Results of roentgen morphological, histochemical, electron microscopic and electron autoradiographic studies of reparative osteogenesis in the conditions of distraction osteosynthesis are given. The data of literature concerning cellular sources of bone tissue and mineralization peculiarities of distraction regenerates are analysed.

Using a method of mathematical modelling it is established, that correction of leg flexion position about the axis, passing through the centre of fibular head, is the most rational way in patients with tibial aplasia. One has occasion to run into the congenitally shortened rigid soft-tissue component only, while correcting leg improper position in patients with tibial aplasia. Its rheological properties allow leg extension with higher daily rate of distraction - 5-6 mm. Clinically it is necessary to calculate Rb/Ra value after their measurement in apparatus-limb system preliminarily after the apparatus application for the purpose of distraction rate determination.

Medical-and-technical procedures, used in treatment of calcaneal fractures with the Ilizarov apparatus, are described in the work. The calculations are given, which substantiate use of these procedures from biomechanical points of view.

14 patients with osteomyelitic involvement of calcaneus were examined, using "Somatom AR-HP" roentgen computer tomograph of the Siemens firm: 14 patients before surgery and 3 patients - in the immediate and long-term postoperative period. The data of CT were used by the authors to work out the classification of calcaneal chronic osteomyelitis, to select treatment technique for patients with chronic osteomyelitis of calcaneus, to evaluate results of treatment.

Summary: We have used numerous methods of transosseous osteosynthesis by Ilizarov in treatment of pathologically changed bones with different localization simultaneously. We have consistently followed the therapeutic schema, applying the methods which has been devised at the Ilizarov School in RNC RTO and making use of the original construction of the Ilizarov apparatus. In our hospital we have treated 102 cases with different pathological changed bones of more bone segments. Mostly of the femur and tibia. Most frequently: false joints, delayed or non union, with or without infection, with or without deformity of the neighboring bone segment, with or without segmental discrepancy and shortening, with or without the foot deformity.
Percent of the bone consolidation: 87-93%;
Percent of deformity correction: 81-91%;
Percent of equalization: 73-89%.

Classifications of talar injuries are systematized and supplemented. In view of character of the latters, techniques of transosseous osteosynthesis with the Ilizarov apparatus are suggested, and peculiarities of controlling its functional units, depending on fracture type and involvement of soft-tissue structures, are described.

According to the data of J. Kolar and B. Drugova (1972), the Becker cyst occurs in 20,8% cases of pathologically changed synovial formations of the knee. S.Y. Doletsky et al. (1989) note, that there are 30% of recurrences in the process of conservative treatment of cysts; as for surgical dissection, there are 5-100% of the cases, which are the most often for multiloculated cysts of the knee. All the above demonstrates current concern of the selected problem to study both for improvement of differential diagnosis of hygromas and cysts of the popliteal fossa and for planning of extent for surgical intervention.We observed 10 patients at the age of 8-64 years with hygromas and cysts of the popliteal region. The Becker cyst was diagnosed in 7 patients, hygroma of the synovial bursa of musculus semimembranosus tendon, using a method of radiopaque arthrography. The formations of the popliteal region were surgically dissected in all the patients. There were no recurrences of the disease.

Some aspects of limb deformities are systematized in the work, as well as classification of the latters is suggested, being of great clinical importance for determination of treatment strategy and tactics to correct multiple segmental bendings.

Results of treatment of limb bone fractures and orthopaedic pathologies in military men, using different techniques of transosseous osteosynthesis, are given in the work. Indications are determined for use of wire devices of external fixation. A device of multidimensional function, put forward by the authors, is described. The analysis of results and complications of treatment, using different devices for transosseous osteosynthesis, is made.

Bone regenerates, which are formed in defects of skull vault bones during transport of pedicle-provided bone fragments in them, are studied experimentally, in adult dogs. The material is studied by transmission and scanning electron microscopy, light microscopy of semithin sections and roentgen electron-probe microanalysis. It is demonstrated, that structure of the bone regenerates, formed in a defect of skull vault bones, has much in common with that of the regenerates, which are formed in the process of fracture healing in long tubular bones and of distraction osteosynthesis. In all the cases they are formed with reticulofibrous bone tissue, cellular source of which is the same - population of low-differentiated perivascular cells, having osteogenic potentials, which grow into diastasis together with vascular terminals and form growth plate of the regenerates. It is established, that spatial organization of the bone regenerates is determined by their angioarchitectonics.

On the basis of the analysis of the materials of VI congress of traumatologists and orthopaedists of Russia (N. Novgorod, 1997) convincing conclusion is drawn in this work about the fact, that there is no alternative to the transosseous osteosynthesis according to Ilizarov in case of such injuries of the locomotor system. The main states are given concerning bone reparative regeneration, being developed by Rusakova-Vinogradova morphologic school, which confirms greatness of G.A. Ilizarov's practical and theoretical discoveries. The method of transosseous osteosynthesis, put forward by him, with out-of-bone arrangement of the fixator, ensuring rigidity of fragmental fixation, necessary for proper bone union, has expressed a high opinion of morphologists, but has not been realized sufficiently in practice of traumatology and orthopaedics for a long time. At present it is used not only by direct apprentices of G.A. Ilizarov's school, but by a large group of surgeons-enthusiasts, dealing with severe injuries of support organs, as well.
The Ilizarov method should become a method of choice for such a category of patients, and organizing measures of the country's health service are necessary for this purpose.

new device for transosseous osteosynthesis of pelvic bone fractures is described in the work; the device offers complete reposition and stable fixation of bone fragments.