Novel femoral shaft fracture closed reduction device based on lever principle

Abstract

The invention designs a novel femoral shaft fracture closed reduction device based on a lever principle. The novel femoral shaft fracture closed reduction device comprises a first reduction assembly and a second reduction assembly, the first reset assembly and the second reset assembly are detachably connected through threads. The first reset assembly comprises a transverse rod and a vertical rod, and the vertical rod is perpendicularly fixed to the transverse rod. Fracture reduction of the femur is conducted through the arranged first reduction assembly and second reduction assembly according to the lever principle, the first reduction assembly can be inserted into the rear portion of a distal femur fracture block, and the front section can be attached to the rear bone surface of the femur; the second reduction assembly is inserted in front of the distal femur fracture block, the front section of the second reduction assembly can be attached to the front bone surface of the femur, and the distal femur fracture block is pried to move forwards and the proximal femur fracture block is pried to move backwards by taking the tensor fasciae as a fulcrum and utilizing the lever principle, so that fractured bones can be close to each other for reduction.

Description

Technical Field

[0001] The present invention relates to the field of medical devices, and particularly to a novel closed reduction device for femoral shaft fractures based on the lever principle. Background Art

[0002] Femoral shaft fractures are a common type of fracture in clinical practice. The preferred treatment method for this type of fracture is closed reduction and interlocking intramedullary nailing (minimally invasive surgery). This surgery is usually completed on a traction table under the supervision of a C-arm X-ray machine.

[0003] However, it is not easy to achieve minimally invasive reduction and fixation of femoral shaft fractures. The strong muscles around the femur pose many difficulties in maintaining reduction during the closed reduction and intramedullary nail insertion processes. To solve this problem, researchers have been exploring faster, simpler, more economical, and effective minimally invasive reduction methods and reduction maintenance tools.

[0004] During the operation, the surgeon first uses a traction table to perform closed reduction on the femoral shaft fracture. The traction table can effectively restore the length of the femur and most of the rotational displacement, but it cannot independently complete the alignment of the fracture (there will still be residual anterior-posterior and medial-lateral displacements after reduction). Therefore, a variety of instruments have been introduced to promote the success of reduction, including invasive tools for direct reduction such as bone hooks, ball nails, and Schanz pins, and non-invasive methods for indirect reduction such as external support tools and reduction frames; however, the above various reduction methods and instruments are affected by individual differences of fracture patients, fracture types, and doctor experience, and their operability and repeatability are relatively poor; at the same time, even if the reduction is completed, it is very difficult to maintain the reduction during the intramedullary nail implantation process.

[0005] In view of the above problems, the patent with the publication number CN213883454U discloses a closed reduction and maintenance device for femoral shaft fractures; this device aims to achieve closed reduction of fractures by correcting shortening, angulation, anterior-posterior, and medial-lateral displacements, thereby facilitating the insertion of the femoral intramedullary nail guide wire; to a certain extent, it is convenient for medical staff. However, during clinical use, it is found that during the operation, the surgeon needs to use an electric drill to drive 2 reduction pins into the femoral shaft in a direction perpendicular to the femur on the body coronal plane, which is very difficult to achieve for the following reasons: 1. There are anterior-posterior, medial-lateral, and angulation displacements at the fracture ends, and the fracture ends are not fixed, making it very difficult to drive the reduction pins completely perpendicular to the femoral shaft direction. 2. During the operation, reduction pins are driven into both the proximal and distal fracture ends, and then the anterior-posterior displacement is reduced by connecting the reduction pins and the reduction rod. The fracture ends can only be adjusted in the direction of the reduction rod. If it is necessary to adjust the rotational displacement of the fracture, the reduction pins need to be removed. 3. Only the outer cortex of the femur can be penetrated in front of the reduction pins (if too much cortex is penetrated, it will affect femoral reaming and intramedullary nail insertion), so the holding force is limited, and the reduction pins are prone to loosening and falling off during fracture reduction in the operation. 4. This device has many components and complex connection relationships, making the operation relatively difficult.

[0006] Therefore, a new type of closed reduction device for femoral shaft fractures based on the lever principle is needed to solve the above technical problems. Summary of the Invention

[0007] In order to solve the above technical problems, the present invention discloses a new type of closed reduction device for femoral shaft fractures based on the lever principle. This device can solve the problems of difficult reduction and maintenance of reduction during the internal fixation surgery of interlocking intramedullary nails for femoral shaft fractures. At the same time, the device consists of two reduction components with similar structures; one of the reduction components can be inserted behind the distal femoral fracture fragment, and the front end can adhere to the posterior bone surface of the femur; the other reduction component is inserted in front of the distal femoral fracture fragment, and the front segment can adhere to the anterior bone surface of the femur. Taking the tensor fasciae lata as the fulcrum, using the lever principle combined with the principle of the F-rod, pry the distal femoral fracture fragment forward and the proximal femoral fracture fragment backward, so that the broken bones can approach each other and form a fixation; it can maintain the reduction of the fracture end and can be adjusted in direction without removing the reduction needle.

[0008] In order to achieve the above technical effects, the present invention designs a new type of closed reduction device for femoral shaft fractures based on the lever principle, including: a first reduction component and a second reduction component; the first reduction component and the second reduction component are detachably connected by threads; the first reduction component includes a cross bar and a vertical bar, and the vertical bar is vertically fixed on the cross bar; A limiting hole is opened on the vertical bar, and a threaded needle is movably installed on the limiting hole. The threaded needle is fixed by a first butterfly nut sleeved at the rear end. A blunt head is opened at the front end of the vertical bar. The blunt head has an arc structure. Two micro limiting strips are fixedly installed on both sides inside the blunt head. The micro limiting strips are bent from the center to both sides and the thickness gradually increases; Further, the bending radian of the blunt head is 0.5rad - 1.5rad, Further, on one side of the vertical bar, an enlarging component is fixedly installed on the cross bar. The enlarging component is perpendicular to the vertical bar and a number of through holes are linearly arranged on the enlarging component. A Kirschner wire is movably installed on the through holes; on the other side of the vertical bar, a limiting ring is fixedly installed at the other end of the cross bar. A circular groove is opened on the cross bar corresponding to the position of the limiting ring; Further, there are three through holes, allowing a Kirschner wire with a diameter of 2.5mm to pass through; Further, the structure of the second reduction component is the same. The difference is that on one side of the vertical bar of the second reduction component, a threaded head is provided at the end of the cross bar. A second butterfly nut is provided on the threaded head. The threaded head is rotatably connected to the limiting ring and fixed by the second butterfly nut.

[0009] The beneficial effects of the present invention are: The present invention designs a novel closed reduction device for femoral shaft fractures based on the lever principle, comprising: a first reduction assembly and a second reduction assembly; the first reduction assembly and the second reduction assembly are detachably connected by threads; the first reduction assembly includes a cross bar and a vertical bar, and the vertical bar is vertically fixed on the cross bar; by setting the first reduction assembly and the second reduction assembly and performing fracture reduction of the femur according to the lever principle, the first reduction assembly can be inserted behind the distal femoral fracture fragment, and the front section can adhere to the posterior bone surface of the femur; the second reduction assembly is inserted in front of the distal femoral fracture fragment, and the front section can adhere to the anterior bone surface of the femur. Taking the tensor fasciae lata as the fulcrum, using the lever principle, pry the distal femoral fracture fragment forward and pry the proximal femoral fracture fragment backward, so that the fractured bones can approach each other for reduction; At the same time, due to the threaded connection method between the first reduction assembly and the second reduction assembly, it can perform rotational movement, and the reduction needle does not need to be removed while it can be fixedly used; In addition, the mutual splicing and rotational fixation of the mechanism of this device can maintain fracture reduction, which is beneficial to femoral reaming and the insertion of intramedullary nails; at the same time, the structure of this device is simple, the operation is more convenient than traditional devices, and the reduction method based on the lever principle is effective and easy to control, which is convenient and practical. Description of the Drawings

[0010] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for describing the embodiments will be briefly introduced below.

[0011] Figure 1 It is a schematic diagram of the overall structure of a novel closed reduction device for femoral shaft fractures based on the lever principle; Figure 2 It is a front view of a novel closed reduction device for femoral shaft fractures based on the lever principle; Figure 3 It is a schematic diagram of the overall top view structure of a novel closed reduction device for femoral shaft fractures based on the lever principle; Figure 4 It is a sectional view of the overall structure of a novel closed reduction device for femoral shaft fractures based on the lever principle; Figure 5 It is an exploded view of a novel closed reduction device for femoral shaft fractures based on the lever principle; Figure 6 It is an enlarged schematic view of part A of a novel closed reduction device for femoral shaft fractures based on the lever principle; Figure 7 It is a flowchart of using a vascular clamp for restoration in the prior art; Figure 8 It is a schematic diagram of the principle of reducing with an F rod; Figure 9 It is a schematic diagram for understanding the anatomical auxiliary position of the human body.

[0012] In the accompanying drawings, the list of components represented by each reference numeral is as follows: 1 - First reset component, 11 - Enlarging component, 111 - Through hole, 112 - Circular groove, 12 - Vertical rod, 121 - Rounded head, 122 - Micro limiting strip, 123 - Limiting hole, 13 - Threaded pin, 131 - First wing nut, 14 - Cross bar, 141 - Limiting ring, 2 - Second reset component, 21 - Second wing nut, 22 - Threaded head, 3 - Kirschner wire. Detailed implementation mode

[0013] Example 1 There are many problems in the existing patent with the publication number CN213883454U (as described above). In view of the above problems and the defects of the prior art, the lever principle is currently widely used in clinical practice for the closed reduction of femoral fractures. Specifically, during traction, the fracture shortening is corrected, and the soft tissue envelope (the broad fascia of the thigh) is used as the fulcrum, and a long curved hemostat is used as the lever arm. The femoral shaft fracture is reduced and maintained through a minimally invasive percutaneous method, and finally fixed with an intramedullary nail. Using the above method, some patients with femoral shaft fractures have been successfully treated in clinical practice, but many problems have also been found: (1) Using the lever principle, a long curved vascular forceps can only reduce the anterior-posterior displacement. For the medial-lateral displacement after traction, additional reduction tools are often used; (2) For fractures with a large span, the vascular forceps cannot be interlocked during the operation, and the surgeon needs to manually maintain the reduction, which undoubtedly increases the radiation exposure of the surgeon; (3) Since there is no fixed connection between the vascular forceps and the bone, the fracture may shift during reaming during the operation, and multiple adjustments and multiple X-ray films are needed to confirm; (4) For fractures that are not fully reduced using the lever principle (the first lever) with the soft tissue envelope (the broad fascia of the thigh) as the fulcrum and a long curved hemostat as the lever arm, there is a lack of other simple methods to further adjust the reduction, which will result in an unsatisfactory lateral alignment after inserting the intramedullary nail.

[0014] Due to the lack of a dedicated tool for reducing femoral fractures based on the lever principle in clinical practice, combined with the clinical experience during such surgeries, a new type of closed reduction device for femoral shaft fractures based on the lever principle is designed to solve the above problems. Its basic concept is that it is easy to operate, can correct the medial-lateral displacement, and for fractures that are not fully reduced anterior-posteriorly using the lever principle (the first lever) with the soft tissue envelope (the broad fascia of the thigh) as the fulcrum, the principle of the "F" rod (the second lever) can also be applied for reduction. After the reduction is completed, the fracture and the reduction tool can be integrally fixed to maintain the reduction.

[0015] Specifically, a new type of closed reduction device for femoral shaft fractures based on the lever principle includes: a first reduction component 1 and a second reduction component 2; the first reduction component 1 and the second reduction component 2 are detachably connected by threads; the first reduction component 1 includes a cross bar 14 and a vertical bar 12, and the vertical bar 12 is vertically fixed on the cross bar 14; by setting the first reduction component 1 and the second reduction component 2 and performing the fracture reduction of the femur according to the lever principle, the first reduction component 1 can be inserted behind the distal femoral fracture fragment, and the front section can adhere to the posterior bone surface of the femur; the second reduction component 2 is inserted in front of the distal femoral fracture fragment, and the front section can adhere to the anterior bone surface of the femur. Taking the tensor fasciae lata as the fulcrum and using the lever principle, the distal femoral fracture fragment is pried forward and the proximal femoral fracture fragment is pried backward, so that the broken bones can approach each other for reduction; In addition, in this embodiment, a limiting hole 123 is opened on the vertical bar 12, and a threaded pin 13 is movably installed on the limiting hole 123. The threaded pin 13 passes through the vertical bar 12 and the fractured femur for fixation. At the same time, the threaded pin 13 is fixed to the vertical bar 12 by a first wing nut 131 sleeved at the rear end. Specifically, it is through the first wing nut 131. A round blunt head 121 is opened at the front end of the vertical bar 12. The round blunt head 121 has an arc-shaped structure. The arc-shaped structure can make it fit well on the bone. At the same time, two micro limiting strips 122 are fixedly installed on both sides inside the round blunt head 121. The micro limiting strips 122 are bent from the center to both sides and the thickness gradually increases. The bending radian of the round blunt head 121 is 0.5rad - 1.5rad. By setting the micro limiting strips 122, the round blunt head 121 can be better fixed on the bone. More importantly, the gradually increasing thickness of the micro limiting strips 122 enables the bone to be limited between the micro limiting strips 122 after the round blunt head 121 is fitted, ensuring the stability of the fixation; In addition, in this embodiment, on one side of the vertical bar 12, an enlarging component 11 is fixedly installed on the cross bar 14. The enlarging component 11 is perpendicular to the vertical bar 12 and a plurality of through holes 111 are linearly arranged on the enlarging component 11. A Kirschner wire 3 is movably installed on the through holes 111. Specifically, three through holes 111 are provided, allowing a Kirschner wire 3 with a diameter of 2.5 mm to pass through. Of course, at least a Kirschner wire 3 with a diameter of 2.5 mm can pass through here, but it is not limited to 2.5 mm. Those skilled in the art can choose according to actual needs; on the other side of the vertical bar 12, a limiting ring 141 is fixedly installed at the other end of the cross bar 14. Corresponding to the position of the limiting ring 141, a round groove 112 is opened on the cross bar 14, and threads are provided on the round groove 112; Meanwhile, the structures of the second reset components 2 are the same. Specifically, the same points are that the cross bars 14 and the vertical bars 12 have the same structures, the threaded pins 13 and the first wing nuts 131 are the same, and the settings of the through holes 111 of the increasing components 11 are the same. The difference lies in that on one side of the vertical bar 12 of the second reset component 2, a threaded head 22 is provided at the end of the cross bar 14, a second wing nut 21 is provided on the threaded head 22, and the threaded head 22 is rotatably connected to the limiting ring 141 and fixed by the second wing nut 21.

[0016] Embodiment 2 In this embodiment, the fixing process is further described by way of use; first, the traditional reset method is to use two hemostats for assisted reset. Specifically, as Figure 7 shown, the method of using the hemostat for reset also utilizes the principle of the lever for assisted reset. However, after using the hemostat for reset, the doctor needs to maintain the reset and constantly adjust it with the help of X-rays. The adjustment of the reset is not accurate enough, and displacement often occurs during intraoperative reaming, requiring multiple adjustments and multiple X-ray films to be taken for confirmation; if the reset cannot be maintained, eccentric reaming (excessive reaming of one femoral cortex) will also occur; This device can well solve the above technical problems. The specific usage process is as follows: First, after the patient is successfully anesthetized, lie supine on the traction bed, with the head facing right and the feet facing left. The bilateral ankles are fixed, the left lower limb is straightened, the right lower limb is lower than the left lower limb and forms a "scissor foot" position with the left lower limb. The left lower limb is tractioned, adducted, and internally rotated for reset to make the patella face the sky (the distal femoral fracture end is parallel to the ground). Fluoroscopy in the anteroposterior and lateral positions of the C-arm X-ray machine is used to determine the position of the fracture ends; After completion, at a distance of 2 - 3 cm from the fracture ends, with the plane of expected reduction (coronal plane) as the standard, make a skin incision about 1 cm long at a position 1 - 2 cm in front of the distal femoral bone fragment on this plane. Insert the vertical rod 12 of the first reduction component 1 behind the distal femoral fracture fragment, and make the front section of the vertical rod 12 of the first reduction component 1 adhere to the posterior bone surface of the femur. At a distance of 2 - 3 cm from the fracture ends, with the plane of expected reduction (coronal plane) as the standard, make a skin incision about 1 cm long at a position 1 - 2 cm behind the proximal femoral bone fragment on this plane. Insert the vertical rod 12 of the second reduction component 2 in front of the distal femoral fracture fragment, and make the front section of the vertical rod 12 of the second reduction component 2 adhere to the anterior bone surface of the femur. Using the tensor fasciae lata as a fulcrum and applying the lever principle, pry the distal femoral fracture fragment forward and the proximal femoral fracture fragment backward; at the same time, since the front sections of the vertical rods 12 of the first reduction component 1 and the second reduction component 2 are arc-shaped structures (arc-shaped structures of the blunt head 121) matching the femoral radius, during reduction and fixation, due to the micro-limiting strips 122 fixedly installed on both sides inside the blunt head 121, the micro-limiting strips 122 can make the blunt head 121 better fixed on the bone. More importantly, the thickness of the micro-limiting strips 122 gradually increases, so that after the blunt head 121 is fitted, the bone can be limited between the micro-limiting strips 122, ensuring the stability of fixation; at this time, the medial and lateral displacement of the fracture ends can be reduced by internal and external traction and pushing. Then assemble the second section of the cross bar 14 of the first reduction component 1 and the second section of the cross bar 14 of the second reduction component 2 together, and tighten the second butterfly nut 21, and the femoral fracture will be initially reduced. At this time, use a C-arm X-ray machine to fluoroscopically evaluate the fracture reduction situation: The specific steps are as follows: S1: Check whether the medial and lateral displacement of the femoral fracture has been corrected. If the medial and lateral displacement has not been corrected, respectively drive the threaded pins 13 into the femur through the vertical rods 12 of the first reduction component 1 and the second reduction component 2 (note that only penetrate the lateral cortex of the femur), and correct the medial and lateral displacement of the femur through the first butterfly nut 131 at the tail end of the threaded pin 13, and confirm with the C-arm X-ray machine. S2: Then check whether the anteroposterior displacement of the femoral fracture has been corrected. If the distal fracture fragment of the femur is still posterior compared to the proximal fracture fragment, then further reduce it by pressing the first section of the cross bar 14 of the second reduction component 2 backward (F-rod principle, as Figure 8 shown); conversely, the fracture ends can be reduced by pressing the first section of the cross bar 14 of the first reduction component 1 backward. After the C-arm X-ray machine fluoroscopically shows satisfactory reduction, drive 2 2.5-mm Kirschner wires 3 into the femur percutaneously through the Kirschner wire 3 holes in the first section of the cross bar 14 of the first reduction component 1 and the Kirschner wire 3 holes in the first section of the cross bar 14 of the second reduction component 2, thus achieving the reduction and maintenance of the femoral fracture.

[0017] In summary, the present device first uses the principle of the lever for preliminary reduction, and then uses the principle of the F rod for further fine reduction, ensuring the reduction and maintenance of femoral fractures. Through the synergistic and compensatory effects of the two, preliminary and fine reduction can be achieved, ensuring the accuracy and maintainability of the reduction.

[0018] The preferred embodiments of the present invention disclosed above are only used to help illustrate the present invention. The preferred embodiments do not describe all the details in detail, nor do they limit the invention to the specific embodiments described.

Claims

1. A novel closed reduction device for femoral shaft fracture based on the lever principle, characterized in that: It comprises a first reset assembly and a second reset assembly; the first reset assembly and the second reset assembly are detachably connected via threads; the first reset assembly comprises a crossbar and a vertical bar, and the vertical bar is vertically fixed on the crossbar; A limiting hole is provided on the vertical rod, and a threaded needle is movably installed on the limiting hole. The threaded needle is fixed by a first butterfly nut sleeved on the rear end. A round blunt head is provided at the front end of the vertical rod, and the round blunt head is in an arc-shaped structure. Micro limit strips are fixedly installed on both sides of the inner part of the round blunt head. The micro limit strips are bent from the center to both sides and the thickness gradually increases.

2. According to claim 1, a new closed reduction device for femoral shaft fracture based on the lever principle, characterized in that: The curvature of the round blunt head is 0.5 rad-1.5 rad.

3. According to claim 1, a novel closed reduction device for femoral shaft fracture based on the lever principle, characterized in that: On one side of the vertical rod, an enlarged component is fixedly installed on the horizontal rod. The enlarged component is arranged perpendicular to the vertical rod and a plurality of through holes are opened in a linear array on the enlarged component, and Kirschner wires are movably installed on the through holes; on the other side of the vertical rod, a limit ring is fixedly installed on the other end of the horizontal rod, and a circular groove is opened on the horizontal rod corresponding to the position of the limit ring.

4. According to claim 1, a novel closed reduction device for femoral shaft fracture based on the lever principle, characterized in that: The structure of the second reset assembly is the same, and the difference is that on one side of the vertical rod of the second reset assembly, a threaded head is provided at the end of the cross rod, and a second butterfly nut is provided on the threaded head. The threaded head can be rotatably connected to the limit ring and fixed by the second butterfly nut.

5. According to claim 1, a new closed reduction device for femoral shaft fracture based on the lever principle, characterized in that: The structure of the second reset assembly is the same, and the difference is that on one side of the vertical rod of the second reset assembly, a threaded head is provided at the end of the cross rod, and a second butterfly nut is provided on the threaded head. The threaded head can be rotatably connected to the limit ring and fixed by the second butterfly nut.

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