RU163736U1 - EXTREME ELEMENTS FOR EXTERNAL OSTEOSYNTHESIS, EXAMPLE SPOKES, RODS - Google Patents

Abstract

Transosseous elements for external osteosynthesis, for example knitting needles, rods made in the form of a metal rod with sharpening of the working part, characterized in that the sharpening of the working part has a crescent shape and consists of external and internal curved surfaces, as well as a sharp end with a vertex located on the axis rod, while on the inner surface perform a cutting edge.

Description

The utility model relates to medical equipment used in traumatology and orthopedics, and is intended for fixation of bone fragments in the treatment of fractures by external osteosynthesis.

It is known that the success of surgical intervention using external osteosynthesis significantly depends on the fixing devices that fasten the damaged bones in the correct position until they are fully consolidated. For strong and rigid fixation of bone fragments, it is important to ensure a solid backlog of the transosseous element (rod, knitting needle) in the walls of the bone. For the postoperative period, a solid primary landing of knitting needles or rods also plays a significant role, since with multiaxial loads, loosening of transosseous elements loosely planted in the bone occurs much faster. The solution to the above problems can be the form of sharpening the point of the spoke, which ensures the penetration of the transosseous element through the cortical layer of the bone. It must also be remembered that when drilling with a spoke, a significant thermal reaction develops, which leads to the formation of ring necrosis.

Known needle for osteosynthesis (see US Pat. RF Utility Model No. 21508, IPC AB 17/58) containing an elongated shaft, shank and cutting part. The cutting part in cross section is made in the form of a parallelogram with sharp edges that fit into a diameter of 2 to 10% larger than the diameter of the rod. The end of the cutting part is made in the form of an angle with the edges beveled to the side from the direction of rotation during cutting. In the area of the chamfered edges, the obtuse angles of the parallelogram of the cutting part are cut off by planes at an angle to the axis of the rod. This needle for osteosynthesis does not provide a sufficiently rigid fixation of the bone or its fragment due to bone resorption along the spoke channel

Known needle for osteosynthesis (see US Pat. RF invention No. 20122277, IPC AB 17/58), suggesting the prevention of bone tissue burn. For this, the cutting part is made in the form of a feather drill with an angle at the apex of 90-120 ° C and an angle of inclination of the transverse edge of 15-30 ° C. The needle is fixed in an electric drill cartridge and the bone fragments required for osteosynthesis are drilled. The disadvantage is that drilling with an electric drill at high speeds leads to an increase in temperature in the area of drilling. In this case, bone microstructures die, designed to hold coaxially the spokes (rods). At the first time after the installation of the spokes, the death of bone trabeculae cells does not affect the quality of their retention, since the detritus formed and the volume of the structures have a certain density and have adhesive properties. Subsequently, cell structures that die from overheating begin to be lysed, thereby increasing the diameter of the drilled hole and reducing the holding properties of the bone.

A knitting needle for osteosynthesis is known (see URL http://linkmed.by/images/medgal/Bone_nails_wires_pines.pdf, p. 3, 10/13/2015), in the form of a metal rod without stop. For the working part, a spear-shaped sharpening is used. To install the knitting needles on the bones, a conical recess is formed first, then the knitting needle is inserted into the bone with an electric drill. The frequency of rotation of the spoke should not exceed 850-1300 rpm. A well-known spoke has all the disadvantages listed above.

The objective of the utility model Transosseous elements for external osteosynthesis, for example, knitting needles and rods, is to ensure the strength and stiffness of fixation of associated bone fragments, and to reduce the invasiveness of the operation.

The problem is solved due to the fact that in transosseous elements for external osteosynthesis, for example, knitting needles and rods, a sickle shape consisting of external and internal curved surfaces, as well as a sharp end, the apex of which is located on the axis of the rod, is used to sharpen the working part. A cutting edge is made on the inner surface.

The proposed sharpening of the crescent-shaped rod, knitting needles allows you to go deep into the bone with a sharp end at low speeds (60-200 rpm) without first drilling the hole. The combination of the tip of the sharp end with the axis of the rod prevents the transosseous element from sliding off the bone surface and minimizes the possibility of trauma to the soft tissues surrounding the bone. At such low speeds, the bone does not undergo overheating, and the diameter of the drilled hole remains constant in the postoperative period.

At low revolutions of the drill with gradual pressure on the tool, there is no expansion of the drilled hole in the bone, because the cutting edge of the transosseous element cuts in a circle of a smaller diameter than the diameter of the spokes of the rod. A tight fit of transosseous elements in the bone is created due to the elastic properties of the bone.

When passing through soft tissues, there is no “winding” of tissues onto the spoke, rod, since due to the presence of a cutting edge along the inner surface of the working part, a spiral-like, gradually deepening dissection of the tissues occurs.

The claimed utility model is illustrated by illustrations, where in FIG. 1 shows a transosseous element (spoke) with a crescent-shaped sharpening.

Transosseous elements are a rod 1 of circular cross section with a crescent-shaped sharpening having a sharp end 2, a cutting inner edge 3 and an outer surface 4.

Transosseous elements for external osteosynthesis, for example, knitting needles and rods, are made of stainless steel or titanium alloys used in medicine, and are smooth, polished, with a protective layer of rods or threaded rods of various diameters and required lengths. The proposed type of sharpening can be performed on knitting needles and rods.

Crescent-shaped rods and knitting needles were used in various surgical interventions for the treatment of fractures in dogs and cats on the basis of the BION veterinary complex in Sevastopol and the RVNITs im. A. Reshetnik. Theodosius from 2013 to 2015.

Crescent-shaped rods and spokes were inserted without preliminary reaming of the bone. When introduced, a standard household screwdriver was used. The rotation speed did not exceed 200 rpm. with the application of a force of not more than 10 kg / s for diameters of 4 mm and 3.2 mm and not more than 5 kg / s for diameters of spokes 2.0 and 1.6 mm. A good reduction of bone fragments was achieved on the operating table, and their fixation remained constantly dense and rigid throughout the postoperative period. The absence of multiaxial loosening of transosseous elements was observed, which resulted in a decrease in the invasiveness of the operation. A total of 647 transosseous patches of rods and spokes were performed during surgical interventions in 116 dogs and cats.

The proposed transosseous elements are industrially applicable, and can be used in traumatology and orthopedics for various types of surgical interventions using external osteosynthesis.

Claims (1)

Transosseous elements for external osteosynthesis, for example knitting needles, rods made in the form of a metal rod with sharpening the working part, characterized in that the sharpening of the working part has a crescent shape and consists of external and internal curved surfaces, as well as a sharp end with a vertex located on the axis rod, while on the inner surface perform a cutting edge.

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