RU2539627C1 - Method for simulating pseudoarthrosis of extremity bone - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: method involves a resection of a bone segment, a fixation of bone fragments with an osteosynthesis apparatus. A defect is formed in a proximal tibial metadiaphysis having a size of 1.5 to 2.5 cm. Herewith, a.nutricia is additionally damaged at the ingress into the bone with creating the conditions for magistral blood flow disturbance along its system in the distal fragment. That is followed by a compression at 2 mm a day. Once achieving a fragment diastasis of 4-5 mm, a neutral fixation mode is actuated.

EFFECT: creating an adequate model of pseudoarthrosis that enables studying the aspects of bone tissue regeneration in treating a false joint in the combined osteosynthesis environment.

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Description

The invention relates to experimental medicine, in particular to scientific research in the field of orthopedics.

A known method of experimental modeling of delayed distraction osteogenesis during shortening of limb bones, including resection of a bone site, fixation of bone fragments by an osteosynthesis apparatus with the possibility of lengthening, distraction at a rate of 1.0 mm in 4 doses per day, characterized in that after resection of a bone site and fixation bone fragments by the osteosynthesis apparatus carry out the rapprochement of the fragments with the preservation of diastasis between them at least 0.5 cm, then conduct distraction at a rate of 1 mm for 4 doses per day until restored the initial limb length (RU 2463668 C1).

However, this method does not allow to simulate pseudarthrosis of the bone.

The objective of the present invention is to develop a method that allows you to simulate a defect-pseudoarthrosis of the bone, to study the features of osteogenesis of distraction and contact regenerates by various treatment methods.

The problem is solved in that when a defect is formed in the proximal tibia metadiaphysis, a.nutricia is damaged, 2 mm of compression is performed per day, and upon reaching diastasis between fragments of 4-5 mm, they go into neutral fixation mode.

The present invention is illustrated by a detailed description and illustrations, which depict:

Figure 1 - x-ray of the bones of the leg of the dog (front and side projection) after modeling the defect;

Figure 2 - radiographs of the bones of the leg of the dog (front and side projection) after 2.5 months;

Figure 3 - the histostructure of the tibial regenerate after 75 days of the experiment; a) the formation of isolated bone fragments that mimic the head and cavity of the false joint. Histogram. Picrofuchsin stain according to Van Gieson. SW - 1.5x; b) fibrous connective tissue in the inter-fragment area. Picrofuchsin stain according to Van Gieson. SW - 25x; c) lamellar bone tissue of endoscopic bone grafting and fibrous cartilage on its surface. Proximal fragment. Hematoxylin and eosin stain. SW - 40x; d) the trabecular bone network and the yellow bone marrow in the intertrabecular spaces. Picrofuchsin stain according to Van Gieson. SW - 25x.

The method is as follows.

To perform the simulation of defect-pseudoarthrosis of the limb bones, transosseous osteosynthesis by Ilizarov apparatus is performed. Using a vibration saw, a 2 cm bone defect is simulated in the upper third of the leg. When a post-resection defect is formed in the proximal tibia metadiaphysis, a.nutricia is damaged at the site of its entry into the bone and, accordingly, the main blood flow is disturbed through its basin in the distal fragment. Then, compression of 2 mm per day is carried out, and upon reaching diastasis of 4-5 mm, bone fragments were left in neutral fixation mode.

An example of a specific implementation.

Dog number 5137. After immersion of the animal in anesthesia and traditional treatment of the surgical intervention area, transosseous osteosynthesis was performed using Ilizarov apparatus. Using a vibration saw, a 2 cm bone defect was simulated in the upper third of the leg. When a defect was formed in the proximal metadiaphysis of the tibia, a.nutricia was damaged at the site of its entry into the bone, which disrupts the main blood flow of the distal fragment. Then, during the week, compression of 2 mm per day was carried out, and upon reaching diastasis of 4-5 mm, bone fragments were left in neutral fixation mode (Figure 1).

After 2.5 months, x-ray in diastasis, single homogeneous shadows are noted, minor osteoporosis is determined (Figure 2). On the histotopograms of the longitudinal cut of the tibial regenerate between the fragments of bone fusion was not observed (Figa). Both fragments were bordered by a continuous strip of plate-type bone tissue with a width of 1.5 to 3.2 mm, merging with the cortical plate of the mother bone of each of the fragments and closing it. On the surface of the bone tissue of the closure plastic of each of the fragments, portions of fibrous cartilage were visualized (Fig.3c). In the inter-fragment area, a layer of well-vascularized fibrous connective tissue with a fat content was formed (Fig. 3b). Combining with the tissues of the periosteum, the inter-fragmentary strand of connective tissue formed a kind of case that isolates fragments from each other in the center and combines them along the periphery, simulating an articular bag. In the bone marrow cavity, the formation of a network of trabeculae of lamellar bone tissue was noted. Localization of the yellow bone marrow and microvessels was observed in the intertrabular spaces (Fig. 3d).

This histological picture indicated the formation of a false joint in the tibial fracture area.

Using the proposed method in FSBI "RRC" WTO "them. G.A. Ilizarova will help to study the features of bone tissue regeneration in the treatment of defect-pseudoarthrosis in conditions of combined osteosynthesis.

Claims (1)

A method for modeling a defect-pseudoarthrosis of the tibia, including resection of a bone site, fixation of bone fragments with an osteosynthesis apparatus, characterized in that the defect is formed in the proximal tibia metadiaphysis with a size of 1.5 to 2.5 cm, and further damage a. nutricia at the site of its entry into the bone, creating conditions for the violation of the main blood flow through its basin in the distal fragment, then they compress 2 mm per day and upon reaching diastasis between the fragments 4-5 mm transition It is in neutral fix mode.

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