Femoral neck plate nail system

Abstract

The present invention discloses a femoral neck plate nail system, including a fixing member and a tension screw, wherein the fixing member is provided with three directional holes arranged in a triangle, and the directional holes are used to install the tension screws in a one-to-one correspondence; wherein a first groove is provided on the head of the tension screw, and an elastic member is provided in the first groove, and the elastic member protrudes radially from the first groove when in a natural state, and the elastic member can be completely retracted into the first groove when squeezed; a second groove is provided on the inner wall of the directional hole, and the directional hole has an interference fit with the head, and the second groove has a clearance fit with the head, and when the tension screw is installed in the directional hole, the second groove accommodates the head and the elastic member protruding from the first groove. The femoral neck plate nail system provided by the present invention can prevent rotation and withdrawal of the nail, and has both reliable resistance to torsion, shear and pressure, and the ability to apply pressure for continuous axial sliding.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and in particular to a femoral neck plate nail system. Background Art

[0002] Femoral neck fractures account for 45%-53% of hip fractures. With increasing life expectancy and widespread osteoporosis in the elderly, the incidence of femoral neck fractures is increasing annually. Currently, femoral neck fractures are primarily treated with cannulated screw fixation or hip replacement. Internal fixation is the preferred treatment for younger patients or elderly patients without significant displacement. Due to the high cost and invasive nature of hip replacement surgery, closed reduction and cannulated screw fixation are more common in younger patients without significant displacement and in elderly patients. The use of three cannulated screws has long been the preferred treatment for femoral neck fractures. Initially, both domestic and international physicians favored an equilateral triangle or zigzag arrangement for cannulated screw placement in the treatment of femoral neck fractures. However, as this procedure has become more widespread, studies have shown that this arrangement creates at least two screw holes in the lateral cortex near the inferior margin of the lesser trochanter. Repeated adjustments during screw placement can also lead to the creation of additional guide pin holes. These issues reduce the tensile stress strength of the lateral femur, increasing the likelihood of subtrochanteric fractures and potentially disrupting blood flow to the posterior medial femoral circumflex artery.

[0003] The inverted triangle arrangement has obvious advantages over the regular triangle arrangement in shortening operation time and reducing blood loss. The inverted triangle hollow nail system developed with this arrangement has gradually become a commonly used medical device for treatment. It is mostly used in internal fixation surgery for proximal femoral neck fractures. It can control the displacement of the fracture site, promote fracture healing, and enable patients to get out of bed and move around as soon as possible.

[0004] However, the femoral neck plate fixing system in the related art is only composed of three hollow lag screws (such as Figure 1During use, a guide is used to insert a Kirschner wire, followed by a cannulated drill and insertion of three cannulated lag screws. The screws, placed into the bone, rely on the "three-point" support of the femoral cortex, medial cortex, and subchondral bone to provide a certain degree of compressive resistance. This inverted triangular cannulated screw system cannot provide stable torsional and shear resistance for femoral neck fractures caused by high-energy trauma. Its use in treating femoral neck fractures has a high revision rate and can lead to screw cutting and screw backout. After internal fixation, femoral neck shortening may occur, which in turn reduces the patient's hip abduction muscle strength, seriously affecting hip function and reducing quality of life. Furthermore, this inverted triangular cannulated screw system is imperfect in construction and cumbersome to operate. The surgeon's experience in inserting the Kirschner wires with the guide often fails to ensure parallelism between the screws, and they sometimes cross each other, subjecting the fractured ends of the femoral neck to different stresses. Consequently, the system has a high failure rate. Even when the fixation screws are parallel, many patients still experience screw backout, which can lead to surgical failure. Summary of the Invention

[0005] The purpose of the embodiments of the present invention is to overcome the defects described in the prior art, thereby providing a femoral neck plate nail system that is simple and convenient to operate, has a good anti-retreat effect, and can effectively solve the problem of poor anti-rotational torsional force and shear resistance. The specific technical solution is as follows:

[0006] A femoral neck plate nail system includes a fixing piece and a lag screw. The fixing piece is provided with three directional holes arranged in a triangle, and the directional holes are used to install the lag screws in a one-to-one correspondence; wherein,

[0007] A first groove is formed on the head of the lag screw, and an elastic member is disposed in the first groove. The elastic member protrudes radially from the first groove when in a natural state, and can be completely retracted into the first groove when squeezed.

[0008] A second groove is provided on the inner wall of the directional hole. The directional hole is interference fit with the head, and the second groove is clearance fit with the head. When the tension screw is installed in the directional hole, the second groove accommodates the head and the elastic member protruding from the first groove.

[0009] As an practicable manner, the first groove is opened along the circumference of the head, and the second groove is an arc-shaped groove.

[0010] As an practicable manner, the elastic member is a clamping ring with a notch, and the shape of the clamping ring is adapted to the second groove.

[0011] As an practicable manner, the thickness of the clamping ring is less than or equal to the depth of the first groove, and the outer diameter of the clamping ring in a natural state is greater than the outer diameter of the head.

[0012] As an practicable manner, the elastic member is a plurality of elastic positioning pins installed in the first slot. Preferably, the elastic positioning pins are arranged in the first slot at equal intervals.

[0013] As an practicable manner, the elastic member is a rubber ring, and the thickness of the rubber ring is greater than the depth of the first groove.

[0014] As an implementable method, the directional hole is a stepped hole, including a first hole and a second hole arranged coaxially, the diameter of the first hole is larger than the diameter of the second hole, the first hole is interference fit with the head of the tension screw, and the second groove is opened in the first hole near the end of the second hole, and the slot width of the second groove is greater than or equal to the height of the head of the tension screw.

[0015] As an implementable manner, a plurality of disassembly blind holes are further provided on the side wall of the first hole, the axes of the disassembly blind holes intersect with the axis of the first hole, and the open ends of the disassembly blind holes extend to the free ends of the first hole.

[0016] As an implementable manner, there are three disassembly blind holes, and the three disassembly blind holes are located on the inferior arc of the free end of the first hole.

[0017] As an implementable manner, the fixing member is a triangular plate-shaped object, the axis of the directional hole is set at an angle with the fixing member, and the value range of the angle is greater than or equal to 125 degrees and less than or equal to 135 degrees.

[0018] As an implementable manner, a limiting hole is further provided on the fixing member, the axis of the limiting hole is arranged perpendicular to the fixing member, and the limiting hole is used to install a locking screw.

[0019] As an practicable manner, the three directional holes are arranged in an isosceles triangle, and the limiting hole is located on the extension line of the vertex bisector of the isosceles triangle.

[0020] As an implementable manner, a positioning hole is further provided on the fixing member, and the positioning hole is provided in the triangle.

[0021] The beneficial effects brought about by the technical solution provided by the present invention are:

[0022] First, the present application is based on the setting of the fixing member. According to the tension band effect, it can provide sufficient support to prevent the femoral head from varus after surgery. When used in conjunction with the lag screws arranged in an inverted triangle, it can provide stable anti-torsion and anti-shear forces for femoral neck fractures caused by high-energy injuries.

[0023] Secondly, the directional holes on the fixture can ensure that the tension screws are set parallel to each other, reducing the rate of surgical errors;

[0024] Furthermore, the arrangement of the first groove on the tension screw, the second groove in the directional hole, and the elastic member between the first groove and the second groove can avoid the occurrence of the nail backing phenomenon. Specifically, when using the femoral neck plate nail system, the elastic member is first placed in the first groove of the tension screw, and then the screw rod of the tension screw is passed through the directional hole. Since the directional hole and the head of the tension screw are in an interference fit relationship, when an external force is applied to the tension screw for installation into the directional hole, such as a downward pulling force or pressure, the elastic member will be squeezed by the side wall of the directional hole and completely retracted into the first groove. As the head moves downward, when the first groove of the tension screw moves to the position aligned with the first groove, the elastic member will completely retract into the first groove. When the second groove in the directional hole corresponds, the elastic member loses the squeezing effect of the side wall of the directional hole and stretches into the second groove. Since the second groove can accommodate the head, as the head continues to move downward, the head of the tension screw will be completely placed in the second groove. Since the second groove can also accommodate the elastic member protruding from the first groove, the head of the tension screw has a certain amount of movable space in the second groove. However, since the elastic member will only deform when subjected to radial compression, even if axial tension or thrust is applied to the tension screw, the elastic member will not deform, and under the limitation of the second groove, it cannot withdraw from the hole, thereby effectively preventing the occurrence of nail withdrawal. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0026] Figure 1 It is a schematic diagram of the installation of the femoral neck plate nail system in the prior art;

[0027] Figure 2 A schematic structural diagram of a femoral neck plate nail system provided by one embodiment of the present invention;

[0028] Figure 3 A side view of a femoral neck plate nail system provided by one embodiment of the present invention;

[0029] Figure 4 for Figure 3 Sectional view along line AA;

[0030] Figure 5 A three-dimensional assembly diagram of a femoral neck plate nail system provided by one embodiment of the present invention;

[0031] Figure 6A schematic structural diagram of a fixing member provided in one embodiment of the present invention;

[0032] Figure 7 A top view of a fixing member provided in accordance with an embodiment of the present invention;

[0033] Figure 8 for Figure 7 Cross-sectional view along line BB;

[0034] Figure 9 for Figure 8 A local enlarged schematic diagram of point I in the middle;

[0035] Figure 10 A schematic diagram of installing the sleeve and the guide pin of the guide on the connecting plate and fixing them by drilling holes on the femur;

[0036] Figure 11 Schematic diagram for removing guide pins and sleeves other than the central guide pin and central sleeve;

[0037] Figure 12 Schematic diagram of assembling the locking screw and lag screw into the fixture and connecting it to the femur, and removing the central guide wire and central sleeve;

[0038] Figure 13 for Figure 12 Schematic diagram from another perspective.

[0039] Description of reference numerals:

[0040] 100. Fixing parts;

[0041] 110, directional hole; 111, second slot; 112, first hole; 113, second hole; 114, disassembly blind hole;

[0042] 120, limiting hole; 121, locking screw; 122, internal thread;

[0043] 130, positioning hole;

[0044] 200, lag screw; 210, first slot;

[0045] 300, elastic member; 310, notch;

[0046] 400, femur;

[0047] 500, sleeve;

[0048] 600. Guide needle. DETAILED DESCRIPTION

[0049] The following description of specific embodiments of the present invention refers to the accompanying drawings. For clarity and convenience, the thickness of lines and the size of structural elements shown in the drawings may be exaggerated. Furthermore, the terms described below are defined based on their functions within the present invention and may vary depending on the intentions or practices of users and operators. Therefore, the definitions of such terms should be based on the overall content of this specification.

[0050] For example, terms such as "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer" indicate positions or locations based on those shown in the accompanying drawings. These terms are intended solely to facilitate and simplify the description of the present invention and are not intended to indicate or imply that the devices or components referred to must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0051] In the description of the present invention, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed, detachable, or integral connections; mechanical or electrical connections; direct or indirect connections through an intermediate medium; and internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on the specific circumstances.

[0052] In addition, the technical features involved in different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0053] In the related art, when treating femoral neck fractures, the tension screws inserted into the bone in a triangular arrangement only rely on the "three points" of the femoral lateral cortex, medial cortex and subchondral bone to provide a certain compressive resistance, but their integrity is not strong and they cannot provide stable anti-torsion and anti-shear forces. The secondary revision rate is high. Moreover, since there is no other locking of the tension screws or the locking structure is imperfect, many patients will experience screw withdrawal after surgery, resulting in surgical failure.

[0054] Based on the analysis and discovery of the above problems, this application is filed.

[0055] The present application provides a femoral neck plate nail system, including a fixing member and a tension screw, wherein the fixing member is provided with three directional holes arranged in a triangle, and the directional holes are used to install the tension screws one by one; wherein, a first groove is provided on the head of the tension screw, and an elastic member is provided in the first groove, and the elastic member protrudes radially from the first groove when in a natural state, and the elastic member can be completely contracted in the first groove when squeezed; a second groove is provided on the inner wall of the directional hole, the directional hole is interference fit with the head, and the second groove is clearance fit with the head, and when the tension screw is installed in the directional hole, the second groove accommodates the head and the elastic member protruding from the first groove.

[0056] The femoral neck plate nail system of the present application has the characteristics of anti-rotation and anti-retrieval. It has reliable resistance to torsion, shear and pressure, and axial sustainable sliding pressurization capability, which is beneficial to early postoperative recovery and fracture healing. It is first based on the setting of the fixing part. According to the tension band effect, it can provide sufficient support to prevent postoperative femoral head varus. When used in conjunction with the tension screws arranged in an inverted triangle, it can provide stable anti-rotational torsion and anti-shear force for femoral neck fractures caused by high-energy injuries; the setting of the directional holes on the fixing part can ensure that the tension screws are arranged parallel to each other, reducing the surgical error rate; the setting of the first groove on the tension screw, the second groove in the lock hole, and the elastic member between the first groove and the second groove can avoid the occurrence of nail retreat. Specifically, when using the femoral neck plate nail system, the elastic member is first placed in the first groove of the tension screw, and then the screw rod of the tension screw is passed through the directional hole. Due to the directional hole and the head of the tension screw The two parts are in an interference fit relationship, so when an external force is applied to the tension screw for installing it into the directional hole, such as downward pulling force or pressure, the elastic part will completely shrink into the first groove under the squeezing action of the side wall of the directional hole. As the head moves downward, when the first groove of the tension screw moves to correspond to the second groove in the directional hole, the elastic part loses the squeezing action of the side wall of the directional hole and stretches into the second groove. Since the second groove can accommodate the head, as the head continues to move downward, the head of the tension screw will be completely placed in the second groove. Since the second groove can also accommodate the elastic part protruding from the first groove, the head of the tension screw has a certain amount of movable space in the second groove. However, since the elastic part will only deform when subjected to radial squeezing, even if an axial pulling force or pushing force is applied to the tension screw, the elastic part will not deform, and under the limitation of the second groove, it cannot withdraw from the hole, thereby effectively preventing the occurrence of nail withdrawal.

[0057] In some optional embodiments, the first groove is formed along the circumference of the head, and the second groove is an arc-shaped groove. In these embodiments, the first groove can be an annular groove formed around the axial direction of the head, and the second groove is configured as an arc. During the downward movement of the lag screw, any position of the first groove can correspond to the second groove. The second groove is configured as an arc rather than an annular shape to further limit the circumferential movement of the elastic member, making it easier to apply upward force to the head after surgery to disengage the lag screw from the directional hole.

[0058] In some optional embodiments, the elastic member is a collar with a notch, and the shape of the collar is adapted to the second groove. In these embodiments, the collar with a notch is selected so that the collar can be radially expanded or contracted.

[0059] In some optional embodiments, the thickness of the collar is less than or equal to the depth of the first groove, and the outer diameter of the collar in its natural state is greater than the outer diameter of the head. In these embodiments, when the thickness of the collar is less than or equal to the depth of the first groove, the collar can be completely retracted into the first groove, thereby allowing the tension screw to be smoothly installed in the directional hole. When the outer diameter of the elastic collar in its natural state is greater than the outer diameter of the head, the second groove can ensure that the collar is retained in place after the tension screw is installed in the directional hole.

[0060] In some optional embodiments, the elastic member is a plurality of elastic locating pins installed in the first slot. Preferably, the elastic locating pins are arranged at equal intervals in the first slot. In these embodiments, the elastic member is configured as elastic locating pins, and the first slot can be a plurality of grooves arranged along the circumference of the tension screw. The elastic locating pins can be arranged in a one-to-one correspondence in the grooves. The elastic locating member comprises a pin body and a spring, with the ends of the spring fixedly connected to the pin body and the bottom wall of the groove, respectively. When arranged at equal intervals, the elastic locating pins can provide a uniform restraining effect on the tension screw.

[0061] In some optional embodiments, the elastic member is a rubber ring having a thickness greater than the depth of the first groove. In these embodiments, the elastic member is a rubber ring having a thickness greater than the depth of the first groove. During use, the rubber ring can be squeezed to allow the tension screw to be smoothly installed into the directional hole. The elasticity of the rubber ring allows it to expand into the second groove, thereby limiting the position of the tension screw.

[0062] In some optional embodiments, the directional hole is a stepped hole, comprising a first hole and a second hole coaxially arranged. The diameter of the first hole is larger than the diameter of the second hole, and the first hole forms an interference fit with the head of the lag screw. The second slot is defined in the first hole near the end of the second hole, and the width of the second slot is greater than or equal to the height of the lag screw head. In these embodiments, the directional hole is configured as a stepped hole, allowing the head of the lag screw to be fully submerged in the first hole. The diameter of the second hole is compatible with the lag screw shank, providing a guide for axial movement during tension settling. The second slot is defined in the first hole near the end of the second hole, allowing the shank to be partially fully seated in the second hole, thereby improving the stability of the lag screw. When the width of the second slot is greater than or equal to the height of the lag screw head, the second slot can fully accommodate the lag screw head. Of course, the width of the second slot can be slightly greater than the height of the lag screw head to avoid poor retaining effect caused by an excessively large width.

[0063] In some optional embodiments, a plurality of disassembly blind holes are further formed on the side wall of the first hole, wherein the axes of the disassembly blind holes intersect with the axis of the first hole, and the open ends of the disassembly blind holes extend to the free ends of the first hole. In these embodiments, once the tension screw is installed in the directional hole on the fixing member, it is difficult to separate the tension screw from the directional hole due to the combined action of the first slot, the second slot, and the elastic member. The provision of the disassembly blind holes can provide a support point for external force. For example, when disassembling the tension screw with a screwdriver, it is difficult for the operator to pull out the tension screw by hand without providing a reverse support force to the screwdriver. However, when a support rod is provided on the screwdriver and the end of the support rod is pressed against the disassembly blind hole, the support rod, supported by the disassembly blind hole, can exert an upward thrust on the screwdriver by rotating the screwdriver, thereby relatively easily separating the tension screw from the fixing member.

[0064] In some optional embodiments, there are three disassembly blind holes, and the three disassembly blind holes are located on the inferior arc of the free end of the first hole. In these embodiments, the three disassembly blind holes can have better stability, and the circumference connecting line of the three disassembly blind holes is the inferior arc, which facilitates force application.

[0065] In some optional embodiments, the fixing member is a triangular plate-like object, and the axis of the directional hole is set at an angle with the fixing member, and the value range of the angle is greater than or equal to 125 degrees and less than or equal to 135 degrees. In these embodiments, the fixing member is set in a triangular shape, which facilitates the arrangement of the directional holes and reduces the volume of the fixing member to maximize its usable space. The triangular fixing member has good stability, and the top angle of the triangle can be rounded to match the shape of the proximal femur. The inclined setting of the directional hole can adapt to the neck-shaft angle of the femoral neck and femoral shaft.

[0066] In some optional embodiments, the fixing member further includes a limiting hole, the axis of which is perpendicular to the fixing member, for receiving a locking screw. In these embodiments, the limiting hole for receiving the locking screw is provided, and the locking screw is tightly locked to the fixing member through the limiting hole, thereby ensuring that the lag screw does not lose its position or rotate deformity within the femoral neck, thereby ensuring sufficient anti-rotation performance.

[0067] In some optional embodiments, the three directional holes are arranged in an isosceles triangle, and the limiting hole is located on the extension line of the vertex bisector of the isosceles triangle. In these embodiments, the positioning of the limiting holes can further ensure the anti-rotation performance of the three tension screws.

[0068] In some optional embodiments, the fixing member is further provided with a positioning hole, which is located in the triangle. In these embodiments, providing the positioning hole can facilitate early perspective positioning and later connection with the guide. Specific embodiments

[0070] See also Figure 2-5 The present application provides a femoral neck plate nail system, including a fixing member 100 and a tension screw 200. The fixing member 100 is provided with three directional holes 110 arranged in a triangle, and the directional holes 110 are used to install the tension screws 200 one by one; wherein, a first groove 210 is provided on the head of the tension screw 200, and an elastic member 300 is provided in the first groove 210. When the elastic member 300 is in a natural state, it protrudes radially from the first groove 210, and the elastic member 300 can be completely contracted in the first groove 210 when squeezed; a second groove 111 is provided on the inner wall of the directional hole 110, the directional hole 110 is interference fit with the head, and the second groove 111 is clearance fit with the head. When the tension screw 200 is installed in the directional hole 110, the second groove 111 accommodates the head and the elastic member 300 protruding from the first groove 210.

[0071] The present application is based on the setting of the fixing member 100. According to the tension band effect, it can provide sufficient support to prevent the femur 400 from varus after surgery. When used in conjunction with the tension screws 200 arranged in an inverted triangle, it can provide stable anti-torsion and anti-shear force for femoral neck fractures 400 caused by high-energy injuries. The setting of the directional holes 110 on the fixing member 100 can ensure that the tension screws 200 are arranged parallel to each other, thereby reducing the surgical error rate. The setting of the first groove 111 on the tension screw 200, the second groove 111 in the directional hole 110, and the elastic member 300 between the first groove 210 and the second groove 111 can avoid the occurrence of nail backing. Specifically, when using the femoral neck plate nail system, the elastic member 300 is first placed in the first groove 210 of the tension screw 200, and then the screw of the tension screw 200 is passed through the directional hole 110, and an external force for installation into the directional hole 110 is applied to the tension screw 200, such as downward pulling force or pressure. When the first groove 210 of the tension screw 200 moves to correspond to the second groove 111 in the directional hole 110, the elastic member 300 loses the squeezing effect of the side wall of the directional hole 110 and stretches to the second groove 111. Since the second groove 111 can accommodate the head, as the head continues to move downward, the head of the tension screw 200 will be completely placed in the second groove 111. Since the second groove 111 can also accommodate the elastic member 300 protruding from the first groove 210, the head of the tension screw 200 has a certain amount of movable space in the second groove 111. However, since the elastic member 300 will only deform when subjected to radial compression, even if axial tension or thrust is applied to the tension screw 200, the elastic member 300 will not deform, and cannot withdraw from the hole under the limitation of the second groove 111, thereby effectively preventing the occurrence of nail withdrawal.

[0072] Please continue reading Figure 3-5 In this application, the first groove 210 is opened along the circumference of the head of the tension screw 200, see Figure 5 The second groove 111 is an arc-shaped groove. Therefore, during the downward movement of the lag screw 200, any position of the first groove 210 can correspond to the second groove 111. The second groove 111 is configured as an arc rather than an annular shape to further limit the circumferential movement of the elastic member 300, making it easier to apply an upward force to the head after surgery to disengage the lag screw 200 from the directional hole 110.

[0073] See also Figure 5In this embodiment, the elastic member 300 is a clamping ring whose shape is adapted to the second groove 111, that is, a notch 310 is opened on the clamping ring. The setting of the notch 310 can enable the clamping ring to have the ability to shrink radially, wherein the thickness of the clamping ring is less than or equal to the depth of the first groove 210, and the outer diameter of the clamping ring in a natural state is greater than the outer diameter of the head. The material of the clamping ring can be selected from titanium alloy and other commonly used implant materials in medicine.

[0074] Of course, the structure of the elastic member 300 is not limited to the clamping ring, but can also be other structures with radial contraction capabilities. For example, the elastic member 300 can be several elastic locating pins installed in the first groove 210. The structure of the elastic locating pin is well known to those skilled in the art and will not be elaborated here. The structure may not be exactly similar, but the working principle is to set a spring in the groove and set a pin body on the top of the spring. Through the expansion and contraction of the spring, the pin body is contracted in the groove or protrudes out of the groove. In this application, the groove is the first groove 210 circumferentially opened on the head of the tension screw 200, and the elastic locating pins are arranged at equal intervals in the first groove 210. Of course, the first groove 210 can also be composed of several independent grooves that correspond one-to-one to the elastic locating pins and are arranged in a ring on the head of the tension screw 200.

[0075] In addition, the elastic member 300 can also be a rubber ring that is compatible with the second groove 111. The thickness of the rubber ring is greater than the depth of the first groove 210. Therefore, when in use, the tension screw 200 can be smoothly installed into the directional hole 110 by squeezing the rubber ring. Through the elasticity of the rubber ring itself, it stretches into the second groove 111, thereby limiting the tension screw 200.

[0076] See also Figure 6-9 In the present application, the directional hole 110 is set as a stepped hole, including a first hole 112 and a second hole 113 arranged coaxially. The diameter of the first hole 112 is larger than the diameter of the second hole 113. The first hole 112 is interference fit with the head of the tension screw 200, that is, the inner diameter of the first hole 112 is equivalent to the outer diameter of the head of the tension screw 200, and the head can be squeezed into the first hole 112 by external force. The second groove 111 is opened in the middle of the first hole 112 near the end of the second hole 113, and the groove width of the second groove 111 is greater than or equal to the height of the head of the tension screw 200, that is, the directional hole 110 is a countersunk hole, that is, the tension screw 200 needs to be squeezed into the first hole 112 under the action of external force, and finally the head of the tension screw 200 can be completely sunk into the second groove 111 of the first hole 112, so that the tension screw 200 can be axially movably limited on the fixing member 100.

[0077] Please continue reading Figure 3-4Considering that once the tension screw 200 is installed in the directional hole 110 on the fixing member 100, it is difficult to separate the tension screw 200 from the directional hole 110 under the joint action of the first groove 210, the second groove 111 and the elastic member 300, the present application provides a plurality of disassembly blind holes 114 on the side wall of the first hole 112, and the open end of the disassembly blind hole 114 extends to the free end of the first hole 112. The setting of the disassembly blind hole 114 can provide a support point for external force, for example, by using a screwdriver to disassemble the tension screw When the tension screw 200 is removed by hand, if a reverse support force is not provided to the screwdriver, it is difficult for the operator to pull out the tension screw 200 with bare hands. However, when a support rod (not shown in the figure) is provided on the screwdriver and the end of the support rod is placed against the disassembly blind hole 114 (i.e., one end of the support rod is fixedly connected to the screwdriver and the other end is in contact with the disassembly blind hole 114), by rotating the screwdriver, the support rod, supported by the bottom wall of the disassembly blind hole 114, will exert an upward thrust on the screwdriver, thereby relatively easily separating the tension screw 200 from the fixing. In the present application, the axis of the disassembly blind hole intersects with the axis of the first hole, which can avoid the screw rod of the screwdriver while applying an upward component of force to the screw rod. In order to provide a more stable reverse force, the disassembly blind holes 114 in this embodiment are provided in three, and in order to facilitate the application of force, the circumference connecting line of the three disassembly blind holes is provided as a minor arc.

[0078] Please continue reading Figure 3 and 5 The fixing member 100 in the present application is a triangular plate-like object, and the axis of the directional hole 110 is set at an angle to the fixing member 100. Considering that the femoral neck and femoral shaft normally have a neck-shaft angle within the range of 130±5°, and have an anteversion angle of about 10° with the plane of the femoral condyle (coronal plane of the human body), the present application sets the value range of the angle to be greater than or equal to 125 degrees and less than or equal to 135 degrees.

[0079] Please continue reading Figure 8-9 In this embodiment, a limiting hole 120 is further provided on the fixing member 100. The axis of the limiting hole 120 is arranged perpendicular to the fixing member 100. The limiting hole 120 is used to install a locking screw 121. The locking screw 121 is used to further fix the fixing member 100 and the femur 400, enhance the fixation effect, and enhance stability. In this application, the three directional holes 110 are arranged in an isosceles triangle. The limiting hole 120 is located on the extension line of the vertex bisector of the isosceles triangle. The limiting hole 120 is set as a trapezoidal hole. The larger diameter of the trapezoidal hole corresponds to the first hole 112, and the smaller diameter corresponds to the second hole 113. At the same time, an internal thread 122 is provided in the trapezoidal hole to fix the locking screw 121, which can further ensure the anti-rotation performance of the three tension screws 200. In addition, a positioning hole 130 is also provided on the fixing member 100. The positioning hole 130 is set in the triangle.

[0080] When using, refer to Figure 10 First, the sleeve 500 and the guide pin 600 are installed on the fixing member 100 through the guide. Specifically, the sleeve 500 is first installed in the directional hole 110 and the positioning hole 130 respectively. Then, the guide pin 600 is used to pre-fix the connecting member 100 through the sleeve 500 located in the center (i.e., in the positioning hole 130). Then, the other three guide pins 600 are inserted into the directional hole 110 where the sleeve 500 is installed for positioning. Then, the guide is removed and a hole is drilled into the femur 400 through the sleeve 500. Please refer to Figure 11 , remove the guide pins 600 and sleeves 500 except the guide pin 600 and sleeves 500 located in the center, refer to Figure 12-13 , screw the locking screw 121 into the limiting hole 120, fix the fixing member 100 on the femur 400, and then respectively pass the three tension screws 200 through the directional holes 110 to form a triangle arrangement to connect the broken bones, and finally remove the central guide pin 600 and the central sleeve 500.

[0081] The locking screw 121 of the present application is fixed to the bone surface through a threaded connection with the fixing piece 100. After the three tension screws 200 are screwed in, a plane is formed, thereby preventing the fixing piece 100 from rotating; since the elastic piece 300 is installed on the head of the tension screw 200, the second groove 111 on the directional hole 110 accommodates the head of the tension screw 200, so that the tension screw 200 has a certain range of motion after being screwed in, but due to the synergistic effect of the first groove 210, the second groove 111 and the elastic piece 300, the tension screw 200 cannot be withdrawn without tools. Therefore, the femoral neck plate nail system of the present application has the characteristics of anti-rotation and anti-retrieval, and has both reliable resistance to torsion, shear and pressure, and axial sustainable sliding pressurization capability, which is beneficial to early postoperative recovery and fracture healing.

[0082] The above are only preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A femoral neck plate nail system, characterized in that: It includes a fixing piece and a tension screw, wherein the fixing piece is provided with three directional holes arranged in a triangle, and the directional holes are used to install the tension screws in a one-to-one correspondence; wherein, A first groove is formed on the head of the lag screw, and an elastic member is disposed in the first groove. The elastic member protrudes radially from the first groove when in a natural state, and can be completely retracted into the first groove when squeezed. A second groove is formed on the inner wall of the directional hole. The directional hole and the head have an interference fit, and the second groove and the head have a clearance fit. When the tension screw is installed in the directional hole, the second groove accommodates the head and the elastic member protruding from the first groove. The first groove is opened along the circumference of the head, and the second groove is an arc-shaped groove; The elastic member is a collar with a notch, and the shape of the collar is adapted to the second groove; The thickness of the collar is less than or equal to the depth of the first groove, and the outer diameter of the collar in a natural state is greater than the outer diameter of the head; The directional hole is a stepped hole, comprising a first hole and a second hole arranged coaxially, the diameter of the first hole being larger than the diameter of the second hole, the first hole being interference fit with the head of the lag screw, the second groove being formed in the first hole near the end of the second hole, and the width of the second groove being larger than or equal to the height of the head of the lag screw; A plurality of disassembly blind holes are further provided on the side wall of the first hole. The axes of the disassembly blind holes intersect with the axis of the first hole, and the open ends of the disassembly blind holes extend to the free ends of the first hole.

2. The femoral neck plate nail system according to claim 1, characterized in that: The elastic members are a plurality of elastic pins installed in the first slots.

3. The femoral neck plate nail system according to claim 2, characterized in that: The elastic pins are arranged in the first slot at equal intervals.

4. The femoral neck plate nail system according to claim 1, characterized in that: The elastic member is a rubber ring, and the thickness of the rubber ring is greater than the depth of the first groove.

5. The femoral neck plate nail system according to claim 1, characterized in that: There are three disassembly blind holes, and the three disassembly blind holes are located on the inferior arc of the free end of the first hole.

6. The femoral neck plate nail system according to any one of claims 1, 4 or 5, characterized in that: The fixing member is a triangular plate-shaped object, and the axis of the directional hole is set at an angle with the fixing member. The value range of the angle is greater than or equal to 125 degrees and less than or equal to 135 degrees.

7. The femoral neck plate nail system according to claim 6, characterized in that: A limiting hole is further provided on the fixing member, the axis of the limiting hole is arranged perpendicular to the fixing member, and the limiting hole is used for installing a locking screw.

8. The femoral neck plate nail system according to claim 7, characterized in that: The three directional holes are arranged in an isosceles triangle, and the limiting hole is located on the extension line of the vertex bisector of the isosceles triangle.

9. The femoral neck plate nail system according to any one of claims 1, 4, 5 or 8, characterized in that: The fixing piece is further provided with a positioning hole, and the positioning hole is arranged in the triangle.

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