CN114176850B

CN114176850B - Knee prosthesis snap-fit device

Info

Publication number: CN114176850B
Application number: CN202111441979.2A
Authority: CN
Inventors: 杨一帆; 黄飞鹏; 黄建峰; 吴震宇
Original assignee: Youshi Medical Technology Suzhou Co ltd
Current assignee: Youshi Medical Technology Suzhou Co ltd
Priority date: 2021-11-30
Filing date: 2021-11-30
Publication date: 2025-04-11
Anticipated expiration: 2041-11-30
Also published as: CN114176850A

Abstract

The present invention discloses a knee joint prosthesis clamping device, comprising: a shell, which has a first accommodating cavity inside, and a first hole is respectively provided at the front and rear ends; an extension portion extending distally from the shell, and the distal end of which forms a stopper downward; a push rod arranged behind the stopper and passing through the first hole, a pad block is provided at the distal end of the push rod, and a ratchet arranged along the axial direction of the push rod is provided on the push rod; a non-return pawl arranged in the first accommodating cavity and fixed in position, and a push block sleeved on the push rod and movable forward and backward, the push block has an active pawl, and the ratchet is respectively engaged with the active pawl and the non-return pawl; a grip and a trigger arranged below the shell, and the upper end of the trigger is engaged with the push block; and a locking component, which is configured to limit the rotation of the push rod and release the restriction on the rotation of the push rod. The pistol-type design is convenient for doctors to operate; the trigger lever-type structure allows surgeons to push the tibial pad into the tibial tray with little effort; an intermittent pushing mechanism is adopted, which is convenient for doctors to stop at any time to observe the clamping state.

Description

Knee joint prosthesis clamping device

Technical Field

The present invention relates to surgical instruments, and in particular to a knee prosthesis engaging device.

Background

Arthroplasty is a well-known surgical procedure for replacing a damaged natural joint of a patient with a prosthetic joint. A typical knee prosthesis includes a patella prosthetic component, a tibial tray, a femoral component, and a polymer insert or support positioned between the tibial tray and the femoral component. The tibia side part of the knee joint prosthesis comprises a metal tibia support and a plastic tibia pad, and the tibia support and the tibia pad are mutually clamped and connected. In order to firmly connect the tibial tray and the tibial insert, the two snap-fit locations are designed to be very tight, which presents the problem that the surgeon needs to exert a great deal of force to push the tibial insert into the tibial tray.

Disclosure of Invention

In order to solve at least one technical problem in the prior art, the invention provides a knee joint prosthesis clamping device.

The knee joint prosthesis clamping device is characterized by comprising a shell, an extension part, a push rod, a cushion block, a check pawl and a push block, wherein a first accommodating cavity is formed in the shell, a first hole is formed in the front end and the rear end of the shell, the extension part extends distally from the shell, the distal end of the extension part faces downwards to form a stop part, the push rod is arranged behind the stop part and penetrates through the first hole, the distal end of the push rod is provided with the cushion block opposite to the stop part, a ratchet is arranged on the push rod along the axial direction of the push rod, the check pawl and the push block are arranged in the first accommodating cavity, the position of the check pawl is fixed, the push block is sleeved on the push rod and can move forwards and backwards, an active pawl is arranged in the push block, the ratchet is meshed with the active pawl and the check pawl respectively, a handle and a trigger are arranged under the shell, the upper end of the trigger extends into the first accommodating cavity and is engaged with the push block to actuate the push block, and the locking part is configured to limit the push rod to rotate and release the limit on the push rod.

The tibia support has the advantages that the handle and the trigger are held by hand, the push rod is driven to advance in a mode of pulling the trigger to push the tibia pad to the tibia support, operation of a surgeon is facilitated, the tibia pad can be pushed into the tibia support by the aid of the trigger lever type structure, and the surgeon can conveniently stop at any time to observe the assembly state of the tibia pad and the tibia support by means of the intermittent pushing mechanism with the aid of the check pawl, the driving pawl and the ratchet.

In some embodiments, the non-return pawl is rotatably connected to the housing below the push rod, the head of the non-return pawl is disposed forwardly relative to the tail of the non-return pawl, the tail of the non-return pawl is biased by the second spring to engage the ratchet teeth in the locked condition, the active pawl is rotatably connected to the push block below the push rod, the head of the active pawl is disposed forwardly relative to the tail of the active pawl, and the tail of the active pawl is biased forwardly by the first spring to engage the ratchet teeth in the locked condition.

In some embodiments, the push rod is a round rod and forms a flat cut surface on the surface extending along the axial direction of the push rod, the locking component comprises a locking plate positioned in the shell and a rotating rod positioned outside the shell, one end of the locking plate is connected with the rotating rod through a rotating pin, the other end of the locking plate is close to the flat cut surface, the rotating pin penetrates through the wall of the shell along the direction perpendicular to the flat cut surface and can rotate around the central axis of the rotating pin relative to the shell, and one end of the locking plate close to the flat cut surface is provided with an arc notch facing the flat cut surface.

In some embodiments, the locking device further comprises a limiting part, at least part of the limiting part is located in a quarter-cylinder area scanned by the process that the locking plate rotates 90 degrees from the state that the generatrix of the arc gap is perpendicular to the push rod to the state that the generatrix of the arc gap is parallel to the push rod, and two side plane boundaries of the quarter-cylinder area are aligned with the surfaces of the corresponding limiting part respectively.

In some embodiments, the rotatable lever has a resiliently retractable detent on the housing surface having a first detent recess and a second detent recess for mating with the retractable end of the detent, the detent mating with the first detent recess in the locked condition and the detent mating with the second detent recess in the unlocked condition.

In some embodiments, the lower trigger half is provided with a torsion spring that applies a forward force to the lower trigger half, the upper trigger half has a pair of spaced apart trigger arms with notches at the ends of the trigger arms, the push block has pins on the left and right sides, the push block is disposed between the trigger arms, and the pins are each freely inserted into a notch of a corresponding trigger arm.

In some embodiments, the stop component comprises a first component and a second component, the second component is arranged behind the first component, the upper end of the second component is rotationally connected with the extension part, the rear side of the first component is provided with a fixing pin, the fixing pin penetrates through the second component and is provided with a limiting protrusion at the free end of the fixing pin for limiting the second component to be separated from the fixing pin, and a reset spring sleeved on the fixing pin is further arranged between the first component and the second component.

In some embodiments, the anterior surface of the spacer is configured in an arc that fits the posterior edge of the tibial insert, the spacer is made of plastic, and the spacer is snapped onto a metal base that is attached to the anterior end of the pushrod by a pin.

In some embodiments, the rotating bar extends in a direction perpendicular to the generatrix of the arcuate gap.

Drawings

Fig. 1 is a perspective view of a knee prosthesis engagement device according to an embodiment of the present invention.

Fig. 2 is an exploded view of a knee prosthesis engagement device according to an embodiment of the present invention.

Fig. 3 is a cross-sectional view of a knee prosthesis engagement device according to an embodiment of the present invention.

Fig. 4 is a plan view showing an unlocked state of the knee prosthesis engagement device according to an embodiment of the present invention.

Fig. 5 is a cross-sectional view of BB in fig. 4.

Fig. 6 is a plan view showing a locked state of the knee joint prosthesis engagement device according to an embodiment of the present invention.

Fig. 7 is a sectional view of CC in fig. 6.

Symbol description:

Housing 1, extension 2, push rod 3, grip 4, trigger 5, locking member 6, stop member 7, spacer 8, first receiving cavity 9, first bore 10, check pawl 11, push block 12, active pawl 13, ratchet 14, second receiving cavity 15, second bore 16, first pin 17, first spring 18, second pin 19, second spring 20, third pin 21, trigger arm 22, torsion spring 23, notch 24, pin 25, locking tab 26, rotary rod 27, pivot pin 28, arcuate notch 29, flush cut surface 30, dowel 31, first dowel groove 32, second dowel groove 33, metal base 34, dowel 35, first member 36, second member 37, dowel pin 38, spacing projection 39, return spring 40, side wall 41, side plate 42, spacing portion 43

Detailed Description

The invention will be described in further detail with reference to the accompanying drawings.

The invention provides a knee joint prosthesis clamping device which is in a pistol shape convenient to operate in appearance, and the operation of pushing a tibia pad into a tibia support is carried out by pulling a trigger 5, so that the operation is simple and labor-saving.

Fig. 1 is a perspective view of a knee prosthesis engagement device in some embodiments. As can be seen from fig. 1, the knee prosthesis engagement device includes a housing 1, an extension 2 extending distally from the housing 1, a push rod 3 penetrating the housing 1 and extending in the anterior-posterior direction, a grip 4 and a trigger 5 provided below the housing 1, and a locking member 6. The distal end of the extension 2 forms a stop member 7 towards the lower side, the push rod 3 is arranged behind the stop member 7 and the distal end of the push rod 3 has a spacer 8 opposite the stop member 7. Within the housing 1 is a one-way transmission mechanism which engages the push rod 3 for unidirectionally intermittently pushing the push rod 3 distally. The trigger 5 is engaged with a one-way transmission mechanism which is triggered when the trigger 5 is actuated, causing the one-way transmission mechanism to push the push rod 3 towards the stop member 7. Manual operation of the locking member 6 may bring the locking member 6 into a locked state and an unlocked state, respectively. In the locked state, the locking member 6 holds the push rod 3 in engagement with the one-way transmission mechanism by restraining the push rod 3, enabling the one-way transmission mechanism to transmit the trigger 5 trigger to the push rod 3 to intermittently push the push rod 3 distally in one direction, and in the unlocked state, the locking member 6 is disengaged from the push rod 3 to disengage the push rod 3 from the one-way transmission mechanism.

When the device is used for assembling the tibia tray and the tibia pad, the front edge of the tibia pad is placed into the notch of the tibia tray in advance, the tibia tray is made to lean against the position stopping component 7, the cushion block 8 is abutted against the rear edge of the tibia pad, and then the push rod 3 is pushed distally intermittently by repeatedly pulling the trigger 5, so that the tibia pad is pushed into the tibia tray gradually.

Fig. 2 illustrates an exploded view of a knee prosthesis engagement device in some embodiments. Fig. 3 shows a longitudinal cross-section of the knee prosthesis engagement device in some embodiments, namely AA cross-section in fig. 4. Referring to fig. 2, the housing 1 includes a side wall 41 surrounded by front, top and rear surfaces and side plates 43 disposed on both sides of the side wall, and the side wall 41 and the side plates 42 define the first accommodating chamber 9 shown in fig. 3. Referring to fig. 2 and 3, the front and rear ends of the housing 1 are provided with first holes 10 aligned with each other, respectively, and the push rod 3 passes through the pair of first holes 10 and is clearance-fitted with the first holes 10. The pair of first holes 10 keeps the push rod 3 movable relative to the housing 1 in the axial direction of the first holes 10, also limiting translation of the push rod 3 in the radial direction of the first holes 10.

A unidirectional transmission mechanism is provided in the first accommodation chamber 9 of the housing 1, and is configured to receive power input from the trigger 5 and to intermittently push the push rod 3 distally in a unidirectional manner. For example, referring to fig. 2 and 3, the unidirectional transmission mechanism includes a fixed-position check pawl 11 and a push block 12 movable back and forth, wherein the push block 12 has an active pawl 13. The ratchet 14 is arranged on the outer wall of the push rod 3 along the axial direction, and the check pawl 11 and the driving pawl 13 are respectively meshed with the ratchet 14 to realize the engagement of the push rod 3 and the unidirectional transmission mechanism.

Referring to fig. 3, the push block 12 is sleeved on the push rod 3, specifically, the push block 12 has a hollow second accommodating cavity 15, the front end and the rear end of the push block 12 are respectively provided with a second hole 16, and the push rod 3 passes through the pair of second holes 16 and is in clearance fit with the pair of second holes 16, so that the push block 12 can slide along the axial direction of the push rod 3.

Referring to fig. 2 and 3, a rotatable driving pawl 13 is disposed in the second accommodating cavity 15, for example, the driving pawl 13 is rotatably connected with the push block 12 through a first pin 17 perpendicular to the axial direction of the push rod 3. The driving pawl 13 is biased by a first spring 18, specifically, a first pin 17 is arranged between the pawl head and the pawl tail of the driving pawl 13, the pawl head of the driving pawl 13 is arranged in front of the pawl tail, the pawl head of the driving pawl 13 is meshed with the ratchet 14 on the push rod 3, the pawl tail of the driving pawl 13 is connected with the first spring 18, the other end of the first spring 18 is connected to the position of the push block 12, which is positioned in front of the pawl tail, so that the first spring 18 applies forward-biased pulling force to the pawl tail of the driving pawl 13, and the pawl head of the driving pawl 13 has a backward-biased trend.

Referring to fig. 2 and 3, the check pawl 11 is rotatably disposed in the first receiving chamber 9 of the housing 1, for example, the check pawl 11 is rotatably connected to the housing 1 by a second pin 19 perpendicular to the axial direction of the push rod 3. The non-return pawl 11 is biased by a second spring 20, specifically, a second pin 19 is arranged between the pawl head and the pawl tail of the non-return pawl 11, the pawl head of the non-return pawl 11 is arranged in front of the pawl tail, the pawl head of the non-return pawl 11 is meshed with the ratchet 14 on the push rod 3, the pawl tail of the non-return pawl 11 is connected with the second spring 20, the other end of the second spring 20 is connected to the position of the housing 1, which is positioned in front of the pawl tail, so that the second spring 20 applies forward pulling force to the pawl tail of the non-return pawl 11, and the pawl head of the non-return pawl 11 has a backward biasing trend.

During the forward pushing of the push block 12 by the trigger 5, the active pawl 13 is meshed with the ratchet 14 on the push rod 3, so that the push rod 3 is pushed forward by the push block 12, the non-return pawl 11 is stirred by the ratchet 14 to rotate and is disengaged from the ratchet 14, and the non-return pawl 11 does not prevent the movement of the push rod 3. During the reverse movement of the push block 12, the check pawl 11 is meshed with the ratchet 14 to prevent the push rod 3 from moving backwards, and meanwhile, the driving pawl 13 is shifted by the ratchet 14 to rotate and is disengaged from the ratchet 14, so that the push block 12 can move backwards while the push rod 3 is kept motionless.

The grip 4 is fixed to the housing 1 and extends downward of the housing 1, and the trigger 5 is provided in front of the grip 4 and rotatably on the housing 1. Specifically, the trigger 5 is rotatably connected to the housing 1 via a third pin 21 extending in the left-right direction, and the trigger 5 is configured as a lever that rotates about the third pin 21. The upper half of the trigger 5 protrudes from the bottom of the housing 1 into the first receiving chamber 9. The upper half of the trigger 5 is provided with a pair of spaced trigger arms 22, and a third pin 21 extends through the pair of trigger arms 22. The lower half of the trigger 5 is provided with a torsion spring, specifically a torsion spring 23 which is fitted over the third pin 21, one end of the torsion spring 23 being against the rear side of the trigger 5 and the other end being against the front side of the grip 4, exerting a forward force on the lower half of the trigger 5. When the external force is removed after the trigger 5 is pulled, the torsion spring 23 returns the trigger 5.

Referring to fig. 3, the upper end of the trigger 5 is configured to engage the push block 12 such that rotation of the trigger 5 causes the push block 12 to be moved. Specifically, the trigger 5 has a notch 24 at the end of the trigger arm 22, the push block 12 has pins 25 on the left and right sides, the push block 12 is placed between the two trigger arms 22, and the pins 25 are freely inserted into the notches 24 of the corresponding trigger arms 22, respectively. Since the push block 12 is fitted over the push rod 3 and the push rod 3 is restrained in its vertical direction, the push block 12 is restrained in a direction perpendicular to the push rod 3, so that the trigger 5 and the push block 12 can always maintain the engagement. The engagement of the trigger 5 with the push block 12 allows the pin 25 to move within the notch 24 so that rotation of the trigger 5 can be translated into linear movement of the push rod 3. In some embodiments, the range of angles of rotation of the trigger 5 is configured such that each actuation of the trigger 5 advances the push rod 3 one ratchet 14 pitch. The movable travel of the push block 12 is related to the rotation angle range of the trigger 5, and the extension of the slit 24 in the length direction of the trigger arm 22 limits the rotation angle range of the trigger 5, so that the advance step of the push rod 3 can be achieved by selecting an appropriate slit 24 length.

When the trigger 5 is not pulled, the torsion spring 23 biases the trigger 5 to an initial state in which the push block 12 abuts against the rear end of the housing 1. When the trigger 5 is pulled, the trigger 5 rotates counterclockwise around the third pin 21, and the trigger arm 22 pushes the push block 12 forward, so as to push the push rod 3 forward.

The locking member 6 is switched in a rotatable manner between a locked state and an unlocked state. Rotating the locking member 6 90 deg. clockwise or counter-clockwise can switch the locking member 6 back and forth between the locked and unlocked state. In the locked state, the locking member 6 can restrict the rotation of the push rod 3, while maintaining the push rod 3 in engagement with the active pawl 13 and the non-return pawl 11, and the tibial insert is pushed into the tibial tray stepwise by repeatedly pulling the trigger 5. In the unlocked state, the locking member 6 can release the restriction on the push rod 3, at which time the user can rotate the push rod 3 to disengage the push rod 3 from the active pawl 13 and the non-return pawl 11, and can manually push the push rod 3 back to remove the tibial tray from the device.

Fig. 4 illustrates a top view of the device in an unlocked state in some embodiments. Fig. 5 is a partial cross-sectional view of the BB section in fig. 4. Fig. 5 illustrates a top view of the device in a locked state in some embodiments. Fig. 6 is a partial cross-sectional view of the CC section of fig. 5. Referring to fig. 2, the push rod 3 is a round rod, the surface of which has an axially extending flat cut surface 30 in addition to the axially arranged ratchet teeth 14. Referring to fig. 2, the locking member 6 includes a locking piece 26 provided in the housing 1 and a rotating lever 27 provided on the surface of the housing 1, one end of the locking piece 26 being connected to one end of the rotating lever 27 by a rotating pin 28. The locking member 6 is rotatably provided to the housing 1, specifically, the rotary pin 28 penetrates the wall of the housing 1 in a direction perpendicular to the flat cut surface 30 and is rotatable relative to the housing 1 about the central axis of the rotary pin 28, so that the rotary motion of the rotary lever 27 can rotate the lock piece 26 about the central axis of the rotary pin 28. With continued reference to fig. 2 and 3, locking tab 26 extends toward planar surface 30 along its central axis of rotation, and the end of locking tab 26 is proximate planar surface 30 and forms an arcuate notch 29 at the end that faces planar surface 30. When turning the turning lever 27, the lock piece 26 rotates around a central axis perpendicular to the flat cut surface 30 at a position opposite to the flat cut surface 30 to keep the end of the lock piece 26 rotatable close to the flat cut surface 30. The inner wall of the arc-shaped notch 29 is cylindrical, so that the arc-shaped notch 29 defines a bus bar, and the bus bar of the arc-shaped notch 29 can be switched between a state parallel to the push rod 3 and a state perpendicular to the push rod 3 by rotating the locking piece 26. Referring to fig. 7, the locking member 6 is configured such that when the lock piece 26 is rotated so that the generatrix of the arc-shaped notch 29 is perpendicular to the axial direction of the push rod 3 in a state where the push rod 3 is engaged with the driving pawl 13 and the check pawl 11, respectively, the end flat portions of the lock piece 26 are completely opposed to the flat cut surface 30 and are brought close to each other, and the rotation of the push rod 3 is restricted by this manner of abutting the flat cut surface 30, thereby holding the push rod 3 in the engaged state with the driving pawl 13 and the check pawl 11. Referring to fig. 6, locking member 6 is further configured such that when lock tab 26 is rotated such that the generatrix of arcuate notch 29 is parallel to the axial direction of push rod 3, arcuate notch 29 of lock tab 26 is adapted to the circular outer contour of push rod 3, the planar end portion of lock tab 26 no longer opposes planar surface 30, the respective positions of the end of lock tab 26 form a gap with push rod 3, lock tab 26 is disengaged from push rod 3 to release the rotational restriction of push rod 3, and push rod 3 is allowed to rotate freely.

The locking member 6 is configured to rotate in an angle range of 0-90 deg., and two extreme positions of rotation correspond to the locked state and the unlocked state, respectively. When locking and unlocking, the user only needs to rotate the locking part 6 to the extreme position, and does not need to judge whether the locking part 6 rotates in place from the rotation angle. The device further comprises a limiting portion 43 for limiting the rotation angle range of the locking member 6 to 0-90 deg.. In the locked state, the generatrix of the arc-shaped notch 29 is perpendicular to the axial direction of the push rod 3, and in the unlocked state, the generatrix of the arc-shaped notch 29 is parallel to the axial direction of the push rod 3. That is, a forward and reverse rotation of locking tab 26 by 90 ° can switch locking member 6 between the locked and unlocked states. During 90 ° rotation of locking tab 26, the area swept by locking tab 26 in space forms two quarter-cylindrical regions. Part or all of the limiting portions 43 are located in one of the quarter-cylindrical regions, and the side plane boundaries of the quarter-cylindrical regions are aligned with the corresponding limiting portion surfaces, respectively. For example, referring to fig. 3, 5 and 7, the limiting portion 43 is a cylindrical pin, one end of the cylindrical pin is connected to the right side plate 42 of the housing 1, the other end of the cylindrical pin extends to the left to a quarter-cylindrical area, and the end of the cylindrical pin extends to a side plane boundary of the quarter-cylindrical area, and the side wall of the cylindrical pin is tangent to the other side plane boundary of the quarter-cylindrical area, so that the cylindrical shape can limit the locking tab 26 to rotate within the range of 0 ° to 90 °.

The turning bar 27 extends in a direction perpendicular to the generatrix of the arc-shaped notch 29. The locking member 6 may be arranged such that the locking member 6 is in an unlocked state as shown in fig. 4 when the rotating lever 27 is rotated to extend sideways, and such that the locking member 6 is in a locked state as shown in fig. 6 when the rotating lever 27 is rotated 90 ° to extend rearward. The locking member 6 is arranged in a manner that is relatively compatible with the operating habits of the housing doctor. Of course, other arrangements of the angle and the direction of extension of the lever 27 are possible in the locked state.

Further, referring to fig. 2, the locking member 6 further includes a positioning pin 31 that can elastically stretch and retract, and a first positioning groove 32 and a second positioning groove 33 that can be matched with the stretch end of the positioning pin 31 in a concave-convex manner are further provided on the surface of the housing 1. The first positioning groove 32 and the second positioning groove 33 may be tapered so that the positioning pin 31 can be separated from the positioning groove when the locking member 6 is slightly rotated with force. The first positioning groove 32 corresponds to the locked state, and the second positioning groove 33 corresponds to the unlocked state. The detent pin 31 is provided parallel to the rotation pin 28 at one end of the rotation lever 27, and the detent pin 31 can rotate around the rotation pin 28 when the rotation lever 27 is rotated. When the locking member 6 is rotated to the locked state, the positioning pin 31 is rotated to exactly the first positioning groove 32, and when the locking member 6 is rotated to the unlocked state, the positioning pin 31 is rotated to exactly the second positioning groove 33. The detent pin 31 can indicate whether the locking member 6 is rotated into place and can hold the locking member 6 in a locked or unlocked state after being in place.

In fig. 3, the active pawl 13 and the check pawl 11 are provided below the push rod 3, the ratchet 14 and the flat surface 30 are provided on opposite sides of the push rod 3, respectively, and the locking member 6 is provided on the upper portion of the housing 1. In some embodiments, the locking member 6 may also be provided on the side of the housing 1, with the flat cut surface 30 being provided at a 90 orientation with respect to the ratchet teeth 14.

Opposite the stop member 7 is an anterior surface of the spacer 8 which is configured in an arc that fits the posterior edge of the tibial insert. Referring to fig. 1 and 2, the pad 8 may be made of plastic and is clamped to a metal base 34, and the metal base 34 is connected to the front end of the push rod 3. The metal base 34 is not completely rigidly connected to the push rod 3, for example, the metal base 34 is connected to the push rod 3 by a pin 35, so that the metal base 34 can be loosened to a small extent.

Referring to fig. 1, the stop member 7 includes a first member 36 and a second member 37, wherein the first member 36 is made of metal and is integral with the extension 2. The second member 37 may be made of plastic material and is disposed behind the first member 36, and an upper end of the second member 37 is rotatably connected to the extension 2. The rear side of the first part 36 is provided with a fixing pin 38, which fixing pin 38 passes through the second part 37 and is provided with a limit projection 39 at the free end of the fixing pin 38, which limit the detachment of the second part 37 from the fixing pin 38. A return spring 40 is also provided between the first member 36 and the second member 37, which is sleeved on the fixing pin 38. The stopper 7 is used for stopping the gasket, and when the gasket is pushed in, a doctor is observed whether the gasket is pushed in or not, and the gasket pushing-in effect can be observed.

What has been described above is merely some embodiments of the present invention. It will be apparent to those skilled in the art that various modifications and improvements can be made without departing from the spirit of the invention.

Claims

1. The knee joint prosthesis clamping device is characterized by comprising:

the shell is internally provided with a first accommodating cavity, and the front end and the rear end of the shell are respectively provided with a first hole;

an extension extending distally from the housing, a distal end of the extension forming a stop member downwardly;

the push rod is arranged behind the stop part and penetrates through the first hole, a cushion block opposite to the stop part is arranged at the far end of the push rod, and a ratchet arranged along the axial direction of the push rod is arranged on the push rod;

The check pawl and the pushing block are arranged in the first accommodating cavity, the position of the check pawl is fixed, the pushing block is sleeved on the pushing rod and can move back and forth, the pushing block is internally provided with a driving pawl, and the ratchet is respectively meshed with the driving pawl and the check pawl;

A handle disposed below the housing and a rotatably disposed trigger having an upper end extending into the first receiving chamber and engaging the push block for actuating the push block, and

A locking member configured to restrict rotation of the push rod and release the restriction of rotation of the push rod,

The locking component comprises a locking plate positioned in the shell and a rotating rod positioned outside the shell, one end of the locking plate is connected with the rotating rod through a rotating pin, the other end of the locking plate is close to the flat cutting surface, the rotating pin penetrates through the wall of the shell along the direction perpendicular to the flat cutting surface and can rotate relative to the shell around the central axis of the rotating pin, and one end of the locking plate close to the flat cutting surface is provided with an arc-shaped notch facing the flat cutting surface;

The stop part comprises a first part and a second part, the second part is arranged at the rear of the first part, the upper end of the second part is rotationally connected with the extension part, a fixing pin is arranged at the rear side of the first part, the fixing pin penetrates through the second part and is provided with a limiting protrusion at the free end of the fixing pin, the limiting protrusion is used for limiting the second part to be separated from the fixing pin, and a reset spring sleeved on the fixing pin is further arranged between the first part and the second part.

2. The knee prosthesis engagement device of claim 1, wherein the non-return pawl is rotatably coupled to the housing below the push rod, the pawl head of the non-return pawl is disposed forward relative to the pawl tail, the pawl tail of the non-return pawl is biased by the second spring to engage the ratchet teeth in the locked condition, the active pawl is rotatably coupled to the push block below the push rod, the pawl head of the active pawl is disposed forward relative to the pawl tail, and the pawl tail of the active pawl is biased forward by the first spring, and the pawl head of the active pawl is engaged with the ratchet teeth in the locked condition.

3. The knee prosthesis engagement device of claim 1, further comprising a stop portion, at least a portion of the stop portion being located within a quarter-cylinder region swept by the locking tab during rotation of the locking tab 90 ° from a state in which the generatrix of the arcuate notch is perpendicular to the push rod to a state in which the generatrix of the arcuate notch is parallel to the push rod, two side planar boundaries of the quarter-cylinder region being respectively aligned with surfaces of the corresponding stop portion.

4. The knee prosthesis engagement device of claim 1, wherein the lever has a resiliently retractable detent on the housing surface having a first detent recess and a second detent recess adapted to mate with the retractable end of the detent, the detent cooperating with the first detent recess in the locked condition and the detent cooperating with the second detent recess in the unlocked condition.

5. The knee prosthesis engaging apparatus of claim 1, wherein the lower portion of the trigger is provided with a torsion spring which applies a forward force to the lower portion of the trigger, the upper portion of the trigger is provided with a pair of spaced apart trigger arms, the ends of the trigger arms are provided with cutouts, the left and right sides of the push block are provided with pins, the push block is interposed between the two trigger arms, and the pins are freely inserted into the cutouts of the corresponding trigger arms, respectively.

6. The knee prosthesis snap-fit device of claim 1, wherein the anterior surface of the spacer is configured in an arc that mates with the posterior edge of the tibial insert, the spacer being made of plastic and the spacer being snapped onto a metal base that is attached to the anterior end of the push rod by a pin.

7. The knee prosthesis snap fit arrangement of claim 3, wherein said swivel rod extends in a direction perpendicular to a generatrix of said arcuate notch.