A bone cement injection device for cranioplasty

Abstract

This invention relates to a bone cement injection device for cranioplasty, comprising an outer sheath, injection structures, and an external pusher. The outer sheath has an axially extending push channel within it. The sheath wall has a first group of holes and a second group of holes symmetrically distributed 180° circumferentially, each group containing multiple through holes arranged at equal intervals axially. Two symmetrically arranged injection structures correspond to the first and second groups of holes, respectively. Each injection structure includes: an injection tube inserted into the push channel, containing an axially extending infusion channel, the infusion channel being open at its proximal end and closed at its distal end; and multiple rigid pins arranged at equal intervals axially along the injection tube and penetrating the sidewall of the injection tube at the same circumferential angle, the inner end of each pin communicating with the infusion channel. This device effectively fills the repair block with bone cement, improving the outcome of cranioplasty.

Description

Technical Field

[0001] This invention belongs to the field of medical technology, specifically relating to a bone cement injection device for cranioplasty. Background Technology

[0002] The applicant filed an application on July 31, 2024, with publication number CN118557338A, entitled "A Skull Repair Component", which discloses a repair block formed by weaving nickel-titanium alloy wire. When repairing a patient's skull, the repair block is implanted into a bone window, and then bone cement is injected and hardened to replace the missing skull, thereby achieving the purpose of skull repair.

[0003] However, in practical applications, the inventors discovered that after the repair block is implanted into the bone window, when injecting bone cement into the repair block, a long needle needs to be inserted into the repair block through the incision. However, since the repair block is made of woven nickel-titanium alloy wire, the needle cannot move laterally inside the repair block. This requires frequent insertion and removal of the needle to fill the bone cement. Moreover, when filling the bone cement, medical staff cannot directly observe the injection of bone cement, which often results in some repair blocks not being filled with bone cement, leading to unsatisfactory surgical results. Summary of the Invention

[0004] In view of this, the present invention provides a bone cement injection device for cranioplasty, which can effectively fill the inside of the repair block with bone cement and improve the effect of cranioplasty repair.

[0005] The technical solution adopted in this invention is as follows:

[0006] A bone cement injection device for cranioplasty includes an outer sheath, a dispensing structure, and an external push rod.

[0007] The outer sheath tube has an axially extending push channel inside it. The outer sheath tube wall is provided with a first group of holes and a second group of holes symmetrically distributed along the circumference at 180°. Each group of holes contains multiple through holes arranged at equal intervals along the axial direction.

[0008] Two symmetrically arranged sub-injection structures are respectively configured to correspond to the first and second orifice groups. Each sub-injection structure includes:

[0009] The injection tube is inserted into the push channel and has an axially extending injection channel inside it. The injection channel is open at the proximal end and closed at the distal end.

[0010] Multiple rigid pins are arranged at equal intervals along the axial direction of the injection tube and penetrate the side wall of the injection tube at the same circumferential angle, with the inner end of each pin communicating with the injection channel;

[0011] The two dispensing structures are a first dispensing structure and a second dispensing structure. The pins on the first dispensing structure are inserted into the through holes of the first hole group, and the pins on the second dispensing structure are inserted into the through holes of the second hole group.

[0012] An external push rod is axially movable between the two injection tubes;

[0013] The dispensing structure has a first station and a second station relative to the outer sheath;

[0014] First station: The external push rod is in the proximal initial position, the two injection tubes are close to each other, and the tip of the insert pin is in the through hole and has not penetrated the outer wall of the outer sheath tube;

[0015] Second station: The outer push rod moves to the far end and wedges between the two injection tubes, forcing the two injection tubes to move in opposite directions radially, so that each needle passes through the outer wall of the outer sheath tube along the long axis of the corresponding through hole.

[0016] Preferably, the outer sheath has an elliptical cross-section, and its major axis is collinear with the radial movement direction of the two dispensing structures;

[0017] The cross-section of the dispensing tube is crescent-shaped with an outward convexity and an inward concaveness, including:

[0018] The convex arc surface that matches the inner wall of the outer sheath tube is in contact with the inner wall of the elliptical push channel in the second position.

[0019] When the radially inward concave arc surfaces are in the first working position, the two concave arc surfaces form an initial transition channel.

[0020] Preferably, the distal end of the outer push rod is provided with a tapered guide portion. When the outer push rod moves to the distal end, the tapered guide portion wedges between the concave arc surfaces of the two dispensing tubes, forcing the initial transition channel to expand radially until the convex arc surfaces of the two dispensing tubes fit against the inner wall of the outer sheath tube.

[0021] Preferably, the first hole group and the second hole group are arranged opposite to each other along the long axis of the outer sheath.

[0022] Along the length of the injection tube, the injection tube is divided into a first part located on the far side and a second part located on the near side, with the far end of the injection channel as the boundary. The first part is provided with a limiting hole that runs through the long axis. The limiting hole includes a large-diameter section and a small-diameter section that are connected to each other. The large-diameter section is located on the radially outer side of the small-diameter section.

[0023] The limiting holes of the two dispensing tubes are radially aligned;

[0024] It also includes a limiting rod, which has circular limiting portions at both ends;

[0025] The limiting rod passes through two limiting holes and slides with the small diameter section. At the second working position, the two limiting parts are respectively engaged in the two large diameter sections to limit the relative movement direction of the two injection tubes.

[0026] Preferably, the length of the first part is no more than 5 mm.

[0027] Preferably, the second part includes a handheld part and a pin part connected to each other, the pin part being located inside the push channel, the handheld part being located outside the push channel, and the pin being connected to the pin part.

[0028] Preferably, the outer sheath is further provided with auxiliary limiting members. The number of auxiliary limiting members is consistent with the number of through holes and corresponds one-to-one. Each auxiliary limiting member includes an upper segment and a lower segment arranged at an interval. The upper segment and the lower segment form an insertion groove. The auxiliary limiting member is connected to the periphery of the corresponding through hole. The length direction of the upper segment and the lower segment is the long axis direction of the outer sheath, so that the insertion groove communicates with the through hole.

[0029] At the first station, the pin passes through the insertion slot.

[0030] Preferably, when the two dispensing pipes move in opposite directions along the radial direction, the free ends of the upper and lower dispensing pipes contact the dispensing pipes and branch off vertically.

[0031] The beneficial effects of this invention are:

[0032] The repair block has a pre-reserved straight filling channel. During surgery, a 2-3cm incision is made in the scalp, allowing the repair module to be inserted into the bone window. The repair module fits perfectly into the bone window, with the waterproof membrane facing downwards and in contact with the pseudodura mater. The entrance to the filling channel is located at the incision. Through this entrance, the bone cement injection device is inserted into the filling channel. At this point, the dispensing structure is in its first position. The external push rod is wedged between the two dispensing tubes from the rear, causing the two dispensing tubes to move in opposite directions. The needle passes through the orifice and pierces the side wall of the filling channel, allowing the needle tip to enter the interior of the repair block. Bone cement is then injected into the perfusion channel from the proximal end. The bone cement is then perfused... The injection channel is filled with bone cement, which is then sprayed from the tips of the various needles, allowing the bone cement to be injected into the repair module (the part outside the filling channel). Because it has two sub-injection structures, each with multiple needles, bone cement can be injected into both sides of the filling channel, ensuring the entire repair module is filled. After the bone cement is filled, the outer push rod is pulled out, and the two sub-injection tubes are moved inward to switch the sub-injection to the first position. The bone cement injection device is then withdrawn, and the filling channel is filled with bone cement through the auxiliary tube. After the bone cement hardens, it can fill the entire bone window, thus ensuring the effectiveness of cranioplasty and improving surgical outcomes.

[0033] At the first station, the tip of the insert is completely retracted into the outer sheath tube, and there are no protrusions on the outer surface of the device, which facilitates unobstructed introduction into the filling channel along the filling channel.

[0034] The external push rod wedges in to drive the two injection tubes to expand radially. The insertion pins precisely penetrate along the long axis of the through hole and pierce the side wall of the filling channel woven with nickel-titanium alloy wire, forming symmetrically distributed injection points on both sides. By injecting bone cement simultaneously from both sides, three-dimensional filling of the inside of the repair module (outside the filling channel) is achieved, significantly reducing cavity residue and ensuring that the bone cement fills the entire repair module.

[0035] The repair block is made of nickel-titanium alloy wire, meaning that the sidewalls of the filling channel are also woven from nickel-titanium alloy wire, giving the repair block a mesh structure. The repair block has multiple pores inside, and similarly, the sidewalls of the filling channel also have pores. When the needle is inserted, the nickel-titanium alloy wire mesh avoids the needle through local elastic deformation, reducing puncture resistance and preventing instrument jamming or structural damage. After the needle enters the repair block, the bone cement sprayed from the needle tip spreads outwards from the needle tip. Because there are two rows of needles, bone cement is simultaneously injected at multiple points on both sides of the filling channel, allowing the bone cement to fill the entire repair block as much as possible.

[0036] After the injection is completed, the external push rod retracts to drive the injection tube to reset to the first position, and the insertion needle is completely retracted into the sheath, thus achieving safe removal of the device.

[0037] Bone cement is added into the filling channel through an auxiliary tube, eventually forming a seamless, continuous layer of bone cement to ensure full-area repair of the bone window. Attached Figure Description

[0038] The above and other objects, features and advantages of the present invention will become clearer from the following description of embodiments of the invention with reference to the accompanying drawings, in which:

[0039] Figure 1 This is a structural diagram of the repair module;

[0040] Figure 2 This is a schematic diagram of the outer sheath.

[0041] Figure 3 This is a schematic diagram of the two separate annotation structures;

[0042] Figure 4 This is a cross-sectional view of the bone cement injection device at the first work station;

[0043] Figure 5 This is a cross-sectional view of the bone cement injection device at the second work station;

[0044] Figure 6 This is a schematic diagram of a single sub-species structure;

[0045] Figure 7 This is a sectional view of the annotation structure;

[0046] Figure 8 yes Figure 7 Enlarged view of section A;

[0047] Figure 9 These are sectional views of the two first parts under the first workstation;

[0048] Figure 10 This is a schematic diagram showing the fit between the limiting rod and the limiting hole;

[0049] Figure 11 This is a schematic diagram showing the fit between the limiting rod and the limiting hole at the second working position;

[0050] Figure 12 This is a structural schematic diagram of the auxiliary limiting component;

[0051] Figure 13 This is a schematic diagram showing the bifurcation of the upper and lower lobes.

[0052] In the diagram: 1. Repair module; 2. Outer sheath; 4. Outer push rod;

[0053] 11. Fill channel; 12. Inlet;

[0054] 21. First aperture group; 22. Second aperture group; 23. Upper segment; 24. Lower segment;

[0055] 31. First dispensing structure; 32. Second dispensing structure; 33. Dispensing tube; 34. Insertion pin; 35. Transition channel; 36. Limiting rod;

[0056] 331. Injection channel; 332. Small diameter section; 333. Large diameter section; 334. Limiting hole; 361. Limiting part. Detailed Implementation

[0057] The present invention is described below based on embodiments, but the present invention is not limited to these embodiments. In the following detailed description of the present invention, some specific details are described in detail, but well-known methods, processes, procedures, and elements are not described in detail in order to avoid obscuring the essence of the present invention.

[0058] Furthermore, those skilled in the art should understand that the accompanying drawings provided herein are for illustrative purposes only and are not necessarily drawn to scale.

[0059] Unless the context explicitly requires it, the words "comprising," "including," and similar terms throughout the specification and claims should be interpreted as encompassing rather than being exclusive or exhaustive; that is, meaning "including but not limited to."

[0060] In the description of this invention, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0061] See Figures 1-13 The present invention provides a bone cement injection device for cranioplasty (hereinafter referred to as "bone cement injection device"), comprising an outer sheath 2, a dispensing structure and an outer push rod 4;

[0062] The outer sheath tube 2 has an axially extending push channel inside it. The outer sheath tube 2 has a first group of holes 21 and a second group of holes 22 that are symmetrically distributed along the circumference at 180°. Each group of holes contains a plurality of through holes that are equally spaced along the axial direction.

[0063] Two symmetrically arranged dispensing structures are respectively configured to correspond to the first hole group 21 and the second hole group 22, and each dispensing structure includes:

[0064] The injection tube 33 is inserted into the push channel and has an axially extending injection channel 331 inside. The injection channel 331 is open at the proximal end and closed at the distal end.

[0065] Multiple rigid pins 34 are arranged at equal intervals along the axial direction of the injection tube 33 and penetrate the side wall of the injection tube 33 at the same circumferential angle. The inner end of each pin 34 is connected to the injection channel 331.

[0066] The two dispensing structures are a first dispensing structure 31 and a second dispensing structure 32. The pins 34 on the first dispensing structure 31 are inserted into the through holes of the first hole group 21, and the pins 34 on the second dispensing structure 32 are inserted into the through holes of the second hole group 22.

[0067] The external push rod 4 is axially movable between the two injection tubes 33;

[0068] The dispensing structure has a first station and a second station relative to the outer sheath tube 2;

[0069] First station: The external push rod 4 is in the proximal initial position, the two injection tubes 33 are close to each other, and the tip of the needle 34 is located in the through hole and has not penetrated the outer wall of the outer sheath tube 2.

[0070] Second station: The outer push rod 4 moves to the far end and weds between the two injection tubes 33, forcing the two injection tubes 33 to move in opposite directions in the radial direction, so that each needle 34 passes through the outer wall of the outer sheath tube 2 along the long axis direction of the corresponding through hole.

[0071] The bone cement injection device of the present invention is used in cranioplasty. Specifically, it is used to inject bone cement into the repair module 1. The repair module 1 includes a repair block and an impermeable membrane. The shape of the repair block is consistent with the shape of the skull to be repaired. The repair block is a mesh structure woven from nickel-titanium alloy wire. The impermeable membrane covers the lower surface of the repair block and the edge of the impermeable membrane is sutured to the side of the repair block.

[0072] The repair block has multiple filling channels 11 arranged side by side, for example, three filling channels 11. The filling channels 11 are straight filling channels 11, and the entrances 12 of all filling channels 11 are located on the same side of the repair block. The multiple filling channels 11 are arranged at equal intervals in the left and right directions.

[0073] The shape of the repair patch can be obtained by scanning the bone window of the patient's head. In other words, the shape of the repair patch is specific for each patient, and the specific shape and size are determined by the actual situation of the bone window of the patient's head.

[0074] The repair block can be prepared according to the following method.

[0075] S100. Scan to obtain the patient's skull and obtain the first three-dimensional data of the bone window; the first three-dimensional data corresponds to the shape of the repair block;

[0076] S200: Generate second three-dimensional data corresponding to the filling channel 11 based on the three-dimensional data;

[0077] S300. Obtain a prefabricated hose, the outer diameter of which is consistent with the inner diameter of the filling channel 11;

[0078] S400. Place the prefabricated hoses according to the second three-dimensional data;

[0079] S500, around the hose, according to the first three-dimensional data, is woven using nickel-titanium alloy wire to form an initial repair block;

[0080] S600, Heat-set the initial repair block;

[0081] S700, remove the hose to obtain the repair block.

[0082] Then, the geomembrane is sewn onto the underside of the repair block to obtain repair module 1.

[0083] Nickel-titanium alloy wire is a shape memory metal that can deform under external force. After the external force is removed, the nickel-titanium alloy wire will return to its initial state. In other words, under natural conditions, the shape of repair module 1 basically corresponds to the first three-dimensional data (the impermeable membrane is a thin film, so the shape of repair module 1 is basically the same as the shape of the repair block). Therefore, under no external force, repair module 1 can fit perfectly with the bone window.

[0084] During the surgery, a 2-3 cm incision is made on the patient's scalp. Surgical instruments are then inserted through this incision to separate the myocutaneous flap from the pseudodura mater until the complete bone margin is exposed. A cavity is formed between the myocutaneous flap, the pseudodura mater, and the bone margin. Physiological saline is injected into the cavity to inflate the myocutaneous flap. Repair module 1 is then inserted into the cavity through the incision. The position of repair module 1 is adjusted so that the repair block precisely fills the bone window, with the inlet 12 facing the incision. The physiological saline in the cavity is drained. Surgical instruments are then inserted... Inside the cavity, the myocutaneous flap is pushed upwards from the inside of the cavity to prevent the local myocutaneous flap from compressing the repair module 1; each filling channel 11 corresponds to a bone cement injection device; the bone cement injection device (outer sheath 2 and two dispensing structures set inside the outer sheath 2, which are in the first position at this time) is inserted into the filling channel 11 along the inlet 12, so that the distal end of the outer sheath 2 reaches the blind end of the filling channel 11; for each bone cement injection device, the external push rod 4 is wedged into the two dispensing structures from the rear. Between the tubes 33, the two injection tubes 33 move in opposite directions, and the needles 34 pass through the through hole and pierce the side wall of the filling channel 11, allowing the needle tip of the needle 34 to enter the interior of the repair block; the proximal end of the injection tube 33 is connected to the bone cement delivery device, and bone cement is injected into the infusion channel 331 from the proximal end. The bone cement passes through the infusion channel 331 and is sprayed out from the needle tips of each needle 34, so that the bone cement can be injected into the repair module 1 (the part outside the filling channel 11). Due to the presence of two injection structures, Each injection structure has multiple pins 34, which allows bone cement to be injected into both sides of the filling channel 11, so that the bone cement can fill the entire repair module 1. After the bone cement is filled, the outer push rod 4 is pulled out and the two injection tubes 33 are moved inward, so that the injection structure switches to the first position. Then the bone cement injection device is withdrawn, and the filling channel 11 is filled with bone cement through the auxiliary tube. After the bone cement hardens, the entire bone window can be filled, thereby ensuring the effectiveness of skull repair and improving the surgical results.

[0085] When the bone cement injection device is withdrawn, the filling channel 11 is exposed. There is a possibility that the filling channel 11 is not filled with bone cement. A straight auxiliary tube is inserted into the filling channel 11, and bone cement is filled into the filling channel 11 through the auxiliary tube. While filling the bone cement, the auxiliary tube is withdrawn. In this way, the filling channel 11 can be filled with bone cement, ensuring that the repair module 1 is filled with bone cement and ensuring the surgical effect.

[0086] The outer sheath tube 2 is provided with a first hole group 21 and a second hole group 22. Regardless of whether it is in the first position or the second position, the insertion pin 34 is inserted into the corresponding through hole, so that the insertion pin 34 can only be pulled along the long axis direction of the through hole. The long axis directions of all the through holes are parallel to each other, so the dispensing tube 33 can only move along the long axis direction.

[0087] Initially, the two injection tubes 33 are close to each other (in the first position). At this time, the tip of the needle 34 is exactly in the through hole, so that the needle 34 will not go out of the through hole. This makes it easy for the outer sheath tube 2 to be inserted into the filling channel 11 without any protrusion. By wedging the external push rod 4 between the two injection tubes 33, the two injection tubes 33 can be moved away from each other, so that the needle 34 can go out of the through hole. This allows the bone cement injection device to switch from the first position to the second position. The switching method is simple and convenient to operate.

[0088] The cross-section of the outer sheath 2 is elliptical, and its major axis is collinear with the radial movement direction of the two dispensing structures.

[0089] The cross-section of the dispensing tube 33 is a crescent shape with an outward convexity and an inward concavity, including:

[0090] The convex arc surface that matches the inner wall of the outer sheath tube 2 is in contact with the inner wall of the elliptical push channel in the second working position;

[0091] When the radially inward concave arc surfaces are in the first working position, the two concave arc surfaces form an initial transition channel 35.

[0092] The outer sheath 2 has an elliptical cross-section, and the push channel is also elliptical. The major axis of the through hole is consistent with the major axis of the ellipse, and the length direction of the insertion pin 34 is consistent with the major axis of the ellipse. The elliptical outer sheath 2 allows the length of the insertion pin 34 to be set to be relatively long, so that in the second station, the insertion pin 34 can be fully inserted into the repair block, ensuring that the repair block can be effectively filled with bone cement.

[0093] The cross-section of the injection tube 33 is crescent-shaped. In the second position, the injection tube 33 can completely adhere to the inner wall of the push channel, thereby supporting the outer sheath tube 2 and preventing the outer sheath tube 2 from deforming when the bone cement is pumped in.

[0094] The concave arc surface creates an initial transition channel 35 between the two injection tubes 33 in the first position, which facilitates the insertion of the outer push rod 4 into the transition channel 35, thereby making it easier to separate the two injection tubes 33.

[0095] After the outer push rod 4 is inserted into the transition channel 35, the radial dimension of the outer push rod 4 is larger than that of the transition channel 35, which causes the two injection tubes 33 to separate, thus making the radial dimension of the transition channel 35 larger.

[0096] The distal end of the outer push rod 4 is provided with a tapered guide. When the outer push rod 4 moves to the distal end, the tapered guide wedges between the concave arc surfaces of the two dispensing tubes 33, forcing the initial transition channel 35 to expand radially until the convex arc surfaces of the two dispensing tubes 33 fit against the inner wall of the outer sheath tube 2.

[0097] The outer push rod 4 includes a tapered guide portion and a long rod portion connected to each other. The tapered guide portion is located on the far end of the long rod portion. From far to near, the radial dimension of the tapered guide portion gradually increases, and the maximum radial dimension of the tapered guide portion is consistent with the radial dimension of the long rod portion. When the outer push rod 4 is wedged between the two dispensing pipes 33, the tip of the tapered guide portion can be easily inserted into the proximal end of the transition channel 35, so that the outer push rod 4 can be easily inserted into the transition channel 35. As the radial dimension of the inserted outer push rod 4 increases, the outer push rod 4 will abut against the two dispensing pipes 33, thereby squeezing the two dispensing pipes 33 to separate from each other, realizing the purpose of switching the dispensing structure to the second station.

[0098] The long part of the external push rod 4 is preferably elliptical. After the external push rod 4 is fully inserted into the transition channel 35, if the long axis of the external push rod 4 is aligned with the long axis of the outer sheath tube 2, the two injection tubes 33 are separated to their farthest positions, which is the second working position. At this time, the needle 34 extends to its longest length. If the short axis of the external push rod 4 is aligned with the long axis of the outer sheath tube 2 (the two injection tubes 33 are always in contact with the external push rod 4), the length of the needle 34 extending out of the outer sheath tube 2 will be smaller. Therefore, the length of the needle 34 extending out of the outer sheath tube 2 can be controlled by rotating the external push rod 4, thereby changing the position of the needle tip of the needle 34 and ensuring that the bone cement can fill the entire repair block.

[0099] In the long axis direction of the outer sheath tube 2, the first hole group 21 and the second hole group 22 are arranged opposite to each other;

[0100] Along the length of the injection tube 33, the injection tube 33 is divided into a first part located on the far side and a second part located on the near side, with the far end of the injection channel 331 as the boundary. The first part is provided with a limiting hole 334 that extends along the long axis. The limiting hole 334 includes a large diameter section 333 and a small diameter section 332 that are connected to each other. The large diameter section 333 is located on the radially outer side of the small diameter section 332.

[0101] The limiting holes 334 of the two dispensing tubes 33 are radially aligned;

[0102] It also includes a limiting rod 36, which has circular limiting portions 361 at both ends;

[0103] The limiting rod 36 passes through two limiting holes 334 and slides with the small diameter section 332. At the second working position, the two limiting parts 361 are respectively inserted into the two large diameter sections 333 to limit the relative movement direction of the two dispensing pipes 33.

[0104] The distal end of the infusion channel 331 is closed, and the solid structure at the closure constitutes the first part. By setting a limiting hole 334 in the first part, for a single bone cement injection device, it only includes one limiting rod 36. The limiting rod 36 passes through the limiting holes 334 of the two injection tubes 33 respectively, and the extension direction of the limiting rod 36 is consistent with the length direction of the needle 34. In this way, the limiting rod 36 limits the relative movement direction of the two injection tubes 33, ensuring that the needle 34 can slide smoothly along the through hole.

[0105] Furthermore, the limiting hole 334 includes a large-diameter section 333 and a small-diameter section 332 that are connected to each other. The two ends of the limiting rod 36 are provided with circular radially protruding limiting portions 361. That is to say, the diameter of the limiting portion 361 is larger than the inner diameter of the small-diameter section 332 and the inner diameter of the large-diameter section 333 are the same. Therefore, the limiting portion 361 cannot pass through the small-diameter section 332, so that the limiting hole 334 always cooperates with the limiting rod 36, and avoids the situation where the dispensing pipe 33 is disengaged from the limiting rod 36.

[0106] The length of the first part is no more than 5 mm. The shorter length of the first part allows the distal pin 34 to be as close as possible to the distal end of the filling channel 11, so that the distal part of the repair block can also be filled with bone cement, ensuring that the bone cement can fill the interior of the repair block and ensuring the surgical effect.

[0107] The second part includes a handheld part and a pin 34 part connected to each other. The pin 34 part is located inside the push channel, and the handheld part is located outside the push channel. The pin 34 is connected to the pin 34 part.

[0108] After the bone cement is injected through the needle 34, the two injection structures need to be switched to the first position. At this time, the outer push rod 4 is pulled out and the two injection tubes 33 are moved inward to bring them closer together. Since the handle is located outside the outer sheath 2, the two injection structures can be moved closer together by controlling the handle outside the surgical opening, thereby achieving the purpose of switching from the second position to the first position.

[0109] The outer sheath tube 2 is also provided with auxiliary limiting members. The number of auxiliary limiting members is the same as the number of through holes and they correspond one-to-one. The auxiliary limiting members include upper segments 23 and lower segments 24 that are arranged at intervals. The upper segments 23 and lower segments 24 form an insertion groove. The auxiliary limiting members are connected to the periphery of the corresponding through holes. The length direction of the upper segments 23 and lower segments 24 is the long axis direction of the outer sheath tube 2, so that the insertion groove communicates with the through holes.

[0110] At the first station, the pin 34 passes through the insertion slot.

[0111] Because the outer sheath 2 is relatively soft, it will deform under external force. If the outer sheath 2 is flattened in the first position, the tip of the insertion needle 34 will be dislodged from the through hole. After the outer sheath 2 recovers, the needle tip of the insertion needle 34 cannot be reinserted into the through hole, thus affecting the operation.

[0112] The radial distal ends of the upper flap 23 and the lower flap 24 are connected to the inner wall of the outer sheath 2. The radial inner ends of the upper flap 23 and the lower flap 24 are free ends (the whole is a cantilever structure), and a connecting groove is formed between the upper flap 23 and the lower flap 24. The needle 34 is inserted into the connecting groove. That is to say, in the first position, the needle 34 is restricted by the connecting groove. Therefore, even if the outer sheath 2 is subjected to a certain external force, causing the needle tip of the needle 34 to disengage from the through hole, the needle 34 will always cooperate with the connecting groove. The connecting groove is aligned with the through hole and directly connected. Therefore, after the outer sheath 2 is restored, the needle tip of the needle 34 can be located at the through hole again under the guidance of the connecting groove, ensuring the subsequent operation.

[0113] When the two dispensing pipes 33 move in opposite directions radially, the free ends of the upper segment 23 and the lower segment 24 contact the dispensing pipe 33 and fork vertically. This ensures that the upper segment 23 and the lower segment 24 do not affect the switching of the dispensing structure from the first station to the second station.

[0114] It should be understood that the above embodiments are merely exemplary and not restrictive. Various obvious or equivalent modifications or substitutions that can be made by those skilled in the art regarding the above details without departing from the basic principles of the present invention will be included within the scope of the claims of the present invention.

Claims

1. A bone cement injection device for cranioplasty, characterized in that, Includes an outer sheath, dispensing structure, and outer push rod; The outer sheath tube has an axially extending push channel inside it. The outer sheath tube wall is provided with a first group of holes and a second group of holes symmetrically distributed along the circumference at 180°. Each group of holes contains multiple through holes arranged at equal intervals along the axial direction. Two symmetrically arranged sub-injection structures are respectively configured to correspond to the first and second orifice groups. Each sub-injection structure includes: The injection tube is inserted into the push channel and has an axially extending injection channel inside it. The injection channel is open at the proximal end and closed at the distal end. Multiple rigid pins are arranged at equal intervals along the axial direction of the injection tube and penetrate the side wall of the injection tube at the same circumferential angle, with the inner end of each pin communicating with the injection channel; The two dispensing structures are a first dispensing structure and a second dispensing structure. The pins on the first dispensing structure are inserted into the through holes of the first hole group, and the pins on the second dispensing structure are inserted into the through holes of the second hole group. An external push rod is axially movable between the two injection tubes; The dispensing structure has a first station and a second station relative to the outer sheath; First station: The external push rod is in the proximal initial position, the two injection tubes are close to each other, and the tip of the insert pin is in the through hole and has not penetrated the outer wall of the outer sheath tube; Second station: The outer push rod moves to the far end and wedges between the two injection tubes, forcing the two injection tubes to move in opposite directions radially, so that each needle passes through the outer wall of the outer sheath tube along the long axis of the corresponding through hole.

2. The bone cement injection device for cranioplasty according to claim 1, characterized in that, The outer sheath has an elliptical cross-section, and its major axis is collinear with the radial movement direction of the two dispensing structures. The cross-section of the dispensing tube is crescent-shaped with an outward convexity and an inward concaveness, including: The convex arc surface that matches the inner wall of the outer sheath tube is in contact with the inner wall of the elliptical push channel in the second position. When the radially inward concave arc surfaces are in the first working position, the two concave arc surfaces form an initial transition channel.

3. The bone cement injection device for cranioplasty according to claim 2, characterized in that, The distal end of the outer push rod is provided with a tapered guide. When the outer push rod moves to the distal end, the tapered guide wedges between the concave arc surfaces of the two injection tubes, forcing the initial transition channel to expand radially until the convex arc surfaces of the two injection tubes fit against the inner wall of the outer sheath.

4. The bone cement injection device for cranioplasty according to claim 1, characterized in that, In the long axis direction of the outer sheath, the first hole group and the second hole group are arranged opposite to each other; Along the length of the injection tube, the injection tube is divided into a first part located on the far side and a second part located on the near side, with the far end of the injection channel as the boundary. The first part is provided with a limiting hole that runs through the long axis. The limiting hole includes a large-diameter section and a small-diameter section that are connected to each other. The large-diameter section is located on the radially outer side of the small-diameter section. The limiting holes of the two dispensing tubes are radially aligned; It also includes a limiting rod, which has circular limiting portions at both ends; The limiting rod passes through two limiting holes and slides with the small diameter section. At the second working position, the two limiting parts are respectively engaged in the two large diameter sections to limit the relative movement direction of the two injection tubes.

5. The bone cement injection device for cranioplasty according to claim 4, characterized in that, The length of the first part is no more than 5mm.

6. The bone cement injection device for cranioplasty according to claim 4, characterized in that, The second part includes a handheld part and a pin part that are connected to each other. The pin part is located inside the push channel, and the handheld part is located outside the push channel. The pin is connected to the pin part.

7. The bone cement injection device for cranioplasty according to any one of claims 1-6, characterized in that, The outer sheath is also provided with auxiliary limiting members. The number of auxiliary limiting members is the same as the number of through holes and they correspond one-to-one. Each auxiliary limiting member includes an upper segment and a lower segment that are arranged at an interval. The upper segment and the lower segment form an insertion groove. The auxiliary limiting member is connected to the periphery of the corresponding through hole. The length direction of the upper segment and the lower segment is the long axis direction of the outer sheath, so that the insertion groove communicates with the through hole. At the first station, the pin passes through the insertion slot.

8. The bone cement injection device for cranioplasty according to claim 7, characterized in that, When the two dispensing pipes move in opposite directions along the radial direction, the free ends of the upper and lower dispensing pipes come into contact with the dispensing pipes and branch off vertically.

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