RU2336052C1 - Compression strip for tubular bone fragment stabilisation in oblique and spiral fractures of small domestic animals - Google Patents

Abstract

FIELD: medicine; veterinary science.

SUBSTANCE: invention represents compression strip for tubular bone fragment stabilisation in oblique and spiral fractures of small domestic animals. Compression strip contains transverse semi-oval flanges from one side interspaced at 5.0 mm. According to invention transverse semi-oval flanges are designed in middle part of compression strip. Grooves for through threaded screw holes with bone fixing necks are provided on ends from above on one side and from bottom on the other side. Screw length is 1/4 more than thickness of compression strip. Compression strip allows for elimination of additional marrow and nutrient artery injury, for prevention of implant microdisplacement, for lowered mechanical effect of metal implants on fracture zone, for prevention of displacement and separation of fragments, as well as of subsequent complications; for higher stability of osteosynthesis, for optimum conditions for endosteal and periosteal callus, for osteosynthesis of animals with weight over 20 kg and active temperament, for reduced bone reparation terms.

EFFECT: higher efficiency of operation considering its availability and simplicity.

3 dwg, 1 tbl

Description

The invention relates to veterinary surgery, namely to osteosynthesis of tubular bones in dogs and cats. Most effective is its use in osteosynthesis of tubular bones with oblique and helical fractures.

Known retainer-coupler, consisting of longitudinal plates, cerclage ribbons and loops [Anischenko S. M., Oleksyuk D. I. Fixator - screed for metal osteosynthesis of oblique, spiral and multi-fragmented fractures // Bulletin of I. I. Grekov Surgery. - L .: Medicine, Leningrad branch, No. 4, volume 112, 1974, p.111-114].

The main disadvantage of the known fixative is the possibility of violation of the trophism of the periosteum. This type of postoperative complication is due to the fact that the retainer-screed is in contact with bone tissue, exerting pressure on the blood vessels of the periosteum. As a result of this, the circulation of the periosteum between the parts of the bone located distally and proximal to the constituent parts of this fixative is limited, or even completely disturbed. A decrease in bone trophism in a certain area of the bone leads to an increase in the duration of bone callus formation. As practice has shown, even with an insignificant load of the animal on the injured limb, the retainer-coupler often does not perform a fixing function. This leads to a discrepancy in the fragments, a violation of the formation of bone callus by primary intention, lengthening the repair period and, in the majority, to the configuration of the bone after fusion of the fragments or to pseudoarthrosis.

Also known is a fixator for fragments of tubular bones in oblique and helical fractures in dogs and cats, represented by a constricting strip with transverse semi-oval protrusions located at a distance of 5.0 mm from each other, on the one hand for resting on the bone and a groove for laying wire on the other side [RF patent for PM No. 42167, Oryol State Agrarian University, 11/27/2004, prototype].

However, after applying a fixator of this design on a control x-ray in a dog weighing over 20 kg, a discrepancy of fragments at an angle was revealed. The immobilizing ability of the tightening strips with limited contact, fixed by a wire, in this case was not sufficient, due to a violation of the integrity of the wire in the place of its twisting. Accordingly, the use of osseous fixators of this design is limited by the individual animal data, namely the mass. It is possible that it is also necessary to take into account the temperament of animals, even with an allowable weight.

The objective of the proposed solution is to eliminate these disadvantages and increase the stability of osteosynthesis.

This object is achieved due to the fact that the known retainer in the form of a constricting strip for fixing fragments of tubular bones in oblique and helical fractures in small pets with transverse semi-oval protrusions on one side located at a distance of 5.0 mm from each other, according to the invention transverse semi-oval the protrusions are located in the middle of the tightening strip, and on the ends are made on one side from above and from the other side from below from the grooves for through holes with thread for a screw with a spike for fixing and in the bone, while the screw is 1/4 longer than the thickness of the tightening strip.

The invention is illustrated by drawings, where:

figure 1. the proposed tightening strip with a screw is presented (A - side view, B - top view);

figure 2. - fixation of fragments of the tubular bone in an oblique fracture with constricting bands (side view);

figure 3. - section aa in figure 2.

The pulling strip 1 has, on one side in the central part, transverse semi-oval protrusions 2 located at a distance of 5.0 mm from each other, and at its ends are made on one side from the top and from the other side from the bottom, grooves 3 for through holes 4 with thread screw 5 with a spike 6, which is fixed in the diaphysis of the bone 7 away from the fracture line 8 and does not penetrate into the medullary canal of the bone 9. Screw 5 along with the transverse semi-oval protrusions 2 limits the pressure of the contracting strip 1 on the blood vessels 10 of the periosteum associated with soft tissues f course 11.

The use of the contracting strip 1 is described by the example of osteosynthesis of a dog's tibia and is carried out as follows.

In oblique fracture of the tubular bone under general anesthesia, surgical reposition is carried out with subsequent fixation of bone fragments by the contracting bands 1. At the same time, two contracting bands 1 are applied: one is laid closer to the proximal part of the fracture line, the other to the distal one.

The tightening strip 1 end part is brought under the diaphysis of the bone 7, pre-positioning it with protrusions 2 to the surface of the diaphysis of the bone 7, and model around its circumference. Then the ends of the contracting strip 1 are compared and a groove 3 of one end is laid on the groove 3 of the other end, so that the through holes 4 with the threads of the opposite ends of the contracting strip 1 coincide. After that, a screw 5 is screwed into the combined through holes 4 with a thread, the spike 6 of which is pressed into the thickness of the diaphysis of the bone 7, which prevents all types of displacement of the contracting strip 1. The insertion of the spike 6 into the diaphysis of the bone 7 is selected at a distance from the fracture line 8 by 0, 5-1.0 cm, displacing the through holes 4 with the thread of the tightening strip 1 to the left or right relative to the fracture line 8 by rotating the tightening strip 1 around the diaphysis of the bone 7. When the screw 5 is screwed in, the opposite ends of the tightening strip 1 are connected in places where there are no transverse semi-oval protrusions 2 tightening strip 1, rising above the diaphysis of the bone 7, is stretched. In addition to the transverse semi-oval protrusions 2 located at a distance of 5.0 mm from each other, a support point also is a screw 5, which, after screwing into the combined through holes 4 with a thread, is located from the transverse semi-oval protrusions 2 at a distance of 5.0-7.0 mm . This preserves the circulation in the blood vessels of the periosteum 10 located distally and proximal to the contracting bands 1. The variability of the distance (from 5.0 to 7.0 mm) of the location of the screw 5 from the transverse semi-oval protrusions 2 depends on the length of the circumference of the bone diaphysis 7, which also depends the length of the contracting strip 1, and, accordingly, the number of transverse semi-oval protrusions 2.

An excess or lack of screw 5 is not observed, since the length of screw 5 is 1/4 longer than the thickness of the contracting strip 1. Fixation of the contracting strip 1 in the tensioned state ensures the stability of osteosynthesis. By tightening the screw 5 into the threaded through holes 4, reliable immobilization of bone fragments 7 in the correct axial position is achieved. In this case, the most tight contact of the contracting strip 1 with the surface of the diaphysis of the bone 7, and, accordingly, of fragments along the fracture line 8. is achieved. An excess or deficiency of the contracting strip 1 is not observed, since its length is selected according to the circumference of the bone diaphysis 7. In this case, no part the contracting strip 1 is not inserted into the bone marrow channel 9 of the bone 7. This prevents additional trauma to the bone marrow and branches of the feeding artery.

For stable fixation of fragments of tubular bones during an oblique fracture, it is necessary to install a second tightening strip 1 at a certain distance from the first. Installation of the second tightening strip 1 is carried out by analogy with the first. At the same time, the correct choice of the place of insertion of the spike 6 of the screw 5 into the diaphysis of the bone 7 is observed. The recommended distance from the fracture line 8 is maintained at 0.5-1.0 cm. In this case, the through holes 4 with the thread of the contracting strip 1 are displaced in the lower wound aperture in the opposite direction relative to the first contracting strip 1. The alignment of the screws 5 is not on the same line increases the rigidity of osteosynthesis.

The surgical wound is sanitized and closed according to the generally accepted method, and when applying wound sutures, the contracting strip 1 and screw 5 are closed with soft tissues of the limb 11. Then, skin knotted sutures are applied.

As a result of the application of the proposed tightening strip, it was found:

- the exclusion of additional trauma to the bone marrow and the feeding artery;

- prevention of implant micro displacements;

- reduction of the mechanical effect of metal implants in the fracture zone;

- prevention of displacement and discrepancy of fragments, as well as subsequent complications;

- increasing the stability of osteosynthesis;

- creation of optimal conditions for the formation of endoostal and periosteal callus;

- accessibility and ease of operation;

- the possibility of osteosynthesis in animals weighing over 20 kg and moving temperament;

- reduction of bone repair time. This greatly improves the efficiency of the operation.

The proposed contracting strip was successfully applied on 7 dogs and 3 cats on the basis of the medical and diagnostic veterinary center of the Federal State Educational Institution of Higher Professional Education “Oryol GAU” (see table).

Table Clamps The number of animals operated Divergence of fragments in animals weighing more than 20 kg Suggested tightening strip 10 - Known tightening strip 10 one

As can be seen from the table, the use of the proposed constricting strip is more effective than the known one and allows to exclude the discrepancy of fragments in animals weighing more than 20 kg and moving temperament.

Claims (1)

A contracting strip for fixing fragments of tubular bones during oblique and helical fractures in small pets with transverse semi-oval protrusions on one side located at a distance of 5.0 mm from each other, characterized in that the transverse semi-oval protrusions are located in the middle of the contracting strip, and the ends are made on one side from the top and on the other side from the bottom, grooves for through holes with a screw thread with a spike for fixing in the bone, while the screw is 1/4 longer than the thickness of the tightening strip.

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