Object: the process of bone growth under conditions of temporary bilateral blocking of its growth plate after blocking is stopped. Aim: to improve the results of surgical treatment of children with a moderate difference in the length of the lower extremities by substantiating and clinically testing the method of temporary bilateral blocking of growth plates in the knee joint area. Methods: clinical, radiological, computed tomography, morphological, statistical. For the first time, based on radiological examination it was proved that temporary bilateral blocking of the distal femoral growth plate of rabbits with incomplete skeletal growth with the use of nonblocking and blocking plates during 3–7 weeks does not lead to the formation of secondary frontal angular deformities. X-ray and morphometry show the restoration of the femur longitudinal growth within 3 weeks after the cessation of five- and seven-week temporary bilateral blocking with different types of plates. New knowledge on structural transformations of the distal femoral growth plate (epiphyseal cartilage) of rabbits with incomplete skeletal growth under conditions of its bilateral blocking during 7 weeks using blocking and nonblocking plates was obtained. A gradual decrease in the height of the epiphyseal cartilage and the area of primary osteogenesis was found, reflecting the delay of longitudinal bone growth, and the progression of destructive changes with increasing duration of blocking (impaired histoarchitectonics, changes in cell density, etc.). For the first time, histological examination has determined the complete restoration of the morphological structure of the epiphyseal cartilage and the area of primary spongiosa 3 weeks after removal of the plates (blocking and nonblocking), which were used for temporary bilateral blocking of the distal femoral growth plate of rabbits for 5 weeks. In the case of termination of bilateral blocking after 7 weeks, the structure of the epiphyseal cartilage and, accordingly, the function is partially restored, reflecting the importance of the time factor for application of this method of treatment. It has been found that the use of blocking plates provides more rigid blocking of the growth plate and takes less time to correct leg length discrepancy, which should be taken into account when planning treatment of LLD in children of the older age group, where longitudinal growth is limited by age. The algorithm of leg length discrepancy treatment in children allows to carry out the differentiated choice of method of surgical treatment and to substantiate using the method of temporary bilateral blocking of long bones growth plate in children, which will help to increase the effectiveness of treatment. Using of method of temporary bilateral blocking of the long bones growth plate for the treatment of moderate leg length discrepancy in children is effective and safe, shows good results with a low percentage of complications. Minimally invasive technique for insertion of the plates when using the method of temporary bilateral blocking of the long bones growth plate was improved, which was less traumatic, took less time and had a better cosmetic result (pat. 133982 UA). The results of the study were introduced into the clinical practice of the State Institution "Sytenko Institute of Spine and Joint Pathology of the National Academy of Medical Sciences of Ukraine", the communal institution "Dnipro Specialized Clinical Medical Center for Mother and Child named after Prof. M.F.Rudnev", scientific medical complex "University Clinic" of the Kharkiv National Medical University of the Ministry of Health of Ukraine, as well as in the educational process of the Department of Traumatology and Orthopedics of the Kharkov Medical Academy of Postgraduate Education of the Ministry of Health of Ukraine. Тraumatology and Orthopaedics.
