Femoral neck fracture fixation device

Abstract

The present invention discloses a femoral neck fracture fixation device, which includes a core rod, a plurality of blades and a locking component. The distal end of each blade includes a front flange portion protruding outward, and the front flange portion is matched and supported on the inner wall of the bone cavity at a corresponding position. A positioning groove is provided along the axial direction on the outer side of the core rod. The core rod is inserted into the center of the bone cavity and the back of each blade on the rear side is matched and embedded in the corresponding axial positioning groove. The core rod is used to support each blade at a corresponding position on the inner wall of the bone cavity, and the rear end of the core rod is fixed at the root of the femoral neck. The present invention first enters the bone cavity with the blade fitting the inner wall of the femoral neck, and the destructiveness of the loose bone part in the bone cavity is minimized. Selecting a suitable blade can completely match and fit the enlarged part of the inner end of the femoral neck, so that the edge contour of each blade completely fits the inner wall of the enlarged part of the bone cavity. After the back of each blade is supported by the core rod, each blade is radially supported on the inner wall of the femoral neck bone cavity.

Description

Technical Field

[0001] The invention belongs to the technical field of femoral neck fracture reduction and fixation instruments, and in particular relates to a femoral neck fracture fixation device. Background Art

[0002] Femoral neck and intertrochanteric fractures are common and frequently occurring diseases in the elderly. When femoral neck fractures or intertrochanteric fractures are fixed with screws and nail plate systems, there are many traditional internal fixation methods for femoral neck fractures. Due to the difficulty in operation and many complications, joint replacement is often required in the end. The femoral neck has a special anatomical structure, with neck-shaft angles and anteversion angles on different planes, and its position is deep and hidden, making it difficult to correctly insert the positioning guide pin. In the clinical internal fixation treatment of femoral neck and intertrochanteric fractures, guide pins must be inserted for positioning first. Usually, guide pins are inserted based on the doctor's clinical experience. The main factor of the traditional fixation method is the problem of loose fixation.

[0003] On the other hand, the femoral neck consists of an outer hard bone part and an inner loose bone part, e.g. Fig.15 As shown in the figure, the loose bone part fills the entire bone cavity. The inner loose bone part is large in volume but low in density. The intramedullary nail fixed in the outer hard bone part has a fixed strength, but the fixed strength in the inner loose bone part is insufficient. In fact, most of the intramedullary nails are in the inner loose bone part. The outer diameter of the root and end of the femoral neck is larger than its neck, and there is a situation where part of the intramedullary nail is exposed outside the neck, which leads to the problem of poor firmness of intramedullary nail fixation.

[0004] In the prior art, there is a structure similar to an expansion wire, which supports the inner wall of the bone cavity by expanding the expansion part in the femoral neck bone cavity. In fact, it supports the loose bone part and compresses the loose bone part to the hard bone inner wall. This expansion-type bone compression device has the following problems: (1) The expansion surface is an arc surface, which cannot completely peel off the loose bone part and directly contact the hard bone inner wall, resulting in insufficient firmness after compression; (2) After expansion and compression, it cannot provide sufficient circumferential restraint force on the femoral neck, and the femoral neck may rotate. Dislocation occurs, (3) it is highly destructive to the loose bone part. When its inner end expands, it destroys all the loose bone parts in the femoral neck cavity. (4) its inner end expansion part cannot completely match the inner wall of the femoral neck cavity and cannot provide sufficient anti-torsion force. Patients with femoral neck fractures need to maintain the lower limb internal rotation position for fracture reduction. This point is embedded in the acetabulum and is not a complete sphere. Body rotation will bring a large torque to the internal support component, resulting in point contact between the inner end expansion part and the inner wall of the femoral neck, resulting in poor internal pressure firmness. For example, the "expansion fixation femoral head internal support body" provided by CN 202146350 U includes a support body and an internal expansion screw. The support body is sleeved outside the internal expansion screw. The top of the support body is arc-shaped. The support body is provided with radial expansion wings. The expansion wings are composed of a number of wing pieces. An expansion gap is formed between the wing pieces. The internal expansion screw is provided with an expansion section. After the internal expansion screw is inserted into the support body, the expansion section can open the expansion wing. The support body and the internal expansion screw are threadedly connected. This patent document has the above problems (1)-(4), and the "Adjustable pressure-fixed expansion bolt for femoral neck fracture" with publication number CN2299593Y has the above problems (1)-(4). The "femoral neck expandable locking pressure screw" with publication number CN2487349Y and the "expansion pressure bone plug" with publication number CN2209507Y have the above problems (2) and (4). Summary of the invention

[0005] In view of the defects and problems existing in various existing femoral neck fixation methods, the present invention provides a femoral neck fracture fixation device which can effectively fix the femoral neck fracture site from the inside and can provide sufficient anti-twisting force to prevent secondary injury in the fixed state by inserting a radial blade with a matching contour into the femoral neck bone cavity and using a core rod to press the blade and position the blade.

[0006] The solution of the present invention to solve the technical problem is to adopt a femoral neck fracture fixation device, which includes a core rod, a plurality of blades and a locking component.

[0007] At least two blades are mounted at corresponding positions of the inner wall of the bone cavity at the end of the femoral neck, and each blade has a front flange portion protruding outward at the distal end, and the front flange portion is matched and supported at the inner wall of the bone cavity at the corresponding position.

[0008] There is a core rod with an axial positioning groove on the outer side of the core rod. The core rod is inserted into the center of the bone cavity and the back of each blade on the rear side is matched and embedded in the corresponding axial positioning groove. The core rod is used to support each blade at the corresponding position of the inner wall of the bone cavity, and the rear end of the core rod is fixed at the root of the femoral neck.

[0009] The proximal end of each blade also includes a rear flange portion protruding outward, which is matched and fitted on the corresponding position of the bone cavity inner wall at the rear side of the femoral neck. The core rod supports each blade so that its rear flange portion supports the corresponding position of the bone cavity inner wall.

[0010] The flange portion of each blade contains latch teeth.

[0011] The rear end of the core rod is provided with a radial fixing hole along the radial direction, and is fixed at the root position of the femoral neck by installing a locking wire.

[0012] The rear end of the core rod is also provided with a connection hole for connection with a fixing frame.

[0013] Beneficial effects of the present invention: The present invention first enters the bone cavity with the blade fitting the inner wall of the femoral neck, and the destructiveness of the loose bone part in the bone cavity is minimized. Selecting a suitable blade can completely match the enlarged part of the inner end of the femoral neck, so that the edge contour of each blade completely fits the inner wall of the enlarged part of the bone cavity, and after the back of each blade is supported by the core rod, each blade is supported radially on the inner wall of the femoral neck bone cavity. This support and fixation method has the following advantages: (1) The blade enters the bone cavity with little destructiveness to the loose bone part in the femoral neck bone cavity, and retains the main part of the loose bone (mainly retaining the part of the loose bone in contact with the hard bone), (2) The edge contour of each blade completely fits the inner wall of the enlarged part of the bone cavity, overcoming the disadvantages of the existing expansion bolt point compression, and can firmly compress and evenly stress, (3) It can effectively provide sufficient circumferential restraint force on the femoral neck to prevent the femoral neck from being dislocated due to rotation. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a schematic diagram of the use status of a structure of the present invention.

[0015] Figure 2 It is a schematic diagram of the structure of the present invention.

[0016] Figure 3 yes Figure 2 A-direction structure diagram.

[0017] Figure 4 It is a schematic diagram of the assembly status of the core rod and the blade.

[0018] Figure 5 It is a three-dimensional structural diagram of the core rod.

[0019] Figure 6 yes Figure 5 Side structural diagram of .

[0020] Figure 7 yes Figure 6 Middle BB cross-section structure diagram.

[0021] Figure 8 yes Figure 6 Middle CC cross-section structure diagram.

[0022] Fig. 9 It is a structural diagram of a blade.

[0023] Fig.10 yes Fig. 9 Bottom view of .

[0024] Fig.11 This is another structural diagram of the blade.

[0025] Fig.12 yes Fig.11 Enlarged structural diagram of part D in the middle.

[0026] Fig.13 It is a schematic diagram of the four-blade assembly structure.

[0027] Fig.14 It is a schematic diagram of another structure of the present invention in use state.

[0028] Fig.15 It is a schematic diagram of the existing fixation of the femoral neck by intramedullary nailing.

[0029] Fig.16 It is a schematic diagram of an additional axial constraint structure between the core rod and each blade.

[0030] Numbers in the figure: core rod 1, axial positioning groove 2, blade 3, blade back holder 4, front flange part 5, rear flange part 5a, radial fixing hole 6, connecting hole 7, clamping tooth 8, outer hard bone part 10, inner loose bone part 11, cone 12, push rod 13, elastic pin 14, pin control 15, clamp head 16, rotating rod 17, screw 18, threaded section 19, tubular cavity 20, clamping groove 21. DETAILED DESCRIPTION

[0031] The traditional method of fixing femoral neck fractures is to implant an intramedullary nail from its root to the end. This fixation method has problems, such as Fig.15In the present invention, the femoral neck includes an outer hard bone part and an inner loose bone part, and the loose bone part fills the entire bone cavity. The inner loose bone part is large in size but low in density. The intramedullary nail fixed in the outer hard bone part has a fixing strength, but the fixing strength in the inner loose bone part is insufficient. In fact, most of the intramedullary nails are in the inner loose bone part. In addition, the outer diameter of the root and end of the femoral neck is larger than its neck (the neck belongs to the fracture site), and there is even a part of the intramedullary nail exposed outside the neck. This leads to the problem of poor firmness of intramedullary nail fixation. To address this problem, the present invention adopts the following method: Figure 2 The femoral neck fracture fixation device shown in the figure is placed in the femoral neck bone cavity as shown in the figure. Figure 1 The present invention is further described below in conjunction with the accompanying drawings and embodiments.

[0032] Embodiment 1: A femoral neck fracture fixation device comprises a core rod and three blades. The device is provided in a variety of models according to different patient body shapes, so as to facilitate selection of suitable models for different patients.

[0033] Core rod Figure 5-8 The core rod 1 is designed as a cylinder or a prism, and has a positioning groove along the axial direction on its outer side. In this embodiment, there are three axial positioning grooves 2 as shown in FIG. Figure 8 For the convenience of application, the distal end of the core rod 1 is provided with a chamfer, and the port positions of each axial positioning groove 2 on the outer side of the core rod can also be provided with a chamfer.

[0034] like Figure 7 As shown, a radial fixing hole 6 is radially arranged at the rear end of the core rod, and is fixed at the root of the femoral neck by installing a locking wire.

[0035] A structural form of the blade 3 is attached Fig. 9 and Fig.10 As shown, the distal end of each blade contains a front flange portion 5 protruding outward, and the front flange portion 5 of each blade can be set according to the contour of the inner wall of the bone cavity where the corresponding blade is located, that is, the front flange portion 5 of each blade has its own unique contour to ensure that the front flange portion 5 of each blade has more contact surface with the inner wall of the bone cavity.

[0036] The assembly relationship between the core rod 1 and each blade 3 is as follows: Figure 4 As shown, the core rod 1 is inserted into the center of the bone cavity and the back of each blade is matched and embedded in the corresponding axial positioning groove 2.

[0037] When the device of the present invention is used, after a hole is opened on the side of the femoral neck root, the three blades are inserted into the corresponding positions of the inner wall of the bone cavity at the end of the femoral neck through the loose bone part one by one under the perspective condition, so that the front flange part 5 of each blade matches the inner wall at the corresponding position, and the loose bone part can keep the position of each blade relatively stable. Then, the core rod 1 is inserted into the center of the bone cavity, and each blade supports the corresponding position of the inner wall of the bone cavity as shown in FIG. Figure 1Finally, the rear end of the core rod 1 is fixed to the root of the femoral neck. In addition, the rear end of the core rod can be further provided with a connecting hole 7 for connecting with a fixing frame.

[0038] Embodiment 2: Based on embodiment 1, a blade having a latching tooth 8 disposed at the front flange portion 5 is used, such as Fig.11 and Fig.12 As shown, after the front flange portion 5 matches the inner wall of the bone cavity, a plurality of latch teeth 8 are provided at the front flange portion 5 to simultaneously support the inner wall of the bone cavity, so as to improve the stability of the supporting portion.

[0039] Embodiment 3: Based on Embodiment 1, each blade has, in addition to the front flange portion 5, a rear flange portion 5a protruding outward at the proximal end, such as Fig.14 As shown. There is a recessed neck position between the front flange portion 5 and the rear flange portion 5a. The front flange portion 5 is used to match and support the inner wall of the end of the bone cavity, and the rear flange portion 5a is matched and fitted on the inner wall of the bone cavity at the corresponding position on the rear side of the neck of the femoral neck. Further, the front flange portion 5 can be set according to the contour of the inner wall of the bone cavity where the corresponding blade is located, that is, the front flange portion 5 and the rear flange portion 5a of each blade have their own unique contours, so as to ensure that the front flange portion 5 and the rear flange portion 5a of each blade have more contact surfaces with the inner wall of the bone cavity at the corresponding position. The core rod 1 supports each blade so that the front flange portion 5 and the rear flange portion 5a support the corresponding position of the inner wall of the bone cavity respectively.

[0040] For femoral neck fractures, in the above-mentioned embodiment 3, the front flange portion 5 and the rear flange portion 5a of each blade are respectively supported on the enlarged inner wall at the root and the enlarged inner wall at the end, so as to prevent torsional movement or detachment of the fracture site. The core rod 1 in this embodiment only needs to provide radial support.

[0041] Embodiment 4: For the above embodiments 1-3, a method such as Fig.14 The four-blade support structure shown is provided with unique contours of the front flange portion 5 and the rear flange portion 5a of each blade according to the corresponding positions of the four blades in the bone cavity, so as to match and fit tightly with the contours of the inner wall of the bone cavity.

[0042] Embodiment 5: With respect to the above-mentioned embodiments 1 and 2, an axial constraint structure may be further provided between the core rod and each blade, for example, a convex-concave structural surface may be provided on the inner wall of each axial positioning groove 2 on the core rod, and a connected convex-concave structural surface may be provided on the blade back holder 4 of each blade, so as to enhance the axial constraint force after the core rod and each blade are assembled. It is not excluded that the bottom surface of the core rod 1 or each axial positioning groove 2 of the core rod may be provided with a taper. Based on the axial constraint structure adopted in this embodiment, the core rod may also be provided with a tubular shape, and an elastic pin assembly may be installed in the tubular cavity, and the blade may be constrained by extending the elastic pin assembly into the corresponding axial positioning groove 2. For example, by using Fig.16 In the elastic pin structure shown, when the adjusting screw 18 is rotated to move axially, the push rod 13 is pushed forward axially by the rotating rod 17, so that the elastic pin can be pushed forward. The elastic pin is an open structure with two, three or four petals. After the elastic pin moves forward, it is supported by the distal cone and dispersed in the radial direction, and then led out from the corresponding pin control 15, and the end of the clamping head 16 is supported in the clamping groove 21 located in the knife back clamping seat.

Claims

1. A femoral neck fracture fixation device, characterized in that: At least two blades are mounted and matched with the inner wall at the corresponding positions of the inner wall of the bone cavity at the end of the femoral neck. The distal end of each blade includes a front flange portion (5) protruding outwards. The front flange portion (5) is matched and supported on the inner wall of the bone cavity at the corresponding position. A core rod (1) is provided. A positioning groove is provided on the outer side of the core rod (1) along the axial direction. The core rod (1) is inserted into the center of the bone cavity and the back of each blade on the rear side is matched and embedded in the corresponding axial positioning groove (2). The core rod (1) is used to support each blade at the corresponding position of the inner wall of the bone cavity. The rear end of the core rod (1) is fixed at the root of the femoral neck. The proximal end of each blade also includes a rear flange portion (5a) protruding outwards. The rear flange portion (5a) is matched and mounted on the inner wall of the bone cavity at the corresponding position on the rear side of the femoral neck. The core rod (1) supports each blade so that its rear flange portion (5a) supports the corresponding position of the inner wall of the bone cavity. The flange portion of each blade includes a latching tooth (8).

2. The femoral neck fracture fixation device according to claim 1, characterized in that: A radial fixing hole (6) is arranged at the rear end of the core rod in the radial direction and is fixed at the root of the femoral neck by installing a locking wire.

3. The femoral neck fracture fixation device according to claim 1, characterized in that: The rear end of the core rod is also provided with a connection hole (7) for connection with a fixing frame.

Images