CN113876473B

CN113876473B - External pin nailing device for elbow joint prosthesis pin shaft and working method of external pin nailing device

Info

Publication number: CN113876473B
Application number: CN202111009294.0A
Authority: CN
Inventors: 吴岩; 张永兴; 章增杰; 莫现安; 王静; 叶招明
Original assignee: Zhejiang University ZJU
Current assignee: Zhejiang University ZJU
Priority date: 2021-08-31
Filing date: 2021-08-31
Publication date: 2022-08-23
Anticipated expiration: 2041-08-31
Also published as: CN113876473A

Abstract

The invention provides an elbow joint prosthesis pin shaft external nail applying device and a working method thereof. It has solved current technical problem. The elbow joint prosthesis pin shaft outer nail feeding device comprises a handle, wherein a third nail rod is arranged at the front end of the handle, a second nail rod with the diameter smaller than that of the third nail rod is arranged at the front end of the third nail rod, a first nail rod with the diameter larger than that of the second nail rod is arranged at the front end of the second nail rod, the first nail rod, the second nail rod and the third nail rod are fixed relatively in the axial direction, and a pin shaft outer nail abutting structure is arranged between the second nail rod and the third nail rod. The invention has the advantages of convenient operation, capability of avoiding the falling off of the outer nail of the pin shaft, shortening the operation time and the like.

Description

Elbow joint prosthesis pin shaft external nail feeding device and working method thereof

Technical Field

The invention belongs to the technical field of medical instruments, and particularly relates to an elbow joint prosthesis pin shaft external nail applying device and a working method thereof.

Background

When the elbow bone is damaged, the elbow joint is damaged and the elbow joint is unstable due to rheumatoid arthritis, osteoarthritis or trauma, the function of the elbow joint is lost. In this case, in order to restore the function of the elbow joint, a replacement operation of the artificial elbow joint is required. For example, during a total elbow replacement procedure, a surgeon implants a prosthetic humeral component into the distal end of the patient's humerus and a prosthetic ulna assembly into the proximal end of the patient's ulna. The prosthetic humeral component and the prosthetic ulnar assembly are typically connected by pin inner and outer pegs which enable pivotal movement between the prosthetic humeral component and the prosthetic ulnar assembly to reproduce the natural anatomical occlusion of the elbow joint.

However, in the actual operation process, there are some disadvantages in the installation process of the external pin nail in the elbow joint prosthesis implantation, for example, the external pin nail falls off the ground due to careless operation, the installation time is too long, so that the external pin nail of the prosthesis is easily solidified, the implantation of the external pin nail of the prosthesis is failed, and the engagement degree of the humerus assembly and the ulna assembly is not good.

In order to solve this problem, research and study have been conducted in long-term production and living practices, for example, chinese patent discloses a multifunctional elbow joint replacement prosthesis [ application No.: 201520833245.2], the invention comprises a humerus component, an ulna component, a radius component and a pin shaft component, wherein the humerus component comprises a humeral stem, a yoke and a humeral capitulum; the ulna component comprises an ulna handle, an ulna neck and an ulna head; the radius assembly comprises a small radius head and a radius intramedullary nail; the pin shaft assembly comprises a pin shaft outer nail of a hollow cylindrical structure and a pin shaft inner nail inserted into the pin shaft outer nail, one end of the pin shaft inner nail is provided with an anti-falling part used for preventing the pin shaft inner nail from being integrally immersed into the pin shaft outer nail, the other end of the pin shaft inner nail is provided with a locking part, and the pin shaft assembly is used for pivoting the ulna assembly around a shaft and fixing a small head of a humerus on the first lug.

The above solution improves some problems of the prior art to some extent, but it also has at least the following drawbacks: the operation of installing the external nail of the pin shaft is unchanged, so that the external nail of the pin shaft is easy to fall off, and the overlong nailing operation time is easy to cause bone cement solidification, so that the implantation of the external nail of the pin shaft of the prosthesis fails.

Disclosure of Invention

The invention aims to solve the problems and provides a nail applying device for an elbow joint prosthesis pin shaft external nail, which is convenient to operate, can prevent the pin shaft external nail from falling off and can shorten the operation time.

The invention also aims to solve the problems and provides a working method of the external pin nailing device of the elbow joint prosthesis pin shaft.

In order to achieve the purpose, the invention adopts the following technical scheme: this outer nail ware of nailing of elbow joint prosthesis round pin axle, including the handle, the front end of handle be equipped with the third nail pole, the front end of third nail pole be equipped with the second nail pole that the diameter size is less than the third nail pole, the front end of second nail pole be equipped with the first nail pole that the diameter size is less than the second nail pole, first nail pole, second nail pole, third nail pole at axial direction relatively fixed, just second nail pole and third nail pole between be equipped with the outer nail butt structure of round pin axle.

In the above external pin nailing device for the elbow joint prosthesis pin shaft, the external pin butting structure comprises a butting boss which is arranged between a second pin rod and a third pin rod and is in a cone frustum shape, the second pin rod is connected with a small head end at the front end of the butting boss, a big head end at the rear end of the butting boss is connected with the third pin rod, and the outer edge of the butting boss forms a butting surface between the small head end and the big head end.

In the external nailing device for the elbow joint prosthesis pin shaft, the second nail rod and the abutting lug boss are of an integrated structure.

In the external nailing device for the elbow joint prosthesis pin shaft, the front ends of the first nail rod, the second nail rod and the handle are respectively provided with a chamfer part; the first nail rod, the second nail rod and the third nail rod are of an integrated structure and are made of titanium alloy, and the outer edge surfaces of the first nail rod, the second nail rod and the third nail rod are high-polishing surfaces.

In the elbow joint prosthesis pin shaft external nail feeding device, the third nail rod is also provided with a spreading component which can extend out of the outer edge of the third nail rod;

strut the subassembly include that the interval inlays to establish and nail a plurality of arc butt pieces that the pole is the same with the third in the circumferencial direction of pole at the third, arc butt piece inboard be equipped with telescopic connection seat, telescopic connection seat inlay establish the flexible inslot of seting up in the pole is followed closely to the third, flexible groove and arc butt piece between be equipped with and let arc butt piece have the return stroke mechanism towards pole axle center movement trend is followed closely to the third, third nail pole and handle between still be equipped with the flexible drive assembly that can drive the synchronous outside distraction of arc butt piece.

In foretell elbow joint prosthesis round pin off-axial is nailed in the ware of nailing outward, return stroke mechanism include the spring body, the spring body be located the spring inslot that sets up in the flexible inslot, the arc butt piece on be equipped with and be L shape and one end inlay the locating pin of establishing in the spring inslot, the both ends of the spring body act on the tank bottom in locating pin and spring groove respectively.

In foretell elbow joint prosthesis round pin off-axial is followed closely in the ware, flexible drive assembly including set up the holding intracavity at third nail pole middle part and can circumferential direction's bull stick body, the bull stick body on the spiro union have two symmetries to set up and relative bull stick body circumference fixed and can follow the drive seat of bull stick body axial reciprocating motion, the both ends of flexible connecting seat bottom side inlay respectively and establish on two drive seats, the drive seat be circular truncated cone type, the conical surface of drive seat on set up a plurality of bar guide slots of circumference interval arrangement, the both ends of flexible connecting seat bottom side inlay respectively and establish in the bar guide slot, the one end of the bull stick body stretch out in handle rear end and circumference fixedly connected with operation knob.

In foretell elbow joint prosthesis round pin off-axial is nailed in the ware, the circumference outside of drive seat still be equipped with a plurality of circumference location protruding muscle, the holding intracavity be equipped with a plurality of bar constant head tanks that set up with the protruding muscle one-to-one of circumference location, the bar constant head tank axial extension on the axial direction of third nail pole, just the protruding muscle of circumference location inlay and establish in the bar constant head tank.

The working method of the external pin nailing and nailing device for the elbow joint prosthesis pin shaft comprises the following steps:

s1, combining the humerus component and the ulna component, adjusting to the joint cavity between the humerus component and the ulna component to be communicated, holding the handle, pushing the handle to enable the third nail rod to extend into the joint cavity between the humerus component and the ulna component, clamping the third nail rod in the joint cavity, and enabling the front end of the handle to abut against the side of the humerus component;

s2, sleeving the outer pin shaft nail on the second nail rod to enable the inner wall of the outer pin shaft nail to be attached to the outer wall of the second nail rod, and continuously pushing the outer pin shaft nail until the lower section inclined plane in the outer pin shaft nail is closely attached to the abutting surface on the abutting boss;

s3, holding the first nail rod by hand and abutting the front end of a finger on the annular flange at the front end of the outer nail of the pin shaft, gradually pushing the outer nail of the pin shaft into the joint cavity through the annular flange, gradually withdrawing the third nail rod from the joint cavity in the process that the outer nail of the pin shaft continuously enters the joint cavity until the outer nail of the pin shaft is completely positioned in the joint cavity, and abutting the inner end of the annular flange at the outer end of the joint cavity.

In the working method of the nail applying device for the pin shaft outer nail of the elbow joint prosthesis, the inclination of the lower end inclined plane of the pin shaft outer nail is the same as that of the abutting surface.

Compared with the prior art, the external pin nailing device for the elbow joint prosthesis pin shaft and the working method thereof have the advantages that: reasonable in design, the third nail pole acts as the outer nail of round pin axle and plays supporting role at last nail in-process, can guarantee that upper arm bone subassembly and ulna subassembly interlock degree are good when last nail, with the outer nail of round pin axle get into first nail pole and second nail pole in proper order in the handle opposite side, then the outer nail of round pin axle pastes on the outer nail butt structure of round pin axle between second nail pole and third nail pole, not only can prevent that the outer nail of round pin axle from falling owing to the operation carelessly at last nail in-process, and can avoid installation time overlength and arouse that bone cement solidifies to lead to false body round pin off-axis to follow closely and put into the failure, the operation of letting go up the nail is more convenient.

Drawings

FIG. 1 is a schematic view of the structure provided by the present invention;

fig. 2 is a cross-sectional view of a structure provided in accordance with the present invention after connection to a humeral component and an ulnar component;

FIG. 3 is a cross-sectional view of the expanded structure of the arc-shaped abutting sheet in the third nail rod provided by the invention;

FIG. 4 is a schematic view of the connection between the arc-shaped contact piece and the driving seat provided by the present invention;

in the figure, a handle 1, a third nail rod 2, a second nail rod 3, a first nail rod 4, a pin shaft outer nail abutting structure 5, an abutting boss 6, a small head end 7, a large head end 8, an abutting surface 9, a chamfer part 10, a spreading component 11, an arc abutting sheet 12, a telescopic connecting seat 13, a telescopic groove 14, a return mechanism 15, a telescopic driving component 16, a spring body 17, a spring groove 18, a positioning pin 19, a rotating rod body 20, a driving seat 21, a strip-shaped guide groove 22, an operating knob 23, an accommodating cavity 25, a circumferential positioning convex rib 24, a strip-shaped positioning groove 26, a humerus component 1a, an ulna component 1b, a joint cavity 1c, a pin shaft outer nail 1d and an annular flange 27.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

As shown in fig. 1-4, the external pin nailing device for the elbow joint prosthesis comprises a handle 1, a third nail rod 2 is arranged at the front end of the handle 1, a second nail rod 3 with the diameter smaller than that of the third nail rod 2 is arranged at the front end of the third nail rod 2, a first nail rod 4 with the diameter smaller than that of the second nail rod 3 is arranged at the front end of the second nail rod 3, the first nail rod 4, the second nail rod 3 and the third nail rod 2 are relatively fixed in the axial direction, and an external pin butting structure 5 is arranged between the second nail rod 3 and the third nail rod 2.

In the course of the work, the articular cavity 1c of upper arm bone subassembly 1a and ulna subassembly 1b is linked together, it makes third nail pole 2 block tightly in articular cavity 1c to push handle 1 tightly, third nail pole 2 acts as the play supporting role of round pin off-axial nail 1d this moment, can guarantee that upper arm bone subassembly 1a and ulna subassembly 1b interlock degree is good when nailing, with round pin off-axial nail 1d get into first nail pole 4 and second nail pole 3 in proper order in handle 1 opposite side, then off-axial nail 1d hugs closely on the off-axial nail butt structure 5 between second nail pole 3 and third nail pole 2, not only can prevent off-axial nail 1d from falling carelessly because of the operation in the nailing process, and can avoid installation time and arouse that bone cement solidifies to lead to prosthesis off-axial nail 1d to put into the failure, this nailing device can let the operation of nailing more convenient.

Preferably, the outer nail butt structure 5 of round pin axle is including setting up the butt boss 6 that just is the circular truncated cone type between second nail pole 3 and third nail pole 2, second nail pole 3 links to each other with the microcephaly end 7 of butt boss 6 front end, the stub end 8 of butt boss 6 rear end links to each other with third nail pole 2, the outer fringe of butt boss 6 forms the butt face 9 between microcephaly end 7 and stub end 8, the inner wall of the lower extreme of the outer nail 1d of round pin axle has the inclined plane, go up the nail in-process, the inclined plane butt is on butt face 9, and the inner wall of the outer nail 1d of round pin axle then laminates at the 3 outer walls of second nail pole, thereby prevent that the outer nail 1d of round pin axle from falling owing to carelessly operating.

Furtherly, the second is followed closely

pole

3 and 6 formula structures as an organic whole of butt boss, and the second is followed closely pole 3 and is 6 formula structures as an organic whole with butt boss and make the structure more reliable, can avoid producing radial displacement between second nail pole 3 and the butt boss 6 and lead to selling 1d off-axis and take place radial displacement. The front ends of the first nail rod 4, the second nail rod 3 and the handle 1 are respectively provided with a chamfer part 10; the first nail rod 4, the second nail rod 3 and the third nail rod 2 are of an integrated structure and are all made of titanium alloy, the outer edge surfaces of the first nail rod 4, the second nail rod 3 and the third nail rod 2 are all high polishing surfaces, the length of the first nail rod 4 is 25mm, and the diameter of the first nail rod is 3 mm; the length of the second nail rod 3 is 25mm, and the diameter is 3.63 mm; the length of the third nail rod 2 is 25mm, the diameter is 6mm, the diameter of the first nail rod 4 is smaller than the diameter of the first nail rod 1d outside the pin shaft, so that the nail 1d outside the pin shaft can smoothly pass through the first nail rod 4, the inner diameter of the nail 1d outside the pin shaft is slightly larger than the diameter of the second nail rod 3, the nail 1d outside the pin shaft can be tightly attached to the second nail rod 3, a high polishing surface is adopted, friction loss can be reduced, and installation accuracy is improved.

Furthermore, the third nail rod 2 is also provided with a spreading component 11 which can extend out of the outer edge of the third nail rod 2; strutting the subassembly 11 and include that the interval inlays to establish on the circumferential direction of third nail pole 2 and a plurality of arc butt pieces 12 that the radian is the same with third nail pole 2, arc butt piece 12 inboard is equipped with flexible connecting seat 13, flexible connecting seat 13 inlays to be established in the flexible groove 14 of seting up in third nail pole 2, be equipped with between flexible groove 14 and the arc butt piece 12 and let arc butt piece 12 have towards the return stroke mechanism 15 of 2 axle center motion trends of third nail pole, still be equipped with the flexible drive assembly 16 that can drive arc butt piece 12 and outwards strut in step between third nail pole 2 and the handle 1.

The arc butt joint piece 12 can set up in flexible groove 14 through flexible drive assembly 16 axial reciprocating stretching, when third nail pole 2 is lieing in joint chamber 1c, can radially stretch out arc butt joint piece 12, make arc butt joint piece 12 support at joint chamber 1c inner wall completely, and then improve radial and axial stability of third nail pole 2 in joint chamber 1c, prevent that the rotation from appearing in the ware of nailing, improve the reliability of nailing work, avoid not having started to go up the nail work and lead to the condition emergence that the ware of nailing just falls out joint chamber 1 c.

The return stroke mechanism 15 includes the spring body 17, the spring body 17 is located the spring groove 18 that sets up in the flexible groove 14, be equipped with on the arc butt piece 12 and be L shape and one end inlays the locating pin 19 of establishing in the spring groove 18, the both ends of spring body 17 act on the tank bottom of locating pin 19 and spring groove 18 respectively, the spring body 17 lets the arc butt piece 12 have towards the 2 axle center motion trends of third nail pole, withdraw from joint chamber 1c in-process at third nail pole 2, the efficiency is higher, prevent that the tension leads to the round pin axle outer pin 1d to get into joint chamber 1c smoothly between joint chamber 1c and the third nail pole 2.

The telescopic driving component 16 comprises a rotating rod body 20 which is arranged in a containing cavity 25 at the middle part of the third nail rod 2 and can rotate in the circumferential direction, two symmetrically arranged driving seats 21 which are circumferentially fixed relative to the rotating rod body 20 and can axially reciprocate along the rotating rod body 20 are screwed on the rotating rod body 20, two ends of the bottom side of the telescopic connecting seat 13 are respectively embedded on the two driving seats 21, the driving seats 21 are in a cone frustum shape, a plurality of strip-shaped guide grooves 22 which are circumferentially arranged at intervals are formed in the conical surface of the driving seats 21, two ends of the bottom side of the telescopic connecting seat 13 are respectively embedded in the strip-shaped guide grooves 22, and one end of the rotating rod body 20 extends out of the rear end of the handle 1 and is circumferentially and fixedly connected with an operation knob 23.

Through the rotary operation knob 23, let two drive seats 21 separate or fold relatively, when two drive seats 21 fold, because in the bar-shaped guide slot 22 of establishing on two drive seats 21 of embedding in flexible connecting seat 13 bottom side, consequently arc butt piece 12 then can be pushed out third nail pole 2 outer wall, otherwise, arc butt piece 12 then can be withdrawed, when withdrawing, spring body 17 can promote the withdrawal of arc butt piece 12 to improve and go up nail efficiency, here handle 1 outer wall still overlaps and is equipped with the silica gel cover.

In addition, the circumference outside of drive seat 21 still is equipped with a plurality of circumference location protruding muscle 24, be equipped with a plurality of bar constant head tank 26 that set up with circumference location protruding muscle 24 one-to-one in the holding chamber 25, bar constant head tank 26 extends axially on the axial direction of third nail pole 2, and circumference location protruding muscle 24 inlays and establishes in bar constant head tank 26, when making rotary operation knob 23 through bar constant head tank 26 and circumference location protruding muscle 24, drive seat 21 only can produce axial displacement and can not take place the circumference and deflect, let the withdrawal that stretches out of arc butt piece 12 more smooth.

The working method of the external nailing device for the elbow joint prosthesis pin shaft comprises the following steps:

s1, combining the humerus component 1a and the ulna component 1b, adjusting to the joint cavity 1c between the humerus component 1a and the ulna component 1b to be communicated, holding the handle 1, pushing the handle 1 to enable the third nail rod 2 to extend into the joint cavity 1c between the humerus component 1a and the ulna component 1b, clamping the third nail rod 2 in the joint cavity 1c and enabling the front end of the handle 1 to abut against the side of the humerus component 1 a;

s2, sleeving the pin shaft outer nail 1d on the second nail rod 3, enabling the inner wall of the pin shaft outer nail 1d to be attached to the outer wall of the second nail rod 3, and continuously pushing the pin shaft outer nail 1d until the lower section inclined plane inside the pin shaft outer nail 1d is tightly attached to the abutting surface 9 on the abutting boss 6;

s3, the first nail rod 4 is held by a hand, the front end of a finger abuts against the annular flange 27 at the front end of the pin shaft outer nail 1d, the pin shaft outer nail 1d is gradually pushed into the joint cavity 1c through the annular flange 27, the third nail rod 2 gradually retreats from the joint cavity 1c in the process that the pin shaft outer nail 1d continuously enters the joint cavity 1c until the pin shaft outer nail 1d is completely positioned in the joint cavity 1c, and the inner end of the annular flange 27 abuts against the outer end of the joint cavity 1 c.

In the above step S2, the slope of the lower end slope of the pin outside pin 1d is the same as the slope of the abutment surface 9.

The device has the advantages that: the pin shaft outer nail 1d is sleeved in the second nail rod 3 at the other side of the handle 1 and is attached to the second nail rod in a clinging manner, when the nail feeding device withdraws from the ulna component b and the humerus component a, the pin shaft outer nail 1d stays in the joint cavity 1c between the ulna component and the humerus component by virtue of the annular flange 27, the pin shaft inner nail can be smoothly inserted into the pin shaft outer nail 1d, the ulna component 1b and the humerus component are prevented from being not well occluded, the pin shaft outer nail 1d with different lengths can be fed, the holding degree of the pin shaft outer nail 1d is enhanced, the application range of the nail feeding device is also improved, particularly in the total elbow joint replacement, the nail feeding time can be shortened, the different nail feeding devices do not need to be replaced according to the length of pedicle screws, convenience is provided for the operation, and the nail feeding device has the advantages of convenience in use, safety and reliability.

The specific embodiments described herein are merely illustrative of the spirit of the invention. Various modifications or additions may be made to the described embodiments or alternatives may be employed by those skilled in the art without departing from the spirit or ambit of the invention as defined in the appended claims.

Although the terms of the handle 1, the third nail rod 2, the second nail rod 3, the first nail rod 4, the external pin abutting structure 5, the abutting boss 6, the small head end 7, the large head end 8, the abutting surface 9, the chamfer part 10, the spreading component 11, the arc abutting sheet 12, the telescopic connecting seat 13, the telescopic groove 14, the return mechanism 15, the telescopic driving component 16, the spring body 17, the spring groove 18, the positioning pin 19, the rotating rod body 20, the driving seat 21, the strip-shaped guide groove 22, the operating knob 23, the accommodating cavity 25, the circumferential positioning convex rib 24, the strip-shaped positioning groove 26, the humerus component 1a, the ulna component 1b, the joint cavity 1c, the external pin 1d, the annular flange 27 and the like are used more frequently, the possibility of using other terms is not excluded. These terms are used merely to more conveniently describe and explain the nature of the present invention; they are to be construed as being without limitation to any additional limitations that may be imposed by the spirit of the present invention.

Claims

1. The utility model provides an elbow joint prosthesis round pin off-axial nailing ware, includes handle (1), the front end of handle (1) be equipped with third nail pole (2), the front end of third nail pole (2) be equipped with second nail pole (3) that the diameter size is less than third nail pole (2), the front end of second nail pole (3) be equipped with first nail pole (4) that the diameter size is less than second nail pole (3), first nail pole (4), second nail pole (3), third nail pole (2) relatively fixed in axial direction, its characterized in that, second nail pole (3) and third nail pole (2) between be equipped with off-axial nail butt structure (5).

2. The external pin nailing device of the elbow joint prosthesis pin shaft according to claim 1, wherein the external pin butting structure (5) comprises a butting boss (6) which is arranged between the second pin rod (3) and the third pin rod (2) and is in a cone frustum shape, the second pin rod (3) is connected with a small head end (7) at the front end of the butting boss (6), a large head end (8) at the rear end of the butting boss (6) is connected with the third pin rod (2), and the outer edge of the butting boss (6) forms a butting surface (9) between the small head end (7) and the large head end (8).

3. The external pin nailing device of elbow joint prosthesis according to claim 2, characterized in that the second nail rod (3) and the abutment boss (6) are of an integral structure.

4. The external pin nailing device of the elbow joint prosthesis pin shaft according to any one of claims 1-3, characterized in that the front ends of the first nail rod (4), the second nail rod (3) and the handle (1) are respectively provided with a chamfer part (10); first nail pole (4), second nail pole (3), third nail pole (2) formula structure as an organic whole and by titanium alloy make, first nail pole (4), second nail pole (3), third nail pole (2) outer fringe surface be the high polished surface.

5. The external pin nailing device of the elbow joint prosthesis pin shaft according to claim 1, characterized in that the third nail rod (2) is further provided with a strutting component (11) which can extend out of the outer edge of the third nail rod (2);

strutting assembly (11) inlay a plurality of arc butt joint piece (12) that establish on the circumferencial direction of third nail pole (2) and radian and third nail pole (2) the same including the interval, arc butt joint piece (12) inboard be equipped with flexible connecting seat (13), flexible connecting seat (13) inlay establish in flexible groove (14) of seting up in third nail pole (2), flexible groove (14) and arc butt joint piece (12) between be equipped with and let arc butt joint piece (12) have return stroke mechanism (15) towards third nail pole (2) axle center motion trend, third nail pole (2) and handle (1) between still be equipped with and drive flexible drive assembly (16) that can drive arc butt joint piece (12) outwards strut in step.

6. The elbow joint prosthesis pin shaft outer nail feeding device according to claim 5, wherein the return mechanism (15) comprises a spring body (17), the spring body (17) is positioned in a spring groove (18) formed in the telescopic groove (14), a positioning pin (19) which is L-shaped and one end of which is embedded in the spring groove (18) is arranged on the arc-shaped abutting piece (12), and two ends of the spring body (17) respectively act on the groove bottoms of the positioning pin (19) and the spring groove (18).

7. The external pin nailing device of elbow joint prosthesis according to claim 5, the telescopic driving component (16) comprises a rotating rod body (20) which is arranged in an accommodating cavity (25) in the middle of the third nail rod (2) and can rotate in the circumferential direction, the rotating rod body (20) is screwed with two driving seats (21) which are symmetrically arranged, circumferentially fixed relative to the rotating rod body (20) and can axially reciprocate along the rotating rod body (20), two ends of the bottom side of the telescopic connecting seat (13) are respectively embedded on the two driving seats (21), the driving seat (21) is in a cone frustum shape, a plurality of strip-shaped guide grooves (22) which are arranged at intervals in the circumferential direction are arranged on the conical surface of the driving seat (21), the two ends of the bottom side of the telescopic connecting seat (13) are respectively embedded in the strip-shaped guide grooves (22), one end of the rotating rod body (20) extends out of the rear end of the handle (1) and is fixedly connected with an operation knob (23) in the circumferential direction.

8. The external nail feeding device for the elbow joint prosthesis pin shaft according to claim 7, wherein a plurality of circumferential positioning ribs (24) are further arranged on the circumferential outer side of the driving seat (21), a plurality of strip-shaped positioning grooves (26) which are arranged in one-to-one correspondence with the circumferential positioning ribs (24) are arranged in the accommodating cavity (25), the strip-shaped positioning grooves (26) axially extend in the axial direction of the third nail rod (2), and the circumferential positioning ribs (24) are embedded in the strip-shaped positioning grooves (26).

9. A working method of a nail applying device for an elbow joint prosthesis pin shaft is characterized by comprising the following steps:

s1, combining the humerus component (1a) and the ulna component (1b), adjusting to enable a joint cavity (1c) between the humerus component (1a) and the ulna component (1b) to be communicated, holding the handle (1), pushing the handle (1) to enable the third nail rod (2) to extend into the joint cavity (1c) between the humerus component (1a) and the ulna component (1b), clamping the third nail rod (2) in the joint cavity (1c), and enabling the front end of the handle (1) to abut against the side of the humerus component (1 a);

s2, sleeving the pin shaft outer nail (1d) on the second nail rod (3) to enable the inner wall of the pin shaft outer nail (1d) to be attached to the outer wall of the second nail rod (3), and continuously pushing the pin shaft outer nail (1d) until the lower section inclined plane inside the pin shaft outer nail (1d) is tightly attached to the abutting surface (9) on the abutting boss (6);

s3, the first nail rod (4) is held by hand, the front end of a finger abuts against the annular flange (27) at the front end of the pin shaft outer nail (1d), the pin shaft outer nail (1d) is gradually pushed into the joint cavity (1c) through the annular flange (27), the third nail rod (2) gradually retreats from the joint cavity (1c) until the pin shaft outer nail (1d) is completely positioned in the joint cavity (1c) in the process that the pin shaft outer nail (1d) continuously enters the joint cavity (1c), and the inner end of the annular flange (27) abuts against the outer end of the joint cavity (1 c).

10. The external pin driver for elbow joint prosthesis according to claim 9, wherein in the above step S2, the slope of the lower end slope of the external pin (1d) is the same as the slope of the abutment surface (9).