[Intramedullary Elastic Transphyseal Tibial Osteosynthesis and Its Effect on Segmental Growth].

BACKGROUND: Intramedullary transphyseal elastic osteosynthesis is used in children for the diseases accompanied by the reduced strength properties of bone tissue, and primarily for osteogenesis imperfecta. OBJECTIVE: The purpose of the experimental study was to investigate tibial growth under the conditions of transphyseal counter-directed insertion of elastic rods without bone integrity breaking, under transverse fracture modeling, as well as under combining transphyseal reinforcement and subperiosteal positioning the titanium mesh with the elastic rods intervolved in it. METHODS: Non-randomized controlled trial was performed. Three series of experiments performed in 18 puppies. Counter-directed transphyseal reinforcement of tibia performed in Series I, transphyseal reinforcement combined with transverse osteotomy of leg bones--in Series II, transphyseal elastic osteosynthesis and subperiosteal positioning the titanium nickelide mesh with intervolved in it elastic rods during transverse leg bone osteotomy performed in Series III. RESULTS: Transphyseal reinforcement resulted in growth retardation of the operated tibia. The loss of residual growth was 3.8 mm (p=0.078) in series I; 7.8 mm (p=0.032)--in series II; 7.7 mm (p=0.042)--in series III. Eccentric insertion of transphyseal rods formed an angular deformity (mean value 7°; p=0.023) of the distal tibial epiphysis in the process of residual growth. Periosteal and endosteal reactions contributed to enlargement of diaphyseal diameter of 3.9 mm (series II; p=0.037) and 3.8 mm (series III; p=0.041). Any difference of diameter between operated and intact tibia was not observed in series I. CONCLUSION: Intramedullary transphyseal reinforcement retards longitudinal bone growth. The positioning of the telescopic systems should be as close as possible to the center of growth plates in order to prevent angular deformities. Subperiosteal reinforcement doesn't retard consolidation of fragments, and it can be combined with intramedullary transnhyseal osteosynthesis.

[The effect of tibial transphyseal reinforcement on the growth and response of leg tissues].

Transphyseal reinforcement of right intact tibia performed with thin steel rods in six mongrel dogs at the age of six months. Contralateral segment served as control. The leg growth and blood supply studied under the created conditions for the next six months. Radiographic, physiologic (surface thermometry, photoplethysmography), and statistical methods used for studying. The significant effect of transphyseally inserted rods on the leg longitudinal growth and blood supply has not been revealed. The changes in natural shape-formation oftibial proximal and distal meta-epiphyses observed influenced by the transphyseal rods in the experiment. In order to evaluate the tissue response and the degree of the functional activity of leg bone meta-epiphyseal zones the most informative areas considered to be the following: the area of medial malleolus in the early period of physiological growth completion, and the area of the tibial lateral condyle--at the late stage.

[Calculation of the main parameters of spokes for intramedullary reinforcement of tubular bones].

The goal of this work was to determine the optimal geometric parameters of plastically deformed spokes inserted into the medullary canal during intramedullary reinforcement performed as a part of perosseous distraction osteosynthesis. The results of clinical application of the suggested technique are described.

[Description of rearrangement of distraction reclaim in the extension of the lower extremities and elimination of their deformity in patients with various etiology of shortening].

The data of X-ray and computed tomographic studies of a long tube distraction reclaim were analyzed in 80 patients who had limb shortening and deformity of varying etiology. The analysis has shown that during distraction there is a positive correlation between the increase in the connective-tissue interlayer area of a distraction reclaim and the overall increase in the area of the distraction reclaim (their ratio is not greater than 30% under the optimal elongation conditions). During fixation there is a decrease in the ratio of the area of a growth zone to the total area of a reclaim and in its total density with a parallel increase in the density of cortical laminae of a newly formed bone. Complete organotypic rearrangement comes to the end in the range of 1-3 years depending on the magnitude of pathomorphological and biomechanical changes and limb function.