Femoral intertrochanteric fracture intramedullary fixing device

Abstract

The invention discloses a femoral intertrochanteric fracture intramedullary fixing device which comprises a nail body, a cavity extending from the near end to the far end along the longitudinal axis is formed in the nail body, and a force carrier system is arranged on the nail body to create dynamic control at the femoral neck and the femoral head of a human body to achieve the controllable transverse power effect to eliminate stress shielding. The force carrier system comprises a movable assembly arranged at the near end of the nail body and at least one third sliding part arranged at the far end of the nail body, the movable assembly plays a role in connecting and fixing the femoral neck and the femoral head and serves as a main power source with the transverse power function, and the third sliding part is used for movably connecting the far end of the nail body and the femoral body. The intramedullary nail can decompose stress concentration and stress shielding of the locking nail on the intramedullary nail, the bending strength is enhanced, and biomechanical stability is achieved. The titanium coating is used at the near end of the intramedullary nail, the friction coefficient is high, the induced initial stability and the long-term bone ingrowth effect are provided, and the occurrence of nail breaking, bone nonunion and delayed bone healing can be effectively reduced.

Description

Technical Field

[0001] The present invention relates to an intramedullary fixation device for intertrochanteric fractures of the femur, belonging to the technical field of medical devices. Background Art

[0002] Intertrochanteric fractures of the femur are common in the elderly. Due to osteoporosis in the elderly, when they fall and land on their buttocks, intertrochanteric fractures of the femur are likely to occur. If not treated, the fracture site may not heal properly, resulting in long-term pain, functional impairment, and even affecting the quality of life. Intertrochanteric fractures of the femur can be conservatively treated by methods such as skeletal traction and drug treatment. Skeletal traction can help reduce the fracture site, and drug treatment can promote fracture healing.

[0003] Currently, the commonly used method of skeletal traction in medicine is to implant an intramedullary nail at the fracture site of the patient, and use a slender metal rod inserted into the medullary cavity to stabilize and support the fractured bone, and use the friction between the nail and the bone and the contact surface between the nail tail and the surrounding tissues to provide stability.

[0004] However, existing ordinary intramedullary nails usually have problems such as concentrated locking stress and stress shielding, and poor anti-torsion ability. As a result, the intramedullary nail is prone to bending or breaking, and the fixation effect is poor, which is not conducive to the healing of the patient's bone. Therefore, there is an urgent need in the art for an intramedullary fixation device with strong structural stability and strong anti-torsion ability to improve the fracture fixation and healing effect of patients. Summary of the Invention

[0005] The problem to be solved by the present invention is that existing ordinary intramedullary nails have problems such as concentrated locking stress and stress shielding, and poor anti-torsion ability, which are prone to bending or breaking of the intramedullary nail, and the fixation effect is poor, which is not conducive to the healing of the patient's bone.

[0006] To solve the above technical problems, the present invention provides an intramedullary fixation device for intertrochanteric fractures of the femur, which can decompose the concentrated locking stress and stress shielding while maintaining the characteristics of the original static intramedullary nail, enhance the bending strength, effectively reduce the occurrence of broken nails, nonunion, and delayed bone healing, and make the fracture fixation and healing effect better.

[0007] To achieve the above technical objectives and reach the above technical effects, the present application is realized through the following technical solutions:

[0008] An intramedullary fixation device for intertrochanteric fractures of the femur, comprising a nail body. A cavity extending from the proximal end to the distal end along the longitudinal axis is provided inside the nail body. A force carrier system is provided on the nail body to create dynamic control at the femoral neck and femoral head of the human body to achieve controllable transverse dynamic action and eliminate stress shielding. The force carrier system includes a movable component provided at the proximal end of the nail body and at least one sliding member three provided at the distal end of the nail body. The movable component serves as the main power source for the transverse dynamic action while connecting and fixing the femoral neck and femoral head, and the sliding member three is used for the movable connection between the distal end of the nail body and the femoral body.

[0009] Preferably, the movable component includes a first sliding member and a second sliding member. A locking hole extending transversely through the nail body is provided on the nail body. The first sliding member transversely penetrates the outer wall of the proximal end of the nail body and the cavity at the proximal end of the nail body through the locking hole. The distal end of the first sliding member has a threaded portion one for connecting the femoral head. The second sliding member transversely penetrates the outer wall of the proximal end of the nail body and the cavity at the proximal end of the nail body and is located below the first sliding member and is slidably engaged with the outer wall of the proximal end of the first sliding member.

[0010] Furthermore, at least one chute is provided on the outer wall of the proximal end of the first sliding member, and a threaded portion two slidably engaged with the chute is provided on the outer wall of the second sliding member.

[0011] Furthermore, the proximal end portion and the distal end portion of the nail body are inclined, and a titanium coating is provided on the outer wall at the folding portion of the proximal end portion and the distal end portion.

[0012] Even further, the locking hole is inclined upward at an angle of 125° and is provided on the proximal end portion.

[0013] Furthermore, the first sliding member is a self-cutting tension screw, and a U-shaped groove is provided on the proximal end face of the first sliding member.

[0014] Preferably, two sliding members three are provided at intervals up and down and both penetrate the outer wall of the distal end of the nail body and the internal cavity of the nail body. The two sliding members three are locking nails with different diameters, and positioning holes adapted to the two sliding members three are provided on the nail body.

[0015] Furthermore, the positioning holes provided on the nail body away from the proximal end of the nail body extend along the axial direction of the nail body and are in the shape of a waist-shaped hole or an oval hole, and the corresponding sliding member three can longitudinally move in the waist-shaped or oval positioning hole.

[0016] Preferably, the distal end of the nail body is designed as a bullet head.

[0017] Preferably, the length of the nail body is 180 mm, the diameter of the internal cavity of the nail body is 8 mm, and the proximal end of the nail body is a cylinder with a diameter ranging from 15.5 mm to 16 mm.

[0018] The intramedullary fixation device for intertrochanteric fracture provided by the present invention has the following advantages:

[0019] 1. For the intramedullary fixation device for intertrochanteric fracture of the present invention, the first sliding member is designed with a self-cutting lag screw, which can reduce the torque of the lag screw and simultaneously reduce the incidence of cut-out. The surface U-shaped groove design provides more contact surfaces for the consumables and bone, has better gripping force, enhances the anti-rotation force and increases the resistance by about 15%.

[0020] 2. For the intramedullary fixation device for intertrochanteric fracture of the present invention, the second sliding member is anchored in the nail body and slidably cooperates with the chute on the first sliding member, creating a dynamically controlled force carrier system at the femoral neck and femoral head, realizing controllable lateral dynamic action, preventing offset when the inner side is in full contact, eliminating the stress shielding effect and promoting fracture healing.

[0021] 3. For the intramedullary fixation device for intertrochanteric fracture of the present invention, the distal end of the nail body is designed with a bullet head, which effectively avoids thigh pain caused by stress concentration. All intramedullary nails are hollow-designed, which is beneficial to reducing the weight and achieving biomechanical stability.

[0022] 4. For the intramedullary fixation device for intertrochanteric fracture of the present invention, the proximal diameter of the nail body is reduced to the range of 15.5 mm to 16 mm, which can not only maintain the same biomechanical strength as traditional products, but also reduce the requirement for medullary cavity expansion.

[0023] 5. For the intramedullary fixation device for intertrochanteric fracture of the present invention, the bending parts at the proximal and distal ends of the nail body use a titanium coating, which has a high friction coefficient and provides induced initial stability and long-term bone ingrowth effect. Description of the Drawings

[0024] Figure 1 It is a schematic structural diagram of an intramedullary fixation device for intertrochanteric fracture provided by Embodiment 1 of the present invention;

[0025] Figure 2 It is a schematic cross-sectional structural diagram of an intramedullary fixation device for intertrochanteric fracture provided by Embodiment 1 of the present invention;

[0026] Figure 3 It is a schematic structural diagram of an intramedullary fixation device for intertrochanteric fracture provided by Embodiment 2 of the present invention;

[0027] In the figure:

[0028] 1-nail body; 11-proximal end; 12-distal end; 13-cavity; 14-locking hole; 15-mounting hole; 16-positioning hole; 2-force carrier system; 21-movable component; 211-first sliding member; 2111-threaded portion one; 2112-U-shaped groove; 2113-slide groove; 212-second sliding member; 2121-threaded portion two; 22-sliding member three; 3-titanium coating. DETAILED DESCRIPTION

[0029] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technical personnel in this field without making creative work are within the scope of protection of the present invention.

[0030] Embodiment 1:

[0031] Reference Figure 1 and Figure 2 A femoral intertrochanteric fracture intramedullary fixation device includes a nail body 1 and a force carrier system 2. The force carrier system 2 is installed on the nail body 1 to create dynamic control at the femoral neck and femoral head of the human body to achieve controllable lateral dynamic action and eliminate stress shielding.

[0032] The nail body 1 includes an integrally formed proximal portion 11 and a distal portion 12. The proximal portion 11 and the distal portion 12 are inclined and the inclination angle is preferably 4°. A cavity 13 extending from the proximal end to the distal end along the longitudinal axis is provided in the nail body 1. The overall length of the nail body 1 is preferably 180 mm, and the bending strength is good; the diameter of the cavity 13 inside the nail body 1 is preferably 8 mm, and the proximal portion 11 of the nail body 1 is a cylinder with a diameter of 15.5 mm to 16 mm. In this embodiment, the diameter of the proximal portion 11 is preferably 15.7 mm, which can maintain the same biomechanical strength as traditional products and reduce the requirements for medullary cavity expansion. The nail body 1 is made of titanium alloy, and the strength of the implant is enhanced by anodizing ion type II surface treatment.

[0033] Furthermore, the distal end 12 of the nail body 1 is designed in a bullet-shaped manner at one end away from the proximal end 11, which can effectively avoid thigh pain caused by stress concentration. All intramedullary nails are hollow in design, which is conducive to reducing weight and achieving biomechanical stability.

[0034] Reference Figure 1 and Figure 2The force carrier system 2 includes a movable component 21 installed at the proximal end of the nail body 1, and at least one sliding component 22 installed at the distal end of the nail body 1. The movable component 21 can connect and fix the femoral neck and femoral head while serving as the main power source for lateral dynamic action. The sliding component 22 is used for the movable connection between the distal end of the nail body 1 and the femoral body.

[0035] The movable component 21 includes a first sliding member 211 and a second sliding member 212. A locking hole 14 extending transversely through the nail body 1 is provided on the nail body 1. The first sliding member 211 transversely penetrates the outer wall of the proximal end of the nail body 1 and the cavity 13 at the proximal end of the nail body 1 through the locking hole 14. The distal end of the first sliding member 211 has a threaded portion 2111 connected to the femoral head. In this embodiment, the first sliding member 211 preferably adopts a self-cutting lag screw to reduce the torque of the lag screw and reduce the incidence of cutting out. A U-shaped groove 2112U is provided on the proximal end surface of the first sliding member 211. The U-shaped groove 2112U is designed to provide more contact surfaces between consumables and bone, have better gripping force, enhance anti-rotation force and increase resistance by about 15%;

[0036] The second sliding member 212 transversely penetrates the proximal outer wall of the nail body 1 and the cavity 13 at the proximal end of the nail body 1 and is located at the lower side of the first sliding member 211 and slidably cooperates with the proximal outer wall of the first sliding member 211. A mounting hole 15 extending transversely through the nail body 1 is provided on the nail body 1 for the penetration of the second sliding member 212, and the mounting hole 15 is connected with the locking hole 14. Specifically, at least one sliding groove 2113 is provided on the proximal outer wall of the first sliding member 211, and a threaded portion 2121 that slidably cooperates with the sliding groove 2113 is provided on the outer wall of the second sliding member 212, and then the sliding limitation of the threaded portion 2121 is achieved through the inner wall of the sliding groove 2113, thereby creating a dynamically controlled force carrier system 2 at the femoral neck and femoral head, realizing controllable lateral dynamic action, preventing displacement when the inner side is fully in contact, eliminating stress shielding effect, and promoting fracture healing.

[0037] Furthermore, the length of the first sliding member 211 and the second sliding member 212 are preferably 130 mm and have a nut, the diameter of the first sliding member 211 is preferably 10.5 mm, the length of the threaded portion 2111 is preferably 30 mm, the diameter of the end of the second sliding member 212 away from the threaded portion 2121 is preferably 6.6 mm, the diameter of the end with the threaded portion 2121 is preferably 5.5 mm and the length of the threaded portion 2121 is preferably 65 mm, the locking hole 14 is inclined upward at an angle of 125° on the proximal portion 11, so that the neck-shaft angle of the intramedullary fixation device is suitable for adapting to the anatomical structure of most Chinese people, and the anteversion angle of the intramedullary fixation device is preferably preset to 15°, and the distance from the end of the proximal portion 11 of the nail body 1 away from the distal portion 12 to the locking hole 14 is preferably 38 mm.

[0038] Reference Figure 1 and Figure 2 , a titanium coating 3 is covered on the outer wall of the folding part between the proximal end 11 and the distal end 12, and the titanium coating 3 on the proximal end 11 starts to cover from the bottom of the mounting hole 15, so as to provide induced initial stability and long-term bone ingrowth effect through the high friction coefficient of the titanium coating 3.

[0039] Reference Figure 1 and Figure 2 , two sliding members three 22 are arranged at intervals up and down and both pass through the outer wall of the distal end of the nail body 1 and the inner cavity 13 of the nail body 1. The two sliding members three 22 are locking nails with different diameters. Positioning holes 16 adapted to the two sliding members three are formed on the nail body. While providing stable connection, dynamic interlocking and static locking can be selected, which is convenient for various fracture fixations.

[0040] The working principle of an intramedullary fixation device for intertrochanteric fractures of the femur of the present invention is as follows:

[0041] The intramedullary fixation device for intertrochanteric fractures of the femur can decompose the stress concentration and stress shielding of the locking nails while maintaining the characteristics of the original static intramedullary nail, enhance the bending strength, and achieve biomechanical stability. The proximal end of the nail body 1 of the intramedullary nail uses a titanium coating 3 with a high friction coefficient to provide induced initial stability and long-term bone ingrowth effect. At the same time, the occurrence of nail breakage, nonunion, and delayed bone healing can be effectively reduced, and a dynamically controlled force carrier system 2 is created at the femoral neck and femoral head to achieve a controllable lateral dynamic effect, providing more contact surfaces between the consumables and the bone mass, having better gripping force, enhancing the anti-rotation force and increasing the resistance by about 15%. Therefore, controllable and effective compressive stress can be generated at the fracture end whether walking or standing. The fracture fixation and healing effect can be made better without adding procedures.

[0042] Embodiment 2:

[0043] Reference Figure 3 , the difference between this embodiment and Embodiment 1 is that: the positioning holes 16 opened on the nail body 1 far from the proximal end 11 of the nail body 1 extend along the axial direction of the nail body 1 and are arranged in a waist-shaped hole or an oval shape, and the corresponding sliding members three 22 can move longitudinally in the waist-shaped or oval-shaped positioning holes 16, so that the intramedullary fixation device can be longitudinally pressurized. Only the waist-shaped hole is taken as an example in this embodiment Figure 3 here.

[0044] The above are only the preferred embodiments of the present invention, and do not impose any formal or substantial limitations on the present invention. It should be noted that for those of ordinary skill in the art of this technology, without departing from the premise of the present invention, several improvements and supplements can still be made, and these improvements and supplements should also be regarded as within the protection scope of the present invention. Any equivalent changes made by those who are familiar with the technology in this field, such as minor modifications, decorations, and evolutions, without departing from the spirit and scope of the present invention, using the technical content disclosed above, are equivalent embodiments of the present invention; at the same time, any equivalent changes, modifications, and evolutions made to the above embodiments based on the essential technology of the present invention still fall within the scope of the technical solutions of the present invention.

Claims

1. An intramedullary fixation device for intertrochanteric fracture of the femur, characterized in that: The invention comprises a nail body (1), wherein a cavity (13) is provided in the nail body (1) and extends from the proximal end to the distal end along the longitudinal axis. A force carrier system (2) is provided on the nail body (1) to create dynamic control at the femoral neck and femoral head of the human body to achieve controllable lateral dynamic action to eliminate stress shielding. The force carrier system (2) comprises a movable component (21) arranged at the proximal end of the nail body (1), and at least one sliding member (22) arranged at the distal end of the nail body (1). The movable component (21) serves as the main power source for the lateral dynamic action while connecting and fixing the femoral neck and femoral head. The sliding member (22) is used for the movable connection between the distal end of the nail body (1) and the femoral body.

2. The intramedullary fixation device for intertrochanteric fracture of femur according to claim 1, characterized in that: The movable component (21) includes a first sliding member (211) and a second sliding member (212); a locking hole (14) extending transversely through the nail body (1) is provided on the nail body (1); the first sliding member (211) transversely penetrates the proximal outer wall of the nail body (1) and the cavity (13) at the proximal end of the nail body (1) through the locking hole (14); the first sliding member (211) has a threaded portion (2111) connected to the femoral head at the distal end; the second sliding member (212) transversely penetrates the proximal outer wall of the nail body (1) and the cavity (13) at the proximal end of the nail body (1) and is located at the lower side of the first sliding member (211) and is slidably matched with the proximal outer wall of the first sliding member (211).

3. The intramedullary fixation device for intertrochanteric fracture of femur according to claim 2, characterized in that: At least one sliding groove (2113) is provided on the proximal outer wall of the first sliding member (211), and a second threaded portion (2121) that slides and cooperates with the sliding groove (2113) is provided on the outer wall of the second sliding member (212).

4. The intramedullary fixation device for intertrochanteric fracture of femur according to claim 2, characterized in that: The proximal end portion (11) and the distal end portion (12) of the nail body (1) are arranged at an inclination, and a titanium coating (3) is provided on the outer wall of the folded portion between the proximal end portion (11) and the distal end portion (12).

5. The intramedullary fixation device for intertrochanteric fracture of femur according to claim 4, characterized in that: The locking hole (14) is opened on the proximal end portion (11) at an angle of 125° and tilted upward.

6. The intramedullary fixation device for intertrochanteric fracture of femur according to claim 2, characterized in that: The first sliding member (211) is a self-cutting tension screw, and a U-shaped groove (2112) is provided on the proximal end surface of the first sliding member (211).

7. The intramedullary fixation device for intertrochanteric fracture of femur according to claim 1, characterized in that: The two sliding members (22) are arranged at intervals in the upper and lower parts and both penetrate the outer wall of the distal end of the nail body (1) and the internal cavity (13) of the nail body (1). The two sliding members (22) are locking nails with different diameters. The nail body (1) is provided with positioning holes (16) adapted to be connected with the two sliding members (22).

8. The intramedullary fixation device for intertrochanteric fracture of femur according to claim 7, characterized in that: The positioning hole (16) on the nail body (1) and away from the proximal end of the nail body (1) is arranged in the form of a waist-shaped hole or an elliptical hole extending axially along the nail body (1), and the corresponding sliding member three (22) can move longitudinally in the waist-shaped or elliptical positioning hole (16).

9. The intramedullary fixation device for intertrochanteric fracture of femur according to claim 1, characterized in that: The distal end of the nail body (1) is designed as a bullet head.

10. The intramedullary fixation device for intertrochanteric fracture of femur according to claim 1, characterized in that: The length of the nail body (1) is 180 mm, the diameter of the internal cavity (13) of the nail body (1) is 8 mm, and the proximal end of the nail body (1) is a cylinder with a diameter of 15.5 mm to 16 mm.

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