[Ankle replacement for severe post-traumatic deformation of the distal tibia: a case report]. / Endoprotezirovanie golenostopnogo sustava pri lechenii gruboi posttravmaticheskoi deformatsii distal'nogo otdela bol'shebertsovoi kosti. Klinicheskii sluchai.

OBJECTIVE: To evaluate the immediate results of ankle replacement with original prosthesis in a patient with severe post-traumatic deformation of the distal tibia. MATERIAL AND METHODS: When developing the original design of ankle prosthesis, we considered foreign analogues of classical and revision models of ankle prostheses taking into account their shortcomings. In this case, an integrated approach was used. Extensive work has been carried out to select materials for prosthetic components. Experimental work with mesenchymal stromal cells of bone marrow was aimed at testing cytotoxicity and biological compatibility. The staff of the department of designing biomechanical structures of the Research Institute of Bionics and Personalized Medicine of the Samara State Medical University carefully studied the proposed design of endoprosthesis using the Ansys software. After cadaver tests on full-scale models, we performed surgical intervention in a patient with severe post-traumatic deformity of the lower third of the left tibia. RESULTS: Our studies revealed convenience and certain advantages of intraoperative installation of original ankle prosthesis. Along with this, this clinical example indicated come features that must be taken into account in revision ankle replacement to avoid possible postoperative consequences. CONCLUSION: Original ankle prosthesis makes it possible to replace the distal tibia and preserve limb function.

[Biomechanics of the first metatarsophalangeal joint after replacement]. / Analiz biomekhaniki pervogo plyusnefalangovogo sustava posle endoprotezirovaniya.

OBJECTIVE: Analysis of biomechanics of the first metatarsophalangeal joint after arthroplasty, interaction between bones and two implants of the first metatarsophalangeal joint using skeletal model of the foot. MATERIAL AND METHODS: We developed anatomically adapted all-ceramic non-coupled endoprosthesis of proximal interphalangeal joint between 2016 and 2021. To create a model of the foot, we used diagnostic computed tomography whose images were applied in 3D sculpting system and computer-aided design system for final geometric modeling of the joint. RESULTS: In dorsal flexion of the first metatarsophalangeal joint under 45° with the presence of implant, cortical bone tissue can withstand a load of up to 40 kg. Cortical bone tissue with implant can withstand a load of up to 305 kg without dorsal flexion. Strength of implant elements made of zirconium ceramics significantly exceeds strength of bone tissue within implant-bone tissue connection. CONCLUSION: Postoperative axial load on the first metatarsophalangeal joint up to 35 kg with maximum dorsal flexion up to 45° is the most appropriate. Higher load and hyperextension over 45° may be followed by postoperative complications such as implant instability, dislocation and periprosthetic fracture.

[Postoperative outcomes in patients with closed patellar fractures]. / Rezul'taty operativnogo lecheniya zakrytogo pereloma nadkolennika.

OBJECTIVE: To improve postoperative outcomes in patients with closed patellar fractures using a new method of surgical treatment. MATERIAL AND METHODS: The authors proposed a new method of patellar osteosynthesis. Technique of osteosynthesis is described, and surgical scheme is presented. Treatment outcomes were analyzed in 68 patients with closed patellar fractures. The control group consisted of 34 patients who underwent Weber osteosynthesis. The authors assessed clinical and radiological data. Moreover, clinical example of a patient with traumatic closed patellar fracture and illustrations of surgical treatment are presented. RESULTS: Clinical data indicate the advantage of treatment in the main group.

[Method of surgical treatment of patients with a chronic rupture of the Achilles tendon]. / Sposob khirurgicheskogo lecheniya patsientov s zastarelym razryvom akhillova sukhozhiliya.

OBJECTIVE: To improve treatment outcomes in patients with long-standing Achilles tendon ruptures with severe diastasis and dysfunction of the calf muscle via the use of a new method of surgical treatment. MATERIAL AND METHODS: The authors proposed a new method of Achilles tendon repair for diastasis from 5 to 10 cm. This technique consists in elimination of diastasis with a tendon of the long peroneal muscle on the distal base. Surgical stages are described. The authors also report a patient with long-standing Achilles tendon rupture. Surgical treatment and postoperative outcomes are described. RESULTS: Postoperative outcomes were assessed in 23 patients. The control group consisted of 21 patients who underwent reconstruction according to Chernavsky's and Krasnov's methods. Assessment was carried out using clinical and biomechanical methods. The authors analyzed gait asymmetry and functional myography data. Their data indicate the advantage of treatment in the main group.

[A new method of surgical treatment of patients with chronic distal Achilles tendon rupture]. / Novyi sposob khirurgicheskogo lecheniya patsientov s distal'nym razryvom akhillova sukhozhiliya.

OBJECTIVE: To improve postoperative outcomes in patients with distal Achilles tendon rupture by using of a new method of surgical treatment. MATERIAL AND METHODS: The authors proposed a new method to restore the Achilles tendon for its distal rupture (within 2 cm from attachment to the calcaneus). This approach implies forming a canal in the calcaneus and minimally invasive harvesting of the plantar tendon. At the next stage, the plantar tendon is passed through the canal of the calcaneus in U-shaped fashion and proximal part of Achilles tendon with maximum approximation of its fragments and imposing of interrupted sutures on the plantar and Achilles tendons to hold the position. The end of plantar tendon is used to reinforce damaged area. The schemes and surgical stages are shown in the figures. We reported a patient with distal Achilles tendon rupture and postoperative outcome. RESULTS: An above-mentioned approach was applied in 26 patients. The control group consisted of 21 patients who underwent recovery with anchor fixers. Early and long-term postoperative results, as well as adverse events were analyzed in both groups. Biomechanical parameters of gait were evaluated from the standpoint of evidence-based medicine using podography and functional myography. We confirmed an advantage of treatment in the main group.

[Technology of manufacturing of personalized reconstructive allogenic bone graft (in Russian only)]. / Tekhnologiia proizvodstva personifitsirovannogo rekonstruktivnogo allogennogo kostnogo implantata.

AIM: To develop the technology of manufacturing of reconstructive allogenic bone graft with individual parameters by using of digital prototyping and modeling. MATERIAL AND METHODS: Allogeneic cadaveric bone blocks were used as material. The following methods were used to develop a manufacturing technology for personalized allogenic reconstructive bone implant: harvesting and special preparation of cadaveric material, primary disinfection, viral inactivation, ultrasound management, lyophilization of bone material, CT-examination of patients with various bone defects, digital prototyping and modeling, milling on a machine with numerical program control, X-ray sterilization. RESULTS: The technology of manufacturing of reconstructive allogenic bone graft with individual parameters was successfully tested in the treatment of 24 patients with post-traumatic, destructive-dystrophic and degenerative defects of jaws in 2012-2015. Final reconstructive allogenic bone implant has a personalized 3D-geometry in accordance with individual maxillofacial anatomy of particular patient. One of implant surfaces is fully congruent to the jaw bone defect, the others form the width, height and volume of reconstructive bone implant considering personified maxillofacial features. All above-mentioned features of bone implant are important to restore chewing function of dental system. CONCLUSION: The problem of bone implant personification may be resolved by using of computed tomography followed by digital analysis of jaw structure, technologies for digital reconstruction of bone defects (digital prototyping and modeling) and digital manufacturing.

[Estimated error of bone digital solid 3D-model construction algorithm]. / Otsenka pogreshnosti algoritma postroeniia tsifrovoi tverdotel'noi 3D-modeli kostnogo fragmenta.

The aim of the study was an experimental estimation of precision of maxilla bone digital solid 3D-model construction algorithm. The experiment was carried out on 12 mutton mandibles used 3D-model construction based on CT data. Estimated error was calculated for each of the stages of proposed processing algorithm including 3 software: ScanIP (triangle mesh calculation, primary solid 3D-model), ArtecStudio 9 (secondary procession for artefacts elimination), ZBrush 4R6 (triangle mesh simplification, final 3D-model). The proposed algorithm provides satisfactory precision for solid 3D-model with individual maxillary bone features.

[New surgical method for chronic rupture of the Achilles tendon]. / Khirurgicheskoe lechenie patsientov s zastarelym razryvom akhillova sukhozhiliia.

AIM: To improve the outcomes in patients with chronic ruptures of the Achilles tendon followed by advanced diastase and reduced function of the gastrocnemius muscle by using of new surgical method. MATERIAL AND METHODS: The authors proposed a new method of Achilles tendon repair for diastase over 10 cm. It imposes transposition of the tendons of short fibular muscle and posterior tibial muscle. Schemes and stages of surgery are presented in figures. The authors described clinical example of patient with chronic rupture of the Achilles tendon, illustrations of surgical stages and the outcome. RESULTS: New surgical approach was applied in 16 patients. The control group consisted of 21 patients who underwent repair by Chernavsky, Krasnov. Clinical and biomechanical methods were used for evaluation. Functional myography and podography to assess the asymmetry of gait were performed. Our data confirmed the advantage of new approach.

[Preclinical tests of additive materials for personified endoprostheses of hand joints]. / Doklinicheskie ispytaniia additivnykh materialov dlia izgotovleniia personifitsirovannykh éndoprotezov sustavov kisti v éksperimente.

AIM: To evaluate the biocompatibility of additive materials for personified endoprostheses of hand joints in vivo. MATERIAL AND METHODS: We tested a material based on titanium that was implanted into muscles and bone tissue in experiment on rabbits. Follow-up was 30 and 90 days. RESULTS: Implantation into muscle tissue is accompanied by reaction against foreign body followed by fibrosis without concomitant inflammation. Induction of osteogenesis and trabecular structures remodeling were detected after implantation into bone tissue. CONCLUSION: Biocompatibility of tested titanium-based material was confirmed.