BG112250A - Fasteners for universal modular systems for osteosynthesis - Google Patents

Abstract

The invention relates to improved fasteners for the elements of universal modular systems for osteosynthesis intended for orthopaedics and traumatology and their application. The fastening compounds of the invention are three, as the second and the third one are variations of the first. In the first fastener, a rotationally wedge-shaped body called a clamp (3) moves along an opening in another body (2) and presses a rod placed in a cross opening that intersects the first one. In the second fastener, the clamp (3) is formed as a hemispherical nut, in which the screw-threaded axle of a bone screw (4) into the bone fragment is screwed. In the third clamping, the clamp is formed as a slotted sphere. The universal modular system for internal osteosynthesis includes bone screws, rods and tiles that can be mounted on the bars. The universal modular system for external osteosynthesis includes bone screws (needles), rods, screw holders and connectors. 1 claim, 23 figures

Description

TIGHTENING JOINTS ......

FOR UNIVERSAL MODULAR SYSTEMS FOR OSTEOSYNTHESIS

FIELD OF APPLICATION

The invention relates to the field of medical inactive implantable devices category 7 according to ISO 15225, used in orthopedics and traumatology, and in particular to clamping joints of the elements of universal modular systems for osteosynthesis. On the basis of the proposed technical solutions for tightening, universal modular systems for internal osteosynthesis and for external osteosynthesis have been invented.

These systems allow the construction of frames that are mounted inside or outside the body. Through these frames, bone fragments are fractured and fixed in fractures. In addition, the systems allow the construction of combined frames for simultaneous external and internal fixation, as well as frames that combine supraperiosteal and intramedullary mounting of the fixing elements.

BACKGROUND OF THE INVENTION

Surgical treatment in orthopedics and traumatology usually uses devices that connect the bone fragments in place and help heal or correct the damaged bone tissue. This method of treatment is called osteosynthesis. There are two main types of osteosynthesis systems - internal (implantable) and external fixators.

I. Internal osteosynthesis systems

In the theory of internal osteosynthesis, four fundamental principles have been formulated, which are still considered valid and taken into account in the design of osteosynthetic devices: anatomical adjustment; stable fixation; protection of blood flow; early active recovery of mobility.

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Many different ‘means’ and ‘methods’ for internal fixation are known, among which the plates and rod (bridge) modular systems closest in characteristics to the system for internal osteosynthesis of the invention are.

Plates are widely used in osteosynthesis. The plate is a plate of biologically tolerable metal in which at least 4 holes are made. They are mounted in the holes

- spherical head screws that are screwed into the bone, tightening the plate to the corticalis of the bone. A strong structure is created that keeps the bone fragments in an appropriate position until the fracture heals.

In order to better comply with the principles of osteosynthesis, plaques have been developed, as a result of which different types of plaques have been developed:

• Traditional plates, also called dynamic compression plates (DCP), because they can perform compression along the axis, thanks to the special geometry of their holes.

• Plates with limited contact (LC - limited contact), on the underside of which (to the bone) are made channels or openings, shaped differently by different companies. The aim is to ensure minimal contact between the plaque and the underlying bone in order to reduce trauma to the vascular (vascular) system and to ensure rapid indirect healing through the callus. A variant of this embodiment is the supraperiosteal plaques, which are located above the periosteum (bone sheath).

• Reconstructive plaques have deep indentations on their edge. These recesses are located between the holes and allow precise contouring of the plate in all directions. These plaques are particularly useful in bone fractures with complex spatial geometry, such as the pelvis, acetabulum, distal humerus, distal tibia, and clavicle.

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Locking plates (LCP - becking Connpte ^ siora :: Plate). At the lower end of the conical head of the bone screws is cut a conical thread corresponding to the thread in the holes of the plate. This allows the screws to be mounted at an angle and effectively locked into the plate and bone. As a result, these plates provide stability against torsion of bone fragments and a more uniform loading of the screws along the structure, instead of being concentrated on a single bone screw, with an increased risk of breakage, as with traditional plates.

In some of the last constructions of plates all positive features of the described types of plates are combined: dynamic compression; limited contact and locking screws, and combined holes are made in the plates.

Despite all the improvements, plaques have a number of disadvantages:

• traditional DCP plates do not have limited contact, cannot easily adapt their shape to the bone and do not provide good angular stability;

• LC plaques still have relatively high contact with bone;

• reconstructive plaques have limited possibilities for changing the shape, as their strength decreases with sharper curves;

• LCP plaques have a complicated shape of the holes and the head of the bone screw, which makes them more expensive. The angle of inclination of the screw is limited. The operational technology of placing the locking plate is complex and difficult to perform: special guides are used to mount the bone screws, and the correct screwing of the screw heads into the plate is a difficult and sometimes impossible task.

• To match the shape and size of the large variety of bone fragments, which is further enhanced by individual anatomical differences, a huge ⁴ ”collection has been created: '*. *:' · ·· * a collection of different plaques that'bo ' lnytsyT & must * maintain in kits.

• Because the screw holes in the plates are pre-made, this imposes a restriction on the mounting locations of the screws in the bone, which can sometimes be unsuccessful, especially in unstable, spiral and other complex fractures.

In order to overcome the shortcomings of the plates, rod (bridge) osteosynthetic systems have been created, to which the system of the invention belongs. The idea of the rod systems is to use modular elements (also called holders or screw holders) instead of a monolithic plate, connected on the one hand with bearing rods and on the other hand with the bone by screws (Fig. 1).

A rod system for osteosynthesis is known from [1]. In this system, a bone screw is screwed into the tile, the head of which has a spherical part and a conical threaded part (Fig. 2). In the last stage of screwing the screw to the bone, its head begins to be screwed into the threaded hole in the lower part of the plate. The spherical part of the screw head touches the bed at the top of the tile hole and the bars in the cross holes of the tile. Due to the screwing of the screw head into the tile, the upper part of the tile approaches the lower one, tightening the rod (rods). At the same time, the screw head touches the rods, tightening them further. In one embodiment, the plate has an extension with additional holes for bone screws designed to fix fragments in the distal part of the bone. The considered system has the following disadvantages: non-standard screws with significantly complicated construction and production technology are used; the screws cannot be screwed at an angle; the thickness of the tile increases due to the need to cut a thread at the bottom of the tile; the universality of the system is reduced due to the use of special plates for the distal parts of the bones.

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The rod calculated * internal * function of [2] is also known. It uses clamps as screw holders, which are tightened on a single rod, using the force of tightening the screw to the bone. When screwing the bone screw into the bone fragment, the lower part of the bracket rests on the bone, and the upper part approaches the lower part under the influence of the screw head. As a result, the clamp is tightened to the rod. To make the axial fixation, there is a tooth at the end of the rod, which grips the special channel of the end bracket. Disadvantages of this system are: it can work with only one rod; does not allow the construction of complex spatial structures; the bracket has a complex shape, complicating the manufacturing technology; mounting and moving the bracket on the rod requires a special tool to keep it open; limited angle of inclination of the bone screw (up to 5 °).

II. External osteosynthesis systems

External fixation is a method of remote osteosynthesis that is performed by inserting needles or screws into the bone below and above the fracture line, connected together outside the human body by a supporting structure called an outer frame.

In orthopedic practice, a large number of external fixation systems with various constructions are known. A widely used class of fasteners in this field are rod (bridge) systems, united by the common feature that they have screw holders connected by bearing rods. The external osteosynthesis system of the invention also belongs to this class.

An external rod retainer of [3] is known, comprising the following types of modules: rods; compressor-distractor tube; dynamizing tube; screw to rod connector; rod-to-rod connector; pipe-to-rod connector. Screw to rod connectors are similar in function to the system of the invention. There are two types of such connectors in the fixing system. One type consists of two tiles that are fastened to each other with screws at both ends.

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In the two tiles are made- ^ semicircle-I .. 'canvases, which · when joining the parts together form holes for the bone screws (5 or 10). When tightening the two parts, the bone screws are pressed between them. Perpendicular to the screw holes, there is a rod tightening connection, which has a similar tightening principle and construction as the screw tightening connection. The other type of screw-to-rod connectors consists of 4 parts that have a central hole through which a screw passes. One pair of parts has a transverse hole consisting of two halves, in which the bone screw is tightened, and the other pair - with a hole of two halves, in which the rod is tightened. The principle of tightening is similar to the first type of couplings, in contrast to which the tightening is done with the central screw. Each pair of parts has a joint made as a channel and a tooth, which prevents the two parts from rotating relative to each other, maintaining the relative position of the two halves of the hole. The two pairs can rotate about a central axis at any angle to each other, providing different angles between the rod and the bone screw. In addition, there is a spring around the central axis, which creates a preliminary tightness in the jaws so that the rod and screws cannot slip out of the holes.

This system for external fixation has the following disadvantages: the connecting modules and the spatial structures built with them are bulky; complex construction of the modules, which increases their cost; for tightening the bone screws and the rod in the modules with 5 or 10 holes, 4 screws are used, which slows down and complicates their installation and final fixing, as well as disassembly; the screws cannot be tilted in different directions relative to the screw holder.

The external fixation system of [4] is also known. The screw and rod connection module consists of two pairs of jaws, one of which tightens the screw (s) and the other the rod. The parts of each of the two pairs are secured by a tooth and a channel against each other.

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The two pairs of jaws can rotate "one" at a time. Another around the central axis, providing different angles between the rod and the bone screw. The differences compared to the construction of the above-mentioned system [3] are: the tightening is done not by a screw, but by an eccentric; the module has channels for two screws, not just one. The disadvantages of the system of [4] are: bulky and complex modules; it is not possible to mount the screws at different inclinations. In addition, since the screw holder can only be connected to one rod, it is necessary to use thicker rods (12 mm for the lower limbs, 9 and 6 mm for the upper limbs). The system has insufficient fixing reliability, as the eccentric clamping clamps self-loosen under cyclic loads.

The bridge system for external fixation of [5] and [6] is also known. In one embodiment (Fig. 3) a plastic sphere with slots is mounted in the central hole of the body of the screw holder, on which a pressure screw touches. The sphere has a central hole, larger in diameter than that of the bone screw. The bone screw is placed in the central hole of the sphere. The slits of the sphere are parallel to the axis of the hole and reach the middle of the sphere, their bottoms being crossed and perpendicular to the axis. When tightening the clamping screw in the body of the screw holder, it presses with its inner conical surface the sphere to the spherical bed in the body. This tightens the sphere, forcing it to contract due to its slits and tighten the bone screw. At the same time, the clamping screw presses the two rods with its outer conical part. An important advantage of this solution is the possibility of spatial tilting of the bone screw in all directions. The disadvantage is the insecure tightening, as the surfaces of the clamping screw cannot rest on each of the two rods and the sphere at the same time, and the sphere must also tighten the bone screw.

An external fixator for trochanteric-lateral fractures is known from [7]. This retainer contains a plate with at least four through ⁸ ”: :··» ”longitudinal grooves, an implant holder connected to the plate and bone implants (screws or needles). The implant holder consists of a body, a nut for tightening the body to the plate, a sphere mounted in the body, a washer with a spherical bed for pressing the sphere and a threaded sleeve for tightening the washer. The sphere has a central hole for an implant screw and slots that allow it to contract. When screwing the threaded sleeve, the sphere between the spherical beds of the washer and the body is pressed. As a result, under the action of the wedge forces, the sphere shrinks, thanks to the slits in its periphery and tightens the implant. The disadvantage of this design is that the change in the location of the screw holders is limited by the size of the plate and the channels in it. This predetermines the specialized application of the fixator for a certain type of fractures.

Sources of information:

1. http://www.walkman.com.cn

2. http://sites.synthes.com/MediaBin/lnternational%20DATA/036.000.550.pdf

3. http://www.osteosynthesis.stryker.com/medias/pdf/ hoffmann2_brochure_50751000c2109.pdf

4. http://intl.orthofix.com/uploads/contentUpload/GF-1101-OPT-E0.pdf

5. Patent DE 3611319 C2 / 11.02.1988.

6. U.S. Patent 4,920,959 / 1.05.1990.

7. Patent BG 66193

SUMMARY OF THE INVENTION

The main purpose of this invention is to provide reliable, compact, technological and easy to use joints for tightening the elements of universal modular internal and external osteosynthesis systems designed for orthopedics and traumatology.

A further object of the invention is to propose constructions of new types of universal modular rod systems for indoor and outdoor based on the proposed clamping joints.

9 * '. · * *. ·. ”·· ,,,. · Osteosynthesis. The purpose of these systems is to read T1o-dr ^ u ^; qualities of the cited similar systems, while adding new functionalities and improving some important features such as: manufacturability and low manufacturing cost; universality; possibility to use all standard bone screws; reliability; ease of installation; reducing patient trauma.

1. Clamping joints

The first clamping joint offered for use in osteosynthesis systems (Fig. 4) comprises a main body 1 in which there are at least two cross-openings which intersect so as to have a common part. In one hole A of the main body is placed with a small gap a second body 2 with a cylindrical or prismatic shape (which will be conditionally called "rod"), and in the other B - a third body 3 (which will be conditionally called "pressed") with rotational shape, which is wedge-shaped in its part (C), which touches the second body. The body 3 can move along the opening B with a small gap. The second and third bodies have the possibility to touch each other, and the contact surfaces can be smooth or have a surface that has been treated in a special way in order to improve adhesion and retention: rolling, grooving, veneering, etc.

When pressed against the rod, due to the wedge-shaped shape of the rod, it pushes the rod against the walls of the hole and jams it. In this way, the three bodies are tightened simultaneously. If the wedge-shaped part (C) is spherical in shape, the clamp may be inclined with respect to the axis of the hole in which it moves before final tightening. This is an essential feature of the proposed compound in terms of its application in osteosynthesis systems.

An example of the application of the first clamping joint is a plate participating in an internal fixation system (Fig. 5).

The second clamping joint used in the invention (Fig. 6) is an embodiment of the first clamping device. : · A connection in which the clamp 34 is a screw hole E, in which the tail with thread C is screwed on a bone screw 4, pre-screwed to a bone fragment 6. The screw is secured against rotation relative to the main body B. At rotating the pressed 3 in a suitable direction, the screw moves linearly and pulls the bone fragment until it rests on another bone fragment 5, which rests on the main body, whereby all bodies, including bone fragments, are tightened simultaneously.

An example of the application of the second clamping joint is a plate used in a system for internal fixation of condylar fractures (Fig. 6).

The third clamping joint used in the invention (Fig. 7) is another embodiment of the first clamping joint, in which the clamp is made of an elastic material and has a wedge shape at least at one end which faces the rods. In the compressed there is at least one hole and exactly one radial slot reaching the hole and located in a plane passing through the axis of the hole. The purpose of the slot is to allow elastic contraction of the body and, accordingly, of the opening, under the action of opposite radial compressive forces located perpendicular to the slot. To improve shrinkage, there is a variant in which the body has at least one additional slot, which is also located in a plane passing through the axis of the hole, but not passable, ie between the slot and the hole remains a thin wall. A fourth body is inserted into the hole pressed with minimal clearance. When pressed against a rod, the clamp contracts under the action of the wedge forces and acts as a collet relative to the fourth body, tightening the other bodies at the same time.

If made of a spherical shape, the clamp may be inclined to the axis of the hole in which it moves before final tightening.

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An example of the application of the third batArJuio.’connection is a screw holder used in an external fixation system.

Based on the three types of clamping joints disclosed in the invention and the principles of clamping the elements used in them, a universal modular system for internal osteosynthesis and a universal modular system for external osteosynthesis are implemented in the invention.

2. Universal modular system for internal osteosynthesis

In one embodiment of the above clamping joints, a universal modular rod system for internal osteosynthesis is created (Fig. 5), which includes bone screws 3, at least one support rod 2, and at least one plate (screw holder) 1 that can be moved along. length of girders in which at least one bone screw can be positioned (in practice at least 4 plates are usually used). According to the invention, bone screws include all types of standard bone screws with a hemispherical head, which by functional purpose are defined as: cortical, spongy and maleolar, etc. Some of them can be cannulated. Non-standard screws with hemispherical, conical or other rotating heads can also be used, as well as bone screws combined with spherical nuts. Standard bone screws, regardless of their type, have one element that unites them - the hemispherical head. The use of screws with spherical heads allows the screws to be fixed in the screw holder at an angle, which is an important advantage of the system. According to ISO 5835-1991, the standard bone screw heads are only 5 sizes with diameters of 3, 4, 5, 6 and 8 mm. This allows you to create a limited range of tiles tailored to these diameters.

The supports are rods of arbitrary cross-section (usually round). The axis of the rods can be in the form of an arbitrary spatial curve and can be shaped for optimal anatomical fit before and during the operation. In one embodiment, the shape of the rod axis is U-shaped with a center-to-center distance of the parallel arms equal to the center-to-center distance of the holes in the tiles (Fig. 10 and Fig. 11). In another embodiment, the rod is grooved with annular grooves of semicircular cross-section (Fig. 9). The heads of the bone screws rest in these channels and thus the axial fixation of the rod is performed.

According to the invention (Fig. 5), each plate 1 is a monolithic body (usually rotary or prismatic) having a central hole A for placing a bone screw 3 and at least one hole D for accommodating a support rod 2 which intersects the central hole, so that they have a common part. In the working position, the rods and the bone screw are mounted in the plate, with the supports in contact with the head B of the screw.

In one embodiment (Fig. 6) an extension A of the plate is made along the axis of the bone screw 4, which serves to guide the screw. A structural element is formed in the hole of the extension B, preventing the rotation of the screw relative to the extension. The screw 4 intended for this type of tile is spongy, and its stem C has a construction that secures the screw against rolling. In one embodiment, the element that prevents the rotation of the bone screw is at least one bevel along the length of the bone screw stem, and the screw hole in the plate extension has a profile that corresponds to the profile of the screw stem. A thread E is cut on the tail of the screw, on which a nut 3 is screwed with a hemispherical surface F facing the plate. The nut 3 rests through the common part of the holes G and H in the rods 2. The bone screw is pre-screwed into the fragment 6, as the stem, which is smaller in diameter than the screw part, passes freely through the hole of the fragment 5. When tightening the nut 3, it rests on the rods and pulls the screw together with the fragment 6 until the two fragments 5 and 6 touch. The rods are tightened in the holes of the plate, and the front I of the plate rests on the surface of the fragment 5.

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Advantages of the osteosynthesis system of the invention

The system fully complies with the four basic principles of osteosynthesis and can perform all the functions of f known types of osteosynthetic plates and rod systems for internal

I ·· osteosynthesis, making the following improvements:

· High reliability - the principle of clamping proposed in the invention ensures strong fixation of the bones and the elements of the system, without the danger of loosening of the connections, twisting or slipping of the individual elements during the whole period of treatment; this is proved by the corresponding mechanical tests of prototypes of the invention;

». · A small number of types of universal modules with simple and technological construction;

• possibility to use all types of standard bone screws with hemispherical head;

• the universal system requires small stocks - it is not necessary to maintain a large warehouse with several sets of all numerous types of plates;

• the plates (screw holders) with the bone screws can be: located anywhere along the bars for optimal compliance of the anatomy and fracture; simplified installation and movement of the screw holders on the rod, which does not require a special tool;

• modeling the correct frame for the respective indication by cutting and unlimited bending of the rods according to the bone before or during surgery;

_t · ability to build stable and reliable frameworks when; U-shaped rods are used, on which tiles with two holes are mounted;

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• Possibility to create new multi-locking dam locking frames, when some of the tiles are mounted only on one arm of the double rod or are mounted on a single rod; this allows local strengthening of the bone fragments by adding side rods and removing part of the screws in an additional plane; such frameworks are used in the treatment of stressed bones and complex fractures;

• in comparison with self-locking plates larger spatial angles of screw mounting (cone with angle at the tip 40 ° against 25-30 ° at the plates);

• due to the possibility of mounting the bone screws at an angle, the frame provides: resistance of the structure against torsion (self-locking); stability due to the fact that the screws can get very close to the fracture; possibility for fixation of more complex fractures;

• the devices under construction are supraperiosteal, with a much smaller contact area than the LC plates; the contact with the bone is only in a narrow area of the plates, and the rods between them are above the bone;

• between each two tiles can be created not only compression (compare with DCP plates), but also distraction;

• compression can be done in another plane - through special screw holders with extension, in which a screw with a threaded tail and a nut with a hemispherical surface is placed;

• it is possible to create devices that combine supracortical and intramedullary osteosynthesis;

• when using a rod grooved with annular grooves, reliable axial fixation is provided;

• easy construction and installation of various osteosynthetic devices; the operative technology has a similar degree of complexity as the plaques, while at the same time there are no restrictions on the surgeon's freedom of choice caused by the limitations of the technical device;

“I- i,’ 15 ”· ** ·. \ ···· - • can be used as · * is «o-creative ^. Thus.m · £ · minimally invasive techniques. It is possible to install the devices with small partial cuts in the places where the plates are mounted with screws, and not with a complete cut.

• the trauma of the surrounding tissues is reduced, as the dimensions of the elements can be smaller at the same t strength of the structure; the dimensions are comparable to those of plates with a similar purpose.

Listed, as well as other features and advantages of the invention are disclosed in the embodiments, with reference to the accompanying figures.

3. Universal modular system for external osteosynthesis

In one variant of using the exposed clamping joints, a universal modular rod system for external fixation of bone fractures is created, which allows the construction of a wide variety of devices with great flexibility in terms of the shape and configuration of the device, the number and mutual arrangement of building blocks. elements and bone screws.

These problems are solved with a modular system including at least one rod carrier or one pair of rod carriers, at least one holder of bone screws (needles) with the possibility of mounting on the bars (Fig. 7), bone screws corresponding to the number of holders, modules for connecting rod supports in different planes and angles, modules using a spherical connection to connect the rods to other external fixation systems.

The bone screw holder (Fig. 7) has a body 1 with at least one step hole A, which at its wide end ends with a thread C and at least one cross hole B for a support located near the narrow end of the step hole. The step opening and the opening for the carrier intersect so that they have a common part.

At the wide end of the step OTBQp.'ft ⁰ . J θ5 · ΜομτΙίρβτ washer 7, which rests on the rods, sphere with slots 3, washer 6, which presses the sphere, and screw 5.

The screw 5 has a thread corresponding to the thread of the step hole of the body, a central hole G through which the implant screw passes and can be tilted, as well as structural elements allowing it to be screwed in with a wrench. The pressure washers 6 and 7 have a spherical or conical bed N. The beds are turned with their wide part towards the sphere and touch it. The pressure washer 7 has bevels I touching the rods.

The slotted sphere 3 has a central hole for attaching a bone screw or needle 4. The hole has a diameter slightly larger than that of the bone screw stem (needle), allowing it to be easily inserted into the hole, but with minimal clearance. There is a slot F on the sphere, which reaches its central hole. This slit lies in a plane passing through the hole. There may be other slots E that are arranged in a similar manner, but a thin wall remains between each of them F and the central opening. These slots provide elastic shrinkage of the sphere under external pressure. Because the sphere works like a collet, it will be called a spherical collet later in the statement.

When tightening the screw 5, it presses through the washer 6 the sphere with slots 3 to the washer 7, and through it - the rods 2 in the holes B of the body 1. Since the sphere is located between two holes shaped like sloping beds, under the action of the forces of the wedge it shrinks and tightens the bone screw 4 firmly inserted in it. When the screw with hole 5 is loosened, the spherical collet 3 can rotate freely, ensuring inclination of the implant screw 4 mounted in it in all directions. At the same time, the screw holder can slide relative to the support rod (s) 2 so that it occupies the required position.

The rod supports can have various profiles and different spatial shapes of the axis. In a preferred embodiment, the shape of the shaft is U-shaped, with an inter-center arrangement: the arms corresponding to the arrangement of the holes in the screw holder.

In another embodiment (Fig. 16), a bracket 1 is strung on the ends of the rods 2. The purpose of this bracket is to strengthen the rod structure, to secure the protruding ends of the rods and to give an aesthetic appearance to the device. Two holes are made in the bracket, the center distance of which is equal to the distance between the rods. In order to keep the bracket, a ring channel B is formed at the ends of the rods, and balls 3 and spring 4 are mounted in the bracket. When the bracket is mounted on the rods , under the pressure of the spring 4, the balls 3 enter the grooves B of the rods 2, providing retention of the clamp. In order to easily insert the rods 2 into the holes of the bracket 1 while pushing the balls 3, the ends of the rods are formed with a bevel A. This construction ensures easy and quick mounting and dismounting of the bracket so that they can be placed or removed on the rods. screw holders or transfer modules.

In another variant of the system, a pair of rods 1 is used, fixed in the openings of a connecting module with a sphere 6 and a nut 3 with a spherical bed (Fig. 17). This module allows the system to be connected to other systems, which include modules with spheres and spherical bearings, for example the systems mentioned in patents BG 61553 B1 / 08.04.94 and BG 100 328 / 31.01.96.

In another embodiment of the system (Fig. 21), a connecting module is used to connect the rod carriers to other rod carriers or implant screws / needles. This module consists of two bodies 1 and 4, which are connected by means of a screw 3 and a nut 6. Each body has at least one hole located crosswise to the hole for the connecting screw. A rod or implant screw / needle is placed in this hole. The holes are arranged in such a way that the hemispherical head of the screw 3 and the hemispherical surface of the nut 6 can rest on the surface A of the supports or screws placed in the cross hole (holes). It's a nut

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• ·· · · · * secured against rolling when tightened · Due to the loose state of the * screw 3, the bodies can rotate relative to each other, changing the angle between the rods placed in the holes. When tightening the screw in the nut, the spherical surfaces of the nut and the screw head press the rods into the holes, while pressing both bodies. This is how all the details are tightened at the same time.

The advantages of this module are the possibilities for:

• arbitrarily chosen angular fixing of the rods to each other;

· Placement in the holes of both rods and implant screws, which allows to create different combinations of rods and screws or only of rods;

· Combination of rods / screws with different diameters.

In another variant of the system, the support rod is placed in the central hole of the spherical collet, and bone screws or needles are placed in the two transverse holes (Fig. 22).

The disclosed embodiments of the elements of the system of the present invention allow the construction of devices similar to the known systems, as well as devices with new functionality.

The system provides versatility that makes it applicable for fixing fractures of all types of bones, including complex fractures that are difficult or impossible to fix with other similar devices. In addition, the devices built with the elements of the system have important qualities for the operational technology such as easy assembly of the appropriate device, easy and quick installation of the device on the treated bone, reliable attachment, light weight and more.

The positive features of the external fixation system according to the invention are the following:

• The rods can be bent to the waist, as well as cut to the required length before and during the operation;

• The screw holders can be located in the exact places corresponding to the bone anatomy and the specific fracture;

• Before the final tightening of the holders to the supports, it is possible to perform compression or distraction between the bone fragments;

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· The screw can be mounted at an angle of up to 20 °, independently of the other screws;

· Fast and reliable simultaneous tightening of the implant, screw holder and rods, guaranteed by the sequential chain of all tightened parts;

• Possibility to tilt at any angle (from 0 to 360 °) the screw holder around the axis of the rod when mounting it on only 1 support rod.

· Possibility for realization of different types of monofixers: with one arm; with two shoulders and a double rigid spherical connection between them; with two arms and a compressor-distractor mounted to them via a spherical connection;

· Possibility to build complex spatial structures of external clamps, including screw holders, rods and connecting modules, including modules with spherical connection;

• Possibility to implement a device for combined internal and external fixation.

Other features and advantages of the invention are disclosed in the embodiments, with reference to the accompanying figures.

DESCRIPTION OF THE ATTACHED FIGURES

In the attached figures from 1 to.; 3. are indications of prior art, wherein:

- Figure 1 shows the idea of the transition from the plate to the rod system;

- Figure 2 shows a previous construction of a bridge system for internal fixation;

- Figures 3 show a construction of a bone screw holder of a prior art external fixation bridge system - US Pat. No. 4,920,959;

Figures 4 to 7 show exemplary embodiments of the types of clamping joints of the invention, wherein:

Figure 4 shows a section of a clamping joint of the first type;

Figure 5 shows a section of a node of an internal osteosynthesis system, which is an application of the clamping joint of the first type;

Figure 6 shows a section of a clamping joint of the second type;

Figure 7 shows a section of a clamping joint of the third type;

Figures 8 to 12 show embodiments of internal fixation devices using the internal fixation modules of the invention.

Figure 8 shows a section illustrating the limited contact of the plates and rods with the bone, shown in the transverse and longitudinal directions;

- Figure 9 shows a three-dimensional drawing of an internal fixing device with a grooved rod;

- Figure 10 shows a three-dimensional drawing of a multi-plane device for internal fixation with a U-shaped rod, extended to the side by an additional single rod and additional reinforcement with tiles with one hole;

Figure 11 shows a three-dimensional drawing of a structure for internal fixation of trochanteric-lateral fractures of the femur, with an additional spongy cannulated screw in the distal part;

• ··· · *

- Figure 12 shows a three-dimensional, «cherU ^ g. *. A device for osteosynthesis with a U-shaped rod and a single rod, in which one arm of the U-shaped rod is used as an intramedullary fixator;

Figures 13 to 23 show examples of implementation of modules for an external fixation system and the application of the system for construction of devices for osteosynthesis, where:

- Figure 13 shows a section of a module used to clamp two Kirschner needles or two rods;

Figure 14 shows an axonometric view of an osteosynthesis device using the two Kirschner needle clamping module of the previous figure;

Figure 15 shows an axonometric view of a hybrid device for internal and external osteosynthesis mounted on bone, in which Kirschner needles are inserted intramedullary into the bone; the ends of the needles, which are outside the bone, are fixed in the holes for the rods of two screw holders for external fixation;

- Figure 16 shows a section of a bracket for strengthening the rod structure;

- Figure 17 shows a section of a connecting module with rod supports and a sphere;

- Figure 18 shows a section of an external fixation device of the "monofixator" type, including a compressor-distractor with spherical bearings at both ends (from another system) and two pairs of rod carriers with a spherical connection connected by the modules of fig. 16 and 17;

Figure 19 shows a three-dimensional drawing of a device for fixing a trochanteric-lateral fracture of the femur;

Figure 20 shows a three-dimensional drawing of a humerus fracture fixation device in which one of the implant screws is inserted intramedullary;

• · · · · · ♦ ·

- Figure 21 shows a section of a module, which can be used to accelerate at any angle rods with rods or rods with implant screws (needles);

Figure 22 shows an axonometric view of an osteosynthesis device in which a rod is placed in the central hole of each screw holder and implant needles are placed in its transverse holes;

Figure 23 shows an axonometric view of an osteosynthesis device, capable of compressing and distracting bone fragments, using the screw holders for external fixation of the invention and an additional mechanism driven by screws;

EXAMPLES OF IMPLEMENTATION

The present invention is illustrated in the accompanying figures and illustrated by the following examples, which are for illustrative purposes only.

Internal osteosynthesis system

In FIG. 5 shows an exemplary module using a clamping joint of the first type according to the invention. The module is a plate (plate) 1, which is attached to the bone 4 by means of a bone screw 3 with a hemispherical head and is connected to the other plates by two rods 2. Each plate 1 is a monolithic body with a rotating shape that provides good manufacturability.

The central hole of the plate is cylindrical, with a bevel at the bottom, providing a greater angle of inclination of the screw. Transverse holes for bearing rods are made in the plate. The dimensions of the plate and the holes in it are selected so that it can be combined with bone screws with a standard hemispherical head. Thanks to its spherical head, the screw 3 can be tilted spatially up to ± 20 °. In one embodiment of the invention, the tile has two holes for support rods. In another embodiment of the invention, used in single-bar constructions, the plate has a hole for a rod, and in the opposite wall of the central.otBop is a shaped spherical bed that supports the head of the bone screw, replacing the second rod. Alternatively, a tile with two holes can be used by placing a short rod in the second hole. In another embodiment, the plate is made with a groove on the lower surface, thereby reducing the contact area with the periosteum. This is clearly shown in fig. 8, 9 and 10.

Figure 6 shows an exemplary module using a clamping joint of the second type according to the invention. This module is used for condylar and trochanteric-lateral fractures. The module includes a tile with extension 1, two rod supports 2, a bone screw 4 and a nut with a hemispherical surface 3. The extension of the tile can be below 90 ° when the tile is used for condylar fractures, or below 130 ° (Fig. 11) - when used for trochanteric-lateral fractures. The plate has a central cylindrical hole, which at its upper end is formed with a spherical bed, and at the end of the body extension passes into a double wall B. In this hole is placed the bone screw, whose stem C is also shaped like a double wall. The double wall allows the screw to move linearly without rotating relative to the body. The body also has two openings H, which are crossed with respect to the central opening, so that they have a common part with it. The rod supports are placed in these holes. A nut with a hemispherical surface F facing the plate is screwed onto the tail with thread E on the bone screw 4. On the reverse side of the nut there is a thin belt D, which can be flattened in the shape of the screw stem (double-walled) after the final installation, in order to prevent the self-unscrewing of the nut 3.

All modules of the internal osteosynthesis system are made of biologically tolerable materials, as they are implanted in the human body.

Figures 9 to 12 show an example of an application; the internal osteosynthesis modules of the invention in the construction of internal fixation devices.

In FIG. 9 shows a device with a rod grooved with transverse circumferential grooves, which allows for stable axial fixation.

Figure 10 reveals the advantage of the invention to be able to create multi-plane devices. In the device shown, some of the tiles are placed on both arms of the U-bar, which guarantees their angular stability. Another part of the tiles are placed only on one arm of the U-bar, and in their other hole is placed a single rod, which allows them to be tilted in another plane. Some of the tiles with one hole are significantly inclined. They serve for lateral stabilization.

Figure 11 shows a structure for internal fixation of trochanteric-lateral fractures of the femur using an extension plate and a spongy screw with a nut. The construction is reinforced with an additional hemispherical screw with a hemispherical head, which is inserted directly between the bars, without a plate, to provide a greater angle of inclination. In the distal part there is an additional spongy cannulated screw, guided when screwing by a Kirschner needle. Additional side reinforcement with 1-hole tiles is provided.

Figure 12 shows an osteosynthesis device with a U-shaped rod and a single rod, in which one arm of the U-shaped rod is used as an intramedullary fixator.

External osteosynthesis system

Figure 7 shows an exemplary screw holder used in the external fixation system according to the invention. Includes a body 1, a clamping screw 5 with a central hole G; spherical collet 3 with slots E and F.

The body 1 has a central step opening A which ends at its wide end with a thread C and at least one cross hole B for a rod located near the narrow end of the step opening. The step opening and the rod opening intersect so that they have a common part. Bevels J are made on the body 1 so that the wrench can be held during tightening. In addition, the bevels allow the holders to get closer to each other.

The clamping screw 5 has a thread corresponding to the thread of the step hole of the body, a central hole G through which the implant screw passes and can be tilted, and slots on the forehead D, allowing it to be screwed with a wrench.

The spherical collet 3 and the washers 6 and 7 shown in the drawing are described in detail in the section "Summary of the invention".

In another embodiment, the slotted screw 5 and the washer 6 that presses the sphere are formed as a monolithic body. In another embodiment, a pressure washer 7 is not used, and the sphere rests directly on the rods 2. This allows a more compact design and a larger angle of inclination of the implant screw.

In another embodiment, the body has an external thread on which a screw cap is screwed, which presses the sphere, performing the functions of the screw 5.

The bone screws of the external fixation system are made of biologically tolerable materials, and the other modules of the system are made of metals or non-metallic materials. The materials used must have mechanical properties that ensure the necessary strength and stability of the devices under construction in the operating conditions. When the modules are made of plastic, the permeability of the built-in X-ray devices is ensured. This facilitates X-ray control during and after surgery.

Figures 13 to 23 show embodiments of the modules for the external fixation system according to the invention and the application of the system for constructing devices for external osteosynthesis.

Figure 13 shows a module used to tighten two Kirchner needles. The screw 3 is screwed into the threaded hole C of the body 1 and through the conical (or spherical) lower part of its head presses the needles into the holes. The screw has a hidden head and an internal hexagon for

26 ............

screwing with a wrench. Figure 14 illustrates a module in an osteosynthesis device using 2 Kirchner needles. The needles are inserted intramedullary into the bone, and their ends, which are outside the bone, are fixed in the clamping module.

Figure 15 shows a device that combines internal and external osteosynthesis. Kirschner needles are inserted intramedullary into the bone similar to the previous example. The difference is that the ends of the needles, which are outside the bone, are fixed in the holes for the rods of two screw holders for external fixation.

In FIG. 16 shows a bracket for strengthening and securing a two-bar rod structure. In FIG. 17 shows the device of a connecting module with a sphere, designed to connect the external fixation system of the invention with other systems that use a spherical connection. The bracket and the connecting module with a sphere are described in detail in the section "Summary of the invention". An application of these modules is shown in fig. 18 - construction of a monofixer. To the two spherical sockets of the compressor-distractor 5 are attached two connecting modules with a sphere 4 and mounted to them pairs of rods 2, ending with brackets 1. On the rods are mounted the screws 3. In another embodiment instead of the compressor a rigid connecting module with 2 spherical sockets (not shown in the drawing).

Figure 19 shows the application of the modules of the external fixation system in a device for fixing a trochanteric-lateral fracture of the femur. The frame consists of screw holders, two U-shaped rod supports bent in the shape of the letter S and a connecting module.

Figure 20 shows the application of the external fixation system in a humerus fracture fixation device in which the rods are shaped according to the anatomy. A distinctive feature is that one of the screws is inserted intramedullary.

Figure 21 shows an embodiment of a module that can connect at any angle rods with rods or rods with implant k n J-

...... ..... _m screws (needles). For more details, see the "Summary of the Invention" section.

Figure 22 shows a variant of using the screw holders of the external fixation system, in which the implant screw and the brackets are interchanged - the support rod is inserted in the central hole of the screw holder and Kirschner needles in the two transverse holes. This allows to build a device operating as a monofix, in which the screw holders can be tilted spatially in all directions due to the spherical connection and the possibility of rotation around the axis of the rod.

Figure 23 shows an osteosynthesis device with capabilities for compression and distraction of bone fragments. The device includes screw holders for external fixation 1, screw drive mechanism and U-shaped rod 3. The screw mechanism consists of 4 screws 2 and two pairs of plates 6 and 7, which can slide on the shoulders of the rod 3. Plank 6 has a through threaded hole , and plate 7 - with a deaf smooth hole. The screw 2 has at its end a smooth part with a ring channel. A tangent pin 8 enters the channel B, which takes away the translational movement of the plate along the axis of the screw, but allows the rotation of the screw relative to the plate. The screw holders 1 are used in a similar way to the device of FIG. 22, but instead of a rod in their central hole is inserted an axis 4 fixed to two opposite plates 6 or 7. When simultaneously rotating by hand the screws 2 through the grooved surfaces A plates 6 and 7 approach or move away, depending on the direction of rotation. This device can be used as a limb reconstruction system (LRS - Limb Reconstruction System).

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Claims (1)

Claims' ^·:. L *: · · Claim 1. Clamping connection of the elements of universal modular systems for osteosynthesis intended for orthopedics and traumatology, comprising at least one plate, with at least two cross holes which intersect partially, at least one hemispherical screw with at least one rod characterized by provided that: * - in one hole of the plate is placed with a gap bone screw, » * so that the screw can move along the axis of the hole and tilt relative to the axis of the hole; - in each of the other openings of the plate, which are crossed on the first one, a rod with a cylindrical or prismatic shape is placed, corresponding in shape and dimensions of the opening in which it is placed, so that there is a small gap; the rod can be straight or curved with a different shape; the surface of the rod can be smooth or treated in a special way so as to increase the friction and and ¹ to improve the fixation: rolling, grooving or veneering. - during tightening of the screw in the bone, the plate touches the bone and the spherical surface of the screw head touches the rods, acting as a wedge; under the action of wedge forces the rods are pressed against the surface of the holes. As a result, all parts are tightened reliably at the same time. Prior to final tightening, the bone screw can be tilted within the clearance of the plate hole, and the plate can be rotated relative to the rod axis when using only one rod or two rods that are not firmly connected to each other.