RU192451U1 - EXTERNAL FIXATION DEVICE FOR TREATMENT OF THE ELBOW JOINT - Google Patents

Abstract

The technical solution relates to medical equipment, to devices used in orthopedics and traumatology, for transosseous fixation of the upper limb in a given position to perform medical tasks to restore the function of the elbow joint. mounted with the possibility of changing the relative position and fixing a predetermined position, connected by a fixed hinged node 3, mounted on the supports of the spokes 12 and bone 13. The fixed hinge 3 is made in the form of two flat half rings 4 and 5 of equal diameter, equipped with through holes 6 superimposed on each other and fixed so that the free end of one half ring 4 is connected through the bracket to the support of the forearm 2, the free end of the second half ring 5 connected through a bracket to the shoulder support 1, while one of the half rings 4 is equipped with an extended arcuate groove 11, in which there are bolts 7 with nuts 8 installed in the through holes 6 of the second half ring 5. The technical result is chshenii treatment outcomes by increasing the reliability of fixing the mutual position of the forearm support and arm support in combination to perform, as required, controlled movements of the elbow joint, and by eliminating the radiographic shadow of parts machine at the elbow, which hinders the objective control of the joint state. 2 s.p. f-ly, 4 ill.

Description

The field of technology.

The technical solution relates to medical equipment, to devices used in orthopedics and traumatology, for transosseous fixation of the upper limb in a given position and to perform therapeutic tasks to restore the function of the elbow joint.

The level of technology.

For the treatment of pathologies of large joints, it is known to use external fixation devices (AVF), compression and distraction devices such as G.A. Ilizarova for transosseous osteosynthesis (source [1]: SU 1055499). Ilizarov’s apparatus [1] is a set of standard parts (flat rings, half rings with holes and grooves, knitting needles, threaded rods, bolts, nuts, brackets, spoke fixators, spoke holders) of various sizes, which are produced as a set of parts from which you can assemble many different, simple and complex layouts of AVF aimed at solving specific medical problems. There are sets of parts for Ilizarov’s apparatus for operations on the upper limb, on the shoulder, on the forearm (source [2]: electronic catalog of products of FSUE Experimental Plant RRC named after Academician G. A. Ilizarov of the Ministry of Health of Russia, available on the company's website http://www.ozrncvto.ru, in the “products” section of the subsection “Instruments and devices for transosseous osteosynthesis according to GA Ilizarov”, “Complete sets of Ilizarov apparatus.” Access mode http://www.ozrncvto.ru/ blank-sto5i). The Ilizarov apparatus [1; 2] contains supports made in the form of flat rings with holes, with spokes and / or screw rods mounted on them, interconnected by distraction rods. To fix bone fragments in the AVF, screws (a Shants screw, a screw shaft) and spokes (Kirchner spokes, flexible elastic metal rods) are used. Knitting needles and screws are secured in the AVF to supports and other parts. Using knitting needles and / or screws through the bone fragments, the forces are transferred to the bone fragments and their fixation. When assembling the apparatus on the upper limb, for fixation and development of the elbow joint, as a rule, a single-axis cylindrical hinge is used, consisting of two brackets connected by a bolt. An assembly is assembled comprising a shoulder support and a forearm support connected by fixed hinge assemblies, with knitting needles and bone screws fixed to the supports. For the movable connection of the shoulder support with the support of the forearm, two cylindrical hinges are used, installed at the same level relative to the elbow joint.

Single-axis cylindrical joints assembled from two brackets, 10 mm wide, connected by an M6 bolt and an S10 nut, are not able to provide reliable fixation of the connected supports in a given mutual position. The hinges are installed at the level of the elbow joint, joint space, while the axis of the hinge is located at a distance from the support, from 30mm to 150mm. The forces acting on the support mounted on the forearm give rise to a moment of force relative to the axis of the hinge, which cannot always be offset by tightening the hinge bolt, since the surface area of the friction in the hinge is not sufficient to provide sufficient resistance to the rotation of one bracket relative to the other. In addition, the location of the hinges at the level of the elbow joint reduces the visibility of the elbow joint in radiographs.

A device for the treatment of the elbow joint (source [3]: RU 12958 patent), comprising knitting needles fixed to the shoulder support and the forearm support, connected by connecting nodes made of threaded rods with flat hinges, and a rotational element, which is made in the form of two half rings connected with the possibility of rotation by means of clamps, the threaded rods of the connecting nodes are located obliquely to the support node of the forearm and perpendicular to the line between the ulnar and coronoid processes of the ulnar bone and are equipped with suppers. Focusing on the axis of rotation of the elbow joint, between the supports of the shoulder and forearm, uniaxial joints made from brackets connected by a bolt are installed from the lateral and medial sides of the joint.

A device for eliminating contractures of the elbow joint (source [4]: RU 1420 patent), containing supports mounted on the shoulder and forearm with the ability to move relative to each other, each of which is made of a pair of half rings interconnected by ties, and knitting needles, fixed in the supports. The end parts of the half rings of each support are interconnected by couplers arranged obliquely, and the power metering element is made of a collapsible rod pivotally connected to an extension element, which is connected with the possibility of rotation and movement from one of the couplers of the forearm support. Between the supports of the shoulder and forearm are installed with the possibility of movement coaxially articulated nodes made of two brackets connected by a bolt.

In analogues [3, 4], the Ilizarov apparatus parts [1; 2] and a cylindrical hinge, also made of two brackets connected by a bolt, are used. The disadvantage of this design is described above, the fixation of the relative positions of the supports is unreliable, due to the low moment of resistance in the hinge, and the hinge nodes close the elbow joint on the radiograph.

A known apparatus for restoring the movements of the elbow joint, containing horizontally and vertically arranged pairs of brackets (supports), interconnected in pairs by couplers (source [5]: MVVolkov, OBOganesyan. Restoring the shape and function of bone joints, M ., Medicine, 1986., s, 9I-93). A pair of horizontally arranged staples is connected to a pair of vertically arranged staples by two distractors, each of which has a double row spherical bearing. One of the supports of a vertically arranged pair is connected to one of the supports of a horizontally located pair by means of a removable bending-bending device. To install, carry the spoke through the joint.

The device [5] provides for strict conduct of the axial knitting needle, which coincides with the axis of rotation of the joint, which can lead to damage to the ulnar nerve and requires additional devices to determine the location of the axial knitting needle. The rods of the bending-bending device are located perpendicular to the plane of the supports, which leads to a decrease in the transmitted force applied to the limb segments. Distractors with a bearing require special manufacture and strict orientation along the axis of rotation of the joint.

A device for the treatment of the elbow joint (source [6]: RU 35968), comprising knitting needles mounted on the supports of the shoulder and forearm, connected by connecting nodes made of threaded rods with flat hinges, inclined to the forearm support and perpendicular to the line between ulnar and coronoid processes. The connecting nodes between the supports of the device are arranged to rotate and move relative to the shoulder support in the sagittal and frontal plane, and the axis of rotation of the monocentric hinge is oriented to the center of the block cut of the ulna. Monocentric joints are located on the distraction rods, the axis of rotation of which is made in the form of a threaded rod, they are fixed by nuts by tightening.

The hinge nodes of the device [6] are made of brackets 10 mm wide, mounted on a threaded rod M6, tightened with s10 nuts, they do not provide reliable fixation of the relative position of the forearm support relative to the shoulder support. Tightening the nuts on the threaded rod, taking into account the contact surface area in the hinge, does not provide the necessary efforts to withstand the moment of force arising from the impact on the forearm support at the existing distance from the hinge axis to the support.

Long-term treatment with the Ilizarov apparatus [1,2] can lead to excessive immobilization of the elbow joint, restriction of passive movements in the joint and, as a consequence, contracture of the elbow joint, therefore the possibility of developing movements in the joint during treatment is an important feature of AVF. The development of the elbow joint is provided by all described and analogues [1 to 6]. However, the possibility of developing an elbow joint should be combined with the possibility of reliable fixation of the achieved mutual position of the forearm support and shoulder support, and the possibility of x-ray control of the joint. The lack of reliable fixation of the relative position of the supports and an inadvertent change in their relative position can lead to undesirable consequences in the treatment process, so the risk of accidentally changing the position of the supports should be eliminated.

Thus, today, when treating the elbow joint using the kit parts with the Ilizarov apparatus, there is a problem that during the treatment period, when the limb is fixed in the apparatus, it is necessary to provide the possibility of developing movements in the elbow joint, so that after performing controlled movements, once again, reliable fixation of the forearm support relative to the shoulder support in a predetermined position was provided.

The objective of the proposed utility model is to develop the layout of the external fixation apparatus using standard parts to ensure sufficient rigidity of fixation of the mutual position of the shoulder support and forearm support, with the possibility of developing the elbow joint as needed, which allows to increase the amplitude of active-passive movements in the elbow joint in the postoperative period with the aim of elimination and prevention of flexion contracture.

The essence of the technical solution.

The technical result consists in improving the treatment results by increasing the reliability of fixing the relative position of the forearm support and shoulder support in combination with the ability to perform, as required, controlled flexion / extension movements in the elbow joint, and by eliminating the radiological shadow from the apparatus parts in the area of the elbow joint , complicating the objective control of the condition of the joint.

The technical result is achieved in that the arrangement of the external fixation apparatus for treating the elbow joint includes a shoulder support and a forearm support, mounted with the possibility of changing the relative position and fixing a predetermined position, connected by a fixed hinge assembly, fixed to the supports of the knitting needles and bone screws. It is characterized in that the fixed hinge unit is made in the form of two flat half rings of equal diameter, equipped with through holes superimposed on each other and fixed so that the free end of one half ring is connected through the bracket to the forearm support, the free end of the second half ring is connected through the bracket to the shoulder support , while one of the half rings is equipped with an extended arcuate groove in which there are bolts with nuts installed in the through holes of the second half ring.

The given set of features allows one to rigidly fix the mutual position of the shoulder and forearm supports, due to the fact that the contact surface, friction in the hinge assembly has a large area equal to the contact area of the half rings. In this case, the axis of rotation of one half-ring relative to the second half-ring (the hinge axis) falls on the region of the elbow joint, and when the mutual contact of the half-rings weakens, it becomes possible to mutually change the position of the shoulder and forearm supports, i.e. the possibility of developing movement in the joint, preventing the development of contractures and increasing the range of movements is provided. Since the hinge assembly is made of half rings, the region of the elbow joint does not close when performing radiographs. Together, these signs provide improved treatment outcomes, improved quality of treatment of the elbow joint.

The half rings relative to the supports are located in the plane of motion of the forearm during its flexion / extension relative to the shoulder, and the center of rotation of one half ring relative to the other coincides with the axis of rotation of the elbow joint, this provides the natural biomechanics of movements in the elbow joint relative to the front axis. The shoulder support is made in the form of two flat half rings connected by threaded rods and contains two knitting needles, the forearm support is made in the form of a strap with holes and contains two bone screws, this provides a fairly rigid fixation of the bones by the apparatus, while the apparatus has relatively small dimensions.

The technical solution is illustrated by graphic materials:

Figure 1 - layout of the external fixation apparatus for the treatment of the elbow joint, in a bent position, left view, photograph of the layout;

Figure 2 - layout of the external fixation apparatus for the treatment of the elbow joint, in a bent position, right view, photograph of the layout;

Figure 3 - layout of the external fixation apparatus for the treatment of the elbow joint, in an unbent position, a photograph of the layout;

Figure 4 - layout of the external fixation apparatus for the treatment of the elbow joint, in an unbent position, photograph of the layout, front view.

Implementation of a technical solution.

The layout of the external fixation apparatus for the treatment of the elbow joint (Fig. 1,2,3,4) comprises a shoulder support 1 (Fig. 1,2,3,4) and a forearm support 2 (Fig. 1,2,3,4). Supports 1 and 2 are installed with the possibility of changing the relative position and fixing the predetermined position by means of the hinge unit 3 (Fig. 1,2,3,4). The supports 1 and 2 are connected by a securely fixed hinge assembly 3. The fixed hinge assembly 3 is made in the form of two flat half rings 4 and 5 (Fig. 1,2) of equal diameter. The half rings 4 and 5 are equipped with through holes 6 (Fig. 1,2). The half rings 4 and 5 are superimposed on each other by flat surfaces and connected by bolts 7 to nuts 8 (Fig. 1,2). The half rings 4 and 5 are mounted on the supports 1 and 2 so that the free end of one half ring 4, through the bracket 9 (Fig. 1,2) is connected, with the support 2 of the forearm, and the free end of the second half ring 5, through the bracket 10 (Fig. 1 , 2) connected to the support of the shoulder 1. One of the half rings 4 (or 5) is equipped with an extended arcuate groove 11 (Fig. 1,2) in which there are bolts 7 with nuts 8 installed in the through holes 6 of the second half ring 5 (or 4). On the supports 1 and 2, spokes 12 (Fig. 1,2) and bone screws 13 (Fig. 1,2) are installed in which the bones 14 (Figs. 1,2,3,4) of the shoulder and forearm are fixed.

The half rings 4 and 5 relative to the supports 1 and 2 are located in the plane of motion of the forearm when it is bent / extended relative to the shoulder, and the center of rotation of one half ring 4 relative to the other half ring 5 coincides with the axis of rotation of the elbow joint, this provides the natural biomechanics of movements in the elbow joint relative to the frontal axis . The shoulder support 1 is made in the form of two flat half rings 15 (Fig. 4) connected by threaded rods and contains two spokes 12. The forearm support 2 is made in the form of a strap 16 (Fig. 4) with holes and contains two bone screws 13, this provides a fairly rigid the fixation of bones by the apparatus, while the apparatus has relatively small dimensions. The layout of the external fixation apparatus can be assembled from parts of the Ilizarov apparatus.

The device is used as follows.

The layout of the external fixation apparatus is used to treat the elbow joint, to prevent contractures in case of traumatic injuries, and can also be used after the reduction of dislocations, to eliminate contractures, after arthroplasty and other surgical interventions on the elbow joint that require fixing the relative position of the shoulder and forearm. To perform transosseous osteosynthesis, the Ilizarov apparatus parts are used (source [2]: electronic catalog of products of the Federal State Unitary Enterprise “Experimental Plant RSC“ WTO ”named after academician G. A. Ilizarov” of the Ministry of Health of Russia, available on the enterprise’s website http: //www.ozrncvto. ru, in the “products” section of the subsection “Instruments and devices for transosseous osteosynthesis according to GA Ilizarov”, “Sets of parts for the Ilizarov apparatus.” Access mode http://www.ozrncvto.ru/blank-sto5i), No. 81 / 823-53 of registration in the State Register of Medical Devices) by standard sizes, manufactured by by the enterprise. The selection of the apparatus size, half rings 4,5,15 strap 16, knitting needles 12 and bone screws 13 for each patient is carried out individually from standard multipurpose parts. The half rings are selected in size so that the distance from the skin to the inner edge of the half ring throughout the semicircle is at least 20 mm. After selection and verification, the components are placed in the cassette, sterilized. To install the apparatus, conducting the needles 12 into the humerus and carrying the bone screws 13 into the ulnar bone are performed. The needles 12 and the bone screws 13 are fixed in the supports 1 and 2. When the needles 12 are fixed, they are tensioned. Next, the supports 1 and 2 are connected together by a hinge assembly 3. The half rings 4 and 5 are superimposed on each other, connected by two bolts 7 with nuts 8, passing them through holes 6 and into an arcuate groove 11. Install the hinge assembly 3, focusing on the center ( axis) rotation of the elbow joint, to prevent decentration during flexion / extension. The semirings 4 and 5 are located relative to the supports 1 and 2 in the plane of motion of the forearm when it is bent / unfolded relative to the shoulder. The free end of one half ring 4, through the bracket 9 is connected to the support 2 of the forearm, and the free end of the second half ring 5, through the bracket 10 (Fig. 1,2,3,4) is connected to the support of the shoulder 1. To connect, use bolts 7 with nuts 8 Establish the desired mutual position of the shoulder relative to the forearm, tighten the bolts 7 with nuts 8, fixing the hinge assembly 3 and the position of the supports 1 and 2. The half rings 4 and 5 are tightly pressed against each other by contacting surfaces and, due to friction forces, maintain a predetermined position when exposed to external forces. On the second day after the operation, targeted flexion-extensor movements are performed in the joints adjacent to the operated segment, isometric contractions of the limb muscles are performed by exercise therapy. Elimination and prevention of contractures of the elbow joint begin in the period from the second to the seventh day after the operation. To perform movements in the elbow joint, loosen the nuts 8 of the bolts 7 connecting the half rings 4 and 5 of the hinge assembly 3. Perform controlled bending / extension with a given range of motion in the elbow joint. The amplitude is limited by the length of the arcuate groove 11. After completing the bending / extension position, the limbs are fixed in the set position by tightening the nuts 8 of the bolts 7 connecting the half rings 4 and 5 of the hinge assembly 3. The doctor can choose the angle of bend in the elbow joint for treating the limb of the patient , and with high reliability to ensure a given mutual position of the forearm and shoulder by fixing the hinge node 3.

Radiography is prescribed to patients once or twice a month to monitor the condition of the joint space and condyle, while the hinge unit 3 does not close the overview of the elbow joint area, there is no radiological shadow from the details of the apparatus in the area of the elbow joint.

Thus, the described device can reduce the risks of adverse outcomes of treatment, improve the results of treatment of the elbow joint, prevent the development of contracture and increase the range of motion in the presence of contractures.

Claims (3)

1. An external fixation apparatus for treating the elbow joint, comprising a shoulder support and a forearm support, mounted to change relative position and fix a predetermined position, connected by a fixed hinge assembly, fixed to the supports of knitting needles and bone screws, characterized in that the fixed hinge assembly is made in in the form of two flat half rings of equal diameter, equipped with through holes, superimposed on each other and fixed so that the free end of one half ring is connected through a bracket to a support shoulder grip, the free end of the second half ring is connected via an arm to the shoulder support, while one of the half rings is equipped with an extended arcuate groove in which bolts with nuts are installed in the through holes of the second half ring. 2. The external fixation apparatus according to claim 1, characterized in that the half rings relative to the supports are located in the plane of motion of the forearm when it is bent / extended relative to the shoulder, and the center of rotation of one half ring relative to the other coincides with the center of rotation of the elbow joint. 3. The external fixation apparatus according to claim 1, characterized in that the shoulder support is made in the form of two flat half rings connected by threaded rods and contains two spokes, the forearm support is made in the form of a strap with holes and contains two bone screws.

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