RU2340010C2 - Model of system of stabilisation of ankle bone at ankle joint dislocation-fractures - Google Patents

Abstract

FIELD: medicine, orthopedy and traumatology.

SUBSTANCE: model allows modeling fractures of bones and ruptures of ligaments of a segment anticnemion-foot. The model contains plastic casts of bones of an anticnemion and foot, including ankle bone bridged among themselves by models of ligaments, with possibility of modelling of places of fractures and damages of the copular apparatus. The models of ligaments executed from two-layer rubber, are fastened to casts of bones in the form of the tape Velcro. The interosseous membrane bridging among themselves shinbones is executed in the form of the tape Velcro, rigidly fixed to casts of shinbones. Models of fractures are executed in the form of saw cut, clamped by rivets.

EFFECT: reproduction of changes of biomechanical status of ankle joint at fractures of segment anticnemion-foot.

12 dwg

Description

The invention relates to medicine, namely to traumatology and orthopedics, and can be used in teaching students and cadets, improves visibility when demonstrating fractures of the ankle joint, shows possible displacement of bone fragments and damage to the ligamentous apparatus of the ankle joint.

A device is known, a model of a fracture of the distal humerus, consisting of a bracket on which the mechanisms of fixation of the humerus and forearm bones are mounted, made in the form of holders and clamps covering the bones. To implement angular and linear displacements of bones and fragments, the mechanisms of angular and linear displacements are used in the form of cylindrical thickenings most distant from the elbow joint with large-scale grids. Lateral displacement is carried out by the lateral displacement mechanism, which is mounted on the bracket and is a housing with a scale, adjusting and guiding screw (see USSR Author's Certificate No. 1239743, CL G09B 23/28, 1984. US Patent No. 4350490, CL G09 23 / 32, 1982). This device is taken as a prototype.

However, the known device, in view of displaying the anatomical segment of the “shoulder-forearm,” does not allow modeling fractures of the ankle joint, clearly showing the sequence of damage and the degree of damage to the structures of the ankle joint, depending on the direction and power of the damaging force.

The purpose of the invention is a visual reproduction of changes in the biomechanical status of the talus, the provisions of fragments with varying degrees of severity of fractures of the ankle joint, combined with subindesmosis, cressindesmosis and suprasindema fractures of the fibula.

The technical result is achieved by the fact that the model contains plastic casts of the tibia, fibula, talus, calcaneus, tarsal bones, metatarsal bones, phalanx of the fingers, which are interconnected by simulators of the ligaments of the anatomical segment of the tibia - foot, made of two-layer rubber, they are attached to the casts of bones by the Velcro tape, and the interosseous membrane connecting the tibia is represented by the Velcro tape, which is attached rigidly to the casts of the tibia, They are in the form of cuts of casts of the tibia, fibula, places of cuts are connected with rivets, rivets are fused into the casts of the bone, in the plane of cuts.

The problem to be solved is the reproduction of deformations during various fractures of the ankle joint, increasing the visibility and understanding of changes in the biomechanical status of the tare bone in the case of subindesmosis, cressindesmosis and suprasindema fractures of the fibula.

The invention consists in simulating a single biomechanical model of the talus stabilization system in the tibia-foot segment, which consists of three stabilization rings (FIGS. 2, 3, 4).

Description of the proposed device and method of its application

The biomechanical model contains: plastic casts of the tibia - 4, fibula - 5, talus - 13, calcaneus - 14, scaphoid - 28, cuboid bone - 29, three sphenoid bones - 30, metatarsal bones - 31, phalanges fingers - 32. Casts of bones are connected by simulators of ligaments, anatomical segment of the “shin-foot” made of two-layer rubber, attached to the casts of bones with a Velcro tape. The interosseous membrane is represented by the Velcro tape, which is attached rigidly to the casts of the tibia and dynamically connecting them. Fracture models - 15, 16, 17, 18, 19, 20 are represented by cuts of casts of the lower leg bones at the level of the inner ankle of the tibia, below the level, through the level and above the level of the distal syndesmosis of the fibula. The cuts are fastened with rivets that are fused into the casts of the bones in the plane of the fracture model.

The "large" stabilization ring - 1, Figs. 5, 6, consists of models: medial collateral ligament - 12, inner ankle - 11, tibia - 4, proximal tibia - 6 and 7, fibula - 5, interosseous membrane - 8, the outer ankle - 23, the lateral collateral ligament - 11, the calcaneus - 14. It is conditionally divided into two rings of stabilization of the talus.

The "axial" (third) stabilization ring, Fig. 5, is located at the level of the distal tibiofibular syndesmosis, consists of the external ankle - 23, the anterior tibial ligament - 9, the tibia - 4, the posterior tibial ligament - 10, Fig. 4. At this level, the “big” ring is divided into two.

The first stabilization ring, - 1, Figure 5, which keeps the talus from shifting in the ankle joint, is located below the distal tibiofibular syndesmosis and consists of models of the distal articular surface of the tibia - 4, the inner ankle - 22, the medial collateral ligament - 11, the calcaneus - 14, the external collateral ligament - 11, the external ankle - 23.

The second stabilization ring, - 2, Figure 1, is located above the distal tibial syndesmosis, consists of models of the fibula - 6, the interosseous membrane - 8, the proximal tibia - 6 and 7, the tibia - 4.

Fractures of the fibula and tibia that occur during fractures of the ankle joint are modeled by sawing plastic casts of these bones. The tibial fracture model is located at the level of the joint space, in the region of the inner ankle. Models of fractures of the fibula are at the sub-, trans-, and suprasindema level. The integrity of the cast of the tibia bones is restored due to the fusion of the fracture, rivet, into the plane of the model. This fastening scheme is shown in FIG. 12, where 1 is a plastic cast of a bone with a fracture model, 2 is a rivet fused into a bone model.

The nature of the damage in the GSS depends on the position of the foot at the time of the injury and the strength of the impact. When modeling damage on this biomechanical model, all 3 possible traumatic forces are recreated: adduction, abduction, rotation.

Subsindesmosis lesions occur during supination, pronation, and rotational foot movements. To recreate this damage on the model: the model’s foot - 33 penetrates and rotates inwardly. The lateral collateral ligaments are tensioned - 11. The next stage is the tear fracture of the external ankle at the ankle joint level - 17 or only the apex of the external ankle - 18. With continued exposure to the traumatic force, the talus bone - 13 with its inner side presses on the inner ankle - 22, breaks it off together with a small portion of the distal metaepiphysis of the tibia - 15. With this type of damage of the ankle joint, it is common that one is damaged - the first ring of stabilization of the talus - 1. These damage are presented in Fig.7, Fig.8.

Cressindesmosis lesions occur during the eversion movement of the foot with pronation elements. The talus bone - 13 with the foot - 33 is retracted around the longitudinal axis of the mannequin and the first step applies pressure to the outer ankle - 23 with the direction of the force outward and backward. At the same time, the anterior tibial ligament - 9, resisting this movement, creates a "conflict of effort" in the anterior part of the fibula at the level of the horizontal fissure of the ankle joint. In the second stage, the posterior - the external block of the talus - 13 abuts against the overhanging posterior tibial ligament - 10, exerts a tearing effect on the fibula - 5 to the level of the upper border of the posterior tibial ligament attachment - 10. There is an interconnected fracture of the fibula - 20, passing through the syndesmosis zone . With this damage, at first a tear fracture of the inner ankle occurs - 22 or a deltoid ligament rupture - 12. The first talus stabilization ring is damaged - 1, and then the second ring - 2, located at the level of the distal tibiofibular syndesmosis - it is common that two stabilization rings are damaged . Damage data are presented in FIG. 10, FIG. 11.

Supersindesmal lesions arise from pronational effort. There is a rotation of the foot - 33 outwards around the longitudinal axis of the foot. At the first stage, as a result of a tensile force in the inner part of the ankle joint, the deltoid ligament is broken - 12 or a tear fracture of the inner ankle. The first talus stabilization ring is damaged, Fig. 9. At the second stage, there is a further displacement of the talus - 13, which puts pressure on the outer ankle - 23, this leads to the bending of the body of the fibula and its fracture 5-7 cm above the distal tibiofibular syndesmosis. Damage to the second stabilization ring of FIG. 10. At the third stage, the broken distal part of the fibula is displaced at an angle to its longitudinal axis, which consequently leads to rupture of the ligaments of the distal tibia syndesmosis - 9 and 10 and interosseous membrane - 8 in the direction from the bottom up. Damage occurs to the third stabilization ring - 3, at the level of the distal tibiofibular syndesmosis Fig. 11. Common for this type of fracture dislocation is damage to 1, 2, 3 rings of stabilization of the talus.

Claims (1)

A model of the talus stabilization system for fractures of the ankle joint, which allows modeling bone fractures and tears of the ligaments of the tibia-foot segment, containing plastic casts of the tibia and foot, including the talus, interconnected by ligament models, with the possibility of modeling fracture sites and ruptures of the ligamentous apparatus, while the ligament models are made of two-layer rubber and are attached to the bone models with a Velcro tape, the interosseous membrane connecting the tibia is made in the form of flax You are a “Velcro” rigidly fixed to the casts of the tibia, and fracture models are made in the form of cuts and fixed with rivets.

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