Fixture for pulling out femoral stem

Abstract

The utility model belongs to the field of medical tools of femoral stems, and discloses a femoral stem pulling-out clamp which comprises a main body, the main body is provided with a sliding way and a locking block assembly located in the sliding way, the locking block assembly is in sliding fit with the sliding way, a first end of the sliding way is provided with a locking hole for the neck of a femoral stem to penetrate, one side of the locking hole is communicated with the sliding way, and the other side of the locking hole is communicated with the locking block assembly. A handle hinged to the main body is arranged at the second end of the slide way, the handle is in transmission fit with the first end of the locking block assembly, and when the handle rotates to a preset angle, the second end of the locking block assembly moves into the lock hole so as to be clamped on a neck clamping structure of a femoral stem, and the femoral stem abuts against the interior of the lock hole; according to the scheme, the number of contact points and the contact area of the clamp in the circumferential direction of the neck of the femoral stem can be increased, so that the tension transmission effect is improved, the neck of the femoral stem is evenly stressed in the circumferential direction, pull-out resistance is avoided, the operation difficulty is reduced, the use experience feeling is improved, and meanwhile the connection stability and the connection strength are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to the medical tool field of femoral stem, especially a femoral stem pulling-out clamp. BACKGROUND

[0002] Femoral stem is a kind of artificial prosthesis, is used to be implanted in the upper end of femur, and is also an important component of artificial hip joint, wherein, after femoral stem is implanted in femur, the lower end of femoral stem is embedded into the upper end of femur, and the neck part of femoral stem is set on the upper end of femoral stem to be used to install femoral head prosthesis, so the neck part of femoral stem and its upper end need to be exposed outside femur together to ensure the smooth assembly and disassembly and normal activity of artificial hip joint.

[0003] The neck part of the existing femoral stem is often provided with a shaft shoulder, a plug hole or a ring groove and other clamping structures to provide a stress point for temporary connection, and the clamp used to pull out femoral stem can be fixed to the neck part of femoral stem through the clamping structure, so as to facilitate the pulling out of femoral stem in femur, and the clamp often adopts an L-shaped hook structure to be fixed to the neck part clamping structure on femoral stem, in specific use, one end of the hook structure is clamped at the shaft shoulder or inserted into the plug hole and ring groove, and then the other end of the hook structure is pulled out, the pulling force is transmitted to femoral stem through the hook structure, and finally femoral stem is pulled out, but since the number of contact points and the contact area of the hook structure and the neck part clamping structure are relatively small, and are distributed on one side of the neck part, the hook structure and the neck part clamping structure are loose after being connected, the transmission effect of pulling force is affected, the operation is difficult, and the circumference of the neck part cannot be uniformly stressed, the pulling force direction is inclined to the axis of femoral stem, the pulling resistance of femoral stem is increased, the operation of the clamp is difficult, and the use experience is poor. UTILITY MODEL CONTENTS

[0004] The utility model aims at providing a femoral stem pulling-out clamp, increasing the number of contact points and the contact area of the clamp in the circumferential direction of the neck part of femoral stem, improving the transmission effect of pulling force, making the neck part of femoral stem be uniformly stressed in the circumference, avoiding the pulling resistance, reducing the operation difficulty, improving the use experience, and improving the connection stability and the connection strength.

[0005] The utility model provides a technical scheme for: femoral stem pulls out clamp, including main part, the main part is equipped with slide and the lock block assembly in the slide, the lock block assembly with the slide sliding cooperation, the first end of the slide is equipped with the lock hole for the neck of femoral stem to wear into, the side of the lock hole with the slide intercommunication, the second end of the slide is equipped with the handle that articulates on the main part, the handle with the first end transmission cooperation of the lock block assembly, when the handle rotates to the preset angle, the second end of the lock block assembly moves to the lock hole, to the neck of femoral stem clamping structure is set on, and the femoral stem is pressed in the lock hole.

[0006] In the femoral stem pulls out clamp, the handle is provided with a cam portion, the cam portion is hinged with the main body, and abuts on the end face of the first end of the lock block assembly.

[0007] In the femoral stem pulls out clamp, the end face of the first end of the lock block assembly is provided with an elastic pad, and the cam portion abuts on the elastic pad.

[0008] In the femoral stem pulls out clamp, the side of the slide is provided with an open mouth penetrating through the main body, the lock block assembly is provided with a stress portion located in the open mouth, and the stress portion is used for driving the lock block assembly.

[0009] In the femoral stem pulls out clamp, the edges of the opposite sides of the open mouth are provided with limiting portions located on the first end of the slide, guide grooves are respectively formed between the limiting portions on the two sides and the inner walls of the slide, the lock block assembly is provided with clamping portions corresponding to the guide grooves on the two sides, the clamping portions are located in the corresponding guide grooves and slide with the corresponding guide grooves.

[0010] In the femoral stem pulls out clamp, strip-shaped grooves corresponding to the clamping portions on the two sides and directly opposite to the clamping portions on the two sides are formed on the opposite sides of the main body.

[0011] In the femoral stem pulls out clamp, the second end of the lock block assembly is provided with a clamping tongue portion.

[0012] In the femoral stem pulls out clamp, the main body is provided with an arc-shaped portion, the lock hole is located on the arc-shaped portion, and the first end of the slide extends to the lock hole along the arc shape of the arc-shaped portion.

[0013] In the femoral stem pulls out clamp, the lock block assembly comprises a top piece and a sliding block located in the slide, the top piece and the sliding block both slide with the slide, the first end of the top piece is in transmission cooperation with the handle, and the second end abuts against the sliding block; the sliding block is an arc-shaped structure matched with the first end of the slide.

[0014] The side surface of the main body is provided with a clamping groove and a mounting hole, the clamping groove, the mounting hole and the slide are sequentially arranged, the slide is communicated with the mounting hole, the lock block assembly extends into the mounting hole, and the handle is hinged in the mounting hole.

[0015] The technical scheme has the beneficial effects that:

[0016] The neck of the femoral stem is clamped in the lock hole, the handle is rotated to drive the lock block assembly to move along the slide to the lock hole and abut against the femoral stem, the neck of the femoral stem is abutted against the inner wall of the lock hole, the contact points and the contact area of the neck of the femoral stem in the circumferential direction are increased, the neck of the femoral stem is uniformly stressed in the circumferential direction, the pulling-out resistance is avoided, the femoral stem is relatively fixed in the radial direction, the lock block assembly is clamped on the neck clamping position of the femoral stem when abutting against the abutting and locking assembly, the femoral stem is relatively fixed in the axial direction, the transmission effect of the pulling force is improved, the stability and the strength of the connection are improved, and the operation difficulty is reduced and the use experience is enhanced. BRIEF DESCRIPTION OF DRAWINGS

[0017] Fig. 1 is a structural schematic view of the femoral stem pulling-out clamp of the embodiment 1 of the utility model;

[0018] Fig. 2 is a structural sectional view of the femoral stem pulling-out clamp of the embodiment 1 of the utility model;

[0019] Fig. 3 is an assembly drawing of the femoral stem pulling-out clamp of the embodiment 1 of the utility model.

[0020] Reference signs: 1, main body; 2, handle; 3, lock block assembly; 4, elastic pad;

[0021] 11, clamping groove; 12, mounting hole; 13, first connecting part; 14, second connecting part; 15, strip-shaped groove; 16, arc-shaped part; 17, lock hole; 18, channel; 19, slide; 191, open mouth; 192, limiting part;

[0022] 21, cam part; 31, top piece; 32, sliding block; 321, stress part; 322, clamping tongue part; 323, clamping position part. DETAILED DESCRIPTION

[0023] The technical scheme of the utility model is further described in detail in combination with specific implementation manners, but does not constitute any limitation on the utility model.

[0024] Example 1:

[0025] like Figs. 1-3 As shown, the femoral stem extraction clamp includes a main body 1. The main body 1 has a slide 19 and a locking block assembly 3 located in the slide 19. The locking block assembly 3 is slidably engaged with the slide 19. The first end of the slide 19 has a locking hole 17 for the neck of the femoral stem to pass through. One side of the locking hole 17 is connected to the slide 19. The second end of the slide 19 has a handle 2 hinged to the main body 1. The handle 2 is drivenly engaged with the first end of the locking block assembly 3. When the handle 2 is rotated to a preset angle, the second end of the locking block assembly 3 moves into the locking hole 17 to lock onto the neck locking structure of the femoral stem and press the femoral stem against the locking hole 17.

[0026] The specific working principle is as follows: a locking hole 17 is provided on the main body 1 of the clamp, through which the neck of the femoral stem is inserted. After the neck of the femoral stem is inserted into the locking hole 17, the neck of the femoral stem is also positioned within the locking hole 17. By rotating the handle 2 on the main body 1, the locking block assembly 3 is moved along the slide 19 into the locking hole 17 and abuts against the femoral stem, thus pressing the neck of the femoral stem against the inner wall of the locking hole 17. This increases the contact point and contact area of ​​the neck of the femoral stem in the circumferential direction, allowing the neck of the femoral stem to be evenly stressed in the circumferential direction, avoiding pull-out resistance, and also providing relative fixation in the radial direction of the femoral stem. While abutting against the locking assembly, the locking block assembly 3 is also engaged in the neck position of the femoral stem, providing relative fixation in the axial direction of the femoral stem, improving the transmission effect of tensile force, and enhancing the stability and strength of the connection, ultimately reducing the difficulty of operation and enhancing the user experience.

[0027] Preferably, the handle 2 is provided with a cam portion 21, which is hinged to the main body 1 and abuts against the end face of the first end of the locking block assembly 3.

[0028] In this embodiment, a cam portion 21 is provided on the handle 2, and the cam portion 21 is used as the hinge fulcrum between the handle 2 and the main body 1. When the handle 2 drives the cam portion 21 to rotate around the hinge fulcrum, the outer peripheral surface of the cam portion 21 abuts against the end face of the first end of the locking block assembly 3. As the cam portion 21 rotates, the contact radius between it and the locking block assembly 3 gradually increases. Taking advantage of the gradually increasing radius, the locking block assembly 3 is gradually pushed along the slide 19 to move towards the lock hole 17 until it moves into the lock hole 17 and abuts against the femoral stem.

[0029] In some embodiments, the handle 2 can be in transmission cooperation with the lock block assembly 3 through a gear part in addition to the cam part 21. In specific applications, the gear part is in rotational cooperation with the main body 1, and correspondingly, the lock block assembly 3 is provided with a rack part in the lock block assembly 3, the rack part is in meshing cooperation with the gear part, and whenever the handle 2 drives the gear part to rotate, the gear part drives the lock block assembly 3 to be pushed into the lock hole 17 through the rack transmission, so that the lock block assembly 3 abuts against the femoral stem, and the transmission cooperation manner of the handle 2 and the lock block assembly 3 is not limited too much in the embodiment.

[0030] Further preferably, the first end of the lock block assembly 3 is provided with an elastic pad 4 on the end face, and the cam part 21 abuts against the elastic pad 4.

[0031] The elastic pad 4 is arranged between the cam part 21 and the lock block assembly 3, so that the cam part 21 and the lock block assembly 3 are in flexible friction when moving relative to each other, avoiding the generation of debris due to the rigid friction between the cam part 21 and the lock block assembly 3, and since the debris is no longer generated, the potential risk of inflammation caused by the debris falling into the human body is also eliminated. The elastic pad 4 itself has a certain deformation characteristic, so that the elastic pad 4 can be more closely abutted against the cam part 21, avoiding poor contact due to the gap between the cam part 21 and the lock block assembly 3. In addition, the elastic pad 4 has a certain self-lubricating property in addition to the certain deformation characteristic, which can reduce the relative resistance of friction with the cam part 21 and improve the smoothness of rotation of the handle 2.

[0032] In actual applications, the elastic pad 4 can be made of medical wear-resistant rubber blocks or PP plastic blocks or other related elastic parts, and the embodiment does not limit too much.

[0033] Further improvement, the side surface of the slide 19 is provided with an opening 191 penetrating the main body 1, and the lock block assembly 3 is provided with a stress receiving part 321 located in the opening 191, and the stress receiving part 321 is used to actuate the lock block assembly 3.

[0034] The opening 191 is arranged to open the side surface of the slide 19, and the lock block assembly 3 in the slide 19 can also be contacted through the opening 191, and whenever the handle 2 is reset, the cam part 21 is reversely rotated, the cam part 21 no longer continuously pushes the lock block assembly 3 into the lock hole 17, and the stress receiving part 321 on the lock block assembly 3 can be contacted through the opening 191 to reset the lock block assembly 3, so that the femoral stem is released from the lock hole 17.

[0035] The force-receiving part 321 can be either a protrusion or a recess. Both protrusions and recesses can provide a force-receiving point on the locking block assembly 3 for pushing the locking block assembly 3. In this embodiment, the force-receiving part 321 is preferably a recess. In addition to providing a force-receiving point, the recess can reduce the weight of the locking block assembly 3 and reduce the force required to move the locking block assembly 3.

[0036] In another improvement of this embodiment, limiting portions 192 are provided on the first end of the slide 19 at the edges of opposite sides of the opening 191. Guide grooves are formed between the limiting portions 192 on both sides and the inner wall of the slide 19. The locking block assembly 3 is provided with locking portions 323 that correspond one-to-one with the guide grooves on both sides. The locking portions 323 are located in the corresponding guide grooves and slide in cooperation with the corresponding guide grooves.

[0037] In this embodiment, a limiting part 192 is provided, forming a guide groove between the limiting part 192 and the inner wall of the slide 19. The locking part 323 on the locking block assembly 3 is inserted into the guide groove, so that the guide groove can guide the movement of the locking block assembly 3 by guiding the locking part 323, and also prevent the locking block assembly 3 from disengaging from the opening 191 into the slide 19. When it is necessary to disassemble the locking block assembly 3, it is only necessary to push the locking block assembly 3 towards the first end of the slide 19 until the locking part 323 is completely withdrawn from the guide groove, so that the locking block assembly 3 can be separated from the slide 19.

[0038] In this embodiment, the locking portion 323 is preferably a protrusion. However, the locking portion 323 can also be a protrusion; this embodiment does not impose excessive restrictions on this.

[0039] Preferably, the main body 1 has strip grooves 15 on its opposite sides that correspond one-to-one with and face each other to the two side locking parts 323.

[0040] The design of the strip groove 15 allows operators to easily observe the position of the locking block assembly 3 from different angles, improving its practicality in actual use.

[0041] In this embodiment, a latch 322 is provided on the second end of the locking block assembly 3.

[0042] The thickness of the latch 322 is less than the thickness of the second end of the locking block assembly 3. When the latch 322 is engaged in the neck locking structure of the femoral stem, the end face of the second end of the locking block assembly 3 and the latch 322 together press the neck of the femoral stem against the inner wall of the locking hole 17.

[0043] As a further improvement of this embodiment, the main body 1 is provided with an arc-shaped portion 16, the lock hole 17 is located on the arc-shaped portion 16, and the first end of the slide 19 extends along the arc of the arc-shaped portion 16 to the lock hole 17.

[0044] In the specific structure of the femoral stem, there is an angle between the axis of the neck of the femoral stem and the axis of the lower end of the femoral stem, meaning that their axes are not on the same straight line. If the femoral stem is pulled along the axis of the neck, the pulling force cannot be fully applied to pull out the femoral stem, and a portion of the pulling force will be converted into resistance to pulling out the femoral stem, hindering its removal. The arc-shaped portion 16 on the main body 1 compensates for the angle between the axis of the neck of the femoral stem and the axis of the lower end of the femoral stem by its arc curvature. This ensures that the axis of the end of the main body 1 away from the arc-shaped portion 16 is on the same straight line as the axis of the lower end of the femoral stem, allowing the pulling force applied to the main body 1 to be fully applied to the lower end of the femoral stem. This optimizes the force transmission effect and improves the pulling effect of the clamp.

[0045] The specific structure of the locking block assembly 3 is as follows: the locking block assembly 3 includes a top member 31 and a slider 32 disposed in the slide rail 19. Both the top member 31 and the slider 32 are slidably engaged with the slide rail 19. The first end of the top member 31 is engaged with the handle 2, and its second end abuts against the slider 32. The slider 32 is an arc-shaped structure that matches the first end of the slide rail 19.

[0046] In specific applications, the second end of the top member 31 is a hemispherical structure, and the top member 31 as a whole can be either a top rod structure or a rack and pinion structure. This embodiment does not impose too many restrictions on this.

[0047] The specific structure of the main body 1 is as follows: the main body 1 includes a first connecting part 13 and a second connecting part 14. The slide 19 and the lock hole 17 are both provided on the second connecting part 14. The second connecting part 14 and the first connecting part 13 are detachably threaded together. The handle 2 is hinged to the first connecting part 13. The first connecting part 13 has a channel 18 located between the handle 2 and the slide 19. The channel 18 is connected to the slide 19. The locking block assembly 3 is provided in the channel 18 and the slide 19.

[0048] In practical applications, the main body 1 of the clamp is detachably connected to the first connecting part 13 and the second connecting part 14, so that after the first connecting part 13 and the second connecting part 14 are separated, the locking block assembly 3 can be removed from the slide rail 19 for easy cleaning and disinfection, and to avoid dirt accumulation.

[0049] In this embodiment, a slot 11 and a mounting hole 12 are provided on the side of the main body 1. The slot 11, the mounting hole 12 and the slide 19 are arranged in sequence. The slide 19 is connected to the mounting hole 12. The locking block assembly 3 extends into the mounting hole 12 and the handle 2 is hinged in the mounting hole 12.

[0050] In specific implementation, the slot 11 and the mounting hole 12 are both located on the first connecting part 13. The slot 11 mainly serves to allow the force-applying component to be mounted on the main body 1. The preferred structure of the slot 11 is an L-shaped structure. The force-applying component includes a sliding rod and a sliding hammer sleeved on the sliding rod. The end of the sliding rod away from the clamp on the main body 1 is provided with an end cap. In actual use, the force-applying component generates an instantaneous impact force by moving the sliding hammer to strike the end cap, thereby driving the clamp and pulling the femoral stem.

[0051] The above embodiments are preferred embodiments of the present utility model, but the embodiments of the present utility model are not limited to the above embodiments. Any changes, modifications, substitutions, combinations, or simplifications made without departing from the spirit and principle of the present utility model shall be considered equivalent substitutions and shall be included within the protection scope of the present utility model.

Claims

1. A femoral stem extraction clamp, comprising a main body, characterized in that, The main body has a slide rail and a locking block assembly located within the slide rail. The locking block assembly slides in conjunction with the slide rail. The first end of the slide rail has a locking hole for the neck of the femoral stem to pass through. One side of the locking hole communicates with the slide rail. The second end of the slide rail has a handle hinged to the main body. The handle is driven in conjunction with the first end of the locking block assembly. When the handle is rotated to a preset angle, the second end of the locking block assembly moves into the locking hole to lock onto the neck locking structure of the femoral stem and presses the femoral stem against the locking hole.

2. The femoral stem extraction clamp according to claim 1, characterized in that, The handle is provided with a cam portion, which is hinged to the main body and abuts against the end face of the first end of the locking block assembly.

3. The femoral stem extraction clamp according to claim 2, characterized in that, An elastic pad is provided on the end face of the first end of the locking block assembly, and the cam portion abuts against the elastic pad.

4. The femoral stem extraction clamp according to claim 2, characterized in that, The slide rail has an opening that penetrates the main body on its side, and the locking block assembly has a force-receiving part located within the opening, which is used to actuate the locking block assembly.

5. The femoral stem extraction clamp according to claim 4, characterized in that, The opening has a limiting part located at the first end of the slide at the edge of the opposite sides. The limiting parts on both sides are respectively formed with the inner wall of the slide. The locking block assembly is provided with a locking part that corresponds to the guide groove on both sides. The locking part is located in the corresponding guide groove and slides with the corresponding guide groove.

6. The femoral stem extraction clamp according to claim 5, characterized in that, The main body has strip grooves on its opposite sides that correspond one-to-one with the two side locking parts.

7. The femoral stem extraction clamp according to claim 1, characterized in that, The second end of the locking block assembly is provided with a latch.

8. The femoral stem extraction clamp according to any one of claims 1-7, characterized in that, The main body is provided with an arc-shaped part, the lock hole is located on the arc-shaped part, and the first end of the slide extends along the arc of the arc-shaped part to the lock hole.

9. The femoral stem extraction clamp according to claim 8, characterized in that, The locking block assembly includes a top member and a slider disposed within the slide rail. Both the top member and the slider are slidably engaged with the slide rail. The first end of the top member is engaged with the handle and the second end abuts against the slider. The slider is an arc-shaped structure that matches the first end of the slide rail.

10. The femoral stem extraction clamp according to any one of claims 1-7, characterized in that, The main body has a slot and a mounting hole on its side. The slot, the mounting hole and the slide are arranged in sequence. The slide is connected to the mounting hole. The locking block assembly extends into the mounting hole. The handle is hinged into the mounting hole.

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