Treatment of Open Fractures of The Long Bones of The Lower Extremities with External Fixation Devices

Backgrоund. In most cases, haematogenic osteomyelitis affects the long bones of the skeleton. Predominantly, the centers of destruction are located in the lower extremities. The orthopedic complications of haematogenic osteomyelitis were observed (according to different data) in 22%71.2% of childhood cases. In 16.2%53.7% of cases, the complications can lead to childhood (nascent) disability. Aim. The purpose of the research is to conduct a retrospective analysis of femoral deformity correction results in children with haematogenic osteomyelitis consequences by applying both an Ortho-SUV Frame (based on passive computer navigation) and following the Ilizarov method. Materials and methods. The study examined 76 patients of both genders aged between 8 and 17 years old who were experiencing the consequences of haematogenic osteomyelitis in the long bones of the lower extremities. A comparative assessment of the parameters reflecting the effectiveness of circular external fixation in combination with an Ortho-SUV Frame and the Ilizarov method was conducted. Reference lines and angles before and after surgery, elongation size, distraction time, deformity correction period, external fixation index, number of complications, and the functional result were all considered. Results. All the children underwent deformity correction surgery, and the length of the afflicted lower extremity segment was reconstructed (restored). The use of the repositioning unit enabled a higher correction accuracy (94.45%) of the femur in comparison with the Ilizarov frame (30%). The frequency of excellent functional results in the first group of patients was more than 1.5 times higher than in the second group, whereas the satisfactory results turned out to be almost twice as low. Fewer complications were observed while using the Ortho-SUV hexapod. Conclusions. The application of the Ortho-SUV Frame at the long-bone-deformity-correction stage facilitates an increase in the efficiency of the circular external fixation method.

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Analysis of the lower jaw exoskeleton in finite element programs

Medical alphabet ◽

10.33667/2078-5631-2021-24-88-92 ◽

2021 ◽

pp. 88-92

Author(s):

D. Yu. D’yachenko ◽

A. A. Vorob’ev ◽

Iu. A. Makedonova ◽

О. N. Kurkina ◽

S. V. D’yachenko ◽

...

Keyword(s):

Finite Element ◽

External Fixation ◽

3D Model ◽

Bone Fractures ◽

Maxillofacial Region ◽

Lower Jaw ◽

Fixation Devices ◽

Bone Fragments ◽

External Fixation Device ◽

Medical University

A special place in the methods of surgical treatment of bone fractures is occupied by transosseous osteosynthesis using external fixation devices of various designs.Objective: to analyze the lower jaw exoskeleton in finite element programs.Materials and research methods. During the research, 36 human lower jaws were involved from the museum of the Department of Oper-ative Surgery and Topographic Anatomy of the Volgograd State Medical University. They were scanned in 3D. All obtained images were loaded into a virtual scene reconstruction program. Fractures of the lower jaws in the corner area were modeled, an apparatus for external fixation of the lower jaw exoskeleton was installed, and the chewing load on the lower jaw was simulated. The place of application of the force was an area on a small fragment of a repositioned 3D model of the mandibular bone corresponding to the place of attachment of the masseter muscle. The evaluation of virtual studies was carried out according to the results of the stress-strain states of the bones and apparatus, the schedule of displacements of objects and the results of the analysis of the safety factor.Research results and discussion. In the course of evaluating the virtual placement of the mini-fixator wires of the apparatus for external fixation of the lower jaw exoskeleton, it was revealed that the main load is applied to the mini-fixator wires on a large fragment and the bone in the area of the wires. For the possibility of precise positioning of the osteofixers of the external fixation device, a device for the safe installation of the spokes of the lower jaw exoskeleton was also developed.Conclusion. Thus, on the basis of computer mathematical analysis, it can be argued that the developed design of the apparatus for external fixation of the lower jaw exoskeleton works under conditions of the maxillofacial region, performs reposition and fixation of bone fragments of the lower jaw under conditions of chewing functioning of the restored fracture of the lower jaw.

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