Auxiliary treatment device for posterior malleolus fracture

Abstract

The utility model discloses an auxiliary treatment device for posterior malleolus fracture, the auxiliary treatment device for posterior malleolus fracture is a self-shaping anti-slip steel plate, the self-shaping anti-slip steel plate is matched with a human posterior malleolus bone, and a plurality of screw holes are formed in the self-shaping anti-slip steel plate; through the design of the self-shaping anti-skid steel plate, the steel plate can be combined with the ankle joint of a patient to fix the ankle joint, the anatomical form of the posterior ankle is met, the ligament structure is not interfered, self shaping can be achieved in the operation, low incisura is achieved, and irritation to soft tissues such as posterior tendons is reduced or even eliminated, so that the medical cost is effectively reduced; the device has the advantages of being capable of accelerating the rehabilitation process of the wounded, good in fixing effect and good in self-plasticity.

Description

Technical Field

[0001] This utility model belongs to the field of medical device technology, specifically relating to an auxiliary treatment device for posterior ankle fractures. Background Technology

[0002] The posterior malleolus is the posterior component of the distal tibia and fibula complex and is an important structure for maintaining ankle joint stability. During human standing and weight-bearing walking, the ankle joint bears a load of approximately 3-5 times the body weight. The proportion of ankle fractures involving the posterior malleolus is relatively high, ranging from about 7% to 44%. In recent years, ankle fractures involving the posterior malleolus have shown an increasing trend. How to enable patients to achieve the greatest possible functional rehabilitation after injury is a problem that must be solved in clinical treatment. Patients with ankle fractures involving the posterior malleolus have a worse prognosis, with a higher incidence of intraoperative complications and postoperative traumatic ankle arthritis. This is especially true for posterior malleolar fractures caused by large traumatic injuries. Because the ankle joint is subjected to both vertical and torsional forces, the fracture fragments are significantly displaced, and a noticeable step appears on the articular surface. Surgical anatomical reduction of the posterior malleolar fracture fragments and articular surface is usually required, along with reliable fixation using appropriate implants, to ultimately restore normal ankle function. Ankle fractures with posterior malleolar fractures also have a significantly worse clinical prognosis, necessitating surgical reduction and fixation. Appropriate internal fixation is key to improving the surgical outcome of posterior malleolar fractures. Ankle fractures with posterior malleolar fractures are the most common type of lower limb fracture, and their clinical prognosis is significantly worse, requiring surgical reduction and fixation.

[0003] Currently, none of the posterior ankle internal fixation materials used clinically are designed with the anatomical characteristics of the Chinese posterior ankle in a three-dimensional manner, or they are simply combinations of two ordinary steel plates. These materials have significant defects and shortcomings in clinical use, such as…

[0004] (1) The shape of the steel plate does not conform to the anatomical characteristics of the posterior ankle of Chinese people, and cannot fix all fracture fragments. Multiple steel plates need to be used in combination.

[0005] (2) If the steel plate is too large or too thick, it will be difficult to shape during the operation and will irritate the soft tissues such as tendons, nerves and blood vessels behind the patient;

[0006] (3) The fixed screw hole position cannot meet the intraoperative fine adjustment, which can easily cause repeated operation during the operation, increase the operation time and the number of fluoroscopy, and bring radiation risks to patients and surgeons;

[0007] Therefore, there is an urgent need to design a simple and practical auxiliary treatment device for posterior ankle fractures to solve the problems existing in the above-mentioned technologies, accelerate the rehabilitation process of the injured, and improve social and economic benefits. Utility Model Content

[0008] To address the shortcomings of the existing technology, the purpose of this invention is to provide an auxiliary treatment device for posterior ankle fractures. Through the design of a self-plasticizing anti-slip steel plate, the steel plate can be integrated with the patient's ankle joint to fix the ankle joint. It conforms to the anatomical shape of the posterior ankle, does not interfere with the ligament structure, can self-plasticize during surgery, and the low notch reduces or even eliminates irritation to soft tissues such as posterior tendons, effectively reducing medical costs. It has the characteristics of accelerating the patient's recovery process, good fixation effect, and good self-plasticity.

[0009] To achieve the above objectives, the technical solution adopted by this utility model is as follows:

[0010] A posterior malleolus fracture adjuvant treatment device, wherein the posterior malleolus fracture adjuvant treatment device is a self-molding anti-slip steel plate, the self-molding anti-slip steel plate is adapted to the human posterior malleolus bone, and a number of screw holes are provided on the self-molding anti-slip steel plate.

[0011] Preferably, the proximal section of the self-shaping anti-slip steel plate is long and thick, while the distal end is wide and twisted forward and arched backward, with the outer side of the distal end being more prominent than the inner side; and the shape of the self-shaping anti-slip steel plate is the same as the anatomical shape of the posterior distal end of the human tibia.

[0012] Preferably, the thickness of the self-shaping anti-slip steel plate gradually decreases from the near end to the far end.

[0013] Preferably, the length of the self-shaping anti-slip steel plate is adapted to the highest point of the tibial insertion of the posterior tibiofibular ligament; the width of the self-shaping anti-slip steel plate is adapted to the width of the posterior tibiofibular ligament and the tibial insertion of the transverse tibiofibular ligament.

[0014] Preferably, the screw hole includes a sliding hole, an adjustable locking screw hole, and a regular locking screw hole.

[0015] Preferably, the adjustable locking screw holes are located at the far end of the steel plate, with 3 holes and 2 holes arranged sequentially from far to near, all with a diameter of 3.5mm. The adjustable locking screw holes allow the screws to be adjusted 30° in all directions.

[0016] Preferably, the ordinary locking screws are provided on the backbone section of the steel plate, arranged in a single row, and the number of screws is adapted to the length of the steel plate.

[0017] Preferably, the sliding hole is located in the middle section of the steel plate, and the length of the sliding hole is equivalent to 3-4 times the diameter of a conventional locking screw hole.

[0018] Preferably, the self-shaping anti-slip steel plate is made of titanium alloy material.

[0019] The beneficial effects of this utility model are as follows: This utility model discloses an auxiliary treatment device for posterior ankle fractures. Compared with the prior art, the improvement of this utility model lies in:

[0020] This utility model designs an auxiliary treatment device for posterior malleolar fractures. The auxiliary treatment device for posterior malleolar fractures is a self-plasticizing anti-slip steel plate. Through the design of the self-plasticizing anti-slip steel plate, during use:

[0021] 1. The proximal section of the steel plate is designed to be long and shaft-like, while the distal end is wide and twisted forward, bulging backward in an arc shape. The lateral side of the distal end is relatively more convex than the medial side to accommodate the Volkman's tubercle of the tibia. This shape is consistent with the posterior anatomical morphology of the distal end of the tibia, making the steel plate fit the bone surface more closely. Furthermore, sliding holes are designed in the steel plate shaft, allowing the distal end of the steel plate to self-shape according to the bone surface morphology when the compression screw is screwed in. It has good self-shaping properties and does not require pre-bending during surgery.

[0022] 2. The thickness of the steel plate is progressively reduced from the proximal end to the distal end. A thinner steel plate can reduce or even eliminate stimulation to soft tissues such as posterior tendons, and improve postoperative discomfort. At the same time, the thinner thickness at the distal end of the steel plate can significantly promote intraoperative self-shaping fracture reduction and fixation and good adherence of the steel plate.

[0023] 3. With adjustable locking screw holes, ordinary locking screw holes and sliding holes, the steel plate can be effectively fixed and installed, and the height of the steel plate can be finely adjusted during the operation, reducing repeated operations during the operation. It has the advantages of accelerating the patient's recovery process, good fixation effect and good self-plasticity. Attached Figure Description

[0024] Figure 1 This is a front view of the posterior ankle fracture auxiliary treatment device of this utility model when in use.

[0025] Figure 2 This is a side view of the posterior ankle fracture auxiliary treatment device of this utility model in use.

[0026] Figure 3 This is a top view of the posterior ankle fracture auxiliary treatment device of this utility model in use.

[0027] Figure 4 This is a schematic diagram of the structure of the posterior ankle fracture auxiliary treatment device of this utility model when in use.

[0028] Figure 5 This is a structural schematic diagram of the self-plasticizing anti-slip steel plate of this utility model from a frontal view.

[0029] Figure 6 This is a side view of the structure of the self-plasticizing anti-slip steel plate of this utility model.

[0030] The components include: 1. Posterior ankle bone, 2. Steel plate, 21. Sliding hole, 22. Adjustable locking screw hole, 23. Ordinary locking screw hole, and 3. Screw. Detailed Implementation

[0031] To enable those skilled in the art to better understand the technical solution of this utility model, the technical solution of this utility model will be further described below in conjunction with the accompanying drawings and embodiments.

[0032] Example 1: Refer to Appendix Figure 1-6 The illustrated auxiliary treatment device for posterior malleolar fractures includes the following design process:

[0033] Step 1: Design Principles

[0034] 1. Anatomy-based implant design

[0035] The posterior malleolus refers to the location of the posterior lip of the distal tibia, but now it generally refers to the posterior border of the distal tibia, encompassing structures such as the posterior aspect of the fibular notch, the posterior tubercle (Volkmann's tubercle), the ankle groove, and the posterior bulb of the medial malleolus. The tibial dome forms a depression proximally, while the posterior lip of the distal tibia extends posteroinferiorly, increasing the contact area between the distal tibia and the top of the talus, and together with the lateral malleolus, limiting excessive posterosuperior displacement of the talus. The posterolateral aspect of the posterior malleolus is the origin of the posterior tibiofibular syndesmosis ligament and the transverse tibiofibular syndesmosis ligament, making it an important component of the ankle joint. The tibiofibular complex and lateral collateral ligaments are the main structures maintaining soft tissue stability. Specifically, the posterior tibiofibular ligament (PITFL) originates from Volkman's tubercle and inserts into the posterolateral aspect of the fibula. Its distal end forms the inferior transverse tibiofibular ligament (ITL). The ITL is a very dense cartilaginous structure, forming a structure similar to the posterior lip of the ankle joint. The PITFL plays the most important role in maintaining the stability of the tibiofibular syndesmosis, accounting for 42% of its stability. The interosseous membrane is also part of the posterior stabilizing structure, thickening distally to form the interosseous tibiofibular ligament (IOL). In addition, the posteromedial tibialis posterior tendon and deltoid ligament are also involved. The posterior ankle layer also provides support and protection for the posterior stability of the ankle joint. Both the bony and ligamentous structures of the posterior ankle play a crucial role in the stability of the ankle joint. Therefore, internal fixation devices, while conforming to the anatomical characteristics of the posterior ankle, should not affect the ligamentous structure or ligament insertion paths. Simultaneously, relying on the ankle joint's own ligamentous stabilizing structure can reduce the need for unnecessary implants. A well-designed implant should supplement and replace the damaged structures after a fracture, fully considering the local anatomical characteristics of the posterior ankle to achieve reliable compression of the fracture ends without interfering with the integrity of the posterior ankle ligaments. Currently, there are no fracture fixation implant designs or products in China based on the anatomical characteristics of the posterior ankle in Chinese individuals, necessitating in-depth exploration and design research in this area.

[0036] 2. Damage-based implant design

[0037] The injury mechanism of posterior malleolar fractures is mostly torsional or vertical torsional force. Torsional injury is the most common injury mechanism of posterior malleolar fractures. Most posterior malleolar fractures occur in Lauge-Hansen supination-external rotation IV and pronation-external rotation IV fractures, with the former being the most common. When the ankle joint is subjected to torsional force, regardless of whether the foot is in pronation or supination, the talus impinges on the distal fibula during external rotation, causing damage to the anterior tibiofibular ligament or avulsion fracture at its attachment point, and a distal fibular fracture. If the energy of the injury has not been completely absorbed and dissipated, it continues to cause damage to the posterior tibiofibular ligament or avulsion fracture at the ligament attachment point. In recent years, with the development of transportation and the faster pace of life, more severe ankle injuries combined with torsional and vertical forces are common in clinical practice. In this type of injury, external rotation of the talus impacts the posterior or posterolateral aspect of the ankle, causing a fracture of the corresponding distal tibial articular surface. This is often accompanied by posterior and superior subluxation / dislocation of the talus. Hansen defined this type of ankle fracture in 2000 as a posterior Pilon fracture, which has a more complex injury pattern and worse clinical prognosis than the traditionally described rotational ankle fracture. If a plate capable of simultaneously resisting longitudinal displacement and torsional forces, and which can fix multiple posteriorly damaged structures via a single surgical approach, could be designed and developed, it would simplify the surgical procedure, reduce surgical trauma for patients, and accelerate their recovery.

[0038] 3. Implant design based on fracture morphology

[0039] Research on the morphology of posterior malleolar fractures has been ongoing. Many scholars hope to use classification systems to indicate the injury mechanism, injury pattern, severity, and guide treatment and prognosis. Currently, the main classifications of posterior malleolar fractures include: Haraguchi classification, Bartonicek classification, Mangnus classification, Mason classification, AO classification, and Lauge-Hansen classification. Among them, the Haraguchi classification is the earliest proposed and most widely accepted classification, with most subsequent classifications being modifications of it. The Bartonicek classification was the first to be based on the anatomical structure of the posterior malleolar fracture and the involvement of the tibia and fibular notch, deepening researchers' understanding of the pathological anatomical characteristics of posterior malleolar fractures. The Mason classification combines fracture anatomy with pathological mechanisms and injury patterns, and is currently considered a relatively ideal classification system for posterior malleolar fractures. Each classification system provides some guidance for the diagnosis, treatment, and prognosis of posterior malleolar fractures. Posterior malleolar fractures in Chinese patients exhibit distinct fracture line heatmap distribution characteristics. While fracture morphology can draw upon international classifications, the proportion of cases in each classification reflects unique Chinese characteristics. Different disease spectra lead to significant variations in treatment methods and internal fixation options. Therefore, it is necessary to develop a corresponding classification system for posterior malleolar fractures in Chinese patients based on extensive case data. Furthermore, considering the morphological characteristics and rehabilitation requirements of posterior malleolar fractures in Chinese patients, a posterior malleolar fracture reduction and fixation implant system suitable for most fracture types in Chinese patients should be designed and promoted.

[0040] 4. Therapeutic-based implant design

[0041] Surgical indications for posterior malleolar fractures include: (1) fractures involving >25%-33% of the articular surface area; (2) displacement >2mm; (3) ankle instability with combined ligament injury; and (4) persistent posterior subluxation of the talus. As an intra-articular fracture, anatomical reduction and strong internal fixation are key to improving surgical efficacy in posterior malleolar fractures. For the selection of internal fixation devices for posterior malleolar fractures, the most commonly used devices in clinical practice are hollow screws or plates, including: tubular plates, distal radius plates, metacarpal plates, oblique T-plates, etc. For patients with comminuted fractures and osteoporosis, the use of hollow screws for fixation is prone to screw loosening and fixation failure. The plates currently used all have defects and shortcomings: (1) The plates do not fit the bone surface well enough, and shaping is required during the operation, which leads to a decrease in the strength of the plates and an increased risk of fatigue fracture of the plates after the operation. In addition, the bending and shaping process of the plates prolongs the operation time; (2) The shape, size and width of the plates are not adapted to the anatomical characteristics of the posterior malleolar, which may cause irritation to the soft tissues such as the posterior tendons; (3) The direction of the plates is not easy to accurately grasp, and there is a risk of the screws being inserted into the ankle joint or the distal tibiofibular syndesmosis, and it is impossible to make fine adjustments during the operation. In recent years, due to the unique characteristics of posterior malleolar fractures, some anatomical locking plates have been used to treat them. However, based on the anatomical features of Western populations, an overemphasis on the mechanical strength of the implant has resulted in relatively thick and heavy plates that cannot achieve large-scale personalized plastic pre-bending. The plate design is also too large for Chinese individuals, requiring extensive surgical incisions and increasing surgical trauma. Furthermore, the plate design does not consider the origin and insertion points of the posterior malleolar ligaments and the course of important structures such as tendons and nerves, increasing the risk of irritation to the soft tissues behind the ankle joint. Based on the needs of orthopedic clinical work and the anatomical characteristics and mechanical mechanisms of posterior malleolar fractures, it is necessary to design and develop a posterior malleolar anti-slip plate that conforms to the anatomical morphology of the Chinese posterior malleolus, can self-shape during surgery, and is adjustable, thereby minimizing complications and improving the surgical efficacy of posterior malleolar fractures.

[0042] Step Two: Design Process of Self-Shaping Anti-Slip Plate 2 (Posterior Ankle Fracture Assistive Treatment Device) Based on the Anatomical Characteristics of the Posterior Ankle of Chinese People

[0043] 1. Anatomical study of the posterior ankle

[0044] Anatomical measurements were performed on the 2C ankle joint specimen. The attachment range of the posterior tibiofibular ligament and transverse tibiofibular ligament complex posterior to the tibia was measured (vertical distance from the lateral edge of the ankle groove to the posterolateral tibial tuberosity line; height of the highest point of the posterior tibiofibular ligament from the joint line; height of the highest point of the transverse tibiofibular ligament from the joint line; width of the tibial attachment zone of the posterior tibiofibular ligament and transverse tibiofibular ligament complex; vertical distance from the lateral edge of the tibial attachment zone of the ligament complex to the posterolateral tibial tuberosity line; vertical distance from the medial edge of the tibial attachment zone of the ligament complex to the lateral edge of the ankle groove). Previous anatomical studies of the posterior ankle and related anatomical measurements have been completed. The preliminary posterior ankle anatomical measurement data and subsequent C-scan measurement data from volunteers provide a reference for the design of a novel self-molding anti-slip plate for the posterior ankle.

[0045] 2. Ankle joint CT scans, 3D reconstruction, and data measurement in Chinese patients

[0046] (1) 30 volunteers with normal ankle joints were selected. The volunteers were over 18 years old and had no abnormal ankle joint movement. They were excluded from having a history of ankle joint injury or congenital developmental abnormalities. All volunteers gave informed consent and signed informed consent forms. They underwent ankle joint spiral CT scans and the results were output in the form of DVD discs.

[0047] (2) Import the CT scan data into Mimics 14.0 software in DICOM format, use Mimics 14.0 software to perform three-dimensional reconstruction of the data, measure the posterior ankle anatomical data, and calculate the relevant anatomical parameters of the posterior ankle.

[0048] (3) Measurement and analysis of three-dimensional data: ① Height of the screw placement safety zone: The height of the horizontal area on the posterolateral surface of the distal tibia where the screw is placed horizontally without penetrating the ankle joint surface; ② Torsion height: The vertical distance from the point where the posterior posterior surface of the tibia begins to twist to the horizontal plane of the screw placement safety zone; ③ Posterior malleolus width: The vertical distance (L) between the lateral edge of the ankle groove and the posterolateral tubercle line of the tibia on the posterior surface of the posterior malleolus, measured every 5 mm from the distal end to the proximal end, up to 40 mm from the distal end of the posterior malleolus; ④ Posterior rotation angle: The angle between the posterolateral surface of the mid-section of the tibia in the coronal plane and the posterior posterior surface of the distal tibia in the sagittal plane; ⑤ Posterior rotation height: The vertical distance from the point where the posterior posterior surface of the distal tibia begins to twist to the horizontal plane of the screw placement safety zone.

[0049] 3. Design, 3D printing, and validation of a steel plate (auxiliary treatment device for posterior malleolar fractures).

[0050] (1) Using the computer-aided design software Unigraphics NX 5.0, a new type of self-shaping anti-slip steel plate was designed based on relevant measurement data, angles, and widths. Using computer three-dimensional imaging technology, the designed new type of self-shaping anti-slip steel plate was matched, fitted, and the implantation screw channel was verified in the three-dimensional space of the posterior ankle. The steel plate template was printed in proportion (1:1) using polyethylene material combined with 3D printing technology.

[0051] (2) A novel self-shaping anti-slip steel plate model of the posterior ankle was fabricated using 3D printing technology and verified in 6 Synbone artificial bone models.

[0052] 4. Development and structural characteristics of the designed self-plastic anti-slip steel plate 2

[0053] 4.1. Shape of self-plasticizing anti-slip steel plate 2

[0054] (1) Based on the anatomical characteristics of the posterior ankle of Chinese people, a new type of self-shaping anti-slip steel plate for the posterior ankle was developed, using titanium alloy material with an elastic modulus similar to that of human bones.

[0055] (2) The proximal section of the steel plate 2 is long and the distal end is wide and twisted forward and arched backward. The outer side of the distal end is relatively more convex than the inner side to adapt to the Volkman's tubercle of the tibia. This shape is consistent with the anatomical shape of the posterior distal end of the tibia, so that the steel plate fits the bone surface better. The steel plate 2 has a sliding hole 21 designed in the shaft. When the compression screw is screwed in, the distal end of the steel plate can be self-shaped according to the shape of the bone surface without the need for pre-bending during the operation.

[0056] (3) The thickness of plate 2 is thinner than that of the conventional posterior ankle anatomical plate, and the thickness decreases progressively from the proximal end to the distal end; the thinner plate thickness can reduce or even eliminate stimulation of soft tissues such as posterior tendons, and improve postoperative discomfort symptoms. At the same time, the thinner distal end of the plate can significantly promote the self-shaping fracture reduction and fixation of the plate during the operation and the good fit of the plate;

[0057] (4) The posterior ankle self-shaping anti-slip steel plate 2 is related to the fixation of the posterior ankle ligaments and the stability of the ankle joint. The length of the steel plate 2 is related to the range of the posterior tibial insertion point of the posterior ankle ligaments. Based on the measurement parameters of the previous posterior ankle anatomy research, the length of the steel plate is determined by the highest point of the tibial insertion point of the posterior tibiofibular ligament; the width of the steel plate is determined by the width of the tibial insertion point of the posterior tibiofibular ligament and the transverse tibiofibular ligament; so as to achieve good reduction and fixation of posterior ankle fracture and restore ankle joint stability.

[0058] (5) In order to adapt to the differences between the Volkmann tubercle on the posterolateral side and the bony structure on the posteromedial side of the posterior ankle, the new self-shaping anti-slip steel plate 2 is designed to be available in two specifications, left and right. At the same time, in order to adapt to the anatomical characteristics of the differences in the width and height of the posterior ankle of Chinese people, the new self-shaping anti-slip steel plate is designed to be available in three models, large, medium and small, with a total of 6 basic steel plates, and can be mass-produced.

[0059] 4.2. Screw holes in self-plasticizing anti-slip steel plate 2

[0060] (1) Adjustable locking screw hole 22: The adjustable locking screw hole 22 is located at the far end of the steel plate 2, near the joint end. There are five of them, which are 3 holes and 2 holes from far to near. They are all 3.5mm screw holes. The screw hole design allows the screw direction to be adjusted and locked by 30° to avoid the distal screw 3 being inserted into the ankle joint or the distal tibiofibular syndesmosis.

[0061] (2) Ordinary locking screw hole 23: Ordinary locking screw 23 is located in the backbone section of steel plate 2 (far from the joint end), arranged in a single row, and its number increases as the length of steel plate increases.

[0062] (3) Sliding hole 21: The middle section of the steel plate 2 is designed with a sliding hole. Its sliding length is equivalent to 3-4 times the length of the ordinary locking screw hole 23, which allows for fine adjustment of the steel plate height during the operation and reduces repeated operations during the operation.

[0063] Example 2: To verify the effectiveness of the self-plasticizing anti-slip steel plate 2 designed as in Example 1, this example is designed to conduct biological research on the self-plasticizing anti-slip steel plate 2.

[0064] 1. Selection of experimental model materials

[0065] The experimental mechanical model used Synbone artificial bone manufactured by Synthes AG, Switzerland. Recommended by the Association for the Study of Internal Fixation (AO) for use in orthopedics and trauma medicine, as well as for teaching and research, this biomimetic bone demonstrates similar biomechanical properties to cadaver bone, while also effectively mimicking fracture mechanisms. The Synbone artificial tibia experimental mechanical model in this study fully represents the anatomical structure and material mechanical properties of a normal cadaver tibia, with the artificial bone representing both cortical and cancellous bone. Its particularly outstanding advantages include its ability to replace human cadaver bone, which is subject to limited availability and difficult preservation, and its ease of processing, making it a relatively ideal alternative material.

[0066] 2. Establishment and grouping of posterior malleolar fracture models

[0067] This embodiment of the project researches and develops a novel self-shaping anti-slip plate for the posterior ankle, designed and manufactured in collaboration with Shanghai Kangding Medical Instrument Co., Ltd. The plate utilizes a titanium alloy material with an elastic modulus similar to that of human bone. A standard posterior ankle locking plate serves as a control. Thirty ankle joint Synbone artificial bone samples were collected to create Haraguchi type I posterior ankle fracture models. These models were randomly divided into three groups: Group 1 consisted of 10 original normal specimens; Group 2 consisted of 10 specimens with a standard posterior ankle locking plate; and Group 3 consisted of 10 specimens with the novel self-shaping anti-slip plate. Biomechanical experiments were then conducted.

[0068] 3. Biomechanical experimental analysis methods

[0069] After Synbone artificial bone was used to create posterior malleolar fracture models, the posterior malleoli of the specimens were fixed. A universal biomechanical testing system was used to conduct biomechanical testing and analysis on the normal group model, the ordinary posterior malleolar locking plate group model, and the novel posterior malleolar self-shaping anti-slip plate group model.

[0070] (1) Axial compressive strength and stiffness of the posterior ankle

[0071] The strength of fixation for posterior malleolar fractures is often mechanically expressed by the axial compressive strength and stiffness of the fixed fracture ends. Strength refers to the malleolar's resistance to fracture after fixation, while stiffness refers to its resistance to deformation. A Synbone artificial bone model was mounted and fixed in a biomechanical testing instrument for axial compressive strength testing. Axial compression was applied to the proximal tibia at a speed of 10 N / s, and the strength and stiffness values ​​of the posterior malleolar under a 500 N load were recorded.

[0072] (2) Torsional mechanical properties of the posterior ankle: torque and torsional stiffness

[0073] The torsional mechanical properties of posterior malleolar fractures were measured by the following indices: torque and torsional stiffness. Using the same fixation method as described above, a torque was applied to the tibia, and the torsional mechanical properties, torque, and torsional stiffness of the tibia under a torque of 5.0 N·M were recorded.

[0074] (3) Contact mechanical characteristics of the tibiotalar joint surface: contact pressure and contact area

[0075] The contact mechanics of the tibiotalar joint reflects the stability of the ankle joint after fixation, and the indicators are contact pressure and contact area. Using the same fixation method as described above, axial compression was applied to the proximal tibia at a loading rate of 10 N / s. Pressure-sensitive pad techniques were used to measure the contact pressure and contact area of ​​the tibiotalar joint surface under a 500 N load.

[0076] (4) Displacement of posterior malleolar fracture fragments

[0077] In addition to the strength, stiffness, and contact mechanics characteristics mentioned above, the mechanical indicators used to evaluate the firmness and stability of the posterior ankle fixation also include measuring the displacement of the fixation bone fragments. An axial load was applied to the proximal tibia at a speed of 10 N / s, and the degree of posterior ankle fracture displacement was recorded under a 500 N load. A CT scan of the fixed ankle joint was then performed to determine the screw placement.

[0078] Through the above biological analysis process, it can be concluded that the self-plastic anti-slip steel plate 2 can effectively improve the surgical efficacy of posterior malleolar fractures and reduce surgical complications.

[0079] The overall social benefits will be improved by enhancing medical safety, increasing patient satisfaction, and reducing the burden on medical insurance.

[0080] The foregoing has shown and described the basic principles, main features, and advantages of this utility model. Those skilled in the art should understand that this utility model is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of this utility model. Various changes and modifications can be made to this utility model without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection of this utility model is defined by the appended claims and their equivalents.

Claims

1. An auxiliary treatment device for posterior malleolar fractures, characterized in that: The auxiliary treatment device for posterior malleolar fracture is a self-molding anti-slip steel plate, which is adapted to the human posterior malleolar bone and has several screw holes. The self-shaping anti-slip steel plate has a long trunk shape in the proximal section and a wide distal end. The distal end is twisted forward and bulges backward in an arc shape, with the outer side of the distal end being relatively more convex than the inner side. The shape of the self-shaping anti-slip steel plate is the same as the anatomical shape of the distal posterior end of the human tibia.

2. The auxiliary treatment device for posterior malleolar fractures according to claim 1, characterized in that, The thickness of the self-shaping anti-slip steel plate gradually decreases from the near end to the far end.

3. The auxiliary treatment device for posterior malleolar fractures according to claim 1, characterized in that: The length of the self-shaping anti-slip steel plate is adapted to the highest point of the tibial insertion of the posterior tibiofibular ligament; the width of the self-shaping anti-slip steel plate is adapted to the width of the posterior tibiofibular ligament and the tibial insertion of the transverse tibiofibular ligament.

4. The auxiliary treatment device for posterior malleolar fractures according to claim 1, characterized in that: The screw holes include sliding holes, adjustable locking screw holes, and ordinary locking screw holes.

5. The auxiliary treatment device for posterior malleolar fractures according to claim 4, characterized in that: The adjustable locking screw holes are located at the far end of the steel plate, with 3 holes and 2 holes in sequence from far to near. The screw holes are all 3.5mm in diameter, and the screw holes of the adjustable locking screw holes allow the screws to be adjusted 30° in all directions.

6. The auxiliary treatment device for posterior malleolar fractures according to claim 4, characterized in that: The ordinary locking screws are installed on the backbone section of the steel plate, arranged in a single row, and the number of screws is adapted to the length of the steel plate.

7. The auxiliary treatment device for posterior malleolar fractures according to claim 6, characterized in that: The sliding hole is located in the middle section of the steel plate, and the length of the sliding hole is equivalent to 3-4 times the diameter of a normal locking screw hole.

8. The auxiliary treatment device for posterior malleolar fractures according to any one of claims 1-7, characterized in that: The self-shaping anti-slip steel plate is made of titanium alloy.

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