Proximal femoral intramedullary fixation device

Abstract

The present application provides a proximal femoral intramedullary fixation device, relates to the technical field of orthopedic implants, and comprises a main nail, a tension screw and a compression nail assembly. The compression nail assembly comprises a compression nail, an elastic element below the compression nail and a ratchet pawl assembly. The proximal end of the main nail is provided with a tension screw hole for installing the tension screw and a central hole for installing the compression nail assembly. One side of the tension screw is provided with a sawtooth groove. The ratchet pawl assembly comprises a pawl and two ratchets. The pawl is connected with the elastic element. The two ratchets are arranged along the axial direction of the main nail and are engaged with each other. One of the ratchets is engaged with the pawl, and the other ratchet is engaged with the sawtooth groove. When the tension screw retreats to the lower right, the sawtooth groove drives the two ratchets to rotate, so that the engagement position of the pawl with one of the ratchets is changed. The compression nail assembly cooperates with the sawtooth groove, the compression is one-way stroke, the fracture is connected tightly and cannot be pulled apart, and the phenomena of bone nonunion and malunion caused by poor fracture fixation are effectively avoided.

Description

Technical Field

[0001] The present invention relates to the technical field of orthopedic implants, and in particular to a proximal femoral intramedullary fixation device. Background Art

[0002] Femoral intramedullary nailing is the preferred treatment option for intertrochanteric fusion of the femoral shaft. Typically, a femoral intramedullary nail consists of a main nail, a lag screw, a locking nail, and a cap. The lag screw is typically in the form of a blade, a screw, or a parent-child nail. The inability to apply pressure to the fracture site after intraoperative lag screw implantation is a common problem. Furthermore, the strong fixation and free sliding of the lag screw and main nail after surgery have negative effects. In particular, the inability to apply pressure to the fracture site prolongs healing time, causing malunion and reducing the patient's quality of life.

[0003] In order to solve the above problems, the present invention provides a proximal femoral intramedullary fixation device. Summary of the Invention

[0004] The present invention proposes a proximal femoral intramedullary fixation device to solve the problems that existing femoral intramedullary nails cannot be pressed into place during surgery and the fracture site cannot be kept stable after surgery, greatly shortening the healing time of the fracture site and avoiding abnormal healing.

[0005] The present invention provides the following technical solutions:

[0006] A proximal femoral intramedullary fixation device includes a main nail, a tension screw and a pressure nail assembly, the pressure nail assembly includes a pressure nail and an elastic member and a ratchet pawl assembly below the pressure nail, the proximal end of the main nail is respectively provided with a tension screw hole for installing the tension screw and a center hole for installing the pressure nail assembly; a serration groove is opened on one side of the tension screw; the ratchet pawl assembly includes a pawl and two ratchets, the pawl is connected to the elastic member, the two ratchets are arranged along the axial direction of the main nail and mesh with each other, and one of the ratchets is meshed with the pawl, and the other ratchet is meshed with the serration groove. When the tension screw retreats obliquely downward, the serration groove drives the two ratchets to rotate, so that the pawl changes its meshing position with one of the ratchets.

[0007] As a preferred solution of the above-mentioned proximal femoral intramedullary fixation device, the pressure nail assembly further includes a receiving member for accommodating and installing the elastic member and the ratchet pawl assembly, and the pressure nail is rotatably connected to the receiving member.

[0008] As a preferred solution of the above-mentioned proximal femoral intramedullary fixation device, a protrusion is provided on one side of the accommodating part, and a longitudinal groove for receiving the protrusion is formed on the side wall of the central hole, and the width of the protrusion is the same as that of the longitudinal groove.

[0009] As a preferred solution of the above-mentioned proximal femoral intramedullary fixation device, the longitudinal groove includes a limiting platform, which is perpendicular to the longitudinal direction of the main nail and is used to limit the protrusion.

[0010] As a preferred solution of the above-mentioned proximal femoral intramedullary fixation device, the pressure nail includes a threaded rod segment and a T-shaped connector arranged at the end of the threaded rod segment, the T-shaped connector includes a connecting rod and a baffle, the baffle and the connecting rod are vertically connected, the connecting rod is connected to the threaded rod segment, the accommodating part includes a main body and a connecting part arranged at the upper end of the main body, the connecting part includes a connecting plate, and a spacing space is provided between the connecting plate and the main body. When the pressure nail is connected to the accommodating part, the baffle is installed in the spacing space, and the connecting rod is passed through the connecting plate.

[0011] As a preferred solution of the above-mentioned proximal femoral intramedullary fixation device, the connecting plate is provided with a through hole with an opening on a side surface, and the connecting rod is installed into the through hole through the opening.

[0012] As a preferred solution of the above-mentioned proximal femoral intramedullary fixation device, a accommodating groove is provided in the accommodating member, the elastic member is fixedly connected to the top of the accommodating groove, the pawl is connected to the elastic member, and the two ratchets are rotatably fixed on the side walls of the accommodating groove.

[0013] As a preferred solution of the above-mentioned proximal femoral intramedullary fixation device, it further includes a locking nail, which is penetrated through the distal end of the main nail.

[0014] As a preferred solution of the above-mentioned proximal femoral intramedullary fixation device, it also includes a tail cap with external threads, and the top end of the central hole is provided with internal threads that are compatible with the external threads on the tail cap.

[0015] The beneficial effects of the present invention are:

[0016] The proximal femoral intramedullary fixation device of the present invention has a serrated groove on the tension screw, and an elastic member and a ratchet pawl assembly are also provided in the pressure nail assembly. The elastic member presses down the pawl, the pawl engages with the first ratchet, and the second ratchet engages with the serrated groove. When the position of the femoral neck fracture moves slightly, the tension screw retreats, driving the fracture part to retreat. The one-way stroke is pressurized, and the fracture is tightly connected and will not be pulled apart, effectively avoiding phenomena such as nonunion and abnormal healing caused by poor fracture fixation.

[0017] Other features and advantages of the present invention will be described in the following description, and in part will become apparent from the description, or understood by practicing the present invention. The purpose and other advantages of the present invention are realized and obtained by the structures particularly pointed out in the description and the drawings.

[0018] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, preferred embodiments are given below and described in detail with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0020] Figure 1 Schematic diagram of the structure of the proximal femoral intramedullary fixation device in an embodiment of the present invention;

[0021] Figure 2 This is a partial enlarged view of point A in an embodiment of the present invention;

[0022] Figure 3 This is a schematic structural diagram of the proximal end of the main nail in an embodiment of the present invention;

[0023] Figure 4 Schematic diagram of the structure of the accommodation component in an embodiment of the present invention.

[0024] In the figure:

[0025] 1. Main nail; 11. Lag screw hole; 12. Center hole; 121. Longitudinal groove; 122. Limiting platform;

[0026] 2. Lag screw; 21. Serrated groove;

[0027] 3. Press nail assembly;

[0028] 31. Press pin; 311. Threaded rod segment; 312. T-shaped connector; 3121. Connecting rod; 3122. Baffle; 32. Elastic member; 33. Ratchet and pawl assembly; 331. Pawl; 332. First ratchet; 333. Second ratchet; 34. Accommodating member; 341. Protrusion; 342. Main body; 343. Connecting portion; 3431. Connecting plate; 3432. Spacing space; 344. Accommodating groove;

[0029] 4. Locking pin; 5. Tail cap. DETAILED DESCRIPTION

[0030] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of them. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0031] To facilitate understanding of this embodiment, a proximal femoral intramedullary fixation device disclosed in the present invention is described in detail below through an embodiment.

[0032] Reference Figure 1-4 As shown, this embodiment provides a proximal femoral intramedullary fixation device, which includes a main nail 1, a tension screw 2 and a pressure nail assembly 3, the pressure nail assembly 3 includes a pressure nail 31 and an elastic member 32 and a ratchet pawl assembly 33 below the pressure nail 31, the proximal end of the main nail 1 is respectively provided with a tension screw hole 12 for installing the tension screw 2 and a center hole 17 for installing the pressure nail assembly; a serration groove 21 is opened on one side of the tension screw 2; the ratchet pawl assembly 33 includes a pawl 331 and two ratchets, the pawl 331 is connected to the elastic member 32, the two ratchets are arranged along the axial direction of the main nail 1 and mesh with each other, and one of the ratchet wheels is meshed with the pawl 331, and the other ratchet wheel is meshed with the serration groove 21. When the tension screw 2 retreats obliquely downward, the serration groove 21 drives the two ratchets to rotate, so that the pawl 331 changes the meshing position with one of the ratchets.

[0033] In this embodiment, the two ratchets are a first ratchet 332 and a second ratchet 333 . The first ratchet 332 is engaged with the pawl 331 , and the second ratchet 333 is engaged with the first ratchet 332 and the serrated groove 21 .

[0034] The proximal femoral intramedullary fixation device of this embodiment has a serrated groove 21 on the tension screw 2, and an elastic member 32 and a ratchet pawl assembly 33 are also provided in the pressure nail assembly 3. The elastic member 32 presses down the pawl 331, the pawl 331 engages with the first ratchet 332, and the second ratchet 333 engages with the serrated groove 21. When the position of the femoral neck fracture moves slightly, the tension screw 2 retreats, driving the fracture part to retreat. The one-way stroke is pressurized, and the fracture is tightly connected and will not be pulled apart, effectively avoiding nonunion and abnormal healing caused by poor fracture fixation.

[0035] like Figure 2As shown, the compression nail assembly 3 further comprises a housing 34 for accommodating and mounting the elastic member 32 and the ratchet pawl assembly 33, and the compression nail 31 is rotationally connected with the housing 34. When the compression nail assembly 3 is assembled into the main nail 1, the compression nail 31 can be rotated to achieve threaded connection while the housing 34 remains non-rotating. One side of the housing 34 is provided with a protrusion 341, and a longitudinal groove 121 for accommodating the protrusion 341 is formed in the sidewall of the central hole 12. The width of the protrusion 341 is the same as that of the longitudinal groove 121. The cooperation between the protrusion 341 and the longitudinal groove 121 can prevent the rotation of the housing 34 in the central hole 12, thereby ensuring the correct assembly of the compression nail assembly 3.

[0036] As shown in Figure 2 and 3 shown, the longitudinal groove 121 comprises a limiting platform 122 which is longitudinally and vertically arranged with the main nail 1, and is used for limiting the protrusion 341. For example, the assembly position of the housing 34 can be limited so that the housing 34 is above the tension screw 2, thereby avoiding the interference of the housing 34 with the tension screw 2 and the like.

[0037] As shown in Figure 2 shown, the compression nail 31 comprises a threaded rod segment 311 and a T-shaped connecting piece 312 arranged at the end of the threaded rod segment 311. The T-shaped connecting piece 312 comprises a connecting rod 3121 and a baffle 3122 which are vertically connected, and the connecting rod 3121 is connected with the threaded rod segment 311. The housing 34 comprises a main body 342 and a connecting part 343 arranged at the upper end of the main body 342. The connecting part 343 comprises a connecting plate 3431, and a spacing space 3432 is arranged between the connecting plate 3431 and the main body 342. When the compression nail 31 is connected with the housing 34, the baffle 3122 is accommodated in the spacing space 3432, and the connecting rod 3121 is arranged through the connecting plate 3431. The connecting plate 3431 is provided with a through hole having an opening on the side surface, and the connecting rod 3121 is arranged through the through hole from the opening. This structure can make the assembly of the compression nail 31 and the housing 34 more convenient without the need for excessive operation.

[0038] As shown in Figure 4 shown, the housing 34 is provided with a receiving groove 344, the elastic member 32 is fixedly connected to the top of the receiving groove 344, the pawl 331 is connected to the elastic member, and the two ratchets are rotatably fixed to the sidewall of the receiving groove 344.

[0039] As shown in Figure 1 shown, in this embodiment, the proximal femoral intramedullary fixation device further comprises a locking nail 4 which is arranged through the distal end of the main nail 1.

[0040] As shown in Figure 1As shown, in the embodiment, the proximal femoral intramedullary fixation device further comprises a tail cap 5 provided with external threads, and the top end of the central hole 12 is provided with internal threads matching the external threads on the tail cap 5. The central hole 12 of the main nail 1 is plugged by the tail cap 5 to avoid tissue growth.

[0041] During surgery, after implanting the main nail, the corresponding tension screw 2 is selected and implanted according to the fracture site and the patient's femoral anatomical shape to pressurize the intertrochanteric or femoral neck fracture site; then the compression nail assembly 3 is installed into the central hole 12, the protrusion 341 is matched with the longitudinal groove 121, and the protrusion 341 abuts against the limiting platform 122, at this time, the second ratchet 333 is engaged with the sawtooth groove 21 on one side of the tension screw 2. The tail cap 5 is implanted to plug the upper part of the main nail 1. The locking nail 4 is implanted to lock the intramedullary fixation system with the femoral shaft, and the normal anatomical shape of the proximal femoral neck and femoral head is maintained by means of the strong cortical bone of the femoral shaft.

[0042] After surgery, under the action of its own gravity, the tension screw 2 moves obliquely downward, the sawtooth groove 21 drives the second ratchet 333 to rotate, the second ratchet 333 drives the first ratchet 332 to rotate, the rotation of the first ratchet 333 drives the pawl 331 to move upward slightly and re-engage with the first ratchet 332; the pawl 331, the first ratchet 332, the second ratchet 333 and the sawtooth groove 21 maintain stable engagement; the proximal femoral intramedullary fixation device in the embodiment is beneficial to bone healing, improves the stability of the fracture site after surgery, avoids malunion, and effectively reduces the patient's pain.

[0043] After surgery, the tension screw 2 does not rotate with the main nail 1, and the bone fracture site can also be continuously reduced and stabilized by using its own weight.

[0044] Finally, it should be noted that the above-described embodiments are merely specific implementations of the present application, which are used to illustrate the technical solutions of the present application, but not to limit the same, and the protection scope of the present application is not limited thereto. Although the present application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that any person skilled in the art can make modifications or easily think of changes to the technical solutions recorded in the foregoing embodiments within the technical range disclosed by the present application, or make equivalent replacements to some technical features; and these modifications, changes or replacements do not make the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application, and should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A proximal femoral intramedullary fixation device, characterized in that: The invention comprises a main nail (1), a tension screw (2) and a pressure nail assembly (3), wherein the pressure nail assembly (3) comprises a pressure nail (31), an elastic member (32) and a ratchet pawl assembly (33) below the pressure nail (31), and a tension screw hole (11) for installing the tension screw (2) and a center hole (12) for installing the pressure nail assembly (3) are respectively provided at the proximal end of the main nail (1); a sawtooth groove (21) is provided on one side of the tension screw (2); the ratchet pawl assembly (33) comprises a pawl (331) and two ratchets, wherein the pawl (331) is connected to the elastic member (32), and the two ratchets are connected to the elastic member (32). The ratchets are arranged along the axial direction of the main nail (1) and mesh with each other, and one of the ratchets meshes with the pawl (331), and the other ratchet meshes with the serrated groove (21). When the tension screw (2) retreats obliquely downward, the serrated groove (21) drives the two ratchets to rotate, so that the pawl (331) changes its meshing position with one of the ratchets. The pressure nail assembly (3) also includes a receiving part (34) for accommodating and installing the elastic part (32) and the ratchet pawl assembly (33). The pressure nail (31) is rotatably connected to the receiving part (34).

2. The proximal femoral intramedullary fixation device according to claim 1, characterized in that: A protrusion (341) is provided on one side of the accommodating part (34), and a longitudinal groove (121) for receiving the protrusion (341) is provided on the side wall of the central hole (12), and the width of the protrusion (341) is the same as the width of the longitudinal groove (121).

3. The proximal femoral intramedullary fixation device according to claim 2, characterized in that: The longitudinal groove (121) comprises a limiting platform (122), wherein the limiting platform (122) is perpendicular to the longitudinal direction of the main nail (1) and is used to limit the protrusion (341).

4. The proximal femoral intramedullary fixation device according to claim 1, characterized in that: The pressure nail (31) comprises a threaded rod section (311) and a T-shaped connecting piece (312) provided at the front end of the threaded rod section (311); the T-shaped connecting piece (312) comprises a connecting rod (3121) and a baffle (3122); the baffle (3122) and the connecting rod (3121) are vertically connected; the connecting rod (3121) is connected to the threaded rod section (311); the accommodating member (34) comprises a main body (342) and a connecting portion (343) provided at the upper end of the main body (342); the connecting portion (343) comprises a connecting plate (3431); a spacing space (3432) is provided between the connecting plate (3431) and the main body (342); when the pressure nail (31) is connected to the accommodating member (34), the baffle (3122) is inserted into the spacing space (3432), and the connecting rod (3121) is passed through the connecting plate (3431).

5. The proximal femoral intramedullary fixation device according to claim 4, characterized in that: The connecting plate (3431) is provided with a through hole with an opening on the side, and the connecting rod (3121) is installed into the through hole through the opening.

6. The proximal femoral intramedullary fixation device according to claim 1, characterized in that: An accommodating groove (344) is provided in the accommodating member (34), the elastic member (32) is fixedly connected to the top of the accommodating groove (344), the pawl (331) is connected to the elastic member (32), and the two ratchets are rotatably fixed on the side walls of the accommodating groove (344).

7. The proximal femoral intramedullary fixation device according to claim 1, characterized in that: It also includes a locking nail (4), which is passed through the distal end of the main nail (1).

8. The proximal femoral intramedullary fixation device according to claim 1, characterized in that: It also includes a tail cap (5) provided with an external thread, and the top end of the central hole (12) is provided with an internal thread that matches the external thread on the tail cap (5).

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