A fixation plate and fixation system for posterior condylar coronal fractures of the femur

Abstract

The application relates to the field of medical devices, in particular to a fixing plate and a fixing system for femoral posterior condylar fracture. Firstly, a fixing plate for femoral posterior condylar fracture is provided, which comprises an integrally-formed fixing plate body, the fixing plate body comprises a straight plate body and an arc-shaped plate body; the straight plate body is plate-shaped and extends along the longitudinal direction and is used for being attached to the femoral diaphysis part, the straight plate body is provided with at least one first screw hole, the arc-shaped plate body is located at the end of the straight plate body and the two are connected through a curved surface, the longitudinal direction of the straight plate body is provided with a plate body center line; the arc-shaped plate body is provided with a concave arc surface which is used for being attached to the femoral posterior condylar articular surface, the thickness of the arc-shaped plate body is smaller than that of the straight plate body; the arc-shaped plate body is provided with a second screw hole and is also provided with a blunt spade anchoring structure which extends along the fracture plane direction. Secondly, according to the fixing plate, a femoral posterior condylar fracture internal fixation system is provided.

Description

Technical Field

[0001] This invention relates to the field of medical devices, and more particularly to a fixation plate and fixation system for coronal fractures of the posterior condyle of the femur. Background Technology

[0002] Hoffa fracture refers to a coronal plane fracture of the lateral or medial femoral condyle, which is a rare femoral condyle injury in clinical practice. Among them, Letenneur type I Hoffa fracture has a fracture line that continues along the posterolateral border of the distal femur and is perpendicular to the tibial plateau articular surface. Due to the special anatomical structure, the posterior femoral condyle is subjected to continuous posterior shear force. This fracture has a tendency to redisplace and the fracture ends are unstable.

[0003] Currently, in clinical practice, a strip-shaped reconstruction locking plate is pre-bent and fixed to the distal posterior condyle of the femur. A locking screw hole is set at the distal end of the plate, and a locking screw is inserted to complete the fixation. This method has the following drawbacks: the plate is difficult to shape, increasing surgical trauma and operation time; the distal force is limited, as the distal end of the plate cannot extend beyond the articular surface of the femoral posterior condyle due to obstruction, and can only accommodate one effective screw to fix the fracture fragment; the shear resistance is insufficient, as a single screw combined with the plate support is still insufficient to completely resist vertical shear force.

[0004] Therefore, how to provide a steel plate that can stably fix fracture fragments and has good plate fit is a technical problem that urgently needs to be solved in the field of Hoffa fracture surgery. Summary of the Invention

[0005] This application first proposes a fixation plate for coronal plane fractures of the posterior femoral condyle to solve the above-mentioned problems. Secondly, this application proposes an internal fixation system for coronal plane fractures of the posterior femoral condyle.

[0006] As a first aspect of this application, a fixation plate for coronal plane fractures of the posterior femoral condyle is proposed, comprising an integrally formed fixation plate body, the fixation plate body comprising a straight plate body and an arc-shaped plate body; The straight plate is plate-shaped and extends longitudinally to fit the femoral shaft. The straight plate has at least one first screw hole. The arc-shaped plate is located at the end of the straight plate and the two are transitioned by a curved surface. The straight plate has a plate centerline in its longitudinal direction. The arc-shaped plate has a concave arc surface, which is used to fit against the posterior condyle articular surface of the femur, and the thickness of the arc-shaped plate is less than the thickness of the straight plate. The arc-shaped plate is provided with a second screw hole and a blunt spade anchoring structure extending along the fracture plane. The center line of the plate along the length of the straight plate is used as a reference line, and the projection of the center line of the plate on the sagittal plane passes through the blunt spade anchoring structure.

[0007] Optionally, the angle between the projection of the blunt shovel central axis of the blunt shovel anchoring structure and the center line of the plate in the sagittal plane is 0° to 10°.

[0008] Optionally, the angle between the projection of the centerline of the plate and the normal of the concave arc at the center of the concave arc surface onto the sagittal plane is 30° to 60°.

[0009] Optionally, the angle between the projection of the center line of the plate and the center line of the screw hole of the second screw hole on the sagittal plane is 0° to 15°.

[0010] Optionally, the blunt shovel anchoring structure is a trapezoid that gradually narrows along the extension direction, and the edges of the trapezoid are rounded.

[0011] Optionally, the arc-shaped plate has two symmetrically arranged side wings, and the number of the second screw holes is two and they are respectively provided on the side wings. The second screw holes are symmetrically arranged on both sides of the blunt shovel anchoring structure with the center line of the plate as the axis.

[0012] Optionally, the fixing plate is made of titanium alloy.

[0013] Optionally, the extended starting point of the blunt shovel anchoring structure is provided with a reinforcing rib for force transmission, the reinforcing rib being a protrusion extending longitudinally along the fixing plate.

[0014] Optionally, the thickness of the arc-shaped plate is 1.2 mm to 1.8 mm, and the width of the arc-shaped plate is 12 mm to 16 mm.

[0015] Optionally, the protruding length of the blunt shovel anchoring structure is 4mm to 8mm, and the root width is 3mm to 5mm.

[0016] As a second aspect of this application, an internal fixation system for coronal plane fractures of the posterior femoral condyle is proposed, comprising the aforementioned fixation plate, and further comprising a long-arm universal screwdriver, a curved guide sleeve, and a locking screw used in conjunction with the fixation plate; the curved guide sleeve is adapted to the first screw hole and / or the second screw hole for guiding the guide pin and / or screw to be implanted into the femur at a fixed angle along the second screw hole; the long-arm universal screwdriver is adapted to the first screw hole and / or the second screw hole for screwing the screw into the femur.

[0017] Optionally, when the fixing plate is provided with reinforcing ribs, it also includes an eccentric driver that cooperates with the blunt shovel anchoring structure. The eccentric driver includes a handle, an eccentric connecting rod, and a driving end. The driving end is provided with a recess for cooperating with the reinforcing ribs.

[0018] The beneficial effects of this application are as follows: 1. The straight plate and the curved plate are integrally molded, with the thickness gradually decreasing from the straight plate to the curved plate and transitioning with a curved surface, which is conducive to achieving a close fit to the fracture site. The concave arc surface of the curved plate matches the shape of the femoral posterior condyle articular surface, which can form a posterior anti-slip barrier to resist the posterior and superior shear displacement of the fracture fragments in Hoffa fractures. The blunt spatula anchoring structure set in the curved plate extends along the fracture plane and can be embedded in the small fracture fragments to form intraosseous anchoring, providing additional anti-rotation effect and enhancing the fixation stability of small fracture fragments. Overall, through the cooperation of the blunt spatula anchoring structure, the straight plate and the second screw hole on the concave arc surface, a fixation structure with anchor anti-rotation, plate anti-slip and screw anti-shear is formed, thereby reducing the risk of complications such as internal fixation loosening, fracture redisplacement and nonunion.

[0019] 2. The projection angle between the central axis of the blunt spade and the central line of the plate is 0° to 10°, which is parallel or nearly parallel. This allows the blunt spade anchoring structure to be embedded along the fracture plane. Its insertion direction is consistent with the direction of the posterior edge of the femoral shaft, avoiding the gap between bone surfaces or uneven force on the blunt spade caused by the deviation of the implantation direction. At the same time, after a coronal plane fracture of the posterior femoral condyle (Hoffa fracture), when the knee joint is flexed, there is an anterior-posterior shear force between the tibial plateau and the articular surface of the posterior femoral condyle. This shear force pushes the posterior condyle fracture fragment from the posterior (posterior part of the tibial plateau), causing the fracture fragment to tend to slide and rotate anteriorly and superiorly. This parallel or nearly parallel relationship makes the direction of action of the blunt spade opposite to the main direction of the posterior shear force, which is conducive to playing an anti-slipping and anti-rotation role.

[0020] 3. The angle between the projection of the centerline of the second screw hole and the centerline of the plate on the sagittal plane is limited to 0° to 15°. This guides the locking screw to be inserted in a direction parallel to the fracture line, which conforms to the biomechanical principle of cross-fracture line fixation and maximizes the shear resistance. This small angle ensures that the screw and the blunt spatula are arranged almost parallel within the bone block, forming a forward load-sharing path and avoiding the wedge-shaped splitting force generated by cross-screw placement. The preset angle relationship eliminates the need for the surgeon to rely entirely on feel to find the direction, which can reduce the difficulty of surgical operation and improve the accuracy of screw placement.

[0021] 4. The blunt spatula anchoring structure adopts a trapezoidal design that narrows along the extension direction, which facilitates the insertion of the fracture fragment along the preset direction and adapts to the size of the Hoffa fracture fragment; the trapezoidal edge is rounded and blunt, without sharp edges, which can reduce the risk of cutting the cortical bone or splitting the cancellous bone during implantation, and reduce the possibility of iatrogenic fracture fragment fragmentation and articular surface damage.

[0022] 5. The arc-shaped plate has two symmetrical side wings, which widen the plate to accommodate two screws while reducing the material volume and weight in the non-screw hole area, thus reducing pressure on the posterior soft tissue. The second screw hole is symmetrically distributed on both sides of the blunt shovel anchoring structure with the plate centerline as the axis, forming a three-point fixing layout with the central blunt shovel. This increases the screw's holding force on the fracture fragment and avoids rotational instability caused by fixing with a single screw. The symmetrical arrangement allows the locking stress to be evenly transmitted to both sides of the fracture fragment, preventing the fracture fragment from rotating around the axis of a single screw and enhancing anti-rotation and anti-shear stability.

[0023] 6. The blunt-edged anchoring structure needs to withstand impact forces along its extension direction during installation. The curved plate itself is relatively thin; if a hammer is directly applied to the curved plate or the root of the blunt-edged shovel, deformation or breakage can easily occur. Therefore, when the blunt-edged anchoring structure is equipped with reinforcing ribs, these ribs are placed at the intersection of the blunt-edged shovel root and the curved plate, forming a locally thickened area. This disperses and guides the load generated during hammering to the overall structure, preventing the thinner area from being stressed and increasing the overall strength and stability of the structure.

[0024] In addition, the reinforcing rib is a raised structure. This raised structure cooperates with the recess at the end of the inserter to constrain the direction of the impact force transmission, ensuring that the impact force is always applied along the predetermined implantation axis of the blunt shovel, and avoiding the blunt shovel from being inserted at an angle due to unstable operation during the operation.

[0025] 7. The fixation system includes an eccentric driver, addressing the limitation of blunt-barreled anchoring structures in insertion. Femoral posterior condyle fracture surgery often employs a prone posterior or posterolateral approach, where the incision is obstructed by abundant soft tissues such as the gluteal muscles and hamstrings. Traditional straight-bar drivers have their handles coaxial with the insertion end, requiring the handle to be directly facing the posterior condyle insertion direction during striking, often hindered by muscles, limiting the operating angle. This eccentric driver, through an eccentric connecting rod, ensures the handle axis is parallel to and eccentrically positioned with the insertion end axis. The handle can be moved to a lateral position with less muscle, allowing the surgeon to strike the tail-end platform vertically from the outside of the incision, providing ample operating space and stable force application. Attached Figure Description

[0026] Figure 1 This is a front view schematic diagram of the fixation plate used for coronal plane fracture of the posterior femoral condyle in this embodiment.

[0027] Figure 2 for Figure 1 A side view diagram showing the angle between the center line of the display panel and the concave arc normal.

[0028] Figure 3 for Figure 1 A side view diagram showing the angle between the center line of the display plate and the center line of the screw hole.

[0029] Figure 4This is a schematic diagram showing the state of the fixation plate used for coronal plane fracture of the posterior femoral condyle in this embodiment at the fracture site.

[0030] Figure 5 for Figure 4 A side view diagram.

[0031] in: 1. Straight plate body; 11. First screw hole; 12. Plate centerline; 13. Third screw hole; 2. Arc-shaped plate; 21. Second screw hole; 211. Screw hole centerline; 22. Blunt chisel anchoring structure; 23. Concave arc normal; 3. Femur; 31. Fracture line. Detailed Implementation

[0032] The present application will be further described in detail below with reference to the accompanying drawings.

[0033] As the first aspect of this specific embodiment, such as Figures 1 to 5 As shown, a fixation plate for coronal plane fracture of the posterior condyle of the femur is proposed, comprising an integrally formed fixation plate body, the fixation plate body comprising a straight plate body 1 and an arc-shaped plate body 2; The straight plate 1 is plate-shaped and extends longitudinally to fit the femoral shaft. The straight plate 1 is provided with at least one first screw hole 11. The arc-shaped plate 2 is located at the end of the straight plate 1 and the two are transitioned by a curved surface. The straight plate 1 is provided with a plate centerline 12 in its longitudinal direction. The arc-shaped plate 2 has a concave arc surface, which is used to fit against the posterior condyle articular surface of the femur 3. The thickness of the arc-shaped plate 2 is less than the thickness of the straight plate 1. The arc-shaped plate 2 is provided with a second screw hole 21 and a blunt shovel anchoring structure 22 extending along the fracture plane. The center line 12 of the plate in the length direction of the straight plate 1 is used as a reference line. The projection of the center line 12 of the plate in the sagittal plane passes through the blunt shovel anchoring structure 22.

[0034] exist Figure 1 In the embodiment shown, there are three first screw holes 11. The number of first screw holes 11 can be adjusted according to actual needs, which will not be elaborated further. Furthermore, in... Figure 1 In some embodiments shown, a third screw hole 13 is also provided. The third screw hole 13 is located at the junction of the straight plate 1 and the arc-shaped plate 2. The third screw hole 13 and the second screw hole 21 form a triangular fit, making the connection between the fixation plate and the femur 3 more stable and reliable.

[0035] like Figure 1As shown, since the blunt shovel anchoring structure 22 extends outward from the center of the main body of the fixed plate, the projection of the plate centerline 12 on the sagittal plane can pass through the blunt shovel anchoring structure 22.

[0036] The straight plate 1 and the curved plate 2 are integrally formed, and the thickness gradually decreases from the straight plate 1 to the curved plate 2 with a smooth and gradual transition of curved surface, which is conducive to achieving a close fit to the fracture site. The concave arc surface of the curved plate 2 matches the shape of the posterior condyle articular surface of the femur 3, which can form a posterior anti-slip barrier to resist the posterior and superior shear displacement of the fracture fragments in Hoffa fractures. The blunt spade anchoring structure 22 set on the curved plate 2 extends along the fracture plane and can be embedded in the small fracture fragments to form intraosseous anchoring, providing additional anti-rotation effect and enhancing the fixation stability of small fracture fragments. Overall, the blunt spade anchoring structure 22, the straight plate 1 and the second screw hole 21 on the concave arc surface cooperate to form a fixation structure with anchor anti-rotation, plate surface anti-slip and screw anti-shear, thereby reducing the risk of complications such as internal fixation loosening, fracture redisplacement and nonunion.

[0037] In some embodiments, the blunt shovel anchoring structure 22 is in a state where the angle between the blunt shovel's central axis and the projection of the plate's centerline 12 in the sagittal plane is approximately parallel, ranging from 0° to 10°. Furthermore, in... Figure 2 and Figure 5 In the embodiment shown, the blunt shovel center axis of the blunt shovel anchoring structure 22 is parallel to the center line 12 of the plate.

[0038] The central axis of the blunt spade is parallel or nearly parallel to the central line 12 of the plate, allowing the blunt spade anchoring structure 22 to be embedded along the fracture plane. Its insertion direction is consistent with the posterior edge of the femoral shaft 3, avoiding uneven bone surface contact or force distribution on the blunt spade due to implantation direction deviation. At the same time, after a coronal plane fracture of the posterior condyle of the femoral 3 (Hoffa fracture) occurs, when the knee joint is flexed, there is an anterior-posterior shear force between the tibial plateau and the articular surface of the posterior condyle of the femoral 3. This shear force pushes the posterior condyle fracture fragment from the posterior (posterior part of the tibial plateau), causing the fracture fragment to tend to slide and rotate anteriorly and superiorly. This parallel or nearly parallel relationship makes the direction of action of the blunt spade opposite to the main direction of the posterior shear force, which is beneficial to exert anti-slip and anti-rotation effects.

[0039] In some embodiments, the angle between the projection of the plate centerline 12 and the concave arc normal 23 at the center of the concave arc surface onto the sagittal plane is 30° to 60°. Figure 2 In the manner shown, the angle between the projection of the plate centerline 12 and the concave arc normal 23 at the center of the concave arc surface on the sagittal plane is 49°.

[0040] The blunt spade anchoring structure 22 is configured to be embedded into the fracture fragment along the fracture plane direction via a bone groove formed on the bone surface below the articular surface of the femoral 3 posterior condyle, until the concave surface of the arc-shaped plate 2 is in contact with the cortex of the femoral 3 posterior condyle, so as to provide an anti-rotation anchoring structure.

[0041] The angle between the centerline 12 of the plate and the normal direction of the concave arc surface is limited to 30° to 60°. The position range of the straight plate 1 and the arc plate 2 allows the blunt spatula anchoring structure 22 set on the arc plate 2 to be inserted into the fracture fragment more smoothly from the direction parallel to the posterior cortex of the femur 3 and the fracture line 31, so as to achieve embedding and locking and avoid damage to the articular cartilage during implantation. This angle range ensures that the blunt spatula has sufficient embedding depth to enter the bone fragment to provide anti-rotation anchoring, but does not protrude excessively and cause iatrogenic damage to the articular surface or posterior soft tissue.

[0042] In some embodiments, the angle between the projection of the plate centerline 12 and the screw hole centerline 211 of the second screw hole 21 onto the sagittal plane is 0° to 15°. Figure 3 In the arrangement shown, the angle between the projections of the plate centerline 12 and the screw hole centerline 211 on the sagittal plane is 9°.

[0043] The projection angle between the center line 211 of the second screw hole 21 and the center line 12 of the plate on the sagittal plane is limited to 0° to 15°. This guides the locking screw to be inserted in a direction parallel to the fracture line 31, which conforms to the biomechanical principle of fixation across the fracture line 31 and maximizes the shear resistance. This small angle ensures that the screw and the blunt spatula are arranged almost parallel within the bone block, forming a forward load-sharing path and avoiding the wedge-shaped splitting force generated by cross-screw placement. The preset angle relationship eliminates the need for the surgeon to rely entirely on feel to find the direction, which can reduce the difficulty of surgical operation and improve the accuracy of screw placement.

[0044] In some embodiments, the blunt shovel anchoring structure 22 is a trapezoid that gradually narrows along the extension direction, and the edges of the trapezoid are rounded.

[0045] Rounded or blunt refers to a state in which a material is smooth and without sharp edges through passivation, chamfering, or rounding.

[0046] The blunt spade anchoring structure 22 adopts a trapezoidal design that narrows along the extension direction, which facilitates the insertion of the fracture fragment along the preset direction and adapts to the size of the Hoffa fracture fragment; the trapezoidal edge is rounded and blunt, without sharp edges, which can reduce the risk of cutting the cortical bone or splitting the cancellous bone during implantation, and reduce the possibility of iatrogenic fracture fragment fragmentation and articular surface damage.

[0047] In some embodiments, the arc-shaped plate 2 is provided with two symmetrically arranged side wings, and the number of the second screw holes 21 is two and they are respectively provided on the side wings. The second screw holes 21 are symmetrically arranged on both sides of the blunt shovel anchoring structure 22 with the plate center line 12 as the axis.

[0048] The arc-shaped plate 2 has two symmetrical side wings, which widen the plate to accommodate two screws while reducing the material volume and weight in the non-screw hole area, thus reducing pressure on the posterior soft tissue. The second screw hole 21 is symmetrically distributed on both sides of the blunt shovel anchoring structure 22 with the plate centerline 12 as the axis, forming a three-point fixing layout with the central blunt shovel. This increases the holding force of the screw on the fracture fragment and avoids rotational instability caused by fixing with a single screw. The symmetrical arrangement allows the locking stress to be evenly transmitted to both sides of the fracture fragment, which can prevent the fracture fragment from rotating around the axis of a single screw and enhance anti-rotation and anti-shear stability.

[0049] In some embodiments, the fixation plate is made of titanium alloy. Titanium alloy has good biocompatibility and corrosion resistance, which can reduce the chemical irritation of human tissues by internal fixation devices and postoperative foreign body reactions, and reduce the risk of infection and rejection. The elastic modulus of titanium alloy is compatible with the stress characteristics of the distal femur, which can provide sufficient support strength while avoiding plate breakage or deformation caused by stress shielding, thus extending the service life of internal fixation devices.

[0050] In some embodiments, the thickness of the arc-shaped plate 2 is 1.2 mm to 1.8 mm, and the width of the arc-shaped plate 2 is 12 mm to 16 mm. The thickness, width, and length parameters of the straight plate 1 are adapted to the anatomical morphology of the posterolateral cortex of the femoral shaft 3, providing stable support for the plate; the arc-shaped plate 2 is thinned to 1.2 mm to 1.8 mm and the concave radius is limited to 14 mm to 16 mm, which can match the curvature of the cartilaginous area of ​​the posterior condyle of the femoral shaft 3, and can naturally conform to the bone surface without intraoperative bending, reducing mechanical stimulation to the posterior soft tissues. The gradient size design with a thicker proximal end and a thinner distal end, combined with the structural transition, optimizes the mechanical transmission path, eliminates stress concentration that may be caused by abrupt changes in thickness, avoids the possibility of plate fracture, and improves fatigue resistance.

[0051] In some embodiments, the protruding length of the blunt spatula anchoring structure 22 is 4 mm to 8 mm, and the root width is 3 mm to 5 mm. The protruding length of the blunt spatula anchoring structure 22 is limited to 4 mm to 8 mm to ensure that the blunt spatula can be fully embedded within the fracture fragment to provide effective intraosseous anchoring, while avoiding excessive length that could penetrate the bone fragment or damage the contralateral articular surface. The gradient dimensions of the root width of 3 mm to 5 mm and the tip width of 2 mm to 3 mm provide sufficient cross-sectional area to resist rotation when the blunt spatula is inserted into the bone fragment, while the narrowed tip facilitates smooth tapping along the fracture plane, adapting to the size limitations of small Hoffa fracture fragments.

[0052] In some embodiments, the thickness of the straight plate 1 is 2.5 mm to 3.5 mm, the width is 8 mm to 12 mm, and the length is 50 mm to 70 mm.

[0053] In some embodiments, the length of the gradual transition zone between the straight plate 1 and the curved plate 2 is 10mm to 15mm, and the radius of the transition arc surface is 15mm to 20mm.

[0054] In some embodiments, the diameter of the second screw hole is 3.5 mm, the center distance of the hole is 3 mm to 5 mm from the root of the blunt shovel anchoring structure 22, and the center line of the second screw hole forms a pre-angle of 10° to 15° with the plane of the plate.

[0055] In some embodiments, the straight plate 1 has 3 to 4 first screw holes with a diameter of 3.5 mm to 4.0 mm evenly distributed on it, with a hole spacing of 10 mm to 15 mm.

[0056] In some embodiments, the extended starting point of the blunt shovel anchoring structure is provided with reinforcing ribs for force transmission. These reinforcing ribs are protrusions extending longitudinally along the fixing plate. The blunt shovel anchoring structure needs to withstand impact forces along its extension direction during implantation. Since the curved plate itself is relatively thin, direct impact with a hammer on the curved plate or the root of the blunt shovel can easily lead to deformation or breakage. Therefore, when the blunt shovel anchoring structure is provided with reinforcing ribs, these ribs are located at the intersection of the blunt shovel root and the curved plate, forming a locally thickened area. This disperses and guides the load generated during hammering to the overall structure, preventing the thinner area from being stressed and increasing the overall strength and stability of the structure.

[0057] As a second aspect of this specific embodiment, an internal fixation system for coronal plane fracture of the posterior condyle of the femur 3 is proposed, including the aforementioned fixation plate, and further including a long-arm universal screwdriver, a curved guide sleeve, and a locking screw used in conjunction with the fixation plate; the curved guide sleeve is adapted to the first screw hole 11 and / or the second screw hole 21, and is used to guide the guide pin and / or screw to be implanted into the femur 3 along the fixed angle of the second screw hole 21; the long-arm universal screwdriver is adapted to the first screw hole 11 and / or the second screw hole 21, and is used to screw the screw into the femur 3.

[0058] In some embodiments, when the fixation plate is equipped with reinforcing ribs, it also includes an eccentric driver that cooperates with the blunt shovel anchoring structure. The eccentric driver includes a handle, an eccentric connecting rod, and an insertion end, with the insertion end having a recess for cooperating with the reinforcing ribs. The fixation system includes an eccentric driver to solve the problem of limited insertion of the blunt shovel anchoring structure. Femoral posterior condyle fracture surgery often uses a prone posterior or posterolateral approach, where the incision is surrounded by soft tissue areas such as the gluteal muscles and hamstrings. With traditional straight-bar driver, the handle and insertion end are coaxial, requiring the handle to be directly facing the posterior condyle insertion direction during striking, often obstructed by muscles, limiting the operating angle. This eccentric driver, through the eccentric connecting rod, makes the handle axis parallel to and eccentrically positioned with the insertion end axis. The handle can be moved to a lateral position with less muscle, allowing the surgeon to strike the end-end striking platform vertically from the outside of the incision, providing ample operating space and stable force application.

[0059] In this embodiment, the fixing plate is used as follows: A bone groove is made on the bone surface below the articular surface of the posterior condyle of the femur 3. The blunt spade anchoring structure 22 is embedded in the bone groove along the fracture plane until the concave surface of the arc-shaped plate 2 is in contact with the cortex of the posterior condyle of the femur 3. The blunt spade anchoring structure 22 is embedded in the fracture fragment to provide anti-rotation anchoring. Locking screws are implanted through the second screw hole 21 on the arc-shaped plate 2. When there are two second screw holes 21, the two locking screws are implanted obliquely inward and outward in a plane parallel to the fracture surface, and are distributed in a divergent manner.

[0060] By first creating a bone groove on the bone surface below the posterior condyle articular surface of the femur 3, a precise entry channel is provided for the blunt spatula anchoring structure 22, avoiding bone cortical fragmentation or deviation of the approach direction caused by the blunt spatula directly striking the bone surface; the blunt spatula is embedded into the bone groove along the fracture plane until the concave arc surface of the arc-shaped plate 2 fits the bone cortex, achieving blunt spatula anchoring while allowing the plate to be naturally positioned as a whole, without the need for repeated adjustments to the plate position or forced bending during the operation; two locking screws are implanted in a divergent distribution, deviating medially and laterally in a plane parallel to the fracture surface, expanding the fixation base and further enhancing pull-out resistance and rotational stability.

[0061] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments according to this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0062] In the description of this application, it should be understood that the orientation or positional relationship indicated by directional terms such as "front, back, up, down, left, right", "horizontal, vertical, horizontal" and "top, bottom" is usually based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing this application and simplifying the description. Unless otherwise stated, these directional terms do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation on the scope of protection of this application; the directional terms "inner" and "outer" refer to the inner and outer contours relative to the outline of each component itself.

[0063] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "provided with" and "connected," etc., should be interpreted broadly. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be a connection within two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0064] The above description is only a preferred embodiment of this application. All equivalent changes and modifications made within the scope of the patent of this application shall fall within the scope of this application.

Claims

1. A fixation plate for coronal fractures of the posterior condyle of the femur, characterized in that, It includes a one-piece molded fixing plate body, which comprises a straight plate body and an arc-shaped plate body; The straight plate is plate-shaped and extends longitudinally to fit the femoral shaft. The straight plate has at least one first screw hole. The arc-shaped plate is located at the end of the straight plate and the two are transitioned by a curved surface. The straight plate has a plate centerline in its longitudinal direction. The arc-shaped plate has a concave arc surface, which is used to fit against the posterior condyle articular surface of the femur, and the thickness of the arc-shaped plate is less than the thickness of the straight plate. The arc-shaped plate is provided with a second screw hole and a blunt spade anchoring structure extending along the fracture plane. The center line of the plate along the length of the straight plate is used as a reference line, and the projection of the center line of the plate on the sagittal plane passes through the blunt spade anchoring structure.

2. The fixing plate as described in claim 1, characterized in that, The angle between the projection of the blunt shovel central axis of the blunt shovel anchoring structure and the center line of the plate in the sagittal plane is 0° to 10°.

3. The fixing plate as described in claim 1, characterized in that, The angle between the projection of the center line of the plate and the normal of the concave arc at the center of the concave arc surface onto the sagittal plane is 30° to 60°.

4. The fixing plate as described in claim 1, characterized in that, The angle between the projection of the center line of the plate and the center line of the screw hole of the second screw hole on the sagittal plane is 0° to 15°.

5. The fixing plate as described in claim 1, characterized in that, The blunt shovel anchoring structure is a trapezoid that gradually narrows along the extension direction, and the edges of the trapezoid are rounded.

6. The fixing plate as described in claim 1, characterized in that, The arc-shaped plate has two symmetrically arranged side wings, and the number of the second screw holes is two, which are respectively located on the side wings. The second screw holes are symmetrically arranged on both sides of the blunt shovel anchoring structure with the center line of the plate as the axis.

7. The fixing plate as described in any one of claims 1 to 6, characterized in that, The extended starting point of the blunt shovel anchoring structure is provided with a reinforcing rib for force transmission, and the reinforcing rib is a protrusion extending longitudinally along the fixing plate.

8. The fixing plate as described in claim 1, characterized in that, The protruding length of the blunt shovel anchoring structure is 4mm to 8mm, and the root width is 3mm to 5mm.

9. An internal fixation system for coronal plane fractures of the posterior femoral condyle, characterized in that, The fixing plate as described in any one of claims 1 to 8 is further comprising a long-arm universal screwdriver, a bending guide sleeve, and a locking screw used in conjunction with the fixing plate; The curved guide sleeve is adapted to the first screw hole and / or the second screw hole to guide the guide pin and / or screw to be implanted into the femur at a fixed angle along the second screw hole; The long-arm universal screwdriver is adapted to the first screw hole and / or the second screw hole for screwing screws into the femur.

10. The internal fixation system for coronal plane fractures of the posterior femoral condyle as described in claim 9, characterized in that, When the fixing plate is provided with reinforcing ribs, it also includes an eccentric driver that cooperates with the blunt shovel anchoring structure. The eccentric driver includes a handle, an eccentric connecting rod and a driving end. The driving end is provided with a recess for cooperating with the reinforcing ribs.

Images