Introduction. In the year of anniversaries of two leading national centers for traumatology and orthopedics, the authors analyzed the main problems and current challenges in specialized trauma and orthopedic care (TOC). Historical parallels in the development of TOC in our country and its problems and trends abroad motivated the authors to conduct an analysis while the need for their comparative assessment determined the purpose of the work which is a brief analysis of the organizational model of TOC and substantiation of a "3DT" concept as a contemporary organizational model of trauma and orthopedic service in the Russian Federation.

Results and discussion. The analysis of current trends in the trauma and orthopedic (TO) service showed its variability over the past three decades. However, the original organizational structure of specialized TO care remained almost the same. A comparative assessment of organizational models has shown that the models for providing specialized care in developed countries are extremely diverse. The availability of assistance does not depend on the population density and tariffs even in the regions of developed countries. In addition, the monetary assessment of treatment of spinal pathology, as an example, has not been standardized and harmonized across countries and regions. It is also important to evaluate the steady increase in high technology care with the use of more developed systems of diagnosis, treatment, rehabilitation and, accordingly, its growing costs. The challenges that our specialty faces may be conditionally divided into technical, socio-economic and organizational ones with the need to create a clear vertical structure of organization, control and referral of patients with organizational decisions for selection of patients with a TO profile according to flows within various areas of subspecialties, the need for justification and feed-back control of financing systems for various types of TO assistance. The challenges described above motivated us to propose a new “3DT” organizational concept as a basis for a more stable and understandable model for the functioning of the national trauma and orthopedic service. The proposed basic model includes 4 direction sectors: D1 (pediatric diseases of the musculoskeletal system and their outcomes); D2 (degenerative and involuntary pathology of the musculoskeletal system); D3 (destructive diseases of the musculoskeletal system of tumor or infectious origin); T (trauma of the musculoskeletal system and its consequences), that all have fundamentally different approaches to organization and planning. The main requirement for the model is its simple application by all participants directly or indirectly involved in the provision of care: orthopedic and trauma specialists, doctors of other specialties, authorities and financial institutions, patients, their relatives and patient communities.

Conclusion. The advantages of the 3DT model lie in the possibility of extrapolating this concept to any region of the Russian Federation, taking into account the difference in their resources. The integral criterion of its effectiveness may be the assessment of the development of these areas as a whole, rather than separate types of assistance. In each sector, it is necessary to indicate the basic, additional and optional amount of assistance. All regions must have the basic level, while the state funding of additional and, moreover, optional assistance should not be carried out without providing the basic one.

Clinical guidelines are an algorithm adapted for use in our country, based on the works systematized by the level of evidence, reflecting current approaches to the diagnosis and treatment of aseptic bone necrosis (osteonecrosis) of various localizations. Purpose of the study. Creation of an algorithm for diagnosis and treatment of osteonecrosis based on the assessment of the evidence level of literature data.

Material and methods. The Guidelines are a systematized algorithm based on the level of evidence for the management of patients with osteonecrosis, reflecting current approaches to diagnosis, treatment and rehabilitation, which are based on literature data and the authors' own experience. Electronic databases of Medline, Embase, Web of Science, and Cochrane Library platforms were searched for related sources. Preference was given to the works with high levels of evidence. References to information sources are given in the order of their appearance in the text. The search depth was 50 years due to the availability of systematic literature reviews in the framework of previous international clinical guidelines. When specific medical procedures related to the diagnosis, conservative or surgical treatment of osteonecrosis were included in the clinical recommendations, their level of evidence was reliability, the appropriateness of their use, taking into account the unified scale for assessing the quality of evidence and the strength of the recommendations for application of medical technologies GRADE.

Results. The Guidelines reflect aspects of clinical, instrumental and laboratory examination of patients with osteonecrosis, treatment options depending on the location of the process and disease stage.

Conclusion. Clinical recommendations on the medical assistance to patients with aseptic osteonecrosis have been compiled according to the requirements imposed on clinical recommendations developed by medical professional non-profit institutions.

Introduction. Surgical treatment of patients with tissue defects of the scalp and face is challenging for surgeons. It is an integral part of the social and labor rehabilitation of such patients. Exposure of the skull bones after extensive polyetiological resections creates a difficult task for reconstruction of complete or partial loss of soft tissues of the head. Autologous dermoplasty, simple in its technical implementation, is impractical on the bones of the facial and cerebral skull because insufficient vascularization of the wound bed creates a risk of early rejection of the graft.

The aim of the study was development and evaluation of the effectiveness of the method of restoring the integrity of the skin of the head and face inh extensive defects with exposure of the bones of the skull.

Materials and methods. Аnalysis of the methods and results of reconstructive surgical treatment of three patients with extensive defects in the tissues of the scalp and face at the Research Institute of the Ochapovsky Regional Clinic Hospital No.1 in 2018-2020.

Results. The immediate result of surgical treatment was a complete restoration of the skin with the maximum possible preservation of underlying deep anatomical structures after a radical one-step removal of non-viable tissues, both soft and bony. Subjectively, the patients were satisfied. The aesthetic result obtained in all cases satisfied both the patients and the surgical team.

Conclusion. The treatment of extensive defects of the soft tissues of the face and bones of the skull is a doable task, provided certain conditions are met. Removal of the affected tissues with simultaneous plasty of the resulting wound defect with a autologous greater omentum and skin autografts allows one to simultaneously solve the problem of plastic closure of wound defects of such localization. When performing osteonecrectomy of the outer cortical plate of the skull to the bleeding layer, conditions are created for survival of a free skin autograft on the bone.

Introduction. Detachment or sharp gross prolonged displacement of the skin, subcutaneous fatty tissue from the underlying fascia over more than 1 % of the body surface with disorders of blood supply to these and sometimes underlying tissues results from high-energy mechanical action of various moving objects and force applied at an angle.

Purpose to develop a classification of integumentary tissue detachments based on the variety of clinical types, severity, extent, combination of injuries with a possible quantitative assessment of their severity and extent.

Methods. Analysis of the literature and our own experience of treating 40 patients with detachments of integumentary tissues enabled to identify criteria for classifying patients into groups.

Results. A classification and rating scales were developed that reflect the area, depth of tissue damage, localization, general condition of the patient and the stage of the pathological process.

Discussion. The analysis of the literature on this topic showed that, to date, none of the proposed classifications is optimal. There is no clear definition of the area of compromised integumentary tissues relative to the entire surface of the human body. The issue of pathological process staging has not been reflected; damage and crushing of bones, muscle tissue, neurovascular formations have not been reflected; there is no clearly formulated algorithm for treating a patient depending on the stage and severity of tissue damage.

Conclusion. Application of the classification of integumentary tissue detachments which has been proposed enables to more objectively assess the nature of local tissue damage, taking into account t he general condition of the patient.

Objective. To review outcomes of the proximal femur fractures repaired with half-pin apparatus in comparison with various types of osteosynthesis.

Material and methods. The study enrolled 86 patients with proximal femur fractures treated at the general hospital of the Tashkent Medical Academy. Of these, 52 were females and 34 were males. The mean age of the participants was 54.1 ± 1.1 years (range, 22 to 92 years). The effectiveness of the treatment was evaluated depending on the treatment method used. The patients were divided into 3 groups: group I included 39 patients who underwent closed percutaneous osteosynthesis with Ilizarov wires; group II consisted of 29 patients who underwent osteosynthesis with bone plates; group III included 18 patients who underwent surgical treatment using the external half-pin fixator we developed.

Results. Outcomes were evaluated in 58 patients at one to two years. In group I, good results were rated as good obtained in 45.8% (n = 11), as fair in 33.3% (n = 8) and poor in 20.9 % (n = 5) of patients due to nonunited fracture, avascular necrosis of the femoral head and hip joint ankylosis. Group II showed 68.4 % (n = 12) good, 4 (21 % (n = 4) fair and 10.5 % (n = 2) poor results. The latter occurred due to patient noncompliance and unauthorized early removal of the plaster cast. Group III demonstrated 73.4 % (n = 11) good, 13.3% (n = 2) fair and 13.3 % (n = 2) poor outcomes. Patients with poor outcomes developed lesion of the femoral neck following a subcapital femoral neck fracture at 2 months of frame removal that healed with a 2.0 cm limb length discrepancy.

Conclusion. The external half-pin fixator offered could facilitate stable bone fixation after reduction and gradual dynamic compression for successful bone healing. The bone fixation period with external half-pin fixation device was dependent on the fracture type and averaged to 4 ± 1 months in type A fracture and 5 ± 1 months in type B fractures. Fixation of the proximal femur fractures with half-pin fixation device allows stabilization of the general state of patients, easier postoperative care, prevention of secondary complications and early exercises for the adjacent joints. The technique offered can be a method of choice among the current technologies

Introduction. Humeral fractures comprise from 5 % to 8 % of all fractures. Nonunion rate of humeral fractures is 5.5–8.7% with open reduction and internal fixation (ORIF) technique and 3–5.6 % with the use of locked intramedullary nailing technique. Its frequent causes are infection, poor vascularity, severe comminution or technical errors. Purpose Analysis of effectiveness of vascularized bone grafting and non-vascularized bone grafting in humeral nonunion and defect treatment.

Material and methods. Surgical management of 69 patients with humeral nonunion was performed from 2010 to 2017 at a single institution in two groups. Vascularized bone grafts were used in 41 cases and non-vascularized ones in 28 cases. X-rays and CT-scans of all the patients were studied.

Results. In the vascularized bone grafting group, union was achieved in 36 cases (88 %) after four to 6 months; in non-vascularized bone group union was achieved in 20 cases (71 %) after eight to 12 months.

Conclusion. In post-traumatic humeral nonunion and bone defects, after two or more failed surgical procedures performed previously, vascularized bone grafting yields more satisfactory results and reduces the total healing time.

Purpose. To determine the effect of biometrical parameters of the radial bone and due to edge defect formed on the radius strength properties using calculation methods.

Materials and Methods. The study of bone strength affecting factors was conducted with the aid of experimental and calculation methods. Biometrical parameters were studied in 10 pairs of the human cadaveric radius as an intact bone initially and after the formation of rectangular or triangle-shaped edge cuts. To determine the stress-strain behaviour, mathematical calculations were performed based on the beam flexural theory for isotropic materials. Computation study were conducted using the finite element method with the NX Siemens software package. Based on assumed mathematical models, the actual areas of safe loads in the presence of cuts and values of destructive loads depending on the depth and shape of a cut taking into account the initial curvature of the bone as well as the criteria of a required residual strength in variation of influencing parameters were identified by means of calculations.

Results. It was established that an increase in bone curvature results in the reduction of longitudinal destructive loads and in increasing values of the normal strength. The 0.05 bone curvature combined with the 0.5 cut causes a decrease in the ultimate load by 20 times (up to 4.8 % for a rectangular cut and to 5.4 % for a triangular cut). A 0.5-deep cut in the bone which curvature is 0.05 enhances the normal stress by 6.9 times for a triangular cut and by 7.8 times for a rectangular one as compared to a bone without curvature. The critical values for the curvature and depth of the cut were established which permit to avoid additional bone reinforcement.

Conclusion. The strength of the radius with a maginal defect depends not only on the depth of a cut but on its location, shape and on the radius curvature

Objective. To compare outcomes of non-union in forearm fractures treated with the use of a comprehensive surgical approach considering the injury pattern and localization.

Material and methods. Based on treatment approaches the cases were categorized into 3 groups with proximal forearm fractures (group I, n = 28; 33.8 %), mid-shaft and distal forearm fractures (group II, n = 32; 38.5 %), and controls (group III, n = 23; 27.7 %). Group I included patients with hypertrophic nonunion (HTNU) of the forearm bones treated with bone graft and plating. Group II consisted of atrophic nonunion, HTNU of the forearm bones repaired with the Ilizarov external fixation. A single 3 mL local injection of autologous bone marrow and a kukumazim solution of 50 PU were used to induce bone fusion in the patients of the two groups. The control group included non-unions with no considerations to the fracture pattern and localization. All patients underwent physical, radiological examinations and laboratory tests.

Results. The control group showed 8.7 % poor and 69.5 % good outcomes at a long term, whereas 3.6 % results were rated as poor and 82.1 % as good in group I, with 3.1 % poor and 87.6 % good outcomes in group II. The ratings can be associated with a differentiated surgical approach considering the injury pattern and localization, the use of kukumazim proteolytic enzymes and autologous bone marrow injection.

Conclusion. Optimization of surgical treatments and considerations for injury pattern and localization allowed for a 2.8-time (3.1 %) decrease in poor outcomes and a 30 % reduction in the limb immobilization period.

Hip osteoarthritis (OA) is an important public health issue. Nonsurgical treatments including changes in lifestyle, physiotherapy, pharmacological therapy can be effective for patients with coxalgia at early stages of hip osteoarthritis.

Objective. To evaluate the effectiveness of percutaneous radiofrequency (RF) denervation (neuroablation) of articular sensory nerves of the hip joint for pain relief in patients with chronic hip pain.

Material and methods. The review included 46 patients (47 joints) with hip OA who were classified as Kellgren-Lawrence grade 3 (n = 37) and Kellgren-Lawrence grade 4 (n = 9). Quantitative and qualitative assessment of pain was produced with VAS scale. The Harris Hip Score (HHS) was used to measure functionality. All patients underwent radiofrequency ablation of the articular branches of the femoral and obturator nerves. The results of treatment were evaluated at 2 weeks, 1, 3, 6 and 12 months.

Results. VAS scores showed significant pain relief immediately after the procedure that persisted in 69.5 % of patients at 6 months and in 56.5 % at 12 months with 43.5% of patients reporting dissatisfaction. HHS scores demonstrated improved quality of life in 85.2 % of patients at 6 months, with patient satisfaction recorded in 58.6 % at 12 months, and 41.3 % reported significant deterioration.

Conclusions. Percutaneous RF denervation of articular sensory nerves of the hip joint was shown to be effective for pain relief in patients with severe hip OA at a short term (up to 6 months). The technique can be recommended for patients who have contraindications to hip replacement surgery.

Introduction. Progressive multiplanar static deformity of the forefoot can result in hallux valgus, metatarsus primus varus, transverse flat foot and associated overload of the metatarsophalangeal joints (MTPJ) with plantar plate degeneration and rupture of MPT joints of the lesser toes leading to hammertoe deformity. Diagnostic ultrasound in the identification of plantar plate tears is easy to use at any medical center of the Russian Federation with orthopaedic services and provide a relatively inexpensive option compared with other advanced imaging modalities.

The goal was to present ultrasound technology for accurate evaluation of the severity of plantar plate injury which may provide guidance for surgical treatment of hammertoe deformity of the lesser toes in patients with multiplanar static forefoot deformity.

Material and methods. The study recruited 88 participants with multiplanar static deformity of the forefoot, who underwent ultrasound evaluation according to the original method (RF Patent No. 2699383 "Method for determining the type of degenerative rupture of the plantar plate of the metatarsophalangeal joint due to overload metatarsalgia”) to objectify the results of a physical examination with the Hamilton-Thompson test performed for identifying the degree of instability of the MTPJ, and nonparametric analysis was produced with Pearson's Chisquare test.

Results. Evaluation of the severity of plantar plate injury in the study group of patients (n = 88) with the Hamilton-Thompson test and ultrasound imaging showed diagnostic error in 22.8 % of cases with the use of clinical methods that allowed reasonable reduction of surgical intervention in 2.3 % and substantial correction of the treatment approaches in 20.5 % preventing a complete plantar plate tear.

Discussion. The ultrasound scanning introduced in the algorithm for diagnosing the degree of plantar plate rupture facilitated an objective approach to the choice of the most appropriate treatment strategy for complicated multiplanar forefoot deformities accompanied by a non-rigid hammertoe deformity of lesser toes. Conclusion Preoperative ultrasound imaging of the plantar surface of the foot for detecting the severity of plantar plate injury should be included in the diagnostic algorithm for patients with complicated multiplanar forefoot deformities accompanied by a non-rigid hammertoe deformity of lesser toes.

Introduction. To date, there is no unified approach to the choice of tactics in surgical treatment of osteoarthritis of the first metatarsophalangeal joint (OA of the first MTP joint). On the other hand, it is known that the technique of autologous matrix-induced chondrogenesis has been successfully used for osteochondral defects in the hip, knee and ankle joints. Therefore, we have proposed to use this technique in the treatment of patients with OA of the first MTP joint.

Purpose. To study the possibility of surgical treatment of patients with OA of the first MTP joint with the use of chondroplasty utilizing the technique of autologous matrix-induced chondrogenesis, to demonstrate the immediate and mid-term results of such operations.

Materials and methods. Chondroplasty was performed in 15 patients (16 feet) with OA of the first MTP joint. The examination determined the range of motion in of the first MTP joint; the condition was assessed according to such scales as VAS for pain, AOFAS, FFI. Chondroplasty in of the first MTP joint was performed with the technique of induced chondrogenesis using a collagen matrix. The results of the operations were evaluated after 3, 6 and 12 months.

Results. As early as 3 months after the operation, there was a marked significant increase in the range of motion and a decrease in pain of the first MTP joint. Moderate positive dynamics were observed after 6 and 12 months.

Conclusion. The results of the operations showed that chondroplasty of the first MTP joint is an effective method of surgical treatment that provides pain relief and significantly improves the quality of life of patients with OA of the first MTP joint. However, it is necessary to study long-term results.

Introduction. Implant instability with the formation of bone defects is one of the complications after primary osteosynthesis and joint arthroplasties. Augments and reinforcing constructs made of titanium with a porous coating have been used for bone defect management in addition to osteoplastic materials. Additive technologies in traumatology and orthopedics for extensive defects in bones and joints have been applied when it is impossible to use standard designs.

The purpose of the study was to evaluate short-term results and perspectives of using additive technologies for bone defects after failed joint arthroplasties and osteosynthesis.

Materials and methods. In 2018 to November 2019, seven patients with lower extremity bone defects underwent treatment at the Department of Traumatology and Orthopedics of the Moscow Regional Research and Clinical Institute with custom-made implants fabricated with additive technologies. The operations were carefully planned using CT scans, 3D modeling, and implant printing. Particular attention was paid to clean the implant from residual metal powder. Patients were distributed depending on the type of defect and the operation performed (arthroplasty, revision arthroplasty).

Results. The short-term results of using customized implants were analyzed in this study. The average Harris hip score before surgery was 37.8 points, and after the surgery it was 80.2 points. Pain after surgery in all patients was also evaluated by Harris scale and was 37.1 points; the functionality of patients after surgery was 38.4 points. The custom-made designs have a number of distinguishing advantages against the standard ones. A customized anatomical design provides easier fixation; ergonomic design allows implant retention without removing metal fixators if exist; there is less soft tissue injury during surgery (allinside principle); and convenient bone grafting around the implant.

Conclusions. The use of additive technologies for bone defects improves the functional results and life quality of the patient. At the moment, practical application of 3D designs has a number of limitations in financial and legal support in practical health care. Further implementation of additive technologies in traumatology and orthopedics will be supported by the grant from the President of the Russian Federation.

Introduction. The paper presents a comparative analysis of one-stage treatment of chronic osteomyelitis using tobramycin-impregnated calcium sulfate and β-tricalcium phosphate mixed with antibiotics impregnated hydroxyapatite to fill in the cavitary defect of long bones.

Material and methods. The retrospective group (group 1, n = 34) was treated with tobramycin-impregnated calcium sulfate (Osteoset T), and the prospective group (group 2, n = 25) received β-tricalcium phosphate mixed with antibiotics impregnated hydroxyapatite (ReproBone).

Results and discussion. There were no significant differences between the groups of patients by gender, age, type of osteomyelitis and duration of the disease. The differences in the operating time, intraoperative blood loss and the size of the cavitary bone defect post debridement were not significant between the groups. There were no significant differences in preoperative level of CRP between the groups, with CRP being higher (p = 0.02) in group 1 than in group 2, prior to the discharge from the hospital. Recurrence was seen in 35 % (n = 12) of group 1 and in 16 % (n = 4) of group 2 at a 21/2-year follow-up. The risk of recurrence was found to be 2.2 times greater with use of commercially available biocomposite loaded with tobramycin that that with β-tricalcium phosphate mixed with hydroxyapatite (HR 2.206; CI 0.806-6.038) impregnated with antibiotics administered with preoperative microbiological findings.

Conclusion. Combined β-tricalcium phosphate based biocomposites mixed with hydroxyapatite impregnated with broad-spectrum antibiotics showed greater efficacy for methicillin-resistant staphylococcus aureus in the treatment of chronic osteomyelitis filling cavitary bone defect of long bones as comp ared to tobramycin-impregnated calcium sulfate.

Introduction. Anterior cruciate ligament (ACL) reconstruction with quadrupled hamstring tendon autograft is a safe and reproducible surgery with good functional outcomes. Currently there is no consensus on capability of graft diameter planning.

Objectives. To investigate the influence of anthropometric data and cross-sectional area of semitendinosus (ST) and gracilis (GR) tendons according to preoperative magnetic resonance imaging (MRI) on intraoperative graft diameter.

Material and methods. The study included 111 consecutive patients (69 men and 42 women), who underwent ACL reconstruction with quadrupled hamstring autograft between 2015 to 2018. Height, weight and BMI were recorded in all patients preoperatively. Semitendinosus and gracilis tendons cross sectional areas (CSAst and CSAgr, respectively) were evaluated on preoperative MRI axial images. We also calculated doubled and quadrupled graft diameters (CSAst+gr and CSA4p, respectively) based on obtained MRI data. Collection of intraoperative data included length of each tendon separately, length and diameter of the resulting autograft. We used linear regression and Pearson correlation coefficient were used. The crosssectional areas were correlated to antropometric and intraoperative data. Using logistic regression, we determined the probability of obtaining a graft diameter of ≥ 7.5 mm. A critical level of statistical significance was set as 5 % (p ≤ 0.05).

Results. The median age accounted 37.4 ± 0.89 (13–58) years, height – 174.6 ± 0.84 (156–200) cm, weight – 78.5 ± 1.52 (45–120) kg, BMI – 25.6 ± 0.37 ( 18.49–41.5). Intraoperatively GR average length was 224.7 ± 3.06 (80–340) mm, ST – 256.3 ± 2.97 (160–340) mm, quadrupled graft – 111.3 ± 1.42 (80–140) mm. The most common graft diameter was 7 mm in females and 7.5 mm in males. We found strong positive correlation between graft diameter and CSA4p, СSAst+gr, CSAst, weight and height. Linear regression showed that graft diameter was influenced by CSA4p, СSAst+gr, CSAst and height. If CSA4p was ≥ 72 mm2, the probability of obtaining a graft of ≥ 7.5 mm at the time of surgery reached 90.6 %.

Conclusion. CSA4p may be used as a predictive characteristic for graft diameter preoperative planning.Our findings show that graft diameter was mainly influenced by height, СSAst+gr, CSAst and CSA4p.

Introduction. Herniated disks are very common. Percutaneous endoscopic lumbar spine surgery for the lumbar disc herniation facilitates minimalized access ports to the operating site with decreased risk of infection, reduced blood loss and less tissue dissection and muscle trauma.

The goal was to compare the results of standard transforaminal endoscopic discectomy for lumbosacral herniation and outcomes of the procedure added by nucleoplasty.

Material and methods. Percutaneous transforaminal endoscopic discectomy was performed for 92 patients and added by nucleoplasty in 43 patients of group I. Preoperative and postoperative evaluation was produced with the Visual Analog Pain Scale (VAS), the Oswestry Low Back Pain Disability Questionnaire (ODI) and the MacNab clinical outcome score. Complication and recurrence rate was reviewed. Microsoft Office Excell and Statistica 8.0 were used to complete data analysis reports.

Results. VAS scores decreased from 7.9 to 3.1 showing 2.5-fold decrease (p less 0.05), and ODI scores decreased from 71.09 to 18.58) (p less 0.001) demonstrating fourfold decrease at one-year follow-up. There were no significant differences in VAS and ODI scores between the groups preoperatively and postoperatively (p > 0.05). The majority of patients of group I (41.86 %) rated their health status as excellent on the MacNab scale, and the majority of patients of group II (53.06 %) rated their health status as good. Postoperative complication rate was 11.63% in group I and 12.24% in group II (p > 0.05). There was no recurrence in group I with the recurrence rate of 6.1% (p less 0.001) in group II.

Conclusion. Endoscopic discectomy for lumbosacral herniation supplemented with nucleoplasty can reduce the recurrence rate.

Relevance. Defects of long bones result in anatomical and functional complex of pathologies in the entire limb. There are few fundamental studies of tissues adjacent to bone defects by using different technologies for management of long bone defects.

Purpose. To study the structural changes in the synovial membrane of the knee joint by modelling the conditions for tibial defect management using the Ilizarov method of non-free bone plasty in combination with the Masquelet technique.

Materials and methods. The conditions of post-resection defect of the tibia (from 15 % of the segment length) by lengthening the distal fragment were modeled in ten mongrel dogs. Temporarily, for 30 days, a cement spacer was implanted into the post-resection defect gap. Upon its removal, the intermediate fragment in the lower third of the leg was transported at a rate of 1 mm in 4 steps until complete contact of the bone fragments. Histomorphometric studies of the synovium were carried out at the observation stages at the end of the fixation period (60 days) and after removing the apparatus (30 days).

Results. Two types of changes were revealed in the synovium: changes of a destructive nature without synovitis (30 % of cases) and with signs of synovitis (70 % of cases, 3 dogs had mild synovitis and 4 dogs had severe synovitis). Changes in the microvessels of the synovial membrane in synovitis indicated impaired microcirculation, high activity of angiogenesis and the development of hypervascularization.

Conclusion. Experimental management of the tibial bone defect by Ilizarov method in combination with the Masquelet technique revealed signs of synovitis of the knee joint in 70 % of cases using histophorphometry methods.

Full-thickness skin grafts are used in reconstructive surgeries.

Objectives. Experimental study of the possibility of long-term preservation of viable skin grafts in severely impaired trophics at remote interaction with entities having stratiform periodic structure.

Material and methods. Full-thickness skin was excised from the rabbits' backside and dissected into explants sized 1.0 × 1.0 cm. The samples (n = 81) were divided into three groups and thermostated for 2 days at 37 °C at a various distance from the metal (aluminum) presented as a 20-layer package of smooth foil forming a stratiform periodic structure (SPS) (series I), chaotic layers of squeezed foil (series II) and a single-piece sheet (series III). Histological analysis was performed for the three series to evaluate the explants' viability after the thermostating.

Results. The highest survival estimates were seen in experimental explants of series I that interacted with the SPS of stratified foil layers. The wave nature of such remote interaction was suggested with delayed dystrophic and necrotic processes developing in the skin samples. Experimental samples of series III appeared to be less viable. The explant vitality in series II was sharply reduced due to rapidly spreading necrosis.

Conclusion. Skin explants were shown to retain viability for a longer time when interacting remotely with stratiform periodic structures in the absent trophics. These promising results can be practical for the development of wound dressings to improve survival of full-thickness skin transplantation in reconstruction of deep skin defects.

Objective. To evaluate the informative value of the carrier status for allelic variations that determine the sensitivity of tissues to calcitriol (VDR) and are involved in familial thrombophilia and hypofibrinolysis (PAI-1) as molecular genetic markers of avascular necrosis of the femoral head (AVNFH).

Material and methods. A clinical and laboratory study of 300 AVNFH patients, residents of European Russia, was carried out. A comparative analysis of the alleles and genotypes frequency distribution of polymorphisms rs11568820 and rs1544410 of the VDR gene, as well as rs1799889 of the PAI-1 gene in AVNFH patients was performed.

Results. AVNFH patients showed a significant increase in the frequencies of the G/G genotype (P = 3.0E-9) and the G allele (P = 0.05) of the rs11568820 VDR polymorphism (P = 2.10E-08) as compared to controls. The frequency of the A/A genotype of the rs1544410 VDR locus in AVNFH individuals was higher than that in controls (P = 0.05).

Discussion. Carriers of the genotype G / G A-3731G (Cdx2) of the VDR gene were shown to have a 2.1-fold increased risk of developing AVNFH; carriers of the G allele appeared to have a 2.3-fold increased risk of AVNFH. The findings showed that the carriership of the 5G allele of the polymorphic locus PAI-1 -675 4G > 5G (rs1799889) is detected 1.4 times more often in AVNFH patients than in individuals from the population sample. The risk of developing the pathology is increased 2 times with the carriership of the 5G/5G genotype of this polymorphic locus.

Conclusion. Carriers of genotypes G/G rs11568820 VDR (allele G), A/A rs1544410 VDR and 5G/5G (allele 5G) at the polymorphic locus rs1799889 PAI-1 have an increased risk of developing AVNFH. This allows the use of the molecular genetic markers in the early diagnosis of AVNFH in individuals who are at greater risk for the disease.

Introduction. Multiple myeloma (MM) is a malignant tumor that causes widespread bone damage. The bone is involved in 90 % of MM patients, and 60% of patients develop pathologic fractures.

Material and methods. We report a case of combined surgical treatment and chemotherapy of a multiple myeloma patient who sustained a pathological diaphyseal fracture of the left femur and later presented with a lytic myeloma lesion in the right femur. Closed reduction and interlocking intramedullary (IM) nailing of the left femur was performed for the patient who was diagnosed with bone destruction in the shaft of the right femur a few months later. The right femur was fixed with interlocking IM nail for prophylaxis.

Results. The left femur consolidated at 6 months. The patient had no pain in the right femur, and enlargement in the bone destruction was not seen in the femur. The patient could ambulate with a cane with signs of deforming arthritis in the adjacent joints of the lower limbs.

Discussion. Three common surgical approaches used for bone tumors being complicated or not complicated by a pathologic fracture include nailing/plating, bone replacement and joint arthroplasty. Bone tumor replacement with oncological endoprostheses can be produced in specialized oncological orthopaedic units and is not available with regular trauma and orthopaedic services for different reasons. The operating orthopedic surgeon is to choose the appropriate implant to address the tumor involvement.

Conclusion. Interlocking IM nailing can be the method of choice for a pathologic fracture or for prophylactic bone fixation with appropriate indications identified with the Mirels's scoring system. Intramedullary nailing offers the advantage of minimally invasive stability for the operated limb and early weight-bearing in contrast to plate fixation treatment for fractures and prophylactic plating.

Introduction. Aseptic necrosis of the femoral head (ANFH) is a severe disease most commonly associated with previous trauma, alcohol intake, administration of corticosteroids or blood diseases. Early diagnosis is difficult, there is no conservative treatment protocol with proven effectiveness, and the organ-preserving surgical treatments which have been used may not always postpone hip arthroplasty. Arthroplasty provides good results in the short and long-term postoperative period, but the prevalence of this disease among young people requires developing new methods of conservative and operative treatment.

Objective. To determine the problems of diagnosis and treatment of aseptic necrosis of the femoral head; to study the experience of current approaches and concepts in the diagnosis and treatment of ANFH; determine the range of the most effective methods for treating this pathology; to establish the relevance of further research on this issue.

Materials and methods. Literature review was conducted of the sources from PubMed and Google Scholar databases. The material was selected that corresponded to the stated purpose of the research topic. For describing some aspects of the aetiology, pathogenesis and development of methods for diagnosing and treating ANFH, earlier publications (2009–2014) were also used.

Results. The main views on the aetiology and pathogenesis of ANFH have been studied. Classical and current diagnostic methods for ANFH were reviewed as well as current operative and conservative approaches to the treatment of this pathology. A review of the main classifications was conducted.

Discussion. Early detection and examination of at-risk patients plays an important role in the diagnosis of ANFH. The results of clinical trials on the use of bisphosphonates seem mixed, as the meta-analysis in five randomized clinical trials (RCTs) in 2016 showed no statistically significant improvement in patients with ANFH. Hyperbaric oxygenation reduces interstitial ischemia by increasing extracellular oxygen concentration and shows encouraging results. Core decompression is recognized as the standard care in the early stages of ANFH. At present, the use of combined treatment with bisphosphonates, core-decompression and mesenchymal stem cells has been investigated. Combined therapy may be effective in slowing the progression of collapse at an early stage of ANFH, but further research is needed to have long-term results.

Conclusion. Aseptic necrosis of the femoral head is a severe polyetiological disease that has not been sufficiently studied. For its diagnosis, it is necessary to take into account the possible risk factors and to ensure an early MRI study. At present, there is no data on a conservative method of treating the early stages of ANFH, which would have high evidence and effectiveness not only in the immediate, but also in the long-term follow-up. It is necessary to conduct additional prospective randomized clinical trials to determine the effectiveness of already known and developed methods of cell therapy in the treatment of ANFH.