Internal fixing structure for posterior cruciate ligament tibia dead center fracture

Abstract

The invention relates to the technical field of medical instruments, in particular to an internal fixing structure for posterior cruciate ligament tibia dead center fractures, which comprises a tail plate, a plurality of movable screw holes are formed in the front side of the tail plate in a penetrating manner, a plurality of locking screw holes are formed in the rear side of the tail plate in a penetrating manner, and two head plates are fixedly mounted at the front end of the tail plate. A notch is formed between the two head plates, a plurality of fixing screw holes are formed in the surfaces of the head plates in a penetrating mode, sliding grooves are formed in the positions, close to the edges, of the left side and the right side of each head plate, and deformable needles formed in a bent mode are arranged in the sliding grooves. By dissecting the attached head and tail plate structures, adopting an encircling type fixing mode and adopting the combined design of the adjustable deformable needles and multiple types of screw holes, multi-angle, dispersive and pressurized stable fixing of the tibia dead center fracture blocks is achieved, and ligament protection and operation flexibility are taken into account while the fixing strength and stability are improved.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and in particular to an internal fixation structure for posterior cruciate ligament tibial insertion fractures. Background Technology

[0002] Posterior cruciate ligament (PCL) insertion fractures are a special type of tibial plateau fracture. They occur deep within the body, involve complex anatomy, and are often accompanied by posterosuperior displacement of the fracture fragments, making surgical treatment challenging. Because the PCL plays a crucial role in limiting posterior tibial displacement and maintaining posterior knee stability, poor restoration of the anatomical structure at its insertion point can easily lead to knee instability, limited range of motion, and even secondary degeneration. Therefore, in clinical treatment, simply reducing the fracture fragments is often insufficient to meet functional recovery needs. It is essential to reconstruct the normal anatomical relationship between the PCL insertion point and the tibial plateau, ensuring stable fracture healing. Precise reduction and reliable fixation can effectively restore the physiological tension and mechanical pathways of the PCL, thereby improving postoperative knee stability, range of motion, and overall functional prognosis.

[0003] However, existing internal fixation devices for fractures of the posterior cruciate ligament of the tibia mostly use a single type of plate or screw for fixation. Their structure is often based on planar compression or point support, which makes it difficult to fully conform to the complex anatomical curvature of the posterior tibia. During fixation, insufficient conformation and concentrated stress are prone to occur. At the same time, some fixation structures lack targeted design when crossing the ligament insertion area, which can easily cause compression or interference to the ligament itself, affecting postoperative functional recovery. Overall, there is still room for improvement in fixation stability and safety. Summary of the Invention

[0004] The purpose of this invention is to address the aforementioned shortcomings in the prior art by proposing an internal fixation structure for tibial insertion fractures of the posterior cruciate ligament.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: An internal fixation structure for tibial insertion fractures of the posterior cruciate ligament includes a tail plate. The tail plate has several movable screw holes through its anterior side and several locking screw holes through its posterior side. Two head plates are fixedly installed at the front end of the tail plate, with a notch between the two head plates. Several fixing screw holes are through the surface of the head plates. Sliding grooves are provided on both the left and right sides of the head plates near their edges, and deformable needles formed by bending are provided inside the sliding grooves.

[0006] Preferably, the plurality of movable screw holes are arranged linearly, and the plurality of locking screw holes are arranged alternately from front to back.

[0007] Preferably, the movable screw hole is elongated, and the locking screw hole is circular, both of which mate with the locking screw.

[0008] Preferably, the front side of the tail plate is curved downwards at a certain arc to adapt to the shape of the tibia itself, so as to fit closely to the surface of the tibia.

[0009] Preferably, the front of the head plate is designed in the shape of a cobra's head, and the side has a certain curvature to form a curved section, which is located on the side near the tail plate.

[0010] Preferably, the back of the headplate has a non-slip rough surface to enhance the friction between the headplate and the tibial surface and improve the stability of fixation.

[0011] Preferably, the notch is V-shaped, with the two sidewalls of the V-shaped notch extending forward and the opening gradually increasing in size so as to allow insertion into the attachment area of ​​the posterior cruciate ligament.

[0012] Preferably, the deformable needle itself can deform and bend according to actual needs.

[0013] Preferably, a ball bearing is installed on the lower side of the deformable needle, and the diameter of the ball bearing is the same as the inner diameter of the sliding groove, so that the ball bearing can slide inside the sliding groove.

[0014] Preferably, the deformable needle can be inserted into the tibia from the corresponding sliding groove using its tip, according to actual needs, to adapt to different fracture types.

[0015] Compared with the prior art, the advantages of the present invention are as follows: 1. This invention utilizes the cobra-shaped head plate and tail plate to ensure stable placement of the device in accordance with the anatomical curvature of the tibia. The anti-slip rough surface effectively increases friction with the bone surface, reducing the risk of loosening during and after surgery. The V-shaped notch formed by the split head plate can precisely cross and engage the tibial insertion bone block of the posterior cruciate ligament, reserving a channel for the ligament body while avoiding compression damage. Structurally, it balances fixation stability with soft tissue protection.

[0016] 2. The cobra-head-shaped head plate of this invention forms a circumferential wrap around the fracture fragment, which can distribute the fixation force more evenly to the surrounding bone and reduce local stress concentration. Multiple locking screws enter the bone fragment and tibia from different directions to achieve multi-plane and multi-angle stable support, which can effectively resist the tendency of the fracture fragment to shift and rotate backward and upward, forming a reliable three-point fixation structure, thereby significantly improving the overall stability after fracture reduction.

[0017] 3. The present invention features sliding grooves on both sides of the head plate, which can be used in conjunction with deformable needles. The needles can be bent to different degrees and angles according to different fracture morphologies, allowing them to enter the tibia through multiple paths. The needles have a smaller diameter, reducing the risk of bone fragment splitting. The arc-shaped bending structure creates a stabilizing effect of continuous pressure behind the bone fragment. At the same time, the ball bearing structure in the sliding grooves facilitates precise adjustment of the position before and during surgery, improving the flexibility and adaptability of the operation.

[0018] 4. The tail plate of the present invention is provided with both locking screw holes and movable screw holes, and the locking screw holes are staggered to the left and right, which helps to enhance the anti-pull-out and anti-rotation capabilities of the rear fixation; the elongated movable screw holes make it easy to select the appropriate nail insertion position according to the fracture site, which can achieve angular stability fixation with locking screws or form pressure fixation with non-locking screws, thereby significantly improving the applicability of the device to various fracture types.

[0019] In summary, this invention achieves multi-angle, decentralized, and pressure-stable fixation of tibial insertion fracture fragments through an anatomically fitted head and tail plate structure, a circumferential fixation method, and a combination of adjustable deformable pins and various types of screw holes. It improves fixation strength and stability while also protecting ligaments and providing operational flexibility. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the overall structure of an internal fixation structure for tibial insertion fractures of the posterior cruciate ligament proposed in this invention.

[0021] Figure 2 This is a schematic diagram of the tailplate and locking screw hole structure of an internal fixation structure for tibial insertion fractures of the posterior cruciate ligament proposed in this invention.

[0022] Figure 3 This is a schematic diagram of the headplate and fixation screw hole structure of an internal fixation structure for tibial insertion fractures of the posterior cruciate ligament proposed in this invention.

[0023] Figure 4 This is a schematic diagram of a deformable pin and ball bearing structure for an internal fixation structure for tibial insertion fractures of the posterior cruciate ligament proposed in this invention.

[0024] In the diagram: 1. Tail plate, 2. Locking screw hole, 3. Movable screw hole, 4. Head plate, 5. Bending part, 6. Fixed screw hole, 7. Sliding groove, 8. Anti-slip rough surface, 9. Deformable needle, 10. Ball bearing, 11. Notch. Detailed Implementation

[0025] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0026] Reference Figures 1 to 4 An internal fixation structure for tibial insertion fractures of the posterior cruciate ligament includes a tailplate 1. The anterior side of the tailplate 1 has several movable screw holes 3 arranged linearly. The posterior side of the tailplate 1 has several locking screw holes 2 arranged alternately from front to back. The movable screw holes 3 are elongated and the locking screw holes 2 are circular. Both are used with locking screws to fix the tailplate 1 to the tibial surface.

[0027] The anterior side of the tail plate 1 is curved downwards to conform to the shape of the tibia and fit the tibial surface. Two head plates 4 are fixedly installed at the front end of the tail plate 1. The front of the head plate 4 is designed in the shape of a cobra's head, and the side is curved to form a curved part 5. The curved part 5 is located on the side close to the tail plate 1. The cobra-shaped head plate 4 can wrap around the fracture fragment and distribute the fixation force more evenly to the surrounding bone. A notch 11 is formed between the two head plates 4. The notch 11 is designed in a V shape. The two side walls of the V-shaped notch 11 extend forward and the opening gradually increases so that the posterior cruciate ligament attachment area can be inserted, while leaving a channel for the ligament itself to avoid compression.

[0028] The headplate 4 has several fixing screw holes 6 running through its surface. These screw holes 6 engage with locking screws to secure the headplate 4 to the tibial surface. The back of the headplate 4 has a non-slip rough surface 8 to enhance friction between the headplate 4 and the tibial surface, improving fixation stability. Sliding grooves 7 are located near the edges on both sides of the headplate 4. Inside each sliding groove 7 is a bent, deformable needle 9. The deformable needle 9 can be bent as needed. A ball bearing 10 is mounted on the underside of the deformable needle 9. The diameter of the ball bearing 10 is the same as the inner diameter of the sliding groove 7, allowing the ball bearing 10 to slide within the groove. The deformable needle 9 can be inserted into the tibial bone through the corresponding sliding groove 7 using its tip, adapting to different fracture types.

[0029] In operation, the cobra-head-shaped head plate 4 is first placed in a suitable position so that the curved part 5 conforms to the curvature of the tibia. The tail plate 1 is then attached to the lower tibial surface. The back of the head plate 4 has a non-slip rough surface 8, which increases the friction with the tibial surface and improves the stability of the fixation. A notch 11 is formed between the two cobra-head-shaped head plates 4. The two side walls of the V-shaped notch 11 can accurately cross over and hold the bone fragment at the tibial attachment point of the posterior cruciate ligament, while leaving a channel for the ligament itself to avoid compression. The cobra-head-shaped head plate 4 can wrap around the fracture fragment, distributing the fixation force more evenly to the surrounding bone. The cobra-head-shaped head plate 4 is designed to grasp the fracture fragment, and with the help of multiple locking screws entering from the fixation screw holes 6, it can provide multi-plane and multi-angle stable fixation, effectively resisting the posterior and superior displacement and rotation of the fracture fragment, and achieving the effect of three-point fixation.

[0030] The headplate 4 also has sliding grooves 7 on both sides, allowing the deformable needle 9 to be bent into a hooked structure. The bent deformable needle 9 has a hook-like structure, with its two pointed ends inserted into the tibia. The arc-shaped structure presses against the posterior of the bone fragment. The deformable needle 9 has a relatively small diameter to prevent the bone fragment from splitting. In addition, the arc-shaped bending structure can fix the bone fragment from the rear, forming a pressure-stabilizing structure. Furthermore, the deformable needle 9 has a ball bearing 10 on its lower side, which can slide within the sliding groove 7 to adjust its position before insertion into the tibia. The headplate 4 also has sliding grooves 7 on both sides, allowing the deformable needle 9 to be bent to different degrees and angles as needed, and inserted into the tibia from different angles or positions to accommodate different fracture types.

[0031] The tail plate 1 on the rear side is provided with a movable screw hole 3 and a locking screw hole 2. The two locking screw holes 2 are arranged alternately from front to back. After the locking screw is driven in, it can achieve a better fixing effect. The movable screw hole 3 in front of the locking screw hole 2 is long and narrow. The appropriate position can be selected for fixing the screw as needed. The movable screw hole 3 can lock and fix with the locking screw, and can also pressurize and fix with the non-locking screw, which improves the applicability of the device.

[0032] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An internal fixation structure for posterior cruciate ligament tibial insertion fractures, comprising a tailplate (1), characterized in that, The tail plate (1) has several movable screw holes (3) through the front side and several locking screw holes (2) through the rear side. Two head plates (4) are fixedly installed at the front end of the tail plate (1). A notch (11) is formed between the two head plates (4). Several fixing screw holes (6) are through the surface of the head plate (4). Sliding grooves (7) are provided on both the left and right sides of the head plate (4) near the edge. A deformable needle (9) is bent inside the sliding groove (7).

2. The internal fixation structure for posterior cruciate ligament tibial insertion fractures according to claim 1, characterized in that, The movable screw holes (3) are arranged linearly, and the locking screw holes (2) are arranged alternately from front to back.

3. The internal fixation structure for posterior cruciate ligament tibial insertion fractures according to claim 2, characterized in that, The movable screw hole (3) is designed in an elongated shape, and the locking screw hole (2) is designed in a circular shape. Both of them are designed to work with locking screws.

4. The internal fixation structure for posterior cruciate ligament tibial insertion fractures according to claim 1, characterized in that, The tail plate (1) is curved downwards at a certain angle to adapt to the shape of the tibia itself so as to fit against the surface of the tibia.

5. The internal fixation structure for tibial insertion fractures of the posterior cruciate ligament according to claim 1, characterized in that, The head plate (4) has a cobra head-shaped design on the front and a curved part (5) on the side with a certain curvature. The curved part (5) is located on the side close to the tail plate (1).

6. The internal fixation structure for tibial insertion fractures of the posterior cruciate ligament according to claim 5, characterized in that, The back of the headplate (4) is a non-slip rough surface (8) to enhance the friction between the headplate (4) and the tibial surface and improve the stability of fixation.

7. The internal fixation structure for tibial insertion fractures of the posterior cruciate ligament according to claim 1, characterized in that, The notch (11) is designed in a V shape, with the two sidewalls of the V-shaped notch (11) extending forward and the opening gradually increasing so that the posterior cruciate ligament attachment area can be inserted.

8. The internal fixation structure for posterior cruciate ligament tibial insertion fractures according to claim 1, characterized in that, The deformable needle (9) can be deformed and bent according to actual needs.

9. The internal fixation structure for posterior cruciate ligament tibial insertion fractures according to claim 8, characterized in that, A ball bearing (10) is installed on the lower side of the deformable needle (9). The diameter of the ball bearing (10) is the same as the inner diameter of the sliding groove (7), so that the ball bearing (10) can slide inside the sliding groove (7).

10. The internal fixation structure for posterior cruciate ligament tibial insertion fractures according to claim 9, characterized in that, The deformable needle (9) can be inserted into the tibia from the corresponding sliding groove (7) with its tip as needed to accommodate different fracture types.

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