RU2323695C2 - Method of modelling pseudoarthrosis - Google Patents

Abstract

FIELD: medicine, traumatology and orthopaedics.

SUBSTANCE: transversal osteotomy of cortical bone in its most narrow area is taken. Medullar canal of proximal and distal bone segments is reamed. Intramedullary osteosynthesis is performed immediately after medullar canal is reamed, by fixing with a rod that has rounded profile and diameter knowingly less than inner diameter of bone-marrow canal.

EFFECT: allows control of absence of stable fixation at transversal osteotomy level by means of rotary movement of distal area of extremity.

9 dwg

Description

A method for modeling pseudoarthrosis relates to modeling in medicine and can be used to model pseudoarthrosis.

Known methods for modeling the movable joints of the musculoskeletal system as normal [SU 903953, 3 G09B 23/32, 02/07/1982], and pathology [SU 936017, 3 G09B 23/28, 06/15/1982; RU 2205458 C1, 7 G09B 23/28, 05.27.2003; RU 2212060 C2, 7 G09B 23/28, 09/10/2003], however, they cannot be used to model pseudoarthrosis as a dynamic process as a whole. Known methods for modeling paraarticular heterotopic ossifications [RU 2203508 C2, 7 G09B 23/28, 04/27/2003], however, it only models paraarticular heterotopic ossifications and can only be used to study the etiology and pathogenesis of extra-skeletal bone formation. The closest is a method for modeling the proximal epimetaphysis of the ulna [RU 2160469 C2, 7 G09B 23/28, A61B 17/56, 10.12.2000], the essence of which is that in the region of the ulnar process of the ulnar bone of a growing rabbit, a closed intraarticular fracture is performed without applying immobilization followed by dosed mobilization of the bone fragment to form a delayed consolidation of bone regenerate, which has a stimulating effect on the growth of epimetaphysis. However, this method can only be used to study the pathogenesis of post-traumatic increase in epimetaphysis of long tubular bones, and does not allow to study the etiology and pathogenesis of pseudarthrosis, clinical and morphological indicators of the formation of the pseudarthrosis process and the development of methods for their correction, degenerative-dystrophic changes after extreme exposure, and the development of new therapeutic measures in the treatment of various stages of pseudoarthrosis (surgical, medical, physical and others).

The objective of this method is the modeling of pseudoarthrosis to study the etiology and pathogenesis of pseudarthrosis, clinical and morphological indicators of the formation of the pseudarthrosis process and the development of methods for their correction, degenerative-dystrophic changes after extreme exposure, and the development of new therapeutic measures in the treatment of various stages of pseudarthrosis (surgical, medication, physical and others).

The solution to this problem is achieved by performing a transverse osteotomy of the tubular bone, reaming of the medullary canal and intermedicular osteosynthesis with a pin having a rounded cross section and a diameter obviously smaller than the inner diameter of the diaphyseal tube.

The method is as follows. The animal is immersed in anesthesia and the area of surgery according to Filonchikov is traditionally treated, an S-shaped incision of the skin and subcutaneous tissue 10-13 cm long is carried out along the outer surface of the thigh, departing 2-4 cm from the greater trochanter. The middle third of the diaphysis of the bone is exposed. Further, with the help of the Jigley saw, a transverse osteotomy is performed in its narrowest place. A stylet is used to drill the medullary canal of the proximal and distal fragments. In order to create favorable conditions for the formation of pseudoarthrosis during intramedullary osteosynthesis, a round pin with a diameter obviously smaller than the diameter of the medullary canal is used. To do this, a pin from the osteotomy area is inserted into the medial canal of the proximal femur fragment until its end is shown under the skin in the region of the greater trochanter. Next, an additional skin incision is made above the tip of the pin and its introduction is continued until it is completely immersed in the proximal fragment. Bone fragments are matched and a pin from the superectal region is inserted into the distal fragment of the bone by hammer blows. Carry out rotational movements of the distal limb, make sure of stability in the absence of stable fixation at the level of osteotomy. An antibiotic is poured into the surgical wound and sutured in layers tightly. A gauze roll soaked in alcohol is hemmed to the skin. This method of suturing the surgical wound reliably protects it from infection. In the postoperative period, all animals are provided with a free dynamic regimen.

An example of a specific implementation was carried out on outbred dogs, selected according to the principle of analogues in compliance with the rules of work using experimental animals and the requirements of the Ministry of Health of the Union of Soviet Socialist Republics No. 12000-496 of April 2, 1980

Surgical interventions were performed with strict adherence to the rules of aseptic and antiseptic using conventional general surgical and special traumatological instruments - bone holders, a wire saw Dzhigli, awl, drill, hammer, pins for intramedullary fixation (Fig. 1. Set of traumatological instruments).

When performing intramedullary osteosynthesis, fixing devices made of 1X18H9T stainless steel were used. Based on the experimental conditions, the pins had a rounded cross section and a diameter obviously smaller than the inner diameter of the diafar tube.

After immersion of the animal in anesthesia and traditional treatment of the surgical area according to Filonchikov, a longitudinal incision of the skin and subcutaneous fatty tissue 10-12 cm long was performed along the outer surface of the thigh, 2-3 cm away from the greater trochanter. In a blunt and sharp way, the deeper layers of the muscles were disconnected, exposing the middle third of the diaphysis of the bone. Further, with the help of a Jigli saw, a transverse osteotomy was performed at its narrowest point (Fig. 2. Transverse osteotomy at the narrowest point of the bone).

A stylet was used to drill the medullary canal of the proximal and distal fragments. In order to create favorable conditions for the formation of pseudoarthrosis during osteosynthesis, a round pin was used with a diameter known to be smaller than the diameter of the medullary canal. For this, a pin from the osteotomy area was inserted into the medullary canal of the proximal femur fragment until its end showed under the skin in the region of the greater trochanter (Fig. 3. The introduction of the intramedullary fixer is retrograde). Further, an additional skin incision was made above the tip of the pin and continued its introduction until completely immersed in the proximal fragment. Bone fragments were compared, and a pin from the superexial region was inserted into the distal fragment of the bone by hammer blows. An antibiotic was poured into the surgical wound and sutured in layers tightly (Fig. 4. Suturing of the surgical wound tightly). A gauze roll soaked in alcohol was sutured to the skin. This method of suturing the surgical wound reliably protects it from infection and licking of sutures to animals. In the postoperative period, all dogs were given a free dynamic regimen.

All animals satisfactorily underwent surgery to induce pseudoarthrosis. Awakening from anesthesia usually occurred 30-40 minutes after the end of the operation. In all dogs, wound healing took place by primary intention. 1.5 months after intramedullary osteosynthesis, in all cases a limp of the hanging limb type was noted. The general condition of the operated animals was satisfactory. Instability of the fracture area was clinically determined. The animals did not include the limb in the process of statolocomotion, as a result of which there was an atrophy of the muscles, as well as a shift in the center of the natural load, which in turn affected the skeletal muscles. Palpation determined the instability of the ends of the bone fragments. There were no signs of consolidation.

An x-ray was traced at the level of osteotomy and minor periosteal layers were visualized. The revealed clinical and radiological symptom complex of structural changes convincingly indicates the development of pseudoarthrosis in all experimental animals, since the diameter of the pins in all cases did not correspond to the diameter of the medullary canal (Fig. 5. The diameter of the pin is much smaller than the diameter of the inner surface of the diaphyseal tube).

A repeated operation to remove the fixator made it possible to carry out a thorough revision of the pseudoarthrosis area and reliably assess the nature of the morphological changes in the osteotomy area. It was found that in the early stages of the postoperative period, granulation tissue with a high content of blood vessels is formed along the periphery of the bone fragments, as well as along the line of the osteotomy, which is the basis for the formation of periosteal callus, which is also richly vascularized.

It is important to emphasize that, against the background of the formation of periosteal callus, the endostatic vasculature is also restored, which was destroyed during the reaming of the medullary cavity. In favor of this may be evidenced by the formed capsule, consisting of granulation and fibrous tissue, separating the intramedullary fixative from the inner surface of the diaphyseal tube (Fig. 6. Connective tissue capsule, separating the fixative from the inner surface of the foreign tube. Hematoxylin and eosin. Lens 10, eyepiece 10 ) At the next stage of osteoreparation, areas represented by chondroid tissue are identified in the paraossal callus, on the periphery of which individual bone beams are formed, while the regenerate is mainly represented by fibrous tissue containing a large number of fibroblastic cells enclosed between bundles of collagen fibers. Moreover, extensive inclusions of adipose tissue are revealed on the outer surface of the corns. The place of contact of the bone fragments with each other is characterized by the development of fibro-cartilaginous regenerate here. However, the macro-mobility of the fragments does not allow him to connect their ends, as a result of which we revealed tears, cystic cavities, minor hemorrhages (Fig. 7. Tears, cystic cavities, minor hemorrhages in the osteotomy zone. Hematoxylin and eosin. Lens 10, eyepiece 10) . It is interesting that in some parts of the paraossal callus located at a considerable distance from the fracture zone, foci of bone tissue appear - a sign of endesmal osteogenesis. The next stage of osteoreparation demonstrates the rapid development of cartilaginous tissue on the surface of the diaphysis, and the space between the fragments gradually fills the chondroid proliferate framing their ends (Fig. 8. The space between the fragments, gradually filling with chondroid proliferate framing their ends. Hematoxylin and eosin. Lens 10, eyepiece. 10). Based on the foregoing, it is safe to say that the presented fragment of morphological studies demonstrates the adequacy of the method for modeling pseudoarthrosis, which is confirmed by a clinically persistent violation of the functional suitability of the limb, its configuration, and painless mobility at the fracture level.

Thus, as a result of the implementation of the proposed method, we obtain, as a technical result, a model that reflects the dynamics of functional and morphological changes in pseudoarthrosis (Fig. 9. Scheme of pseudoatrosis), brings it closer to the clinical course due to the completeness of reproduction of the morphological picture and the receipt of the same type of lesions, increases the accuracy modeling due to the reproduction in the model of topographic, anatomical and histopathological changes, increases the reproducibility of the method and can be used and to ensure the educational process, increase the visibility when studying the course "Pathological anatomy, sectional course and forensic veterinary examination", "Veterinary surgery" [State educational standard of higher professional education. Specialty 310800 "Veterinary Medicine". Qualification - Veterinarian. - M .: MO RF, 2000. - P.20] and allows you to bring the model closer to the real mechanism of the process, to study the morphology of the biological material of the components of the musculoskeletal system in the conditions of destructive processes, brings the experimental conditions closer to the clinical ones, given the increasing influence of stressful situations on life body, as close as possible to the morphological structure of the biological material of the components of the musculoskeletal system after extreme exposure, simplifies the technique of intervention, standardizes the strength Get inside and closer to the original mechanism of the pathological process.

Claims (1)

A method for modeling pseudoarthrosis, including osteotomy of the tubular bone and intramedullary osteosynthesis, carried out by introducing a fixative into the medullary canal, characterized in that the transverse osteotomy of the tubular bone is carried out at its narrowest point, the medullary canal of the proximal and distal fragments of the bone is drilled, and the intramedullary medullary canal the medullary canal by fixing with a pin having a rounded cross section and a diameter obviously smaller inside the diameter of the bone marrow canal, controlling the lack of stable fixation at the level of transverse osteotomy by means of rotational movement of the distal limb.

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