RU2696198C1 - External fixators system for transosseous osteosynthesis - Google Patents

Abstract

FIELD: medicine.SUBSTANCE: invention relates to medicine. System of external fasteners for transosseous osteosynthesis comprises transosseous elements, supports, fastening nuts and pins, as well as a clamp in the form of a bracket with a connecting element, in which an opening is made under the transosseous element. Bracket is supplemented with a holder for spokes made as a bracket in the form of a washer, at the end of which there are radially directed teeth. Washer is arranged on outer side of bracket coaxially with opening at bracket end. Additionally, a clamping transmission washer is installed in the wall of the bracket in the form of a tetrahedral prism with an axial through central hole, on the side face of which there is a semicircular groove for the support placement. Connecting element is a rod with a hole at the end under the transosseous rod or a pin connecting the bracket and clamping transmission washer, aligning central hole of clamping transmission washer with holes at bracket ends.EFFECT: invention provides stabilization of bone fragments and required stiffness of fixation with freedom in selection of fixation point of pin on support.6 cl, 17 dwg, 1 tbl

Description

The invention relates to medicine and veterinary medicine, and is intended for use in the construction of devices for transosseous osteosynthesis by external fixation.

Systems for external fixation of bones, consisting of standard parts, for example, various sizes of flat rings, half rings, knitting needles, transosseous and supporting rods, bolts, nuts, special fixators, are widely used to solve specific medical problems. In these systems, external transosseous rods are fixed on supports and the effectiveness of treatment and the patient's recovery rate depend on the rigidity and strength of the fixation of the clamping mechanism.

Known Rod compression and distraction apparatus (US Pat. 2140224, RF, IPC АВВ 17/56, 1998), containing supporting arcs with holes connected by rods on which the nodes of the fixing holders are placed. Each holder consists of two detachable identical housings connected by a fastener, in one of which a transosseous rod is fixed, and the other is a rod retainer on the rod. In each case there is a central conical hole for washers and a groove for mounting on a rod or for mounting a transosseous rod, offset from this hole. The known design provides the necessary degree of fixation, but can lead to deformation of the fixed elements during operation. In addition, the disadvantage is the high requirements for surface treatment, because the entire assembly is assembled and fastened with one fastener.

Known clamps for distraction rods used in an external fixation apparatus for transosseous osteosynthesis (US Pat. 2663636, RF, IPC АВВ 17/56, 2017). Each clamp consists of two joined elements to cover the support from two opposite sides. Each of the joined elements has a groove at one end from the side of the joined surface for the location of the support. At the other end there is a through hole for the distraction rod or spoke bolt, with the axis of the hole perpendicular to the axis of the groove. One of the holes of the abutting clamping elements has a chamfer on the non-abutting side. When connecting the elements, the axis of the holes are aligned, and the grooves are opposite each other. The bolt spoke is made in the form of a rod with a threaded thread and a hexagonal head, the place of transition of the rod into the head is made in the form of a conical rim for positioning the clamp element in the chamfer, a groove for the spoke is cut on the conical rim. Supports in cross section are in the form of a hexagon. Known clip for the rods does not provide strength fixation due to the fact that it is made detachable. In addition, the clamp-clamp is not universal, because Designed for placement on a hex support.

Closest to the claimed is the external clamp and system (US Pat. 5976133A, US, IPC АВВ 17/56, 1997), designed to connect the transosseous rod with the supporting element. The clamp comprises a housing in the form of a U-shaped cross-section bracket, into which a cylindrical support is placed in the transverse direction, a connecting element and a fixing bolt. The size of each bracket corresponds to a specific diameter of the support. The connecting element has a radial hole for receiving the transosseous rod, an axial threaded hole for the mounting bolt. The proximal end of the connecting element is made in the form of a truncated cone. A fixing bolt is inserted through a central hole in the bracket for engagement with a connecting member holding the transosseous rod. After assembling the clamp, when tightening the fixing bolt, the transosseous rod is attracted to the distal outer surface of the bracket, preventing rotation of the connecting element and the transosseous rod itself. At the same time, the connecting element having a conical surface in contact with the support wedges the support inside the bracket, increasing the stiffness of the clamp, preventing rotation of the clamp around the support and rotation of the connecting element in the clamp housing. But the simultaneous clamping of two elements with one fixing bolt (support and transosseous rod) with the same stiffness to prevent displacement is difficult, therefore, during operation, slipping of the rods is observed. The design of the clamp and operating conditions place increased demands on the quality of processing, which affects its cost. The disadvantage is the low versatility of the clamp, because each bracket is used with a support of a certain diameter and the surgeon has the opportunity to use only a specific and appropriate pair of bracket support.

The objective of the invention is to develop the design of clamping mechanisms for fixing and placing transosseous rods and spokes on the main support with the possibility of inclusion in various systems of hardware structures.

The technical result from the use of the invention is the expansion of the arsenal of technical means used for bone osteosynthesis to stabilize bone fragments, to provide the necessary fixation stiffness with freedom in choosing the place of fixation of the spokes on the support, at a low construction cost, ease of assembly / disassembly, reliability and strength of fixation structural elements both in monolateral and bilateral versions, and in combination with arc-ring structures used for transosseous ostomy osynthesis.

The specified technical result is achieved due to the fact that a system of external fixators for transosseous osteosynthesis is proposed, consisting of transosseous elements, supports, fasteners and a clamp in the form of a bracket with a connecting element in which an opening for the transosseous rod is made. In the indicated system, the bracket additionally on the outside has, made integral with the bracket coaxially with the hole at the end of the bracket, a spoke holder in the form of a washer, on the end of which there are radially directed teeth. A clamping transmission washer in the form of a tetrahedral prism with an axial through-hole central hole is placed on the bracket side, a semicircular groove is made along its lateral edge to jam the supports in it. As a connecting element, a rod is used with an opening at the end for a transosseous rod or a spoke, which connects the bracket and the pressure transmission washer, aligning the central hole with the holes at the ends of the bracket.

In this case, the surface of the groove of the clamping washer is made corrugated; the through hole of the clamping transmission washer has a constant diameter; part of the through hole of the clamping transmission washer is made with a large diameter; the stem has a constant diameter; the part of the rod on which the hole for the transosseous rod is located is made with a large diameter.

The differences of the claimed invention from the prototype are that:

- the addition of the bracket with a holder for knitting needles designed to hold the transosseous rod and prevent it from unscrewing, increases the rigidity of fixation of the external rods;

- the implementation of the clamping transmission washer in the form of a tetrahedral prism with an axial through-hole central hole, on the lateral side of which a semicircular grooved groove is made to place the support, allows you to squeeze the support onto the pressure washer and provide subsequent jamming of the rod holding transosseous elements;

- installation of the clamping transmission washer with a groove in the bracket barrel allows you to firmly hold the clamp on the support, prevents the clamp from turning around the support, allows you to install the clamp with a threaded rod anywhere on the support;

- the connection of the bracket and the clamping transmission washer using the rod holding the transosseous element is easy to operate and provides reliable fixation of the transosseous element in the clamp;

- the design of the clamp allows sequentially fixing the transosseous rod in the clamp and fixing on the support, which can be done separately, which increases ease of use;

- the implementation of staples with semicircular grooves allows you to firmly fix the clamp on supports made of polymeric materials;

- the execution of the rod with a figured hole for installing transosseous element allows you to install transosseous elements of three different diameters on a bracket of the same size,

- execution at the ends of the supports of the internal thread (for supports of larger diameter) and the external thread (for supports of small diameter) allows you to attach the support to various arc-ring structures.

These distinctive features allow us to conclude that there is novelty in the proposed technical solution. The patent studies carried out by the author, as well as the study of available scientific publications related to the design of devices for transosseous osteosynthesis by external fixation, did not find solutions that have signs similar to the claimed invention, which allows us to conclude that the criterion meets the technical level.

The invention is illustrated by a description and illustrative material, where:

FIG. 1 is an assembly diagram of a system of external fixators for transosseous osteosynthesis;

FIG. 2 - section of the clamp;

FIG. 3 - bracket with a spoke holder;

FIG. 4 - section staples along AA (option 1);

FIG. 5 - section staples along AA (option 2);

FIG. 6 is an assembly diagram of a system of external fixators for transosseous osteosynthesis of external fixation with an additional bracket for fixation of the carbon rod;

FIG. 7 - bracket with semicircular grooves;

FIG. 8 - a washer-holder of knitting needles;

FIG. 9 - clamping transmission washer;

FIG. 10 - a section along aa clamping transmission washer (option 1);

FIG. 11 is a section along aa clamping transmission washer (option 2);

FIG. 12 - rod for supports and transosseous elements of large diameter;

FIG. 13 - rod hole with a profile groove of a triangular section;

FIG. 14 - rod hole with a profile groove of square section;

FIG. 15 - rod of constant diameter;

FIG. 16 - support with an external thread at the ends of the support;

FIG. 17 is a fragment of a support with an internal thread.

The system of external fixators for transosseous osteosynthesis (Fig. 1) consists of transosseous rods 1, support 2 and a clamp for fixing transosseous rods, spokes and placing them on a support that contains (Fig. 2) bracket 3, clamping transmission washer 4, rod 5 (Fig. 2), as well as fixing nuts 6, bolts 7. The system is used as follows. The transosseous rod 1 (or a knitting needle) is inserted into the hole in the rod 5. The pressure transmission washer 4 is installed in the bracket 3, aligning coaxially with the holes of the bracket and the pressure transmission washer 4, into which the rod 5 is inserted and fixed with a nut 6. The support 2 is inserted into the bracket 5. and with the fixing bolt 7, the support 2 is pressed out onto the clamping transmission washer 4. At the same time, the force is transmitted to the rod 5 and an additional retention of the rod in the transverse direction is achieved, which allows for more firm fixation of the transosseous element 1 in the hole of the rod 5, p edotvratit its movement, particularly when a rotational load. Parts are made of stainless steel or titanium alloy on conventional equipment and do not require increased requirements for processing quality.

The bracket (Fig. 3) has a U-shaped cross section and a threaded hole 8 in the back of the bracket for the fastener, which is inserted perpendicular to the axis of the support 2 and squeezes the support 2 onto the pressure transmission washer 4. The holes on the ends of the bracket 3 are designed to install the rod 5. Holes 9 (Fig. 4) can have the same diameter d or holes 9, 10 (Fig. 5) can have different diameters dD. The bracket 3 includes a holder of knitting needles 11 in the form of a washer, made integral with the bracket, placed on the outside of the bracket coaxially with the hole at the end of the bracket. At the end of the spoke holder 11, radially directed teeth are made on which the transosseous rod 1 is placed after the rod 5 is installed. When working with supports made of polymer composite materials, for example carbon supports, a bracket 12 is proposed, which is additionally mounted on the assembled clamp to prevent carbon fiber slipping rod in the clamp and increase the rigidity of fixation (Fig. 6). The bracket 12 (Fig. 7) has semicircular grooves at the ends 13. The bracket 12 is mounted on the stud 7 of the assembled clamp and squeezed onto the support 2 with the fastening nut, achieving a rigid fixation of the carbon support 2. In cases of using an external fixation system, the brackets (see US Pat. No. 2680593.2017, RF), to hold a spoke or transosseous rod, it is advisable to use a separate washer 14, at the end of which radially directed teeth 15 are made (Fig. 8). The washer 14 for the purpose and design features (teeth) is similar to the washer of the holder of the spokes 11 of the bracket 3.

the claimed system of external fixation offers staples of various sizes for the possibility of installing on the staple barrel supports of the main diameter, as well as supports of a smaller diameter and without precision reference (Table).

The above table is intended to illustrate the possibility of installing three supports of different diameters in one bracket. If necessary, the support may have a diameter of 12, 14, 16 mm, with a corresponding increase in the size of the alignment of the bracket, which does not contradict the general concept of the invention.

The clamping transmission washer 4 is installed in the target of the bracket 3 to hold the clamp on the support 2 and transmits the clamping force from the fixing bolt fixing the support 2 to the rod 5, fixing transosseous element 1. The housing of the clamping transmission washer 4 (Fig. 9) is made in the form a tetrahedral prism with an axial through-hole central hole 16. The through hole 16 may have a constant diameter d along the entire length of the washer (Fig. 10) and may be with diameters dD (Fig. 11). A semicircular groove 17 is made along the side face of the clamping transmission washer 4, the surface of which contacts the support 2 when installing the clamping washer 4 in the bracket 3. It is advisable to groove the groove surface with grooves to additionally prevent the bearing from slipping. The increase in clamp rigidity, the prevention of rotation of the clamp around the support 2 occurs due to the contact of the clamping transmission washer 4 with the support 2, fixed by the fixing pin 7.

The rod 5 (Fig. 12) is designed to install transosseous rod and forming a connection between transosseous rod and support. The rod is made in the form of a cylindrical solid rod with a thread at one end of the rod and a hole 18 for transosseous rod at the opposite end. In accordance with the invention (see US Pat. No. 2680593, 2017, RF), a profile groove is made in the hole, which may have a triangular section (Fig. 13), or a square section (Fig. 14). For supports of large diameter (12 mm, 14 mm or more), the part of the rod on which the hole for the transosseous rod is located is made with a large diameter, and for supports with a diameter of 10 mm or less, a rod 19 of constant diameter is used (Fig. 15). When assembling the clamping unit for the rod 5, a clamping transmission washer 4 is used with the hole in FIG. 11, and for the rod 19, the clamping transmission washer 4 with the hole in FIG. 10. It is obvious that for the formation of the connection, it is necessary that the diameter of the rod does not exceed the diameters of the holes at the ends of the bracket 3, as well as the holes 16 of the clamping transmission washer 4.

As an external support 2 for installing clamps and fixing transosseous rods, the invention uses cylindrical rods of a certain length and a certain diameter (Fig. 16). Small diameter supports have a short external thread at both ends, larger diameter supports have threaded holes for adapter studs from the end ends (Fig. 17). External threaded rods are designed for mounting various options for hardware designs to the ring support.

The proposed clamps of external rods and supports can be used in monolateral, bilateral, as well as in hybrid hardware designs; if necessary, fasten the supports to the ring supports of various external fixation devices, regardless of the manufacturer, provided that there are coaxial holes of the corresponding diameter in the ring support.

The use of the invention is not limited to the above examples, but provides for various assembly options in accordance with the general concept set forth in the claims.

Claims (6)

1. The system of external fixators for transosseous osteosynthesis, containing transosseous elements, supports, fastening nuts and studs, as well as a clip in the form of a bracket with a connecting element, in which a hole is made under the transosseous element, characterized in that the bracket is complemented by a holder for integral with the bracket for spokes in the form of a washer, on the end of which radially directed teeth are made, and the washer is placed on the outer side of the bracket coaxially with the hole at the end of the bracket, additionally, a clamping a transmission washer in the form of a tetrahedral prism with an axial through-hole central hole, on the lateral side of which a semicircular groove is made to place the support, and a rod with an opening at the end under the transosseous rod or spoke is used as a connecting element, which connect the bracket and the pressure transmission washer, combining the central hole of the clamping transmission washer with holes at the ends of the bracket. 2. The system according to claim 1, characterized in that the groove surface of the clamping transmission washer is grooved. 3. The system according to claim 1, characterized in that the through hole of the clamping transmission washer has a constant diameter. 4. The system according to p. 1, characterized in that the part of the through hole of the clamping transmission washer is made with a large diameter. 5. The system according to p. 1, characterized in that the rod has a constant diameter. 6. The system according to claim 1, characterized in that the part of the rod on which the hole for the transosseous rod is located is made with a large diameter.

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