Intramedullary fixation device for intertrochanteric fractures of the femur

Abstract

The application discloses an intramedullary fixation device for femoral intertrochanteric fracture, which comprises a nail body, a cavity extending along a longitudinal axis from a proximal end to a distal end is arranged in the nail body, a force carrier system is arranged on the nail body to create a dynamic control at a human femoral neck and femoral head to eliminate stress shielding and realize controllable transverse dynamic force, the force carrier system comprises a movable assembly arranged at the proximal end of the nail body and at least one sliding piece arranged at the distal end of the nail body, the movable assembly serves as a main power source of the transverse dynamic force while playing a connecting and fixing role on the femoral neck and femoral head, and the sliding piece is used for the movable connection between the distal end of the nail body and the femoral body. The application can decompose the stress concentration and stress shielding of the locking nail on the intramedullary nail, enhances the bending strength, and realizes the stability of biomechanics. The proximal end of the intramedullary nail is coated with titanium, has a high friction coefficient, provides initial stability and long-term bone ingrowth effect, and can effectively reduce the occurrence of broken nail, bone nonunion and delayed bone healing.

Description

TECHNICAL FIELD

[0001] The present application relates to an intramedullary fixation device for intertrochanteric fracture of femur, belonging to the technical field of medical treatment instruments. BACKGROUND

[0002] Intertrochanteric fracture of femur is common in the elderly. Due to osteoporosis in the elderly, the hip is prone to fracture after falling. If not treated, the fracture site may not heal properly, leading to long-term pain, dysfunction, and even affecting the quality of life. Intertrochanteric fracture of femur can be treated conservatively by bone traction, drug treatment, etc. Bone traction can help reduce the fracture site, and drug treatment can promote bone healing.

[0003] The existing bone traction method commonly used in medicine is to implant an intramedullary nail at the fracture site of the patient, and to stabilize and support the fractured bone by inserting an elongated metal rod into the medullary cavity, and to provide stability by the friction between the nail and the bone and the contact surface between the nail tail and the surrounding tissue.

[0004] However, the existing ordinary intramedullary nail generally has the problems of locking stress concentration and stress shielding, poor torsional resistance, which can easily cause the intramedullary nail to bend or break, and poor fixation effect, which is not conducive to the healing of the patient's bone. Therefore, the technical field urgently needs an intramedullary fixation device with stable structure, strong torsional resistance to improve the fixation and healing effect of the patient's fracture. SUMMARY

[0005] The problem to be solved by the present application is that the existing ordinary intramedullary nail has the problems of locking stress concentration and stress shielding, poor torsional resistance, which can easily cause the intramedullary nail to bend or break, and poor fixation effect, which is not conducive to the healing of the patient's bone.

[0006] To solve the above technical problems, the present application provides an intramedullary fixation device for intertrochanteric fracture of femur, which can decompose the locking stress concentration and stress shielding, enhance the bending strength, effectively reduce the breakage of the nail, and reduce the occurrence of nonunion and delayed union, so as to improve the fixation and healing effect of the fracture.

[0007] To achieve the above technical purposes and effects, the present application realizes the following technical solutions:

[0008] An intramedullary fixation device for femoral intertrochanteric fracture, comprising a nail body, a cavity in the nail body extending along a longitudinal axis from a proximal end to a distal end, a force carrier system on the nail body to create a dynamic control at the human femoral neck and femoral head to achieve a controllable transverse dynamic force to eliminate stress shielding, the force carrier system comprising a movable assembly at the proximal end of the nail body and at least one sliding member three at the distal end of the nail body, the movable assembly serving as a main power source for the transverse dynamic force while connecting and fixing the femoral neck and femoral head, and the sliding member three being used for the movable connection between the distal end of the nail body and the femoral body.

[0009] Preferably, the movable assembly comprises a first sliding member and a second sliding member, a locking hole extending transversely through the nail body is formed on the nail body, the first sliding member passes through the locking hole to transversely penetrate the proximal end outer wall of the nail body and the cavity at the proximal end of the nail body, the distal end of the first sliding member has a threaded portion one connected to the femoral head, and the second sliding member transversely penetrates the proximal end outer wall of the nail body and the cavity at the proximal end of the nail body and is located on the lower side of the first sliding member and in sliding cooperation with the proximal end outer wall of the first sliding member.

[0010] Further, at least one sliding groove is formed on the proximal end outer wall of the first sliding member, and a threaded portion two is formed on the outer wall of the second sliding member and in sliding cooperation with the sliding groove.

[0011] Further, the proximal end portion and the distal end portion of the nail body are arranged in an inclined manner, and a titanium coating is arranged on the outer wall at the reverse bending position of the proximal end portion and the distal end portion.

[0012] Further, the locking hole is formed in an inclined upward manner at an angle of 125° on the proximal end portion.

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

[0014] Preferably, two sliding members three are arranged in an upper and lower spaced manner and penetrate the distal end outer wall of the nail body and the internal cavity of the nail body, and the two sliding members three are locking nails with different diameters, and positioning holes are formed on the nail body to adapt to the penetration of the two sliding members three.

[0015] Further, the positioning holes formed on the nail body away from the proximal end of the nail body extend in an axial direction of the nail body in a waist-shaped hole or an elliptical hole, and the corresponding sliding member three can move longitudinally in the waist-shaped or elliptical positioning hole.

[0016] Preferably, the distal end of the nail body is designed in 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 cylindrical body with a diameter of 15.5 mm to 16 mm.

[0018] The intramedullary fixation device for intertrochanteric fractures of the femur provided by this invention has the following advantages:

[0019] 1. The intramedullary fixation device for intertrochanteric fracture of the femur of the present invention adopts a self-cutting traction screw design for the first sliding member, which can reduce the torque of the traction screw and at the same time reduce the incidence of cutout. The surface U-shaped groove design provides more contact surface for consumables and bone, has better gripping force, enhances anti-rotation force and increases resistance by about 15%.

[0020] 2. In the intramedullary fixation device for intertrochanteric fracture of the femur of the present invention, the second sliding member is anchored in the nail body and slides and cooperates with the groove on the first sliding member to create a dynamically controlled force carrier system at the femoral neck and femoral head, so as to realize controllable lateral dynamic action, prevent displacement when the medial side is in full contact, eliminate stress shielding effect, and promote fracture healing.

[0021] 3. The intramedullary fixation device for intertrochanteric fractures of the femur of the present invention features a bullet-shaped design at the distal end of the nail body, effectively avoiding thigh pain caused by stress concentration. All intramedullary nails have a hollow design, which helps reduce weight and achieve biomechanical stability.

[0022] 4. The intramedullary fixation device for intertrochanteric fractures of the femur of the present invention has a proximal diameter of the nail body reduced to the range of 15.5mm to 16mm, which can maintain the same biomechanical strength as conventional products and reduce the requirement for medullary canal expansion.

[0023] 5. The intramedullary fixation device for intertrochanteric fractures of the femur of the present invention uses a titanium coating at the proximal and distal bends of the nail body, which has a high coefficient of friction and provides excellent initial stability and long-term bone ingrowth effect. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of an intramedullary fixation device for intertrochanteric fracture of the femur provided in Embodiment 1 of the present invention;

[0025] Figure 2 This is a cross-sectional structural diagram of an intramedullary fixation device for intertrochanteric fractures of the femur provided in Embodiment 1 of the present invention;

[0026] Figure 3 This is a schematic diagram of the structure of an intramedullary fixation device for intertrochanteric fracture of the femur provided in Embodiment 2 of the present invention;

[0027] In the picture:

[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 assembly; 211 - first slider; 2111 - threaded part one; 2112 - U-shaped groove; 2113 - sliding groove; 212 - second slider; 2121 - threaded part two; 22 - third slider; 3 - titanium coating. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0030] Embodiment one:

[0031] With reference to Figure 1 and Figure 2 An intramedullary fixation device for femoral intertrochanteric fracture, comprising a nail body 1 and a force carrier system 2, the force carrier system 2 is installed on the nail body 1 to create a dynamic control at the human femoral neck and femoral head to achieve controllable transverse dynamic effect and eliminate stress shielding.

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

[0033] Further, the distal end 12 of the nail body 1 away from the proximal end 11 is designed as a bullet head, which can effectively avoid thigh pain caused by stress concentration. All the intramedullary nails are hollow designed, which is beneficial to reduce the mass and realize the stability of biomechanics.

[0034] With reference to Figure 1 and Figure 2The force carrier system 2 comprises a movable assembly 21 mounted on the proximal end of the nail body 1 and at least one sliding member three 22 mounted on the distal end of the nail body 1, the movable assembly 21 can serve as the main power source of the transverse power while connecting and fixing the femoral neck and the femoral head, and the sliding member three 22 is used for the movable connection of the distal end of the nail body 1 and the femoral body.

[0035] The movable assembly 21 comprises a first sliding member 211 and a second sliding member 212, and the nail body 1 is provided with a locking hole 14 extending transversely through the nail body 1, the first sliding member 211 is transversely arranged through the outer wall of the proximal end of the nail body 1 and the cavity 13 of the proximal end of the nail body 1, the distal end of the first sliding member 211 is provided with a threaded portion one 2111 connected with the femoral head, in the embodiment, the first sliding member 211 preferably adopts a self-cutting tension screw, which can reduce the torque of the tension screw and at the same time reduce the incidence of cutting, and a U-shaped groove 2112U is arranged on the proximal end surface of the first sliding member 211, the U-shaped groove 2112U is designed to provide more contact surface for the consumables and bone quality, has better holding force, enhances the anti-rotation force and increases about 15% resistance;

[0036] The second sliding member 212 is transversely arranged through the outer wall of the proximal end of the nail body 1 and the cavity 13 of the proximal end of the nail body 1 and is located below the first sliding member 211 and is in sliding cooperation with the outer wall of the proximal end of the first sliding member 211, the nail body 1 is provided with a mounting hole 15 extending transversely through the nail body 1 for the arrangement of the second sliding member 212, the mounting hole 15 is in communication with the locking hole 14, specifically, at least one sliding groove 2113 is arranged on the outer wall of the proximal end of the first sliding member 211, the outer wall of the second sliding member 212 is provided with a threaded portion two 2121 in sliding cooperation with the sliding groove 2113, and the sliding limiting of the threaded portion two 2121 is realized through the inner wall of the sliding groove 2113, a dynamic control force carrier system 2 is created at the femoral neck and the femoral head, the controllable transverse power effect is realized, the deviation when the inner side is completely contacted is prevented, the stress shielding effect is eliminated, and the fracture healing is promoted.

[0037] Further, the lengths of the first sliding member 211 and the second sliding member 212 are preferably 130 mm and are provided with nuts, the diameter of the first sliding member 211 is preferably 10.5 mm, the length of the threaded portion one 2111 is preferably 30 mm, the diameter of the end of the second sliding member 212 away from the threaded portion two 2121 is preferably 6.6 mm, the diameter of the end provided with the threaded portion two 2121 is preferably 5.5 mm and the length of the threaded portion two 2121 is preferably 65 mm, the locking hole 14 is inclined upward by 125° on the proximal end 11, so that the neck-shaft angle of the intramedullary fixation device conforms to the anatomical structure of most people in the world, and the anteversion angle of the intramedullary fixation device is preferably pre-set to 15°, and the distance from the end of the proximal end 11 of the nail body 1 away from the distal end 12 to the locking hole 14 is preferably 38 mm.

[0038] With reference to Figure 1 And Figure 2 , the outer wall of the proximal end part 11 and the reverse folding part of the distal end part 12 is covered with a titanium coating 3, and the titanium coating 3 on the proximal end part 11 covers from the bottom of the mounting hole 15, and further can provide the initial stability and long-term bone growth effect by the high friction coefficient of the titanium coating 3.

[0039] With reference to Figure 1 And Figure 2 , two sliding members three 22 are arranged in the upper and lower positions and are arranged through 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 three 22 are locking nails with different diameters, and the nail body is provided with positioning holes 16 matched with the two sliding members three for penetrating, which can be used for dynamic interlocking and static locking while providing stable connection, and provides convenience for various bone fracture fixation.

[0040] The working principle of the femoral intertrochanteric fracture intramedullary fixation device is as follows:

[0041] The femoral intertrochanteric fracture intramedullary fixation device can decompose the locking nail stress concentration and stress shielding while maintaining the original static intramedullary nail characteristics, enhances the bending strength, and realizes the stability of biomechanics. The nail body 1 of the intramedullary nail uses a titanium coating 3 at the proximal end, which has a high friction coefficient and provides initial stability and long-term bone growth effect. At the same time, it can effectively reduce the occurrence of broken nails, bone nonunion and delayed bone healing, and create a dynamic control force carrier system 2 at the femoral neck and femoral head, realize controllable transverse dynamic action, provide more contact surface with consumables and bone quality, have better holding force, enhance the anti-rotation force and increase about 15% resistance. Therefore, whether walking or standing, the fracture end can produce controllable and effective compressive stress. Without increasing the procedure, the fracture fixation and healing effect can be better.

[0042] Example two:

[0043] With reference to Figure 3 The difference between the embodiment and the embodiment one is that the positioning hole 16 on the nail body 1 away from the proximal end part 11 of the nail body 1 is arranged in the form of a waist-shaped hole or an elliptical hole along the axial direction of the nail body 1, and the corresponding sliding member three 22 can move longitudinally in the waist-shaped or elliptical positioning hole 16, so that the intramedullary fixation device can be longitudinally pressurized. Figure 3 In the embodiment, only the waist-shaped hole is taken as an example.

[0044] The above merely describes preferred embodiments of the present application, and is not intended to limit the present application in any form or in essence. It should be noted that those skilled in the art can make some improvements and supplements without departing from the present application, and these improvements and supplements should also be considered as the protection scope of the present application. For those skilled in the art, some slight changes, modifications and equivalent changes made by using the disclosed technical content without departing from the spirit and scope of the present application are equivalent embodiments of the present application; meanwhile, any equivalent changes, modifications and evolution made according to the essential technology of the present application to the above embodiments are still within the scope of the technical solutions of the present application.

Claims

1. An intramedullary fixation device for intertrochanteric fractures of the femur, characterized in that, The device includes a nail body (1), which has a cavity (13) extending from the proximal end to the distal end along the longitudinal axis. The nail body (1) is provided with a force carrier system (2) to create dynamic control at the femoral neck and femoral head to achieve controllable lateral dynamic action and eliminate stress shielding. The force carrier system (2) includes a movable component (21) disposed at the proximal end of the nail body (1) and at least one sliding member (22) disposed at the distal end of the nail body (1). The movable component (21) serves as the main power source for 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. The movable component (21) includes a first slider (211) and a second slider (212). The nail body (1) has a locking hole (14) that extends laterally through the nail body (1). The first slider (211) passes laterally through the locking hole (14) through the proximal outer wall of the nail body (1) and the cavity (13) at the proximal end of the nail body (1). The distal end of the first slider (211) has a threaded portion (2111) for connecting to the femoral head. The second slider (212) passes laterally through 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 below the first slider (211) and slides in cooperation with the proximal outer wall of the first slider (211). The proximal outer wall of the first slider (211) has at least one groove (2113), and the outer wall of the second slider (212) has a threaded portion (2121) that slides in cooperation with the groove (2113). Two sliding members (22) are arranged at intervals above and below, and both pass through 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) that are adapted to fit and pass through the two sliding members (22). The positioning holes (16) opened on the nail body (1) away from the proximal end of the nail body (1) extend along the axial direction of the nail body (1) and are set as waist-shaped holes or elliptical holes. The corresponding sliding members (22) can move longitudinally within the waist-shaped or elliptical positioning holes (16).

2. The intramedullary fixation device for intertrochanteric fractures of the femur as described in claim 1, characterized in that, The proximal end (11) and distal end (12) of the nail body (1) are inclined, and a titanium coating (3) is provided on the outer wall of the folded part of the proximal end (11) and distal end (12).

3. The intramedullary fixation device for intertrochanteric fractures of the femur as described in claim 2, characterized in that, The locking hole (14) is inclined upward at a 125° angle on the near end (11).

4. The intramedullary fixation device for intertrochanteric fractures of the femur as described in claim 1, characterized in that, The first sliding member (211) is a self-cutting tension screw, and a U-shaped groove (2112) is provided on the near end face of the first sliding member (211).

5. The intramedullary fixation device for intertrochanteric fractures of the femur as described in claim 1, characterized in that, The distal end of the nail body (1) is designed in the shape of a bullet.

6. The intramedullary fixation device for intertrochanteric fractures of the femur as described in claim 1, characterized in that, The nail body (1) is 180 mm long, the internal cavity (13) of the nail body (1) is 8 mm in diameter, 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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