprising a rotation preventing structure that maintains the rotating body pressed against the rotating body housing member in a direction perpendicular to the rotation axis.