WO2004069099A1 - Tension probe for ligament - Google Patents

Abstract

A tension probe for ligament allowing the degree of the tension of an artificial ligament to be easily and objectively confirmed, wherein the artificial ligament (J) is hooked to a pair of hooks (17) opened in the right and left directions, and a pressing body (16) is pressed against the center part thereof to detect, with a load cell (11), the strain thereof according to a pressing force produced in pressing so as to digitize the degree of the tension of the artificial ligament (J) installed in a body.

Description

Technical field of ligament tension probe

 The present invention relates to a ligament tension probe suitable for confirming the tension of a tendon graft implanted in a human body or animal instead of a torn ligament in place of a torn ligament. Background art

 When a ligament such as the anterior cruciate ligament has been torn, for example, as described in Japanese Patent Publication No. In some cases, a tendon or the like obtained from a tissue force or a tendon graft made of an artificial ligament is attached to the body instead of the torn ligament.

 In the following description, a tendon graft attached to the body by surgery is referred to as an artificial ligament.

 The tension of the artificial ligament is adjusted by a port or the like buried in the bone.Taking the anterior cruciate ligament as an example, loosening or overstretching of the artificial ligament can cause knee collapse, meniscus and articular cartilage. Can cause damage to osteoarthritis.

 For this reason, it is necessary to set the tension of the artificial ligament at an appropriate tension according to the use site. Usually, the tendon graft is set to the desired tension and then fixed by tightening bolts, etc., so that the final tension of the artificial ligament is not the desired tension In some cases.

 Conventionally, when checking the tension of the above-mentioned artificial ligament, a probe rod made of a metal rod is generally used. In other words, the user grips the tail end (upper end) of the probe and places the tip of the probe on the surface of a hole (usually a hole with a diameter of about 8 mm). And insert it towards. Subsequently, the prosthesis is gently pushed or pulled at the tip of the probe, and the tension is determined based on the reaction and resistance transmitted to the gripper through the probe at that time.

Note that the use of the probe is not only for examining the ligament tension. In addition, the lengths of the ligaments vary.

 However, the conventional method has a problem that it lacks objectivity because it relies on the feel of the user.

 The present invention has been made in view of the above-described problems, and has as its object to provide a ligament tension probe that can easily and more objectively confirm the tension of an artificial ligament. . Disclosure of the invention

 The invention described in claim 1 of the present invention is a tension probe for checking the tension of a ligament, the probe body having a hook for hooking the ligament, and a probe main body having a hook for hooking the ligament. And a tension detecting means for detecting the tension.

 Next, the invention described in claim 2 is a tension probe for confirming the tension of the ligament with respect to the configuration described in claim 1.

 A tubular body; a pair of hooks supported by the tubular body and protruding forward from the distal end of the tubular body; and a distal end supported by the tubular body in a state capable of moving forward and backward toward a space between the pair of hooks. A rod-shaped body having a pressing body pressed against the ligament; and load detecting means for detecting a load input to the pressing body.

 According to the present invention, by pushing the pressing body toward the substantially central portion of the ligament hooked on the pair of hooks and supported at two points, the load input to the pressing body from the ligament according to the tension of the ligament That is, a load according to the tension of the ligament is detected by a load detecting means such as a load cell.

 Next, the invention described in claim 3 is characterized in that, in addition to the configuration described in claim 2, an enlargement mechanism for increasing the distance between the tip portions of the pair of hooks is provided. .

According to the present invention, even if the hole into which the probe distal end is inserted is small, the distance between the hook distal ends, that is, the distance between the two points supporting the ligament can be set wide. Next, the invention according to claim 4 is directed to an outer cylinder and a nested arrangement that are relatively movable in the axial direction with respect to the configuration described in claim 2 or claim 3. And an inner cylinder, and a rod-shaped body supported so as to be movable only in the axial direction with respect to the inner cylinder. A pair of hooks is attached to a distal end of the inner cylinder, and a distal end of the rod-shaped body is a pressing body. The load detecting means is in contact with the tail end of the rod-shaped body.The invention described in claim 5 is the same as the structure described in claim 4. On the other hand, there is provided a first panel for urging the inner cylinder toward the tail end side relatively to the outer cylinder, and a second spring for urging the rod-shaped body toward the tail end side relatively to the inner cylinder. When the elastic force of the second panel is set to be stronger than the elastic force of the first panel, and when the inner cylinder is advanced with respect to the outer cylinder, the distance between the pair of hook tips supported by the inner cylinder is increased. It is characterized by having an enlargement mechanism to increase the distance.

 According to the present invention, the inner cylinder, that is, the pair of hooks can be protruded to secure the distance between the tips of the pair of hooks, that is, the distance between the two supporting points, and then the pressing body can be pressed toward the ligament. . This operation can be performed continuously. Next, the invention described in claim 6 is different from the configuration described in any one of claims 2 to 5 in that the rod-shaped body is positioned halfway in the axial direction. It has a third spring, and the elastic force of the third panel is stronger than the elastic force of the first and second panels.

 According to the present invention, since the load from the pressing portion is input to the load cell via the third panel, even if the axial displacement of the pressing portion pushed back from the ligament during the load measurement is large, The displacement applied to the load cell can be suppressed within a predetermined range. Next, the invention described in claim 7 is a tension probe for confirming the tension of a ligament, wherein the rod is a main body, A probe body having a hook portion for hooking a ligament at the tip of the body and having a grip portion to be gripped by hand at the tail end side of the rod is located between the tip portion and the grip portion. It is characterized in that the-part of the rod is a thin part having a small thickness along the direction in which the hook part projects, and a strain gauge is attached to the thin part. According to the present invention, since the rigidity of the thin portion of the rod is the smallest, when the artificial ligament is hooked on the hook portion and pulled, stress concentrates on the thin portion and the tension is applied to the artificial ligament according to the tension of the artificial ligament. Deflection occurs in the thin portion.

The flexure (stress) generated in the thin part according to the tension of the artificial ligament is measured by a strain gauge. Once detected, it becomes possible to represent the degree of tension of the artificial ligament, for example, in numerical form.

 FIG. 1 is a cross-sectional view showing an initial state of a tension probe according to a first embodiment of the present invention.

 FIG. 2 is a cross-sectional view showing a state where the inner tube of the tension probe according to the first embodiment of the present invention has advanced.

 FIG. 3 is a cross-sectional view showing a state where the pressing body of the tension probe according to the first embodiment of the present invention has advanced.

 FIG. 4 is a cross-sectional view showing a state where the pressing body is pushed back from the ligament of the tension probe according to the first embodiment of the present invention and is equilibrated.

 FIG. 5 is an enlarged cross-sectional view showing a state of a distal end portion of the tension probe according to the first embodiment of the present invention.

 FIG. 6 is an enlarged cross-sectional view showing a state where a pair of hooks at the distal end of the tension probe according to the first embodiment of the present invention are open.

 FIG. 7 is a side view showing a hook according to the first embodiment based on the present invention. FIG. 8 is a view of the tension probe according to the first embodiment of the present invention as viewed from the distal end side.

 FIG. 9 is a diagram illustrating a relationship between a load, a displacement, and a strain amount.

 FIG. 10 is a tension probe according to a second embodiment of the present invention, wherein (a) is a side view and (b) is a rear view.

 FIG. 11 is an enlarged view of a portion A in FIG.

 FIG. 12 is a diagram showing another example of the hook portion.

 FIG. 13 is a diagram showing another example of the hook portion.

 FIG. 14 is a cross-sectional view showing an example in which a display unit is provided on the rod itself. BEST MODE FOR CARRYING OUT THE INVENTION

 Next, a first embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a cross-sectional view showing a ligament tension probe according to the present embodiment. First, the configuration will be described. As shown in FIG. 1, an outer cylinder 3, an inner cylinder 6 that is coaxially arranged in the outer cylinder 3 and supported by the outer cylinder 3 so as to be able to advance and retreat only in the axial direction, A rod-shaped body 10 coaxially arranged in the cylinder 6 and supported by the inner cylinder 6 so as to be able to advance and retreat only in the axial direction, and a load cell 11 abutting on the other end (tail end) of the rod-shaped body 10. And The outer cylinder 3 and the inner cylinder 6 constitute a cylinder main body.

 In the following description, the right side in FIG. 1 is referred to as the tail end side, and the left side is referred to as the front end side.

 The outer cylinder 3 includes an outer cylinder main body 1 and an outer cylinder small-diameter portion 2 that extends coaxially and continuously with a distal end of the outer cylinder main body 1. By setting the inner diameter of the outer cylinder small-diameter portion 2 to be smaller than the inner diameter of the outer cylinder body 1, the outer cylinder body 1 and the outer cylinder small-diameter portion 2 are provided on the inner diameter surface of the outer cylinder 3 along the axial direction. A step 3a is formed at the boundary of. Further, a flange portion 3b to be gripped to take a reaction force is formed on the tail end side of the outer cylinder body 1.

 The inner cylinder 6 extends coaxially with the inner cylinder main body 4 guided by the outer cylinder main body 1 continuously at the leading end of the inner cylinder main body 4 and is guided by the outer cylinder small diameter section 2. A small-diameter section 5 is provided. The inner cylinder small-diameter portion 5 is set to have a smaller diameter than the inner cylinder main body 4, so that the inner cylinder body 4 and the inner cylinder small-diameter section extend along the axial direction on the inner diameter surface and the outer diameter surface of the inner cylinder 6. Steps 6 a. And 6 b are formed at the boundary between 5 and 5.

 In the outer cylinder main body 1, a first coil spring SP 1 is disposed coaxially with the inner cylinder small-diameter portion 5 on the outer peripheral side of the inner cylinder small-diameter portion 5. One end of the first coil spring SP 1 is seated on the step 6 a on the outer diameter surface side of the inner cylinder body 4 and the inner cylinder small diameter section 5, and the other end is connected to the outer cylinder body 1 and the outer cylinder small diameter. It is seated on the step 3a on the inner diameter surface side with the part 2. The first coil spring SP1 urges the inner cylinder 6 toward the tail end (retreating direction) with respect to the outer cylinder 3, thereby positioning the inner cylinder 6 with respect to the outer cylinder 3 at no load. Is The first coil spring SP 1 transmits an axial load between the inner cylinder 6 and the outer cylinder 3.

 The rod 10 is supported by the inner cylinder 6 via the intermediate cylinder 7 so as to be movable only in the axial direction.

The intermediate cylinder 7 is inserted into the inner cylinder main body 4 and is supported by the inner cylinder main body 4 so as to be movable only in the axial direction. At an intermediate position in the axial direction on the outer diameter surface of the intermediate A small-diameter portion 7a is formed by a fixed length, and an inner diameter surface of the inner cylinder main body 4 is provided with an overhang portion 4a fitted into the small-diameter portion 7a of the intermediate cylinder body 7. It regulates the amount of advance and retreat of the intermediate cylinder 7 relative to 6. Further, a second coil spring SP 2 is disposed coaxially with the intermediate cylinder 7 on the outer periphery of the small diameter portion 7 a of the intermediate cylinder 7. The second coil spring SP2 has one end seated on the surface on the tail end side in the small diameter portion 7a and the other end seated on the surface on the tail end side of the overhang portion 4a. The intermediate cylinder 7 is biased toward the tail end side with respect to the inner cylinder body 4.

 In the initial state, the tip of the projecting portion 4a is pressed against the wall of the tip of the small-diameter portion 7a by the spring of the second coil / spring SP2. Body 7 position is set. Further, the axial load is transmitted between the intermediate cylinder 7 and the inner cylinder 6 by the second coil spring SP2. An outward flange 7b is formed at the tail end of the intermediate cylinder 7, and a load cell 11 is disposed so as to face an opening at the center of the tail end side end surface of the intermediate cylinder Ί, Further, the load cell 11 is fixed to the end face of the intermediate cylinder 7 by the cap member 12. Reference numeral 15 indicates a screw. The load cell 11 constitutes a load detecting means.

 The rod-shaped body 10 includes a tail-end-side rod 8 inserted into the intermediate cylinder 7, a tail-end end inserted into the inner cylinder small-diameter part 5, and a tail-end-side end inserted into the inner cylinder body 4 and the intermediate cylinder. And a tip-side rod-shaped body 9 inserted into the body 7.

 Here, the portion where the tail end side rod-shaped body 8 and the front end side rod-shaped body 9 are connected on the inner diameter surface of the intermediate cylindrical body 7 is a large-diameter portion 7c having a larger diameter than other portions. ing. The tail-end-side rod-shaped body 8 abuts on the load cell 11 at the tail-end-side end surface, and has a front end located at the large-diameter portion 7 c of the intermediate cylindrical body 7. A cylindrical first piston 13 is attached to the tip. The first piston 13 is supported by the large diameter portion 7c so as to be movable in the axial direction. Here, the length of the tail end side rod-shaped body 8 is set so that a slight gap is formed between the tail end side end surface of the first piston portion 13 and the tail end side surface of the large diameter portion. As a result of the setting, the axial load applied to the tail end rod 8 can be reliably transmitted to the load cell 11.

A cylindrical second piston portion 14 is also provided at the tail end of the rod-shaped body 9 at the distal end. And is supported by the large diameter portion 7c so as to be movable in the axial direction. The third coil spring SP 3 is disposed between the second piston portion 14 and the first piston portion 13, so that the load input to the distal-end-side rod 9 is reduced by the third coil spring SP 3. It can be transmitted to the tail end rod 8 and the load cell 11 via the three coil springs SP 3.

 The second piston portion 14 has a small diameter at the tip end side to form a step, and the opening at the tip end portion of the large diameter portion has a diameter capable of fitting the small diameter portion of the second piston portion 14. By setting to, the stepped portion 7 d abutting the step of the second biston portion 14 is formed, thereby preventing the second biston portion 14 from falling off from the large diameter portion 7 c. ing.

 Further, a pressing body 16 made of rubber or the like is attached to the front end of the front end side rod-shaped body 9.

 As shown in FIGS. 5, 7, and 8, a pair of hooks 17 are supported at the distal end of the inner cylinder small diameter portion 5. The pair of hooks 17 are arranged so as to face each other with the pressing body 16 interposed therebetween, and can swing in the facing direction H, in particular, the direction in which the hooks 17 separate from each other. 5 is supported at the tip.

 As shown in FIG. 5, each of the hooks 17 has a support portion that is slightly curved and extends so that the center portion of the hook portion 17a can be viewed from the distal end side as shown in FIG. The artificial ligament J can be hooked across the 6. A plurality of constrictions are formed at the center of the hooked portion 17a, so that the ligament can be easily hooked on the center.

An outward projection 20 is provided at the base of the support portion of the hook 17, and an inward projection 21 axially opposed to the projection 20 is provided at the distal end of the inner cylinder small diameter portion 5. Is formed, and the inner diameter surface of the inward projection 21 is inclined so that the diameter increases toward the tip. As a result, the inner cylinder small-diameter portion 5 moves forward in the axial direction with respect to the outer cylinder small-diameter portion 2, and when the root of the support portion of the hook 17 moves to the tip of the outer cylinder small-diameter portion 2, As shown in FIG. 6, each of the hooks 17 rotates outward (in a direction away from each other) as shown in FIG. 6 by the projections 20 facing the inward projections 21. Slant outer surface restricted by inclined inner surface 2 1 a The distance between the tips of the pair of hooks 17 is set wide. The protrusions 20 and 21 and the mechanism for moving the inner cylinder relative to the outer cylinder constitute an enlargement mechanism. Here, regarding the panel force of the above three coil springs, the third coil spring SP3 is the strongest, the second coil spring SP2 is the second strongest, and the first coil spring SP1 is the weakest. That is, the first coil spring SP1 bends first, and then the second coil spring SP2 and the third coil spring SP3 are easily bent in that order.

 Next, the operation, effect, and the like of the probe having the above configuration will be described.

 As shown in Fig. 1, insert the tips of a pair of hooks 17 into a hole A with a diameter of about 8 mm opened in the body surface, and hook the hooks 17 formed at the tips of the pair of hooks 17 a is hooked on the artificial ligament J.

 In this state, a finger (for example, the index finger and the middle finger) is hooked on the flange, and a reaction force is applied to the flange 3b. When it is pushed in toward the side, the force is transmitted to the tail end side wall surface of the small diameter part → the second coil spring SP 2 → the overhang part 4 & → the inner cylinder main body 4 → the first coil spring SP 1, As shown in FIG. 2, the inner cylinder 6 moves forward by being piled on the panel of the first coil spring SP 1 (the first coil spring SP 1 is in a bent state). As the inner cylinder main body 4 moves forward, the pair of hooks 17 also move forward, and the outward projections 20 are hooked on the inward projections 21, so that the pair of hooks 17 are fixed as shown in FIG. Opening left and right at the inclination angle of, the distance between the hooks of the pair of hooks 17 increases.

 Next, when the inner cylinder 6 moves until the first coil spring SP 1 is completely bent, the movement of the inner cylinder 6 stops. Subsequently, the intermediate cylinder 7 is pressed against the panel of the second coil spring SP 2. As shown in FIG. 3, the pressing portion at the tip of the rod 10 comes into contact with the central portion of the artificial ligament J supported by the pair of hooks 17, and the rod 10 advances. Press artificial ligament J.

Then, a reaction force corresponding to the tension from the artificial ligament J to the artificial ligament J is input to the pressing body 16 and the tip-side rod 9, and the tip-side rod 9 is pushed back, and as shown in FIG. As a result, the third coil spring SP 3 is deflected by the amount corresponding to the reaction force, The corresponding stress is transmitted to the load cell 11 via the tail end rod 8. The load cell 11 generates a distortion corresponding to the stress transmitted from the rod 10 and outputs a signal corresponding to the distortion to the display device 19. That is, the tension of the artificial ligament J can be displayed numerically. Therefore, the determination of the tension of the artificial ligament J can be made more objective. Here, the display device 19 includes a conversion unit 19a that converts a signal from the load cell 11 into a numerical value corresponding to stress, and a display unit 19b that displays the numerical value converted by the conversion unit.

 More specifically, the greater the tension of the artificial ligament J, the smaller the amount of protrusion of the pressing body 16 abutting on the artificial ligament J located between the pair of hooks 17 and the more the third coil spring SP 3 As a result, the load detected by the load cell 11 increases. That is, a load corresponding to the degree of tension of the artificial ligament J is detected by the load cell 11, and the tension of the artificial ligament J can be estimated from the load detected by the load cell 11.

 Here, in the present embodiment, by providing the third coil spring SP3 in the middle of the rod-shaped body 10, the displacement of the pressing body 16 according to the tension of the ligament is once converted into a spring force, and then the load cell is loaded. Since the force is transmitted to the load cell 11, the displacement of the pressing body 16 according to the load from the ligament is prevented from being directly applied to the load cell 11, and the load cell 11 is protected.

 Also, if the distance between the tips of the hooks 17 supporting the artificial ligament J is too small, the accuracy of the measured values will be reduced accordingly, but the hole A for inserting the probe is usually as small as about 8 mm in diameter. . On the other hand, in the probe of the present embodiment, the distance between the tip portions of the pair of hooks 17 can be increased after inserting into the hole A. This also makes it possible to design the pressing body 16 to be large, and to stably contact the pressing body 16 with the artificial ligament. Moreover, only a series of operations of pushing the cap portion 12 by taking a reaction force on the flange portion 3b automatically spreads the space between the tip portions of the pair of hooks 17 and furthermore, the pressing body 16 It is pressed against the artificial ligament J and the tension of the artificial ligament J is measured quantitatively.

 Here, the shape of the hook 17 is not limited to the above-mentioned L-shape.

Further, in the present embodiment, the display device 19 is described as being located at another place, but a display device may be attached to the cap portion 12. In the above description, the signal from the load cell 1 is quantified and displayed on the display device 19, but it may be displayed as a graph of the load over time.

 "Example"

 In order to confirm the effectiveness of a tension probe that supports the ligament at the above two points and presses the central part, the relationship between the load applied to the pressing body 16 and the amount of strain at the load cell 11, and its The relationship between the amount of displacement of the pressing body 16 and the amount of strain in the load cell 11 at that time was determined, and the results shown in FIG. 9 were obtained. An arrow is a graph of a load-strain diagram, and an arrow Υ is a graph of a displacement-strain diagram. Each measurement was performed four times.

 As can be seen from FIG. 9, the displacement and strain in the pressing body 16 are proportional to each other, and the load and the strain input to the pressing body 16 at that time are also in a proportional relation. It can be seen that the value measured by the tension probe is proportional to the ligament tension.

 Next, a second embodiment of the present invention will be described with reference to the drawings.

 FIG. 10 is a view showing a ligament tension probe of the present embodiment.

 First, the configuration will be described. A rod 31 made of a metal such as stainless steel is used as a main body, and a tip end (lower end) is bent in an L shape to form a hook part 32. As shown in FIG. 11, a plurality of constricted portions 32 a is formed on the horizontally extending hook body 32 す る constituting the hook portion 32, so that the artificial ligament S can be easily hooked.

 Further, the tail end side (upper part) of the rod body 31 serves as a gripping part 33 gripped by the user. An intermediate portion located between the hook portion 32 and the grip portion 33 includes a thin thin portion.

3 4 are formed. Since the thin portion 34 is cut so that the thickness of the hook portion 32 in the extending direction L becomes thin, the thin portion 34 is particularly easily bent in the extending direction L of the hook portion 32.

A strain gauge 35 is attached to the surface of the thin portion 34 at the thin position, and the displacement (tensile stress and compression) corresponding to the bending of the hook portion 32 in the projecting direction L of the thin portion 34. Is detected, and the signal is output to the display device 36. The display device 36 displays a conversion unit 36A for converting the electric signal from the strain gauge 35 into a value proportional to the stress in the thin portion 34, and a numerical value converted by the conversion unit 36A. And a display unit 36B shown in FIG. In addition, it is preferable that only the maximum value per predetermined time (for example, per 3 seconds) be displayed on the display unit 36B. Here, the above-mentioned ligament tension probe is generally inserted into a body through a hole having a diameter of about 8 mm opened in the body surface to check the tension of the artificial ligament S. Good. Note that, in the present embodiment, the case where the rod 1 is formed of a round bar is illustrated, but the cross-sectional shape such as a square bar is not particularly limited.

 The diameter of the rod 1 is 2 mm, but the thickness of the thin portion 34 in the above-mentioned overhanging direction L is set to 1 mm. The length of the hook body 32 A, which protrudes horizontally, of the hook portion 32 is 7 mm, and the hook portion 32 can be inserted into the body through the hole by inserting it obliquely into the hole. The thin portion 34 is formed at a position 3 O mm above the tip end side. This position is selected because it is preferable that the thin portion 34 does not enter the body when the tip is inserted into the body. The length of the thin portion 34 along the axial direction of the rod 1 is 1 O mm. The length of the portion of the rod 31 above the thin portion 34 is set to 16 O mm, enabling sufficient gripping.

 Next, the use of the tension probe and the like will be described.

 When the attachment of the artificial ligament S into the body by the operation is completed, the tension probe is gripped, the distal end is inserted through the opened hole, and the hook 32 formed at the distal end is hooked on the target artificial ligament S. In addition, it is usually performed while confirming using an endoscope.

At this time, by forming a plurality of constrictions 32a on the horizontally extending hook body 32A, the artificial ligament S can be easily hooked on the hook body 32A without slipping. Next, the user gently pulls the tension probe up several times with the same force. Then, a resistance (repulsive force) corresponding to the tension of the artificial ligament S acts as a load on the hook portion 32, and the thinnest portion 34, which is the thinnest portion, bends. The tensile stress or the compressive stress corresponding to the deflection is detected by the strain gauge 35 and displayed as a numerical value on the display section 36B. Thus, the tension of the artificial ligament S is quantified by simple means. Therefore, the determination of the tension of the artificial ligament s can be made more objective.

 Here, the shape of the hook portion 32 is not limited to the above-described L-shape, and various shapes can be adopted, for example, as shown in FIGS. 12 and 13. In the shape of the hook portion 32 shown in FIGS. 12 and 13, the artificial ligament S can be hooked substantially coaxially with the axis of the rod 1. Here, as for the shape of the hook portion, the ligament is more surely fixed at a fixed position near the axis of the rod 1 as shown in FIGS. 12 and 13 than the shape shown in FIG. It is preferable to have a hook shape. The reason is that the influence of offset 1 due to the difference in the thickness of the ligament is reduced, and the variation in the measurement can be suppressed accordingly.

 However, four strain gauges are attached to the thin-walled part 34 so that they face each other in front and back, and are also attached so that they face each other in the left and right directions, and the tension is detected based on the difference in stress at each of the two opposing locations. You may do it. In this case, the variation in the measurement can be suppressed even if the shape is not particularly as shown in FIGS.

 Further, in the above embodiment, the position of the center of gravity of the thin portion 4 is formed so as to be eccentric with respect to the axis of the rod 31, but it may be concentric.

 Also, as shown in FIG. 14, a small display device 36 is provided at the upper end (tail end) of the rod 31, and a wire 37 connecting the strain gauge 35 to the display 36 is formed. It may be arranged so as to pass through the inside of the rod 31 for further simplification. Reference numeral 38 denotes a through hole through which the line 37 passes.

Although FIG. 14 illustrates a case where the diameter of the upper side of the thin portion 34 is increased, it is not always necessary to increase the diameter. In addition, the side opposite to the side to which the strain gauge 35 is attached is also shown as an example of shaving, but it is not necessary to sharpen.

Further, in the above-described embodiment, the probe is described as being made of metal, but may be made of another material as long as required rigidity such as hard plastic is ensured. However, since it is assumed that the material is inserted into the body, a material that does not cause an allergic reaction is preferable. Industrial applicability As described above, by adopting the present invention, the tension of the artificial ligament can be numerically and simply and easily determined, and can be determined with more objectivity.

Claims

The scope of the claims 1. A tension probe for checking the tension of a ligament, comprising a probe main body having a hook for hooking the ligament, and tension detecting means for detecting the tension of the ligament hooked on the hook. Ligament tension probe. 2. A tension probe for checking the ligament tension,  A tubular body, a pair of hooks supported by the tubular body and protruding forward from the distal end of the tubular body, and a distal end supported by the tubular body in a state of being able to advance and retreat toward a space between the pair of hooks. A rod-shaped body having a pressing body pressed against the ligament; and a load detecting means for detecting a load input to the pressing body. Tension probe.  3. The tension probe for a ligament according to claim 2, further comprising an enlargement mechanism for increasing a distance between tip portions of the pair of hooks.  4. An outer cylinder and an inner cylinder which are nested and can move relative to each other in the axial direction, and a rod which is supported so as to be movable only in the axial direction with respect to the inner cylinder. The pair of hooks are attached, and the tip of the rod forms a pressure member, and the load detecting means contacts the tail end of the rod. 3. A ligament tension probe according to item 3.  5. A first panel that urges the inner cylinder toward the tail end side relatively to the outer cylinder and a second panel that urges the rod-shaped body toward the tail end side relative to the inner cylinder. When the elastic force of the second panel is set to be stronger than that of the first panel and the inner cylinder is advanced with respect to the outer cylinder, the pair of hook tips supported by the inner cylinder is 5. The tension probe for a ligament according to claim 4, further comprising an enlargement mechanism for increasing a distance between the ligaments. 6. The rod-shaped body has a third spring in the middle of the axial direction, and the elastic force of the third panel is stronger than the elastic force of the first and second panels. A ligament tension probe according to any one of claims 2 to 5. 7. A tension probe for checking the tension of the ligament, which has a rod as the main body, a hook at the tip of the rod for hooking the ligament, and is gripped by hand at the tail end of the rod. With respect to the probe body having a grip portion, a part of the rod positioned between the tip portion and the grip portion is thinned by reducing the thickness along the direction in which the hook portion extends. 2. The tension probe for a ligament according to claim 1, wherein the tension portion is a thick portion, and a strain gauge is attached to the thin portion.