CN114948159A - Femoral neck plate nail system - Google Patents

Abstract

The invention discloses a femoral neck plate nail system which comprises a fixing piece and lag screws, wherein the fixing piece is provided with three directional holes which are arranged in a triangular manner, and the directional holes are used for installing the lag screws in a one-to-one corresponding manner; the head of the lag screw is provided with a first groove, an elastic part is arranged in the first groove, the elastic part protrudes out of the first groove in the radial direction when in a natural state, and the elastic part can be completely contracted in the first groove when being extruded; the inner wall of the directional hole is provided with a second groove, the directional hole is in interference fit with the head, the second groove is in clearance fit with the head, and when the lag screw is installed in the directional hole, the second groove accommodates the head and an elastic piece protruding out of the first groove. The femur neck plate nail system provided by the invention can prevent rotation and withdrawal, and has reliable torsion resistance, shear resistance and pressure resistance as well as axial and sustainable sliding pressurization capacity.

Description

Femoral neck plate nail system

Technical Field

The invention relates to the technical field of medical instruments, in particular to a femoral neck plate nail system.

Background

Femoral neck fractures account for 45% -53% of hip fractures. With the prolongation of the life expectancy of people, osteoporosis generally exists among the elderly people, and the incidence of femoral neck fracture is increased year by year. At present, the fracture of the neck of femur is treated by adopting a method of internal fixation of a hollow screw or hip joint replacement. The young patients or the old patients without obvious displacement are preferably treated by internal fixation, and because the hip replacement surgery has higher cost and larger trauma, the young patients have no obvious displacement, and the old patients are more inclined to select the internal fixation of the closed reduction hollow screw. Three hollow screws are a preferred method for treating femoral neck fractures for many years, in the case of treating femoral neck fracture by hollow compression screws, doctors at home and abroad in early days prefer a regular triangle or delta-shaped arrangement mode for arrangement and placement positions of the hollow screws, but with popularization and application of the formula, researches show that the regular triangle or delta-shaped arrangement can cause at least two screw holes to be formed in the outer cortex near the lower edge of a lesser trochanter, and if the nail placing process is repeatedly adjusted, more guide pin holes can be formed, so that the outer tensile stress strength of the femur is reduced, the probability of fracture under the trochanter of a patient is increased, and the inner arterial blood circulation of the posterior femoral rotation can be damaged.

The inverted triangle arrangement has obvious advantages in shortening operation time and reducing bleeding compared with regular triangle arrangement, an inverted triangle hollow nail system generated along with the arrangement form gradually becomes a common medical instrument for treatment, is mainly used for internal fixation operation of proximal femur neck fracture, can control displacement of fracture part, promotes fracture healing, and enables patients to get out of bed as soon as possible.

However, in the related art, the femoral neck plate fixing system is only composed of three cannulated tension screws (as shown in fig. 1), when in use, a kirschner wire is driven into the femoral neck plate fixing system based on the help of a guide, then a hollow drill is used for drilling a hole, the three cannulated tension screws are screwed in, and a certain pressure resistance is provided by the 'three-point' support of the outer cortex, the inner cortex and the subchondral bone of the femur through the screws arranged in the bone. The inverted-triangular hollow nail system cannot provide stable anti-rotation torque force and anti-shearing force for femoral neck fracture caused by high-energy injury, is used for treating the femoral neck fracture, has high secondary revision rate, can possibly cause the phenomena of screw cutting, nail withdrawing and the like, can also cause femoral neck shortening after internal fixation, further causes the reduction of hip joint abduction muscle strength of a patient, seriously influences hip joint function and reduces life quality. In addition, the inverted triangular hollow nail system has an imperfect structure and is complex to operate, and the screw nails cannot be ensured to be parallel to each other and are sometimes crossed to enable the fracture ends of the femoral neck to bear different stresses based on the fact that an operator empirically drives the guide into the kirschner wire, so that high failure rate exists, even if the fixing nails are parallel, a plurality of patients can still have screw withdrawal, and the operation can also be failed.

Disclosure of Invention

The embodiment of the invention aims to overcome the defects in the prior art, so that the femoral neck plate nail system is provided, is simple and convenient to operate and good in anti-withdrawal effect, can effectively solve the problems of poor anti-torque force and anti-shearing force, and has the following specific technical scheme:

a femoral neck plate nail system comprises a fixing piece and lag screws, wherein the fixing piece is provided with three oriented holes which are arranged in a triangular manner, and the oriented holes are used for installing the lag screws in a one-to-one corresponding manner; wherein the content of the first and second substances,

the head of the lag screw is provided with a first groove, an elastic part is arranged in the first groove, the elastic part protrudes out of the first groove in the radial direction when being in a natural state, and the elastic part can be completely contracted in the first groove when being extruded;

the inner wall of the directional hole is provided with a second groove, the directional hole is in interference fit with the head, the second groove is in clearance fit with the head, and when the lag screw is installed in the directional hole, the second groove accommodates the head and an elastic piece protruding out of the first groove.

As an implementable manner, the first groove is formed along the circumferential direction of the head, and the second groove is an arc-shaped groove.

As an implementation manner, the elastic member is a collar having a notch, and the shape of the collar is adapted to the second groove.

As an implementable manner, 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.

As an implementation manner, the elastic member is a plurality of elastic positioning pins installed in the first groove. Preferably, the elastic positioning pins are arranged in the first groove at equal intervals.

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

As an implementation manner, the directional hole is a stepped hole and includes a first hole and a second hole that are coaxially disposed, a diameter of the first hole is greater than a diameter of the second hole, the first hole is in interference fit with the head of the lag screw, the second groove is opened in an end portion of the first hole close to the second hole, and a width of a notch of the second groove is greater than or equal to a height of the head of the lag screw.

As an implementation manner, the side wall of the first hole is further provided with a plurality of dismounting blind holes, the axes of the dismounting blind holes are intersected with the axis of the first hole, and the open ends of the dismounting blind holes extend to the free ends of the first hole.

As a practical way, there are three blind dismounting holes, and the three blind dismounting holes are located on the minor arc of the free end of the first hole.

As an implementation manner, the fixing member is a triangular plate-shaped object, an axis of the orientation hole and the fixing member form an included angle, and a value range of the included angle is greater than or equal to 125 degrees and less than or equal to 135 degrees.

As an implementation mode, the fixing part is further provided with a limiting hole, the axis of the limiting hole is perpendicular to the fixing part, and the limiting hole is used for installing a locking screw.

As an implementation manner, the three directional holes are arranged in an isosceles triangle, and the limiting hole is located on an extension line of a vertex angle bisector of the isosceles triangle.

As an implementation manner, the fixing member is further provided with a positioning hole, and the positioning hole is disposed in the triangle.

The technical scheme provided by the invention has the following beneficial effects:

firstly, the fixing piece is arranged, enough support can be provided according to the tension band effect, the postoperative femoral head is prevented from being inverted, and the fixing piece is matched with the tension screws arranged in an inverted triangle, so that stable anti-rotation torque force and anti-shearing force can be provided for femoral neck fracture caused by high-energy injury;

secondly, the arrangement of the directional holes on the fixing piece can ensure that the lag screws are arranged in parallel, so that the error rate of the operation is reduced;

furthermore, the arrangement of the first groove on the lag screw, the second groove in the directional hole and the elastic element between the first groove and the second groove can avoid the nail withdrawing phenomenon, specifically, when the femoral neck plate nail system is used, the elastic element is firstly arranged in the first groove of the lag screw, then the screw rod of the lag screw passes through the directional hole, because the directional hole and the head of the lag screw are in interference fit, when external force for installing the lag screw into the directional hole is applied to the lag screw, such as downward pulling force or pressure, the elastic element can be completely retracted into the first groove under the extrusion action of the side wall of the directional hole, along with the downward movement of the head, when the first groove of the lag screw moves to correspond to the second groove in the directional hole, the elastic element loses the extrusion action of the side wall of the directional hole, expands into the second groove, because the second groove can accommodate the head, along with the continuous downward movement of the head, the head of lag screw can put into the second groove completely, because the second groove can also hold protrusion in the elastic component of first groove, then lag screw's head has certain activity space in the second inslot, nevertheless just can warp because the elastic component receives radial extrusion, consequently, even have and exert axial pulling force or thrust to the lag screw, the elastic component can not take place deformation yet, and under the injectment in second groove, can't withdraw from outside the hole to the appearance of the effectual nail condition of preventing moving back.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a schematic view of the installation of a prior art femoral neck plate nail system;

FIG. 2 is a schematic structural view of a femoral neck plate nail system provided in accordance with an embodiment of the present invention;

FIG. 3 is a side view of a femoral neck plate nail system provided in accordance with an embodiment of the present invention;

FIG. 4 is a cross-sectional view taken along line A-A of FIG. 3;

FIG. 5 is a perspective assembly view of a femoral neck plate nail system provided in accordance with one embodiment of the present invention;

FIG. 6 is a schematic structural view of a fastener according to an embodiment of the present invention;

FIG. 7 is a top view of a fastener provided in accordance with an embodiment of the invention;

FIG. 8 is a cross-sectional view taken along line B-B of FIG. 7;

FIG. 9 is an enlarged partial view at I of FIG. 8;

FIG. 10 is a schematic view of the guide pin of the guide and sleeve being mounted on the connection plate and fixed by drilling on the femur;

FIG. 11 is a schematic drawing with the removal of the other leads and sleeves except for the central lead and central sleeve;

FIG. 12 is a schematic view of the assembly of the locking screw and lag screw on the fixture for attachment to the femur with the central guide pin and central sleeve removed;

fig. 13 is a schematic view of fig. 12 from another perspective.

Description of reference numerals:

100. a fixing member;

110. a directional hole; 111. a second groove; 112. a first hole; 113. a second hole; 114. disassembling the blind hole;

120. a limiting hole; 121. a locking screw; 122. an internal thread;

130. positioning holes;

200. a lag screw; 210. a first groove;

300. an elastic member; 310. a notch;

400. the femur;

500. a sleeve;

600. and (6) guiding the needle.

Detailed Description

In the following, a description will be given of a specific embodiment of the present invention with reference to the accompanying drawings, in which the thickness of the lines or the size of the structural elements, etc. shown in the drawings may be exaggerated for clarity and convenience of description. Also, the terms described below are defined in consideration of functions in the present invention, and may be different according to intentions or conventions of users and operators. Therefore, the definition of such terms should be defined based on the contents of the present specification as a whole.

For example, the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," "outer," and the like, indicate an orientation or positional relationship based on that shown in the drawings, merely to facilitate the description of the invention and to simplify the description, and do not indicate or imply that the referenced device or element must have a particular orientation, be constructed and operated in a particular orientation, and thus should not be construed as limiting the invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present invention, it should be noted that, unless otherwise explicitly specified or limited, the terms "mounted," "connected," and "connected" are to be construed broadly, e.g., as meaning either a fixed connection, a removable connection, or an integral connection; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood in specific cases to those skilled in the art.

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

In the related technology, when the femoral neck fracture is treated, certain compression resistance is provided only by relying on three points of the lag screws which are arranged in the bone in a triangular row on the lateral cortex, the medial cortex and the subchondral bone of the femur, but the integrity is not strong, stable anti-rotation torque force and anti-shearing force cannot be provided, the secondary revision rate is high, and due to the fact that other locking or incomplete locking structures are not carried out on the lag screws, the phenomenon of nail withdrawal of many patients after the operation can occur, and operation failure is caused.

The present application is made based on the analysis and finding of the above-mentioned problems.

The application provides a femoral neck plate nail system which comprises a fixing piece and tension screws, wherein the fixing piece is provided with three directional holes which are arranged in a triangular mode, and the directional holes are used for mounting the tension screws in a one-to-one correspondence mode; the head of the lag screw is provided with a first groove, an elastic part is arranged in the first groove, the elastic part protrudes out of the first groove in the radial direction when in a natural state, and the elastic part can be completely contracted in the first groove when being extruded; the inner wall of the directional hole is provided with a second groove, the directional hole is in interference fit with the head, the second groove is in clearance fit with the head, and when the lag screw is installed in the directional hole, the second groove accommodates the head and an elastic piece protruding out of the first groove.

The femoral neck plate nail system has the characteristics of rotation prevention and nail withdrawal prevention, has reliable torsion resistance, shear resistance and compressive resistance, has axial sustainable sliding pressurization capacity, and is beneficial to early postoperative rehabilitation and fracture healing; the arrangement of the directional holes on the fixing piece can ensure that the lag screws are arranged in parallel, thereby reducing the error rate of the operation; the first groove on the tension screw, the second groove in the lock hole and the elastic part between the first groove and the second groove can avoid the nail withdrawing phenomenon, specifically, when the femoral neck plate nail system is used, the elastic part is firstly arranged in the first groove of the tension screw, then the screw rod of the tension screw passes through the orientation hole, because the orientation hole and the head of the tension screw are in interference fit, when external force for installing the tension screw into the orientation hole is applied to the tension screw, such as downward tension or pressure, the elastic part can be completely retracted into the first groove under the extrusion action of the side wall of the orientation hole, along with the downward movement of the head, when the first groove of the tension screw moves to correspond to the second groove in the orientation hole, the elastic part loses the extrusion action of the side wall of the orientation hole, stretches into the second groove, because the second groove can accommodate the head, along with the continuous downward movement of the head, the head of lag screw can be put into the second groove completely, because the second groove can also hold protrusion in the elastic component of first groove, then lag screw's head has certain activity space in the second inslot, nevertheless just can warp because the elastic component receives radial extrusion, consequently, even have and exert axial pulling force or thrust to the lag screw, the elastic component can not take place deformation yet, and under the limited in second groove, can't retreat outside the hole to the appearance of the effectual nail condition of preventing retreat.

In some optional embodiments, the first slot is opened along the circumferential direction of the head, and the second slot is an arc-shaped slot. In these embodiments, the first groove may be an annular groove formed around the axial direction of the head, the second groove is configured to be arc-shaped, any position of the first groove may correspond to the second groove in the downward moving process of the lag screw, and the second groove is configured to be arc-shaped and not configured to be annular, so that the circumferential movement of the elastic member is further limited, and an upward force is applied to the head after the operation to separate the lag screw from the directional hole.

In some alternative embodiments, the elastic member is a collar having a notch, and the shape of the collar is adapted to the second groove. In these embodiments, the collar is selected to have a gap such that radial expansion or contraction of the collar may be achieved.

In some alternative embodiments, the collar has a thickness less than or equal to the depth of the first groove, and the collar has an outer diameter in its natural state 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 fully retracted into the first groove, so that the lag screw can be smoothly installed into the orientation hole, and when the outer diameter of the elastic collar in a natural state is larger than that of the head, the second groove can be used for limiting the collar after the lag screw is installed into the orientation hole.

In some alternative embodiments, the elastic member is a plurality of elastic positioning pins installed in the first groove. Preferably, the elastic positioning pins are arranged in the first groove at equal intervals. In these embodiments, the elastic component is in the form of an elastic locating pin, the first groove may be a plurality of grooves arranged along the circumferential direction of the lag screw, the elastic locating pins may be disposed in the grooves in a one-to-one correspondence, the elastic locating property is composed of a pin body and a spring, two ends of the spring are respectively fixedly connected with the bottom walls of the pin body and the grooves, and when the elastic locating pins are arranged at equal intervals, the elastic component can play a role in uniformly limiting the lag screw.

In some optional embodiments, the elastic member is a rubber ring, and the thickness of the rubber ring is greater than the depth of the first groove. In these embodiments, the elastic component is the rubber circle that thickness is greater than the first groove degree of depth, can make its lag screw install smoothly and get into the directional downthehole through the extrusion to the rubber circle when using, through the elasticity of rubber circle self, and stretch out to the second groove in, realize spacing to the lag screw.

In some optional embodiments, the directional hole is a stepped hole and includes a first hole and a second hole coaxially arranged, a diameter of the first hole is larger than a diameter of the second hole, the first hole is in interference fit with the head of the lag screw, the second groove is opened in the first hole at an end close to the second hole, and a width of a notch of the second groove is larger than or equal to a height of the head of the lag screw. . In the embodiments, the directional hole is a stepped hole, so that the head of the lag screw can be completely sunk into the first hole, meanwhile, the diameter of the second hole is matched with the screw rod of the lag screw, a certain guiding effect can be achieved for the axial movement of the lag screw, the second groove is formed in the first hole at a position close to the end part of the second hole, the screw rod can be partially and completely arranged in the second hole, and the stability of the lag screw is improved; when the width of the notch of the second groove is greater than or equal to the height of the head of the lag screw, the second groove can completely accommodate the head of the lag screw, and the width of the second notch is slightly greater than the height of the head of the lag screw, so that poor limiting effect caused by overlarge is avoided.

In some optional embodiments, the side wall of the first hole is further provided with a plurality of blind dismounting holes, the axis of the blind dismounting holes intersects with the axis of the first hole, and the open ends of the blind dismounting holes extend to the free end of the first hole. In these embodiments, it is considered that once the lag screw is installed in the directional hole of the fixing member, under the combined action of the first groove, the second groove and the elastic member, the lag screw is difficult to separate from the directional hole, and the blind dismounting hole can provide a supporting point for external force.

In some alternative embodiments, there are three blind disassembly holes, and three blind disassembly holes are located on a minor arc of the free end of the first hole. In the embodiments, the number of the dismounting blind holes is three, so that the dismounting blind holes have better stability, and the circumferential connecting lines of the three dismounting blind holes are minor arcs so as to facilitate force application.

In some optional embodiments, the fixing member is a triangular plate, an axis of the directional hole and the fixing member form an included angle, and a value range of the included angle is greater than or equal to 125 degrees and less than or equal to 135 degrees. In the embodiments, the fixing piece is arranged to be triangular, so that the arrangement of the directional holes is facilitated, the volume of the fixing piece is reduced, the use space of the fixing piece is maximized, the stability of the triangular fixing piece is good, the vertex angle of the triangle can be provided with a fillet to match the shape of the proximal end of the femur, and the inclination of the directional holes can be matched with the neck shaft angle of the femur neck and the femur shaft.

In some optional embodiments, the fixing member is further provided with a limiting hole, an axis of the limiting hole is perpendicular to the fixing member, and the limiting hole is used for installing a locking screw. In the embodiments, the limiting hole for installing the locking screw is arranged, and the locking screw and the fixing piece are tightly locked through the limiting hole, so that the tension screw cannot lose the position and rotate and deform in the femoral neck, and the tension screw has enough anti-rotation performance.

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

In some optional embodiments, the fixing member further has a positioning hole, and the positioning hole is disposed in the triangle. In these embodiments, the locating holes are provided to facilitate early perspective positioning and later attachment to the guide.

In the concrete embodiment, according to the method,

referring to fig. 2-5, the present application provides a femoral neck plate nail system, which includes a fixing member 100 and tension screws 200, wherein the fixing member 100 is provided with three oriented holes 110 arranged in a triangular shape, and the oriented holes 110 are used for installing the tension screws 200 in a one-to-one correspondence manner; the head of the lag screw 200 is provided with a first groove 210, an elastic element 300 is arranged in the first groove 210, the elastic element 300 protrudes out of the first groove 210 in the radial direction when in a natural state, and the elastic element 300 can be completely contracted in the first groove 210 when being extruded; the inner wall of the directional hole 110 is provided with a second groove 111, the directional hole 110 is in interference fit with the head, the second groove 111 is in clearance fit with the head, and when the lag screw 200 is mounted in the directional hole 110, the second groove 111 accommodates the head and the elastic member 300 protruding out of the first groove 210.

Based on the arrangement of the fixing piece 100, the femur 400 can be supported sufficiently according to the tension band effect, the postoperative femur 400 can be prevented from being inverted, and the tension screw 200 which is arranged in an inverted triangle can be used in cooperation with the tension screw to provide stable anti-rotation torque force and anti-shearing force for the femur 400 neck fracture caused by high-energy injury; the arrangement of the directional holes 110 on the fixing member 100 can ensure that the lag screws 200 are arranged in parallel, thereby reducing the error rate of the operation; the first groove 111 of the lag screw 200, the second groove 111 of the directional hole 110, and the elastic member 300 between the first groove 210 and the second groove 111 can prevent the nail withdrawing phenomenon, specifically, when the femoral neck plate nail system is used, the elastic member 300 is firstly placed in the first groove 210 of the lag screw 200, then the screw rod of the lag screw 200 passes through the directional hole 110, and an external force for installing into the directional hole 110, such as a downward pulling force or a pressing force, is applied to the lag screw 200, the elastic member 300 is completely retracted into the first groove 210 under the pressing action of the side wall of the directional hole 110, as the head moves downwards, when the first groove 210 of the lag screw 200 moves to correspond to the second groove 111 of the directional hole 110, the elastic member 300 loses the pressing action of the side wall of the directional hole 110 and stretches into the second groove 111, as the second groove 111 can accommodate the head, as the head moves downwards, the head of the lag screw 200 can be completely placed in the second groove 111, the second groove 111 can also accommodate the elastic element 300 protruding out of the first groove 210, the head of the lag screw 200 has a certain moving space in the second groove 111, but the elastic element 300 can be deformed only by radial extrusion, so that the elastic element 300 can not be deformed even if axial pulling force or pushing force is applied to the lag screw 200, and the elastic element cannot be withdrawn out of the hole under the limitation of the second groove 111, thereby effectively preventing the situation of screw withdrawal.

Referring to fig. 3-5, in the present application, the first slot 210 is formed along the circumferential direction of the head of the lag screw 200, and referring to fig. 5, the second slot 111 is an arc-shaped slot. Any position of the first groove 210 may correspond to the second groove 111 during the downward movement of the lag screw 200, and the second groove 111 is not arranged in a circular arc shape so as to further limit the circumferential movement of the elastic member 300 and facilitate the upward force applied to the head after the operation to separate the lag screw 200 from the directional hole 110.

Referring to fig. 5, in the present embodiment, the elastic member 300 is a collar having a shape matching the second groove 111, that is, a notch 310 is formed on the collar, and the notch 310 is configured to enable the collar to have a radial contraction capability, wherein a thickness of the collar is smaller than or equal to a depth of the first groove 210, an outer diameter of the collar in a natural state is larger than an outer diameter of the head, and a material of the collar may be a material of a medical implant, such as titanium alloy.

Certainly, the structure of the elastic element 300 is not limited to the collar, and may also be other structures having a radial contraction capability, for example, the elastic element 300 may be a plurality of elastic positioning pins installed in the first groove 210, the structure of the elastic positioning pins is known to those skilled in the art, and is not described herein, and the structures may not be similar to each other, but the working principle is that a spring is disposed in a groove, a pin body is disposed at the top of the spring, and the pin body is contracted in the groove or protruded outside the groove through the expansion and contraction of the spring, in this application, the groove is the first groove 210 circumferentially disposed at the head of the lag screw 200, the elastic positioning pins are disposed in the first groove 210 at equal intervals, and of course, the first groove 210 may also be formed by a plurality of independent groove bodies which correspond to the elastic positioning pins one to one and are annularly disposed at the head of the lag screw 200.

In addition, the elastic member 300 may also be a rubber ring adapted to the second groove 111, and the thickness of the rubber ring is greater than the depth of the first groove 210, so that the lag screw 200 may be smoothly installed into the directional hole 110 by squeezing the rubber ring when in use, and the lag screw 200 may be extended into the second groove 111 by the elasticity of the rubber ring itself, thereby achieving the limitation of the lag screw 200.

Referring to fig. 6-9, in the present application, the directional hole 110 is configured as a stepped hole, and includes a first hole 112 and a second hole 113 coaxially disposed, a diameter of the first hole 112 is larger than a diameter of the second hole 113, the first hole 112 is in interference fit with a head of the lag screw 200, that is, the inner diameter of the first hole 112 is equivalent to the outer diameter of the head of the lag screw 200, the head can enter the first hole 112 by being pressed by an external force, the second groove 111 is opened in the end of the first hole 112 near the second hole 113, the width of the notch of the second groove 111 is greater than or equal to the height of the head of the lag screw 200, i.e., the directional hole 110 is counter bored, i.e., the lag screw 200 needs to be pressed into the first hole 112 by an external force, and finally, the head of the lag screw 200 can be completely sunk into the second groove 111 of the first hole 112, so that the lag screw 200 can be axially and movably limited on the fixing member 100.

Referring to fig. 3-4, considering that once the lag screw 200 is installed in the directional hole 110 of the fixing member 100, the lag screw 200 is difficult to separate from the directional hole 110 under the combined action of the first groove 210, the second groove 111 and the elastic member 300, the present application provides a plurality of blind dismounting holes 114 on the sidewall of the first hole 112, the open end of the blind dismounting holes 114 extends to the free end of the first hole 112, the blind dismounting holes 114 are arranged to provide a supporting point for external force, for example, when the lag screw 200 is dismounted by a screwdriver, it is difficult for an operator to pull out the lag screw 200 by hand without providing a reverse supporting force to the screwdriver, and when a support rod (not shown in the figures) is arranged on the screwdriver and the end of the support rod abuts against the blind dismounting holes 114 (i.e. one end of the support rod is fixedly connected to the screwdriver and the other end of the support rod contacts with the blind dismounting holes 114), by rotating the screwdriver, the support rod, supported by the bottom wall of the dismounting blind hole 114, pushes the screwdriver upwards, so that the lag screw 200 can be easily separated from the fixing piece. In this application, the axis of dismantling the blind hole is crossing with the axis of first hole, can dodge screwdriver's screw rod this moment, can exert ascending component force to the screw rod again simultaneously. In order to provide a stable counter force, the number of the blind dismounting holes 114 in the embodiment is three, and for facilitating the application of force, the circumferential connecting lines of the three blind dismounting holes are arranged to be minor arcs.

With continued reference to fig. 3 and 5, the fixing element 100 of the present application is a triangular plate, and the axis of the orientation hole 110 is disposed at an angle with respect to the fixing element 100, considering that the femoral neck and the femoral shaft normally have a shaft angle, within a range of 130 ± 5 °, and an anteversion angle with respect to the plane of the femoral condyle (human coronal plane), about 10 °, and the angle is set to a range greater than or equal to 125 degrees and less than or equal to 135 degrees.

Referring to fig. 8-9, in the present embodiment, the fixing member 100 is further provided with a limiting hole 120, an axis of the limiting hole 120 is perpendicular to the fixing member 100, and the limiting hole 120 is used for installing the locking screw 121. The locking screw 121 is used to further fix the fixing member 100 and the femur 400, so as to enhance the fixing effect and stability. Three directional hole 110 is isosceles triangle and arranges in this application, and spacing hole 120 is located isosceles triangle's apex angle bisector's extension line, and spacing hole 120 sets up to trapezoidal hole, and the great bore in trapezoidal hole corresponds with first hole 112, and less bore corresponds with second hole 113, and simultaneously, the trapezoidal downthehole internal thread 122 that is equipped with to fix locking screw 121, can further guarantee three lag screw 200's anti-rotation performance. In addition, a positioning hole 130 is formed on the fixing member 100, and the positioning hole 130 is disposed in the triangle.

In use, referring to fig. 10, the sleeve 500 and the guide pin 600 are first installed on the fixture 100 through the guide, specifically, the sleeve 500 is first installed in the positioning hole 110 and the positioning hole 130 respectively, and then fixes the connector 100 in advance through the sleeve 500 positioned at the center (i.e. in the positioning hole 130) using the guide pin 600, then another three guide pins 600 are inserted into the guide holes 110 mounted with the sleeve 500 for positioning, the guide is then removed, a hole is drilled into the femur 400 through the sleeve 500, see fig. 11, the guide pin 600 and sleeve 500, except for the centrally located guide pin 600 and sleeve 500, are removed, see fig. 12-13, the locking screw 121 is threaded into the stop hole 120, the fixture 100 is secured to the femur 400, then, three lag screws 200 are respectively arranged in a triangular shape through the directional holes 110, the broken bones are connected, and finally the central guide pin 600 and the central sleeve 500 are removed.

The locking screw 121 and the fixing member 100 are connected and fixed on the bone surface through thread matching, and after the three lag screws 200 are screwed in, a plane is formed, so that the fixing member 100 can be prevented from rotating; because the elastic element 300 is arranged at the head of the lag screw 200, and the second groove 111 on the orientation hole 110 is used for accommodating the head of the lag screw 200, the lag screw 200 has a certain range of motion after being screwed in, but because the first groove 210, the second groove 111 and the elastic element 300 cooperate to ensure that the lag screw 200 can not be withdrawn without tools, the femoral neck plate nail system has the characteristics of rotation prevention and nail withdrawal prevention, and has reliable torsion resistance, shear resistance and compression resistance, and axial sustainable sliding and pressurizing capacity, thereby being beneficial to early postoperative rehabilitation and fracture healing.

The above description is only exemplary of the invention and should not be taken as limiting the scope of the invention, which is intended to cover any variations, equivalents, or improvements included within the spirit and scope of the invention.

Claims (11)

1. The femoral neck plate nail system is characterized by comprising a fixing piece and tension screws, wherein the fixing piece is provided with three oriented holes which are arranged in a triangular manner, and the oriented holes are used for installing the tension screws in a one-to-one corresponding manner; wherein the content of the first and second substances,

a first groove is formed in the head of the lag screw, an elastic piece is arranged in the first groove, the elastic piece protrudes out of the first groove in the radial direction when being in a natural state, and the elastic piece can be completely contracted in the first groove when being extruded;

the inner wall of the directional hole is provided with a second groove, the directional hole is in interference fit with the head, the second groove is in clearance fit with the head, and when the lag screw is installed in the directional hole, the second groove accommodates the head and an elastic piece protruding out of the first groove.

2. The femoral neck plate nail system of claim 1, wherein the first slot opens in a circumferential direction of the head portion and the second slot is an arcuate slot.

3. A femoral neck plate nail system according to claim 1 or 2, wherein the resilient member is a collar having a gap, the collar being shaped to fit the second slot.

4. A femoral neck plate nail system according to claim 3, wherein the collar has a thickness less than or equal to the depth of the first groove, the collar having an outer diameter in a natural state greater than the outer diameter of the head portion.

5. A femoral neck plate nail system according to claim 1 or 2, wherein the resilient member is a plurality of resilient pins mounted in the first slot; preferably, the elastic pins are disposed in the first groove at equal intervals.

6. The femoral neck plate nail system of claim 1, wherein the resilient member is a rubber ring having a thickness greater than a depth of the first groove.

7. The femoral neck plate nail system according to any one of claims 1-2, 4 or 6, wherein the directional hole is a stepped hole comprising a first hole and a second hole coaxially arranged, the first hole having a diameter greater than a diameter of the second hole, the first hole having an interference fit with the head of the lag screw, the second slot opening in the first hole at an end proximal to the second hole, the second slot having a slot width greater than or equal to a height of the head of the lag screw.

8. The femoral neck plate nail system according to claim 7, wherein the side wall of the first hole is further provided with a plurality of blind dismounting holes, the axis of the blind dismounting holes intersects with the axis of the first hole, and the open end of the blind dismounting holes extends to the free end of the first hole;

preferably, there are three blind dismounting holes, and the three blind dismounting holes are located on a minor arc of the free end of the first hole.

9. The femoral neck plate nail system according to any one of claims 1-2, 4, 6 or 8, wherein the fixing member is a triangular plate, the axis of the directional hole is disposed at an included angle with the fixing member, and the included angle has a value in a range of 125 degrees or more and 135 degrees or less.

10. The femoral neck plate nail system according to claim 9, wherein the fixing member further comprises a limiting hole, the axis of the limiting hole is perpendicular to the fixing member, and the limiting hole is used for installing a locking screw;

preferably, the three directional holes are arranged in an isosceles triangle, and the limiting hole is located on an extension line of a vertex angle bisector of the isosceles triangle.

11. The femoral neck plate nail system according to any one of claims 1-2, 4, 6, 8 or 10, wherein the fixture further comprises a locating hole, and the locating hole is arranged in the triangle.

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