JP6521671B2 - Total knee arthroplasty tibial trial - Google Patents

Description

  The present invention relates to a tibial trial for total knee arthroplasty for determining the thickness of the tibial side plate in a prosthetic knee joint.

  In general, an insert which is one of the components of an artificial knee joint is prepared in several types with different thicknesses. This is because the insert of appropriate thickness for each patient varies with the size, position, and shape of the patient's bones, cartilage, ligaments and muscles. Traditionally, orthopedic surgeons have used multiple insert trials to determine inserts of appropriate thickness. The insert trial is used to check the condition of the patient's knee joint by being placed on the tibial tray which is one of the components of the tibial template, tray trial, or artificial knee joint. The operator experimentally attached each insert trial to the patient, confirmed the movement of the patient's knee joint, etc., and determined the insert with the optimum thickness. However, in this method, many insert trials have to be prepared, replaced and installed, which is cumbersome.

  On the other hand, for example, according to Patent Document 1, a base (fixed side member) fixed to the excision site of the tibia and a movable supported on the fixed side member through the vertical movement mechanism so as to be vertically movable. There is disclosed a tibial trial jig for total knee arthroplasty, comprising: a portion (movable side member). In this trial jig, the movable side member can be moved up and down by rotating the adjustment screw screwed into the screw hole formed in the fixed side member. Then, according to this trial jig, the knee joint in a state where the trial jig is attached is moved, and an insert having a thickness corresponding to the upper and lower positions of the movable side member such that the movement is most smooth is selected. Then, an insert of appropriate thickness can be determined. That is, according to the jig disclosed in Patent Document 1, as in the prior art, it is not necessary to mount each of a plurality of insert trials on a patient's knee joint to check the operation, thereby reducing complexity. .

  Patent Document 2 discloses various structures capable of adjusting the vertical position of the movable portion with respect to the base.

Japanese Patent Application Laid-Open No. 9-276304 U.S. Patent Application Publication 2012/0158152

  In the trial jig disclosed in Patent Document 1, the operated portion of the adjusting screw for adjusting the vertical position of the movable side member is the upper surface of the movable side member, that is, the sliding of the femoral component in the artificial knee joint. Exposed to moving surface. Therefore, since the shape and the sliding surface of the tibial insert used in practice are different, there is a possibility that the motion state can not be accurately grasped. On the other hand, the trial jig disclosed in Patent Document 2 has a relatively complicated shape, and the posture of the movable side member with respect to the fixed side member may be unstable.

  The present invention is intended to solve the above-mentioned problems, and the object thereof is to shape the sliding surface of the femoral component in the movable side member in the tibial trial for total knee arthroplasty capable of adjusting the clearance of the knee joint. To stabilize the attitude of the movable side member with respect to the fixed side member.

(1) A tibial trial for total knee arthroplasty according to one aspect of the present invention for achieving the above object is a stationary side member fixed to the tibial side and a femoral side of the stationary side member A movable side member having a sliding surface on which a femoral component slides and movable relative to the fixed side member, and a shaft portion formed on one of the fixed side member and the movable side member is the fixed side In the state of being inserted into the shaft hole formed in the other of the member and the movable side member, the shaft relative to the shaft hole along the extending direction which is the direction in which the shaft extends. By moving linearly, the movable side member linearly moves with respect to the fixed side member, and the position of the movable side member with respect to the fixed side member in the extending direction can be adjusted, and in the extending direction In the vertical direction The movable side member includes a rotating operation portion provided between the fixed side member and the movable side member in the extending direction and having an exposed portion that protrudes out, and a rotational force input to the rotational operation portion. And a conversion mechanism configured to convert the linear drive force linearly moved relative to the fixed side member, and the rotation operation unit is rotatably provided about an axial center extending in the extension direction. The rotational operation portion has an annular shape when viewed in the extending direction, and the shaft hole portion is inserted through the inner peripheral surface thereof, and the outer peripheral surface is rotated around the extending direction. It is provided as an annular plate formed in a shape .

  With the tibial trial for total knee arthroplasty according to the present invention, the separation width between the proximal end of the tibia and the distal end of the femur in the knee joint (ie, the knee) with the trial attached to the patient's knee joint Joint clearance can be adjusted. Specifically, when using the tibial trial for total knee arthroplasty, first, the shaft side portion (or shaft portion) of the fixed side member fixed to the tibial side is The shaft (or shaft hole) is inserted.

  In this state, when the operator rotates the rotation operation unit, the rotational force is converted by the conversion mechanism into a linear driving force in which the movable side member linearly moves with respect to the fixed side member. Thereby, the movable side member linearly moves with respect to the fixed side member. As described above, in the tibial trial for total knee arthroplasty, the shaft portion (or shaft hole portion) of the movable side member is inserted into the shaft hole portion (or shaft portion) of the fixed side member. The side members move linearly along the direction in which the shaft extends (extending direction). Thereby, since the movable side member can be moved linearly along the shaft, it is possible to prevent the movable side member from being inclined with respect to the fixed side member.

  Moreover, in this structure, the rotation operation part for operating the movable side member linearly is provided between the fixed side member and the movable side member. Thus, the rotation operation portion can be provided without affecting the shape of the sliding surface on which the femoral component slides on the movable side member.

  Therefore, in this configuration, in the knee replacement trial for total knee arthroplasty capable of adjusting the clearance of the knee joint, the movable side with respect to the stationary side member is not affected on the shape of the sliding surface of the femoral component in the movable side member. The posture of the member can be stabilized.

  (2) Preferably, the rotation operation unit is provided rotatably about an axis extending in the extension direction.

  In this configuration, it is possible to linearly move the movable side member by rotating the rotation operation portion about an axial center extending in the extension direction of the shaft portion. Moreover, in this configuration, it is possible to easily configure a rotation operation unit that can be held by the operator with a finger and rotated.

  (3) More preferably, the rotational operation portion has an annular shape when viewed in the extending direction, and the shaft hole portion is inserted into the inner peripheral surface thereof and the outer peripheral surface is centered on the extending direction Is provided as an annular plate formed in the form of a plate that is rotated.

  In this configuration, the rotation operation unit is provided as a plate-like member formed in an annular shape. Thereby, the shape of the rotation operation unit can be simplified.

  (4) More preferably, the conversion mechanism is formed on the surface on the movable side member side of the annular plate or on the surface on the fixed side member side, and a plurality of surface portions having different heights in the extension direction The annular plate is formed so as to protrude from the surface of the movable side member facing the plurality of surface portions or the surface of the fixed side member opposite the plurality of surface portions. And a protrusion whose tip end abuts on any of the plurality of surface portions.

  In this configuration, when the operator rotates the annular plate, the distal end of the protrusion abuts on any of the plurality of surface portions formed on the annular plate. Since the plurality of surface portions are different in height as described above, the distance between the fixed side member and the movable side member (the gap of the knee joint) differs depending on which surface portion the projecting portion abuts on. . That is, according to this configuration, it is possible to simplify the conversion mechanism capable of easily adjusting the clearance of the knee joint.

  (5) More preferably, the plurality of surface portions are arranged along the rotation direction of the annular plate and in such a manner that the heights of the respective surface portions are gradually increased along one direction of the rotation direction. ing.

  In this configuration, when the operator rotates the rotation operation portion in one direction, the height of the surface portion with which the protrusion abuts gradually increases. Thereby, the clearance of the knee joint can be gradually changed stepwise.

  (6) More preferably, each of the surface portions is a portion on the side of the lower surface portion of the two adjacent surface portions in the rotational direction of the annular plate to a portion on the surface portion of the higher surface side. It is provided as an inclined surface whose height gradually increases toward the end.

  In the tibial trial for knee replacement, in which the femoral component abuts on the sliding surface of the movable member, a load on the movable member acts on the movable member. . Therefore, in this configuration, since the movable side member is pressed to the fixed side in the state of being attached to the knee joint, the tip end portion of the projecting portion is positioned at the lowest height among the abutting surface portions. It will be done. Thereby, as compared with the case where the heights of the respective surface portions are uniform, for example, the annular plate is unexpectedly rotated and the protrusion moves to the next surface portion, so that the gap of the knee joint is unintentionally changed. It is possible to avoid the situation of changing.

  (7) Preferably, the rotation operation unit is provided rotatably about an axis extending in a direction perpendicular to the extending direction.

  In this configuration, it is possible to linearly move the movable side member by rotating the rotation operation portion about an axis extending in a direction perpendicular to the extending direction of the shaft portion. Moreover, in this configuration, it is possible to easily configure a rotation operation unit that can be rotated by using a wrench or a driver.

  (8) More preferably, the shaft portion is formed in the movable side member, the shaft hole portion is formed in the fixed side member, the conversion mechanism is formed in a tubular shape, and the outer peripheral surface is the shaft A cylindrical portion is rotatably provided on the inner peripheral surface of the hole, and a screw thread formed on the outer peripheral surface of the shaft is screwed into a thread groove formed on the inner peripheral surface, and integrally with the cylindrical portion A second bevel gear portion provided or fixed, the first bevel gear portion having a rotation axis concentric with the axis of the cylindrical portion, and the second bevel gear portion provided in the rotation operation portion and meshing with the first bevel gear portion And.

  In this configuration, when the operator rotates the rotation operation portion, the first bevel gear portion meshing with the second bevel gear portion is rotated. Then, since the cylindrical portion rotates with the first bevel gear portion, the shaft portion screwed with the screw groove formed on the inner circumferential surface of the cylindrical portion, that is, the movable side member linearly moves relative to the fixed side member . Thus, the conversion mechanism can be configured with a relatively simple configuration having two bevel gear portions and the like.

  (9) Preferably, in the tibial trial for total knee arthroplasty, the movable side member is fixed when the movable side member is linearly moved with respect to the fixed side member by rotating the rotation operation unit. It further comprises a rotation restricting mechanism that restricts rotation with respect to the side member.

  In this configuration, since the rotation restricting mechanism can restrict the movable side member from rotating relative to the fixed side member, the movable side member can be appropriately linearly moved relative to the fixed side member.

  (10) Preferably, the fixed side member is provided as a tray trial, and the movable side member is provided as an insert trial.

  In this configuration, the insert trial can be moved linearly relative to the tray trial.

  (11) Preferably, the tibial trial for total knee arthroplasty comprises a tibial insert trial disposed on the tibial side, and a femoral insert trial disposed on the femoral side of the tibial insert trial, The stationary side member is provided as the tibial side insert trial, and the movable side member is provided as the femoral side insert trial.

  In this configuration, the femoral insert trial can be moved linearly relative to the tibial insert trial. And, with this configuration, it is possible to move the femoral insert trial linearly with respect to the tibial insert trial fixed to the tray trial or the template. That is, according to this configuration, as in the case of handling a conventional insert trial, the insert trial may be applied to a conventional tibial template, a conventional tray trial, or a tibial tray which is one of the components of an artificial knee joint. It is possible to set up and check the condition of the patient's knee joint.

  According to the present invention, in the knee replacement trial for total knee arthroplasty capable of adjusting the clearance of the knee joint, the movable side member with respect to the fixed side member without affecting the shape of the sliding surface of the femoral component in the movable side member. Can stabilize the attitude of

It is a schematic diagram which shows an example of the usage aspect of the tibial trial for total knee arthroplasty concerning this embodiment, Comprising: It is a figure which shows the state with which a patient's femur and tibia were mounted | worn. It is a figure which shows the shape of the tray trial shown in FIG. 1, Comprising: (A) is a top view, (B) is a front view which shows a part in a cross section, (C) is a bottom view. It is a figure which shows the shape of the rotation plate shown in FIG. 1, Comprising: (A) is a top view, (B) is a side view, (C) is a bottom view. It is a figure which shows the shape of the insert trial shown in FIG. 1, Comprising: (A) is a top view, (B) is a front view, (C) is a bottom view, (D) is a side view. It is a schematic diagram for demonstrating the operation | movement of the tibia trial for total knee arthroplasty which concerns on this embodiment, Comprising: (A) is a figure which shows the state mounted on a patient's knee, (B) is a rotation plate. It is a figure which shows the state to which the insert trial moved upward compared with the state shown to (A) by being carried out. It is a perspective view of the tibial trial for total knee arthroplasty according to a modification. It is the fragmentary sectional view which looked at the tibia trial for total knee arthroplasty shown in FIG. 6 from the front. It is a perspective view of the tibial trial for total knee arthroplasty according to a modification. It is a perspective view of the tibial side insert trial of the tibial trial for total knee arthroplasty shown in FIG. FIG. 9 is a perspective view of a rotating plate of the tibial trial for total knee arthroplasty shown in FIG. 8; It is a figure which shows the shape of the femoral side insert trial of the tibial trial for total knee arthroplasty shown in FIG. 8, Comprising: (A) is a perspective view, (B) is the perspective view seen from another direction. It is a perspective view of the tibial trial for total knee arthroplasty according to a modification. FIG. 13 is a perspective view of the tibial trial for total knee arthroplasty shown in FIG. 12, as viewed from a direction different from that of FIG. 12. It is a bottom view of the tibial trial for total knee arthroplasty shown in FIG. It is a disassembled perspective view of the tibial trial for total knee arthroplasty shown in FIG. It is a figure which shows the shape of the plate part of the tibial side insert trial of the tibial trial for total knee arthroplasty shown in FIG. 12, Comprising: (A) is a perspective view, (B) is a front view, (C) is another direction. And FIG. It is a figure which shows the shape of the shaft hole part of the tibial side insert trial of the tibial trial for total knee arthroplasty shown in FIG. 12, Comprising: (A) is a perspective view, (B) is a top view, (C) is a front view. Is. It is a figure which shows the shape of the rotation plate of the tibial trial for total knee arthroplasty shown in FIG. 12, Comprising: (A) is a perspective view, (B) is a top view. It is a figure which shows the shape of the femoral side insert trial of the tibial trial for total knee arthroplasty shown in FIG. 12, Comprising: (A) is a perspective view, (B) is the perspective view seen from another direction.

  Hereinafter, the tibial trial 1 for knee replacement surgery for determining the thickness of the tibial side plate in the knee prosthesis will be described.

[overall structure]
FIG. 1 is a schematic view showing an example of a usage mode of the tibial trial 1 for total knee arthroplasty according to the present embodiment, and shows a state of being mounted on a knee joint (tibia 100 and femur 110) of a patient. FIG. As shown in FIG. 1, the tibial trial 1 for total knee arthroplasty includes a tray trial 20 as a stationary member, an insert trial 30 as a movable member, and a rotary plate 10 as an annular plate. There is. In the tibial trial 1 for total knee arthroplasty, the tray trial 20 is fixed to the proximal end of the tibia 100. Then, the insert trial 30 is disposed above the tray trial 20 with the rotating plate 10 sandwiched between the insert trial 30 and the tray trial 20 in the vertical direction. In each of the drawings described below, for convenience of description, the direction indicated by the arrow indicated by the upper side is referred to as upper side or upper side, and the direction indicated by the arrow indicated by the lower side is referred to as lower side or lower side.

  2A and 2B are diagrams showing the shape of the tray trial 20, where FIG. 2A is a plan view, FIG. 2B is a front view partially showing the cross section, and FIG. 2C is a bottom view. As shown in FIG. 2, the tray trial 20 includes a tray side plate portion 21 and an axial hole portion 22, which are integrally formed.

  As shown in FIG. 2, the tray side plate portion 21 is a portion which is substantially elliptical in a plan view and which is formed in a plate shape having a predetermined thickness in the vertical direction. The upper surface 23 and the lower surface 24 of the tray side plate portion 21 are both formed flat. As shown in FIG. 1, the rotary plate 10 is superimposed on the upper surface 23, while the lower surface 24 is in close contact with the resected surface 101 of the tibia 100 and is attached to the resected surface 101.

  The shaft hole portion 22 is provided as a hole-like portion extending downward from the tray side plate portion 21. The axial hole portion 22 has a cylindrical portion 25 which is a cylindrical portion extending in the vertical direction, and a bottom portion 26 provided at a lower end portion of the cylindrical portion 25. These are integrally formed. A shaft portion 32 of an insert trial 30, which will be described in detail later, is inserted through the inner circumferential surface 25a of the cylindrical portion 25.

  A key 27 extending in the vertical direction is formed on the inner peripheral surface 25 a of the shaft hole 22 from the upper surface 23 of the tray side plate 21 to the bottom 26 of the shaft hole 22. The key 27 has a cross-sectional shape perpendicular to the direction (vertical direction) in which the key 27 extends, and is formed in the same rectangular shape from the upper end to the lower end of the key 27.

  Further, a plurality of ribs 28 are formed between the outer peripheral surface of the shaft hole 22 and the lower surface 24 of the tray side plate 21. Thereby, the stress generated between the tray side plate portion 21 and the shaft hole portion 22 can be relieved.

  FIG. 3 is a view showing the shape of the rotation plate 10, wherein (A) is a plan view, (B) is a side view, and (C) is a bottom view. The rotation plate 10 is provided as a rotation operation unit capable of rotating operation by the operator.

  As shown in FIG. 3A, the rotation plate 10 is a plate-like member formed in an annular shape in a plan view by forming the through holes 11 penetrating in the vertical direction in the central portion. The lower surface 12 of the rotating plate 10 is formed flat. Further, the inner diameter of the through hole 11 of the rotating plate 10 is formed to have substantially the same size as the inner diameter of the inner peripheral surface 25 a of the shaft hole 22. The shaft portion 32 of the insert trial 30 is inserted through the through hole 11 in a state where the through hole 11 is overlapped with the inner circumferential surface 25 a of the shaft hole portion 22 of the plate portion 21 in the vertical direction.

  On the upper side of the rotating plate 10, a plurality of (six in the present embodiment, as shown in FIG. 3A, six) step portions 13a to 13f are formed. Each stepped portion 13a to 13f has surface portions 14a to 14f and falling portions 15a to 15f. Each of the stepped portions 13a to 13f is configured to gradually increase in the direction of the arrow A in FIG. 3A. In the present embodiment, the step 13a is the lowest and the step 13f is the highest. Thus, the upper side of the rotating plate 10 is formed in a spiral step shape.

  Each of the surface portions 14a to 14f is formed in a substantially fan shape having the same shape and area as each other in plan view (see FIG. 3A). Each of the surface portions 14 a to 14 f is provided as an inclined surface which is inclined along the circumferential direction of the rotating plate 10. Specifically, each of the surface portions 14a to 14f is higher in the direction from the portion on the surface portion on the lower side of the two surface portions adjacent in the circumferential direction to the portion on the surface side on the higher side. Is formed so as to become gradually higher. However, the height of the highest surface portion 14 f among the six surface portions gradually increases from the portion on the surface portion 14 e side to the portion on the surface portion 14 a side. Further, the height of the lowest surface portion 14 a among the six surface portions gradually increases from the portion on the surface portion 14 a side toward the portion on the surface portion 14 b side.

  The falling portions 15a to 15f are provided to extend in the vertical direction (the axial direction of the rotary plate 10) so as to connect the end portions of the surface portions 14a to 14f in the circumferential direction.

  FIG. 4 is a view showing the shape of the insert trial 30, where (A) is a plan view, (B) is a front view, (C) is a bottom view, and (D) is a side view. As shown in FIG. 4, the insert trial 30 has an insert side plate portion 31, a shaft portion 32 and a projecting portion 36, which are integrally formed.

  As shown in FIG. 4, the insert-side plate portion 31 is formed in a substantially elliptical shape in plan view, and is provided as a slightly flat portion in the vertical direction. The upper surface of the insert-side plate portion 31 is provided as a sliding surface 33 on which the femoral component 111 fixed to the femur 110 slides. The lower surface 34 of the insert side plate portion 31 is formed flat.

  The shaft portion 32 is provided as a round bar-like portion extending downward from a substantially central portion of the lower surface 34. That is, the extension direction of the shaft portion 32 and the extension direction of the shaft hole portion 22 described above are both in the vertical direction. The outer diameter of the shaft portion 32 is slightly smaller than the inner diameter of the shaft hole portion 22 of the tray side plate portion 21 and the inner diameter of the through hole 11 of the rotating plate 10. Thereby, the shaft portion 32 can be inserted into the shaft hole portion 22 and the through hole 11.

  A key groove 35 extending in the vertical direction is formed on the shaft portion 32 from one end to the other end in the direction in which the shaft 32 extends. The key 27 formed in the shaft hole 22 fits into the key groove 35. Thereby, the insert trial 30 can not rotate with respect to the tray trial 20 in a state where the shaft portion 32 is inserted into the shaft hole portion 22. That is, the key 27 and the key groove 35 are provided as a rotation restricting mechanism 6 which restricts the insert trial 30 from rotating with respect to the tray trial 20.

  The protrusion 36 is provided to protrude downward from the lower surface 34. The projecting portion 36 is formed such that the cross-sectional shape perpendicular to the direction in which the projecting portion 36 projects is elliptical. An inclined surface 37 which is slightly inclined with respect to the lower surface 34 is formed at the tip of the projection 36. The inclined surface 37 is in surface contact with any of the plurality of surface portions 14 a to 14 f formed on the rotating plate 10 in a state in which the tibial trial 1 for total knee arthroplasty is used (see FIG. 1).

[Method of using tibial trial for total knee arthroplasty and operation of each mechanism]
FIG. 5 is a view for explaining the operation of the tibial trial 1 for total knee arthroplasty according to the present embodiment. Specifically, FIG. 5 (A) shows a state in which the tibial trial 1 for total knee arthroplasty is mounted on a patient's knee, and FIG. 5 (B) shows that the rotation plate 10 is operated. It is a figure which shows the state which the insert trial 30 moved upward compared with the state shown to FIG. 5 (A).

  At the time of use of the tibial trial 1 for knee replacement, the tray trial 20 is fixed to the proximal end of the tibia 100. Then, as shown in FIG. 5A, the upper surface 23 of the tray trial 20 and the lower surface 12 of the rotating plate 10 are arranged such that the axial hole portion 22 of the tray trial 20 and the through hole 11 of the rotating plate 10 axially overlap. The shaft portion 32 of the insert trial 30 is inserted into the shaft hole portion 22 and the through hole 11 in a state in which the shaft portion 22 and the through hole 11 are overlapped. In this state, the inclined surface 37 of the projecting portion 36 of the insert trial 30 is in surface contact with any of the surface portions 14a to 14f of the rotating plate 10 (in the case shown in FIG. 5A, the surface portion 14d). . In this state, the side surface 16 of the rotating plate 10 functions as an exposed portion exposed from between the tray trial 20 and the insert trial 30 in the vertical direction.

  As described above, in a state in which the tibial trial 1 for total knee arthroplasty is set, the operator holds the side surface 16 of the rotation plate 10 with a finger and rotates it in the direction of the outlined arrow in FIG. Then, the projecting portion 36 moves relatively along the surface portion 14d while being pushed up by the surface portion 14d provided as the inclined surface. At this time, since the tray trial 20 and the insert trial 30 are keyed together by the key 27 and the key groove 35, the projection 36 does not rotate, and the projection 36 is upward (in a direction away from the tray trial 20). Move to

  Then, when the tip end of the protrusion 36 reaches the falling portion 15 d, the protrusion 36 reaches the next surface 14 e, and the inclined surface 37 is higher than the surface 14 e, ie, the surface 14 d. Surface contact is made (see FIG. 5 (B)). Thereby, the operator can adjust the height position of the insert trial 30 with respect to the tray trial 20 (the separation width between the proximal end of the tibia and the distal end of the femur, the gap of the knee joint). Here, the projecting portion 36 and the surface portions 14a to 14f in the tibial trial 1 for total knee arthroplasty perform rotational force input to the rotating plate 10, and the insert trial 30 linearly moves in the vertical direction with respect to the tray trial 20. Function as a conversion mechanism 5 for converting into a linear driving force.

  Then, the operator rotates the rotation plate 10 to adjust the gap of the knee joint, confirms the tension of the ligament of the knee joint, and bends the knee joint. Then, the clearance of the knee joint at which the knee joint moves smoothly is determined, and a tibial plate having a thickness corresponding to the clearance is selected. This makes it possible to determine a tibial plate of appropriate thickness.

[effect]
As described above, in the tibial trial 1 for total knee arthroplasty according to the present embodiment, when the operator rotates the rotating plate 10, the rotational force is inserted into the tray trial 20 by the conversion mechanism 5. The trial 30 is converted into a linear driving force that linearly moves. Thereby, the insert trial 30 linearly moves with respect to the tray trial 20. As described above, in the tibial trial 1 for knee replacement, since the shaft portion 32 of the insert trial 30 is inserted into the shaft hole portion 22 of the tray trial 20, the shaft portion 32 of the insert trial 30 is It moves linearly along the extending direction (extension direction). As a result, the insert trial 30 can be moved linearly along the shaft 32 reliably, so that the insert trial 30 can be prevented from being inclined with respect to the tray trial 20.

  Further, in the tibial trial 1 for total knee arthroplasty, a rotation plate 10 for linearly moving the insert trial 30 is provided between the tray trial 20 and the insert trial 30. Thereby, the rotation plate 10 can be provided without affecting the shape of the sliding surface 33 which is a surface on which the femoral component slides in the insert trial 30.

  Therefore, according to the tibial trial 1 for knee replacement, the posture of the insert trial 30 with respect to the tray trial 20 can be stabilized without affecting the shape of the sliding surface 33 of the femoral component in the insert trial 30. it can.

  In addition, in the tibial trial 1 for knee replacement, the insert trial 30 can be moved linearly by rotating the rotation plate 10 about an axial center extending in the extension direction of the shaft portion 32. Further, in the tibial trial 1 for total knee arthroplasty, the operator can hold the side surface 16 of the rotation plate 10 with his / her finger and easily rotate it.

  Further, in the tibial trial 1 for total knee arthroplasty, the rotation plate 10 is provided as a plate-like member formed in an annular shape. Thereby, the shape of the rotating plate 10 can be simplified.

  Further, in the tibial trial 1 for total knee arthroplasty, when the operator rotates the rotation plate 10, the inclined surface 37 of the protrusion 36 is any of the plurality of surface portions 14a to 14f formed on the rotation plate 10. Abut on. Since the plurality of surface portions 14a to 14f are different in height from each other as described above, the distance between the tray trial 20 and the insert trial 30 (the knee joint depends on which surface portion 14a to 14f the projection 36 abuts) The gap between) is different. That is, according to the tibial trial 1 for knee replacement surgery, the conversion mechanism 5 capable of easily adjusting the gap of the knee joint can be simplified.

  Further, in the tibial trial 1 for total knee arthroplasty, when the operator rotates the rotation plate 10 in one direction, the heights of the surface portions 14a to 14f with which the projecting portion 36 abuts gradually increase. Thereby, the clearance of the knee joint can be gradually changed stepwise.

  In addition, in the tibial trial 1 for knee replacement, in which the femoral component 111 abuts on the sliding surface 33 of the insert trial 30, the insert trial 30 is provided with the tray trial 20. The load acts. Therefore, in the tibial trial 1 for total knee arthroplasty, the insert trial 30 is pressed toward the tray trial 20 in a state of being attached to the knee joint, so the inclined surface 37 of the projection 36 is in contact with the surface portion 14a. It is located in the place where height is the lowest among -14f. Thereby, as compared with, for example, the case where the heights of the respective surface portions are uniform, the rotary plate 10 is unexpectedly rotated and the projection 36 is moved to the adjacent surface portions 14a to 14f, contrary to the intention. It is possible to avoid the situation in which the distance between the knee joints changes.

  Further, in the tibial trial 1 for total knee arthroplasty, since the rotation restricting mechanism 6 can restrict the insert trial 30 from rotating with respect to the tray trial 20, the insert trial 30 can be properly straightened with respect to the tray trial 20. It can be moved.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to the above-mentioned embodiment, As long as it describes in the claim, various changes are possible. For example, the following modifications may be made.

[Modification]
(1) In the above embodiment, the axial hole portion 22 is provided in the tray trial 20 and the axial portion 32 is provided in the insert trial 30, but the present invention is not limited to this. Specifically, the shaft may be provided on the tray trial and the shaft hole may be provided on the insert trial.

  (2) In the above embodiment, one protrusion 36 is provided in the insert trial 30, but the present invention is not limited to this. Specifically, a plurality of protrusions may be provided. Thereby, the insert trial can be supported more stably with respect to the tray trial.

  (3) In the said embodiment, although several step part 13a-13f formed in spiral step shape was formed in the surface at the side of the insert trial 30 in the rotation plate 10, it does not restrict to this. Specifically, a plurality of steps may be formed on the surface of the rotating plate on the tray trial side. In this case, the protrusions to be in contact with the plurality of steps may be formed in the tray trial.

  (4) FIG. 6 is a perspective view of the tibial trial 2 for total knee arthroplasty according to a modification, and FIG. 7 is a partial cross-sectional view of the total tibia trial 2 for total knee arthroplasty shown in FIG. It is.

[overall structure]
As shown in FIG. 6 and FIG. 7, the tibial trial 2 for total knee arthroplasty according to the present modification has a tray trial 40 (fixed side member) and an insert trial 50 (movable side member) different in shape from the above embodiment. ), A first bevel gear 60, and a second bevel gear 65.

  The tray trial 40 includes a tray side plate portion 41 and an axial hole portion 42, which are integrally formed. The tray side plate portion 41 is a portion formed in a plate shape having a predetermined thickness in the vertical direction. A cylindrical portion 62 of a first bevel gear 60, which will be described in detail later, is inserted into the inner circumferential surface 43 of the shaft hole portion 42, and is rotatable relative to the shaft hole portion 42.

  A groove 44 extending in the vertical direction is formed at the outer peripheral edge of the tray side plate portion 41. A rod portion 55 of an insert trial 50, which will be described in detail later, is inserted through the groove 44.

  The first bevel gear 60 includes a first bevel gear portion 61 and a cylindrical portion 62, which are integrally formed. The first bevel gear portion 61 is placed on the upper surface of the tray side plate portion 41 such that the bevel teeth are on the upper side. The cylindrical portion 62 is a portion formed in a cylindrical shape extending downward from the central portion of the first bevel gear portion 61. The outer peripheral surface 63 of the cylindrical portion 62 is inserted into the inner peripheral surface 43 of the shaft hole portion 42. A screw hole 64 is formed on the inner peripheral surface of the cylindrical portion 62.

  The insert trial 50 has an insert side plate portion 51 and a shaft portion 52, which are integrally formed.

  The insert-side plate portion 51 is provided as a slightly flat portion in the vertical direction. The upper surface of the insert-side plate portion 51 is provided as a sliding surface 53 on which the femoral component 111 fixed to the femur 110 slides.

  The shaft portion 52 is provided as a round bar-like portion extending downward from a substantially central portion of the lower surface of the insert side plate portion 51. An external thread 54 is formed on the outer peripheral surface of the shaft 52. As shown in FIG. 7, the male screw 54 is screwed into a screw hole 64 formed in the cylindrical portion 62 of the first bevel gear 60.

  Further, a rod-like portion 55 is integrally formed on the insert side plate portion 51. The rod-like portion 55 is provided as a rod-like portion extending downward from the outer peripheral edge portion of the insert side plate portion. The rod-like portion 55 is inserted into the groove 44 of the tray side plate 41 as shown in FIGS. 6 and 7 and is slidable in the vertical direction with respect to the groove 44. As a result, the insert trial 50 can slide in the vertical direction with respect to the tray trial 40 and can not rotate. That is, the groove portion 44 and the rod portion 55 are provided as a rotation restricting mechanism 6 a that restricts the insert trial 50 from rotating with respect to the tray trial 40.

  The second bevel gear 65 is provided as a rotation operation unit capable of rotating operation by the operator. The second bevel gear 65 includes a second bevel gear portion 66 and a shaft portion 67, which are integrally formed. The second bevel gear 65 is provided rotatably with respect to the tray side plate portion 41. The second bevel gear portion 66 meshes with the first bevel gear portion 61. The shaft portion 67 is formed in a substantially cylindrical shape extending in the horizontal direction (direction perpendicular to the vertical direction) from the first bevel gear portion 61. A hexagonal hole 68 is formed at the tip of the shaft 67. The hexagonal hole portion 68 is provided as an exposed portion that is exposed in the horizontal direction between the tray side plate portion 41 and the insert side plate portion 51.

[Method of using tibial trial for total knee arthroplasty according to this variation and operation of each mechanism]
In the tibial trial 2 for total knee arthroplasty according to the present modification, the operator rotates the second bevel gear 65 as the rotation operation unit using a hexagonal wrench (not shown), thereby the first umbrella The gear 60 is rotated. Then, the rotational force of the first bevel gear 60 is transmitted to the insert trial 50. However, the insert trial 50 can not rotate with respect to the tray trial 40 due to the rod portion 55 and the groove portion 44. Therefore, the rotational force of the first bevel gear 60 can be converted to the linear driving force of the insert trial 50 with respect to the tray trial 40 by the screw holes 64 formed in the first bevel gear 60 and the external thread 54 formed in the insert trial 50. It is converted. That is, the first bevel gear 60, the second bevel gear 65, and the external thread 54 of the insert trial 50 convert the rotational force input to the second bevel gear 65 into a linear driving force of the insert trial 50 with respect to the tray trial 40. Function as a conversion mechanism 5a.

[effect]
As described above, in the tibial trial 2 for total knee arthroplasty according to the present modification, as in the above embodiment, the shape of the sliding surface 53 of the femoral component in the insert trial 50 is not affected. The posture of the insert trial 50 with respect to the tray trial 40 can be stabilized.

  In addition, in the tibial trial 2 for total knee arthroplasty, the insert trial is performed by rotating the second bevel gear 65 as the rotation operation unit about an axial center extending in a direction perpendicular to the extending direction of the shaft 52. 50 can be moved in a straight line. Further, in this configuration, the operator can easily rotate the second bevel gear 65 using a hexagonal wrench or the like.

  Further, in the tibial trial 2 for artificial knee joint replacement, when the operator rotates the second bevel gear 65, the first bevel gear portion 61 meshing with the second bevel gear portion 66 is rotated. Then, the cylindrical portion 62 rotates with the first bevel gear portion 61, so that the shaft portion 52 screwed into the screw hole 64 formed in the inner peripheral surface of the cylindrical portion 62, that is, the insert trial 50 is Move in a straight line. Thereby, conversion mechanism 5a can be constituted by comparatively easy composition which has two bevel gear parts 61 and 66 grade.

  Further, in the tibial trial 2 for total knee arthroplasty, since the rotation restricting mechanism 6a can restrict the insert trial 50 from rotating with respect to the tray trial 40, the insert trial 50 can be properly straightened with respect to the tray trial 40. It can be moved.

  In the present modification, the conversion mechanism 5a for converting the rotational force input by the operator into a linear driving force is constituted by the two bevel gears 60, 65, etc., but the present invention is not limited to this. Specifically, for example, a pinion gear, a rack gear, or the like may be used.

  (5) FIG. 8 is a perspective view of a tibial trial 3 for total knee arthroplasty according to a modification. Although the tray trial is provided as the fixed side member and the insert trial is provided as the movable side member in the embodiment and the modification described above, the present invention is not limited thereto. In this modification, the insert trial is divided into upper and lower parts, and the lower part (part on the tibia side) is the tibial insert trial, which is the fixed side member, and the upper part (part on the femur) is the femoral side insert The trial is provided as a movable side member.

  As shown in FIG. 8, the tibial trial 3 for total knee arthroplasty according to the present modification includes a tibial insert trial 70, a rotation plate 80, and a femoral insert trial 90.

  FIG. 9 is a perspective view of the tibial insert trial 70. The tibial insert trial 70 includes a plate portion 71 and an axial hole portion 72, which are integrally formed. The plate portion 71 is a substantially elliptical member in which a substantially triangular notch 71a is formed in a plan view. The upper surface 73 and the lower surface 74 of the plate portion 71 are both formed flat. Further, on the upper surface 73 of the plate portion 71, a recessed portion 75 recessed in a substantially circular shape is formed at a central portion in a plan view.

  The shaft hole portion 72 is provided as a substantially cylindrical portion that protrudes from the central portion of the concave portion 75 of the plate portion 71. On the inner peripheral surface of the shaft hole portion 72, two keys 76 extending in the extension direction of the shaft hole portion 72 are formed.

  FIG. 10 is a perspective view of the rotating plate 80. As shown in FIG. The rotating plate 80 has a configuration similar to that of the rotating plate 10 of the above-described embodiment. However, the rotation plate 80 according to the present modification is largely different from the rotation plate 10 of the above embodiment in that a plurality of teeth 17 are formed on the side surface 16.

  The rotating plate 80 has a plurality of stepped portions 13a to 13f as in the case of the rotating plate 10 of the above embodiment. And these several step parts 13a-13f are comprised by the surface parts 14a-14f and the falling parts 15a-15f, respectively. Since these configurations are the same as those in the above embodiment, the description thereof is omitted.

  The plurality of teeth 17 are formed on the side surface 16 of the rotating plate 80. The teeth 17 project radially outward from the side surface 16 and are arranged at equal intervals in the circumferential direction.

  FIG. 11 is a view showing the shape of the femoral insert trial 90, wherein (A) is a perspective view and (B) is a perspective view as viewed from another direction. The femoral insert trial 90 has a main body 91, a shaft 92, and a protrusion 93, which are integrally formed.

  The main body portion 91 is formed to overlap the plate portion 71 of the tibial insert trial 70 in a plan view. A sliding surface 94 on which the femoral component 111 slides is formed on the upper side of the main body 91. On the other hand, in a central portion of the lower surface of the main body portion 91, a substantially round concave portion 95 is formed in a plan view.

  The shaft 92 is formed in a round bar shape extending downward from the recess 95. The shaft portion 92 is inserted into the shaft hole portion 72 of the tibial insert trial 70 and slides along the axial direction of the shaft hole portion 72. Further, on the outer peripheral surface of the shaft portion 92, two groove portions 92a extending in the vertical direction are formed. A key 76 formed in the shaft hole 72 enters each of the two groove portions 92a. Thus, the rotation of the femoral insert trial 90 with respect to the tibial insert trial 70 is restricted in a state where the shaft 92 is inserted into the axial hole 72. That is, the key 76 and the groove 92 a are provided as a rotation restricting mechanism 6 b that restricts the rotation of the femoral insert trial 90 with respect to the tibial insert trial 70.

  The protrusion 93 is formed to protrude downward from the recess 95. The tip end portion of the projecting portion 93 is provided as a tip end surface 93 a in surface contact with the surface portions 14 a to 14 f of the rotating plate 80.

  In the tibial trial 3 for total knee arthroplasty according to the present modification, although not shown, the lower surface 74 of the tibial insert trial 70 is fixed to a tray trial or a tibial template fixed to the proximal end of the tibia. On the other hand, the femoral component 111 is installed on the sliding surface 94 of the femoral insert trial 90. In this state, when the operator rotates the rotation plate 80, the tip end surface 93a of the protrusion 93 formed on the femoral insert trial 90 is any of the plurality of surface portions 14a to 14f having different heights. Make face contact with That is, in the present modification, the projecting portion 93 and the surface portions 14a to 14f linearly move the rotational force input to the rotating plate 80 in the vertical direction with respect to the tibial side insert trial 70 with respect to the tibial side insert trial 70. It functions as a conversion mechanism 5b that converts into a linear driving force. Thereby, as in the case of the above embodiment, the clearance of the knee joint can be adjusted. The tibial template is a plate-like member used to form a stem hole for fixing the tray trial to the tibia.

  As described above, according to the present modification, as in the case of the above embodiment and the above modification, the tibial side is not affected on the shape of the sliding surface 94 of the femoral component in the femoral insert trial 90. The posture of the femoral insert trial 90 with respect to the insert trial 70 can be stabilized.

  Moreover, according to the tibial trial 3 for knee replacement surgery according to the present modification, the tibial insert trial 70 as a stationary member can be attached not only to the tray trial but also to the template. Thereby, even when the tray trial is fixed to the tibia (the template is fixed to the tibia), an appropriate knee joint gap can be determined.

(6) FIG. 12 is a perspective view of a tibial trial 4 for total knee arthroplasty according to a modification. FIG. 13 is a perspective view of the tibial trial 4 for total knee arthroplasty as viewed from a direction different from that in FIG. FIG. 14 is a bottom view of the tibial trial 4 for total knee arthroplasty. FIG. 15 is an exploded perspective view of the tibial trial 4 for total knee arthroplasty.

  In this modification, as in the modification shown in FIGS. 8 to 11, the insert trial is divided into upper and lower parts, and the tibial insert trial that is the lower part (part on the tibia side) is the stationary side member, the upper part The femoral insert trial, which is the (femoral side) part, is provided as the movable side member. However, the present modification differs from the modifications shown in FIGS. 8 to 11 in the specific configuration, and this point will be described. In the description of the modified example shown in FIGS. 12 to 15 and FIGS. 16 to 19 described later, the direction corresponding to the vertical direction in the human body of the patient is described as the vertical direction as in the description of the above embodiment. Do. That is, in the drawings (see FIG. 12, FIG. 13, FIG. 16 (A) and FIG. 17 (C)), the direction indicated by the arrow described above is referred to as the upper or upper direction, and the arrow described as the lower The direction indicated is referred to as downward or downward.

  As shown in FIGS. 12 to 15, the tibial trial 4 for total knee arthroplasty according to the present modification includes a tibial insert trial 120, a rotation plate 130, and a femoral insert trial 140. .

  FIG. 16 is a view showing the shape of the plate portion 121 of the tibial insert trial 120, wherein (A) is a perspective view, (B) is a front view, and (C) is a perspective view as viewed from another direction; is there. FIG. 17 is a view showing the shape of the shaft hole portion 122 of the tibial insert trial 120, wherein (A) is a perspective view, (B) is a plan view, and (C) is a front view.

  The tibial insert trial 120 is configured to include a plate portion 121 and a shaft hole portion 122. The plate portion 121 and the shaft hole portion 122 are provided not as an integral member but as separate members. The tibial insert trial 120 is configured as an integral element by fixing the shaft hole portion 122 to the plate portion 121. A further modification may be implemented in which the plate portion 121 and the shaft hole portion 122 are provided not as separate members but as an integral member.

  The plate portion 121 is provided as a plate-shaped member having a substantially line-symmetrical outer shape in which a plurality of notch portions are formed. The upper surface 123 and the lower surface 124 of the plate portion 121 are both formed flat. Further, the plate portion 121 is provided with a fitting hole 125 of a rectangular cross section penetrating in the vertical direction. The fitting hole 125 is provided as a hole into which the lower end portion of the shaft hole portion 122 described later is fitted and fitted.

  In addition, the plate portion 121 is provided with two cylindrical portions (126, 127). Each cylindrical part (126, 127) is provided as a part which extends in a short cylindrical shape upward from the flat part of the plate part 121. Each cylindrical portion (126, 127) is provided with a through hole (126a, 127a) penetrating the plate portion 121 in the vertical direction.

  The through hole 126 a is provided as a through hole of a circular cross section inside the cylindrical portion 126. The through hole 127 a is provided as a through hole of a circular cross section inside the cylindrical portion 127. In addition, the through hole 127a is provided as a through hole having a diameter larger than that of the through hole 126a. Each of the through holes (126a, 127a) is configured to allow insertion of cylindrical shaft-like projections (145, 146) provided in the femoral insert trial 140 described later.

  The shaft hole portion 122 is provided as a screw shaft member that extends in a short cylindrical shape, and an external thread portion 122 a is provided on the outer periphery. The inner circumferential surface 122 b of the shaft hole portion 122 defines a hole extending in the vertical direction in the rectangular cross section. At the lower end portion of the shaft hole portion 122, a fitting portion 122c which is short in the vertical direction with a rectangular cross section is provided. The fitting portion 122 c is provided as a portion to be fitted to the fitting hole 125 of the plate portion 121. The shape of the outer periphery of the fitting portion 122 c is formed into a shape that fits into the inner periphery of the fitting hole 125. The shaft hole portion 122 is fixed to the plate portion 121 by fitting and fitting the fitting portion 122 c at the lower end portion of the shaft hole portion 122 into the fitting hole 125 of the plate portion 121. Thereby, the plate part 121 and the axial hole part 122 are comprised as the tibial side insert trial 120 of an integral state.

  FIG. 18 is a view showing the shape of the rotation plate 130, where (A) is a perspective view and (B) is a plan view. The rotation plate 130 is provided as a rotation operation unit capable of rotating operation by the operator. The rotating plate 130 is a plate-like member formed in an annular shape in a plan view by forming a through hole penetrating in the vertical direction in the central portion.

  A plurality of convex portions 131 are provided on the outer peripheral side surface of the rotating plate 130. The plurality of convex portions 131 project radially outward on the outer peripheral side surface of the rotary plate 130 and are arranged at equal intervals in the circumferential direction. The plurality of convex portions 131 are provided as portions operated by the operator when the rotation operation of the rotation plate 130 is performed by the operator.

  A female screw portion 132 is provided on the inner periphery of the through hole of the rotating plate 130. The female screw portion 132 is configured to be screwed with the male screw portion 122 a on the outer periphery of the shaft hole portion 122 of the tibial insert trial 120. The rotation plate 130 is configured to be rotatable with respect to the shaft hole portion 122 in a state in which the male screw portion 122 a of the shaft hole portion 122 is screwed with the female screw portion 132. Thus, the rotation plate 130 is configured to be able to be displaced relative to the shaft hole 122 along the axial direction (that is, the vertical direction) of the shaft hole 122 by rotating around the shaft hole 122. ing.

  Further, the upper surface 130a and the lower surface 130b of the rotating plate 130 are formed flat. The rotation plate 130 is configured to abut on the lower surface side of the femoral insert trial 140 described later on the upper surface 130a. The rotation plate 130 is configured to be able to abut on the upper surface 123 of the plate portion 121 of the tibial insert trial 120 on the lower surface 130 b.

  FIG. 19 is a view showing the shape of the femoral insert trial 140 shown in FIG. 12, wherein (A) is a perspective view and (B) is a perspective view as viewed from another direction. The femoral insert trial 140 is configured to include a main body portion 141, a shaft portion 142, protrusions (145, 146), and the like. The main body portion 141, the shaft portion 142, and the protrusions (145, 146) are integrally formed.

  The main body portion 141 is formed to have a schematic shape corresponding to the outer shape of the plate portion 121 of the tibial insert trial 120 in a plan view. A sliding surface 144 on which the femoral component 111 slides is formed on the upper side of the main body portion 141. On the other hand, in a central portion of the lower surface of the main body portion 141, a substantially round concave portion 143 is formed in a plan view.

  The recessed portion 143 is provided with a rotating plate contact surface 143a which is a flat surface extending in an arc shape along a circumferential direction around a shaft 142 described later. The rotary plate contact surface 143a is configured as a surface on which the upper surface 130a of the rotary plate 130 contacts.

  The shaft portion 142 is formed in a rectangular rod shape extending downward from the recess 143. That is, the shaft portion 142 is provided as a shaft portion extending in a cantilever shape downward from the recess portion 143 in a rectangular cross section. The shaft portion 142 is inserted into the shaft hole portion 122 of the tibial insert trial 120, and is configured to be slidable along the axial direction (that is, the vertical direction) of the shaft hole portion 122 with respect to the shaft hole portion 122 There is.

  More specifically, the outer peripheral side surface 142 a of the shaft portion 142 is configured to be slidable with respect to the inner peripheral surface 122 b of the shaft hole portion 122. The rectangular cross-sectional shape of the shaft portion 142 (that is, the rectangular cross-sectional shape of the outer peripheral side surface 142a in a cross section perpendicular to the axial direction of the shaft portion 142) substantially corresponds to the rectangular cross-sectional shape of the inner peripheral surface 122b of the shaft hole portion 122. It is formed in shape. Thereby, in a state in which the shaft portion 142 is inserted into the shaft hole portion 122, the rotation of the femoral insert trial 140 with respect to the tibial side insert trial 120 is restricted. That is, the outer peripheral side surface 142a of the shaft portion 142 and the inner peripheral surface 122b of the shaft hole portion 122 function as a rotation restricting mechanism 6c that restricts the rotation of the femoral insert trial 140 relative to the tibial insert trial 120. There is.

  Each of the protrusions (145, 146) is provided as a cylindrical shaft-like portion extending downward from the lower surface of the main body portion 141 in a cantilevered manner. The diameter of the circular cross section of the protrusion 146 is set to be larger than the diameter of the circular cross section of the protrusion 145. The diameter of the circular cross section of the protrusion 145 is set to a size substantially corresponding to the diameter of the circular cross section of the through hole 126 a of the cylindrical portion 126. Then, the protrusion 145 is inserted in a state in which it can slide in the axial direction (that is, in the vertical direction) with respect to the through hole 126 a. Further, the diameter of the circular cross section of the projection 146 is set to a size substantially corresponding to the diameter of the circular cross section of the through hole 127 a of the cylindrical portion 127. Then, the protrusion 146 is inserted in a state in which the protrusion 146 can slide in the axial direction (that is, in the vertical direction) with respect to the through hole 127 a.

  In this modification, first, the fitting portion 122c of the shaft hole portion 122 is fitted into the fitting hole 125 of the plate portion 121, and the shaft hole portion 122 is fixed to the plate portion 121 and integrated. The tibial insert trial 120 is configured. Then, the rotation plate 130 is screwed into the shaft hole portion 122, and the femoral insert trial 140 is attached to the plate portion 121, so that the tibial trial 4 for total knee arthroplasty is integrated. It will be assembled.

  In this state, the shaft portion 142 is slidably inserted inside the shaft hole portion 122 inside the rotation plate 130, and the respective projections (145, 146) are inserted into the respective through holes (126a, 127a). ing. The upper surface 130 a of the rotation plate 130 is in contact with the rotation plate contact surface 143 a of the recess 143 of the femoral insert trial 140. Further, a part of the outer peripheral side surface on which the plurality of convex portions 131 are provided in the rotation plate 130 is between the femur side insert trial 140 and the plate portion 121 of the tibial side insert trial 120 arranged side by side in the vertical direction. , Exposed to the outside so that the operator can operate. That is, a part of the outer peripheral side surface of the rotating plate 130 functions as an exposed portion exposed in the perpendicular direction in the extending direction which is the extending direction of the shaft portion 142.

  In the tibial trial 4 for total knee arthroplasty according to the present modification, although not shown, the lower surface 124 of the plate portion 121 of the tibial insert trial 120 is a tray trial or a tibial template fixed to the proximal end of the tibia. It is fixed. The tibial template is a plate-like member used to form a stem hole for fixing the tray trial to the tibia. On the other hand, the femoral component 111 is installed on the sliding surface 144 of the femoral insert trial 140. In addition, in a state in which the tibial trial 4 for total knee arthroplasty has been installed as described above, the femoral side insert trial 140 and the tibial side insert trial 120 approach each other by the force acting from the ligaments of the knee joint. It is biased toward the Therefore, the state in which the upper surface 130a of the rotation plate 130 abuts on the rotation plate abutment surface 143a of the femoral insert trial 140 is maintained.

  In the above-mentioned state, when the operator rotates the rotating plate 130 screwed into the shaft hole portion 122, the rotating plate 130 is axially displaced while rotating with respect to the shaft hole portion 122. As described above, the upper surface 130 a of the rotary plate 130 is in contact with the rotary plate contact surface 143 a of the femoral insert trial 140. Furthermore, the shaft portion 142 is inserted in the shaft hole portion 122 so as to be slidable in the vertical direction. For this reason, when the rotary plate 130 is axially displaced with respect to the shaft hole portion 122 while being rotated, the femoral insert trial 140 is also axially displaced with respect to the shaft hole portion 122. That is, in this modification, the shaft portion 142, the inner peripheral surface 122b of the shaft hole portion 122, the male screw portion 122a, and the female screw portion 132 of the rotating plate 130 are used to transmit the rotational force input to the rotating plate 130 to the femoral bone insert trial. It functions as a conversion mechanism 5c that converts a linear driving force 140 linearly moving in the vertical direction with respect to the tibial insert trial 120. Thereby, as in the case of the above-described embodiment, the clearance of the knee joint can be adjusted.

  As described above, according to the present modification, as in the above-described embodiment and the above-described modification, the shape of the sliding surface 144 of the femoral component in the femoral insert trial 140 is not affected. The posture of the femoral insert trial 140 with respect to the tibial insert trial 120 can be stabilized.

  Further, according to the tibial trial 4 for knee replacement surgery according to the present modification, the tibial insert trial 120 as the stationary member can be attached not only to the tray trial but also to the template. Thereby, even when the tray trial is fixed to the tibia (the template is fixed to the tibia), an appropriate knee joint gap can be determined.

  The present invention can be widely applied as a tibial trial for total knee arthroplasty for determining the thickness of the tibial side plate in a prosthetic knee joint.

1,2,3,4 tibial trial for total knee arthroplasty 5,5a, 5b, 5c conversion mechanism 10,80,130 rotation plate (rotation operation part)
16 Side (exposed part)
20, 40 tray trial (fixed side member)
22, 42, 72, 122 shaft hole 30, 50 insert trial (movable side member)
32, 52, 92, 142 Shaft portion 33, 53, 94, 144 Sliding surface 65 Second bevel gear (rotation operation portion)
68 Hexagon Socket (Exposed)
70, 120 Tibial insert trial (fixed component)
90, 140 Femoral side insert trial (movable side member)
100 tibia 110 femur 111 femur component

Claims (7)

A stationary side member fixed to the tibia side, and a movable side member attached to the femur side of the stationary side member and having a sliding surface on which the femoral component slides, and movable with respect to the stationary side member; Equipped
In a direction in which the shaft extends in a state in which a shaft formed on one of the fixed side member and the movable side is inserted into a shaft hole formed on the other of the fixed side member and the movable side The movable side member linearly moves relative to the fixed side member by the linear movement of the shaft relative to the axial hole portion along a certain extension direction, and the movable side relative to the fixed side member The position of the side member in the extending direction can be adjusted;
A rotational operation unit having an exposed portion exposed in a direction perpendicular to the extending direction, and provided between the fixed side member and the movable side member in the extending direction;
And a conversion mechanism for converting a rotational force input to the rotation operation unit into a linear driving force in which the movable side member linearly moves with respect to the stationary side member ,
The rotation operation unit is provided rotatably about an axis extending in the extension direction,
The rotational operation portion has an annular shape when viewed from the extending direction, and the shaft hole portion is inserted into the inner peripheral surface thereof, and the outer peripheral surface is rotated in the plate shape around the extending direction. A tibial trial for total knee arthroplasty, characterized in that it is provided as a formed annular plate . In the knee replacement trial for total knee arthroplasty according to claim 1 ,
The conversion mechanism is
A plurality of surface portions which are formed on the surface on the movable side member side of the annular plate or the surface on the fixed side member side, the heights of which are different in the extending direction;
The annular plate is rotated as it protrudes from the surface of the movable side member facing the plurality of surface portions or the surface of the fixed side member opposite the plurality of surface portions. A projection whose tip end abuts on any of the plurality of surface portions;
A tibial trial for total knee arthroplasty, comprising: In the knee replacement trial for total knee arthroplasty according to claim 2 ,
The plurality of surface portions are arranged so that the heights of the respective surface portions gradually increase along one direction of the rotational direction so as to follow the rotational direction of the annular plate. , Tibial trial for total knee arthroplasty. In the knee replacement trial for total knee arthroplasty according to claim 3 ,
Each of the surface portions has a height gradually increasing from a portion on the side of the lower surface portion of the two adjacent surface portions in the rotational direction of the annular plate to a portion on the surface side of the higher height portion. A tibial trial for total knee arthroplasty, characterized in that it is provided as a rising slope. In the knee replacement trial for total knee arthroplasty according to any one of claims 1 to 4 ,
When the movable side member is moved linearly with respect to the fixed side member by rotating the rotation operation unit, the movable side member is further provided with a rotation restricting mechanism which restricts the rotation of the movable side member with respect to the fixed side member. A tibial trial for total knee arthroplasty, characterized in that In the knee replacement trial for total knee arthroplasty according to any one of claims 1 to 5 ,
The stationary side member is provided as a tray trial.
The movable side member is provided as an insert trial, The tibial trial for total knee arthroplasty. In the knee replacement trial for total knee arthroplasty according to any one of claims 1 to 5 ,
The insert trial further includes a tibial side insert trial disposed on the tibial side, and a femoral side insert trial disposed on the femur side of the tibial side insert trial.
The stationary member is provided as the tibial insert trial.
The movable side member is provided as the femoral insert trial, The tibial trial for total knee arthroplasty.

Images