Endoscopic push through tragal cartilage tympanoplasty: A 10-year retrospective review of our technique and outcomes

BACKGROUND Endoscopic ear surgery(EES)provides a magnified,high-definition view of the otological surgical field.EES allows otologists to avoid surgical incisions and associated postoperative complications.It is an ideal technique for the perfor-mance and teaching of tympanoplasty.AIM To examine the efficacy of total Endoscopic Push Through Tragal Cartilage Tympanoplasty(EPTTCT),at our institution over a 10-year period.METHODS A retrospective analysis of 168 cases of EPTTCT for closure of small to medium tympanic membrane perforations from 2013-2023 was conducted.Patient sex,age range(pediatric vs adult),etiology of injury,success rate,complications,and postoperative hearing status were collected.RESULTS Graft uptake results indicated success in 94%of patients,with less than a 2%complication rate.Postoperative pure tone audiometry demonstrated hearing status improvement in 69%of patients.CONCLUSION EPTTCT has been shown to be effective in tympanic membrane perforation closures with minimal complications.This study further demonstrates the efficacy and safety of these procedures in a single-center review.

Nano“Undercover Agents”Lodge in Cartilage to Treat Osteoarthritis

The relentless pain and disability caused by osteoarthritis stem from the body’s own cartilage cells going rogue under inflammatory conditions.They secrete enzymes that devour the cushioning cartilage matrix,leading to joint damage.Conventional drugs cannot effectively reach this inflammatory source within the dense cartilage.

Repairing articular cartilage defects with tissue-engineering cartilage in rabbits

客观：为了调查 cancellous 的效果，骨头矩阵明胶(BMG ) 在在 rabbits.Methods 修理关节的软骨缺点与 allogeneic 设计了 chondrocytes：Chondrocytes 被播种到三维的 cancellous BMG 上并且在为 12days 到的 vitro 有教养准备 BMG-chondrocyte 建筑群。在有 2.5% pentobarbital 钠(1ml/kg 身体重量) 的麻醉下面，关节的软骨缺点在 38 只健康 NewZealand 白兔子的右膝关节上被做(不管性别，年老的 4-5 月和称的 2.5-3 kg ) 并且缺点然后与 2.5% 胰岛素被对待。然后 BMG-chondrocyte 建筑群(组 A， n = 18 ) ， BMG (组 B， n = 10 ) ，并且没有东西(组 C， n = 10 ) 分别地被植入进软骨缺点。Therepairing 效果被估计由宏观， histologic，传播电子显微镜(TEM ) 观察，免疫组织化学的检查并且在 situ 杂交察觉，分别地在在操作以后的 2， 4， 8， 12 和 24 个星期。结果：Cancellous BMG 在操作以后在 8 个星期以内被降级。在组 A，淋巴细胞渗入在接枝附近被观察。在在操作以后的 24 个星期，软骨缺点被软骨纸巾和关节的软骨和代用品修理软骨的骨头很熟被愈合。Proteoglycan 和类型Ⅱ骨胶原被 Safranin-O 染色和免疫分别地的组织化学的染色在修理纸巾的矩阵检测。在 situ，杂交在修理纸巾在细胞质 ofchondrocytes 证明了类型Ⅱ骨胶原的基因表示。TEM 观察证明在修理纸巾的那个 chondrocytes 和软骨矩阵作为在正常关节的软骨的那些几乎一样。在组 B，缺点被软骨含纤维的纸巾修理。在组 C，缺点仅仅由含纤维的纸巾被修理。结论：Cancellous BMG 能为软骨织物工程被认为是自然房间脚手架。关节的软骨缺点能被 cancellous BMGengineered 与 allogeneic chondrocytes 修理。修理纸巾的性质接近正常软骨。胰岛素的本地管理能支持修理纸巾的坚持招待纸巾。allogeneic chondrocytes 的移植有 immunogenicity，但是有免疫力的反应是弱的。

Research and progress of cartilage tissue-engineering scaffold materials

Due to the limited self healing capacity of human cartilage,the repair of defects gives rise to a challenging clinical problem.Cartilage tissue engineering provides a new method to solve cartilage repair.However,the search for a suitable biological vector material has long been the focus of research interest in this regard.In this paper,the present situation of cartilage tissue engineering vector materials is reviewed.

The role of TGF-beta3 in cartilage development and osteoarthritis

Articular cartilage serves as a low-friction,load-bearing tissue without the support with blood vessels,lymphatics and nerves,making its repair a big challenge.Transforming growth factor-beta 3(TGF-β3),a vital member of the highly conserved TGF-βsuperfamily,plays a versatile role in cartilage physiology and pathology.TGF-β3 influences the whole life cycle of chondrocytes and mediates a series of cellular responses,including cell survival,proliferation,migration,and differentiation.Since TGF-β3 is involved in maintaining the balance between chondrogenic differentiation and chondrocyte hypertrophy,its regulatory role is especially important to cartilage development.Increased TGF-β3 plays a dual role:in healthy tissues,it can facilitate chondrocyte viability,but in osteoarthritic chondrocytes,it can accelerate the progression of disease.Recently,TGF-β3 has been recognized as a potential therapeutic target for osteoarthritis(OA)owing to its protective effect,which it confers by enhancing the recruitment of autologous mesenchymal stem cells(MSCs)to damaged cartilage.However,the biological mechanism of TGF-β3 action in cartilage development and OA is not well understood.In this review,we systematically summarize recent progress in the research on TGF-β3 in cartilage physiology and pathology,providing up-to-date strategies for cartilage repair and preventive treatment.

Inhibition of fibroblast activation protein ameliorates cartilage matrix degradation and osteoarthritis progression

Fibroblast activation protein(Fap)is a serine protease that degrades denatured type I collagen,α2-antiplasmin and FGF21.Fap is highly expressed in bone marrow stromal cells and functions as an osteogenic suppressor and can be inhibited by the bone growth factor Osteolectin(Oln).Fap is also expressed in synovial fibroblasts and positively correlated with the severity of rheumatoid arthritis(RA).However,whether Fap plays a critical role in osteoarthritis(OA)remains poorly understood.Here,we found that Fap is significantly elevated in osteoarthritic synovium,while the genetic deletion or pharmacological inhibition of Fap significantly ameliorated posttraumatic OA in mice.Mechanistically,we found that Fap degrades denatured type II collagen(Col II)and Mmp13-cleaved native Col II.Intra-articular injection of r Fap significantly accelerated Col II degradation and OA progression.In contrast,Oln is expressed in the superficial layer of articular cartilage and is significantly downregulated in OA.Genetic deletion of Oln significantly exacerbated OA progression,which was partially rescued by Fap deletion or inhibition.Intra-articular injection of r Oln significantly ameliorated OA progression.Taken together,these findings identify Fap as a critical pathogenic factor in OA that could be targeted by both synthetic and endogenous inhibitors to ameliorate articular cartilage degradation.

Morphological MRI and T2 mapping of cartilage repair tissue after mosaicplasty with tissue-engineered cartilage in a pig model

The aim of this study was to evaluate the efficacy of mosaicplasty with tissue-engineered cartilage for the treatment of osteochondral defects in a pig model with advanced MR technique. Eight adolescent miniature pigs were used. The right knee underwent mosaicplasty with tissue-engineered cartilage for treatment of focal osteochondral defects, while the left knee was repaired via single mosaicplasty as controls. At 6, 12, 18 and 26 weeks after surgery, repair tissue was evaluated by magnetic resonance imaging （MRI） with the cartilage repair tissue （MOCART） scoring system and T2 mapping. Then, the results of MRI for 26 weeks were compared with findings of macroscopic and histologic studies. The MOCART scores showed that the repaired tissue of the tissue-engineered cartilage group was statistically better than that of controls （P 〈 0.001）. A significant correlation was found between macroscopic and MOCART scores （P 〈 0.001）. Comparable mean T2 values were found between adjacent cartilage and repair tissue in the experimental group （P 〉 0.05）. For zonal T2 value evaluation, there were no significant zonal T2 differences for repair tissue in controls （P 〉 0.05）. For the experimental group, zonal T2 variation was found in repair tissue （P 〈 0.05）. MRI, macroscopy and histology showed better repair results and bony incorporation in mosaicplasty with the tissue-engi- neered cartilage group than those of the single mosaicplasty group. Mosaicplasty with the tissue-engineered cartilage is a promising approach to repair osteochodndral defects. Morphological MRI and T2 mapping provide a non-invasive method for monitoring the maturation and integration of cartilage repair tissue in vivo.

Divergent chondro/osteogenic transduction laws of fibrocartilage stem cell drive temporomandibular joint osteoarthritis in growing mice

The anterior disc displacement(ADD)leads to temporomandibular joint osteoarthritis(TMJOA)and mandibular growth retardation in adolescents.To investigate the potential functional role of fibrocartilage stem cells(FCSCs)during the process,a surgical ADDTMJOA mouse model was established.From 1 week after model generation,ADD mice exhibited aggravated mandibular growth retardation with osteoarthritis(OA)-like joint cartilage degeneration,manifesting with impaired chondrogenic differentiation and loss of subchondral bone homeostasis.Lineage tracing using Gli1^(-)CreER^(+);Tm^(fl/-)mice and Sox9-CreER^(+);Tm^(fl/-)mice showed that ADD interfered with the chondrogenic capacity of Gli1+FCSCs as well as osteogenic differentiation of Sox9+lineage,mainly in the middle zone of TMJ cartilage.Then,a surgically induced disc reposition(DR)mouse model was generated.The inhibited FCSCs capacity was significantly alleviated by DR treatment in ADD mice.And both the ADD mice and adolescent ADD patients had significantly relieved OA phenotype and improved condylar growth after DR treatment.In conclusion,ADD-TMJOA leads to impaired chondrogenic progenitor capacity and osteogenesis differentiation of FCSCs lineage,resulting in cartilage degeneration and loss of subchondral bone homeostasis,finally causing TMJ growth retardation.DR at an early stage could significantly alleviate cartilage degeneration and restore TMJ cartilage growth potential.

Cartilage Wear in Healthy and Osteoarthritis Joints

This study is designed to determine whether the outermost layer of articular cartilage is deficient in Osteoarthritis (OA). Phospholipids present in healthy and osteoarthritis (OA) synovial fluid show significant differences in their concentration. While examining the surface properties of OA joints, we found that OA PLs molecules cannot support lubrication, and increased friction was observed. Our lubrication mechanism was based on a surface active phospholipids (SAPL) multibilayer which in OA condition was deactivated and removed from the cartilage surface under OA conditions. Cartilage wettability study clearly demonstrated a significant decrease in hydrophobicity, the contact angle, θ (theta), dropping from 103° from bovine healthy cartilage to 65° in surface partially depleted and 35.1° for completely depleted surface. These results are discussed in the context that surface active phospholipid (SAPL) and lubricin, each has specific roles in a lamellar-repulsive lubrication system. However, deactivated phospholipid molecules are major indicator of cartilage wear (model) introduced in this study.

Purifi cation and identification of anti-inflammatory peptides from sturgeon (Acipenser schrenckii) cartilage

Cartilage is a nonedible byproduct with little saleable value.However,previous studies have proposed the possibility of producing peptides from cartilage with immune function modulation potential.The current study aimed to investigate the potential anti-inflammatory activity of peptides derived from sturgeon(Acipenser schrenckii)cartilage in lipopolysaccharide(LPS)-stimulated RAW264.7 macrophages.Five peptide sequences,including four novel peptides,were identified from ethanol-soluble cartilage hydrolysates.Among these five peptides,LTGP,LLLE,LLEL and VGPAGPAGP reduced the production of nitric oxide(NO)and interleukin-6(IL-6)while increasing interleukin-10(IL-10)excretion.Transcriptome analysis suggested the inhibition of activated mitogen-activated protein kinase(MAPK)and interleukin-17(IL-17)signaling pathways after LLEL intervention.MAPK,which is involved in the IL-17 signaling pathway,was further proved to be blocked by downregulating the phosphorylation of p38,extracellular-signal regulated protein kinase(ERK),and c-jun N-terminal kinase(JNK).This novel peptide offers an attractive approach to develop functional foods.

Robotic in situ bioprinting for cartilage tissue engineering

Articular cartilage damage caused by trauma or degenerative pathologies such as osteoarthritis can result in significant pain,mobility issues,and disability.Current surgical treatments have a limited capacity for efficacious cartilage repair,and long-term patient outcomes are not satisfying.Three-dimensional bioprinting has been used to fabricate biochemical and biophysical environments that aim to recapitulate the native microenvironment and promote tissue regeneration.However,conventional in vitro bioprinting has limitations due to the challenges associated with the fabrication and implantation of bioprinted constructs and their integration with the native cartilage tissue.In situ bioprinting is a novel strategy to directly deliver bioinks to the desired anatomical site and has the potential to overcome major shortcomings associated with conventional bioprinting.In this review,we focus on the new frontier of robotic-assisted in situ bioprinting surgical systems for cartilage regeneration.We outline existing clinical approaches and the utilization of robotic-assisted surgical systems.Handheld and robotic-assisted in situ bioprinting techniques including minimally invasive and non-invasive approaches are defined and presented.Finally,we discuss the challenges and potential future perspectives of in situ bioprinting for cartilage applications.

3D printing of personalized polylactic acid scaffold laden with GelMA/autologous auricle cartilage to promote ear reconstruction

At present,the clinical reconstruction of the auricle usually adopts the strategy of taking autologous costal cartilage.This method has great trauma to patients,poor plasticity and inaccurate shaping.Three-dimensional(3D)printing technology has made a great breakthrough in the clinical application of orthopedic implants.This study explored the combination of 3D printing and tissue engineering to precisely reconstruct the auricle.First,a polylactic acid(PLA)polymer scaffold with a precisely customized patient appearance was fabricated,and then auricle cartilage fragments were loaded into the 3D-printed porous PLA scaffold to promote auricle reconstruction.In vitro,gelatin methacrylamide(GelMA)hydrogels loaded with different sizes of rabbit ear cartilage fragments were studied to assess the regenerative activity of various autologous cartilage fragments.In vivo,rat ear cartilage fragments were placed in an accurately designed porous PLA polymer ear scaffold to promote auricle reconstruction.The results indicated that the chondrocytes in the cartilage fragments could maintain the morphological phenotype in vitro.After three months of implantation observation,it was conducive to promoting the subsequent regeneration of cartilage in vivo.The autologous cartilage fragments combined with 3D printing technology show promising potential in auricle reconstruction.

Biological Evaluation of Tissue-Engineered Cartilage Using Thermoresponsive Poly(<i>N</i>-isopropylacrylamide)-Grafted Hyaluronan

In order to contribute to the development of minimally invasive surgery techniques for autologous chondrocyte implantation, a novel self-assembling biomaterial consisting of thermoresponsive poly(N-isopropylacrylamide)-grafted hyaluronan (PNIPAAm-g-HA) has been synthesized as an injectable scaffold for cartilage tissue engineering. The aim of this study was to investigate the efficacy and cytocompatibility of PNIPAAm-g-HA to normal chondrocytes by using reverse transcription-polymerase chain reaction (RT-PCR) analysis and histochemical staining in preliminary in vitro and in vitro experiments. Hematoxylin and eosin staining showed homogeneous distribution of cells in the PNIPAAm-g-HA hydrogel in 3-dimensional in vitro cultivation. Alcian blue staining also indicated that abundant extracellular matrix formation, including acidic glycosaminoglycans, occurred in tissue-engineered cartilage over time in vitro. Cartilage-related gene expression patterns, which were tested in rabbit normal chondrocytes embedded in the hydrogel, were almost maintained for 4 weeks. Transforming growth factor-β1 (TGF-β1) stimulation enhanced the expression of SRY-related HMG box-containing gene 9 (Sox9) and type X collagen genes suggesting promotion of chondrogenic differentiation. Histochemical evaluation showed neocartilage formation following subcutaneous implantation of the chondrocyte-gel mixture in nude mice. Furthermore, TGF-β1 stimulation promoted production and maturation of the extracellular matrix of the in situ tissue engineered hyaline cartilage. These data suggested that PNIPAAm-g-HA could be a promising biomaterial, i.e., a self-assembling and injectable scaffold for cartilage tissue engineering.

Regeneration of Hyaline Cartilage Using a Mechanically-Tuned Chondrocyte-Seeded Biomimetic Tissue-Engineered 3D Scaffold: A Theoretical Approach

The limited ability of cartilage tissue to repair itself poses a functionally impairing health problem. While many treatment methods are available, full restoration of the tissue to its original state is rare. Often, complete joint replacement surgery is required to obtain long-term relief. Tissue engineering approaches, however, provide new opportunities for cartilage replacement. They seek to provide mechanisms to repair or replace lost tissue or function. A theoretical method is presented here for regenerating hyaline cartilage in vitro using a chondrocyte-seeded three-dimensional biomimetic engineered scaffold with mechanical properties similar to those occurring naturally. The scaffold composition, type II collagen, aggrecan, hyaluronan, hyaluronan binding protein (for link protein), and BMP-7, were chosen to encourage synthesis of hyaline cartilage by providing a more native environment and signaling cue for the seeded chondrocytes. The scaffold components mimic the macrofibrillar collagen network found in articular cartilage. Type II collagen provides tensile strength, and aggrecan, the predominant proteoglycan, provides compressive strength.

Evaluation of <i>in vivo</i>migration of chondrocytes from tissue-engineered cartilage that was subcutaneously transplanted in mouse model

For regenerative medicine, clarification of in vivo migration of transplanted cells is an important task to secure the safety of transplanted tissue. We had prepared tissue-engineered cartilage consisting of cultured chondrocytes with collagen hydrogel and a biodegradable porous polymer, and we clinically applied it for treatment of craniofacial anomaly. To verify the safety of this tissue-engineered cartilage, we had syngenically transplanted the tissue-engineered cartilage using chondrocytes harvested from EGFP-transgenic mice into subcutaneous pocket of wild type mice, and investigated localizations of transplanted chondrocytes in various organs including cerebrum, lung, liver, spleen, kidney, auricle, gastrocnemius, and femur. After 8 to 24 weeks of the transplantation, accumulation of cartilaginous matrices was observed in tissue-engineered cartilage, while EGFP-positive transplanted chondrocytes were localized in this area. Otherwise, no EGFP was immunohistochemically detected in each organ, suggesting that subcutaneously-transplanted chondrocytes do not migrate to other organs through the circulation. In cartilage tissue engineering using cultured chondrocytes, risk for migration and circulation of transplanted cells seemed negligible, and that ectopic growth of the cells was unlikely to occur, showing that this is safe technique with regard to the in vivo migration of transplanted cells.

Usefulness of Agarose Mold as a Storage Container for Three-Dimensional Tissue-Engineered Cartilage

The efficiency of substance exchange may be decreased when the thickness and volume of such a tissue-engineered cartilage that is composed of cultured cells and porous scaffold increase. Moreover, during the transport of this construct with complicated shapes, excessive and focal mechanical loading may cause deformation. The establishment of incubation and transport methods is necessary for the three-dimensional tissue-engineered cartilage. Therefore, we investigated the preparation of an agarose mold with a concavity similar to the shape of 3-dimensional tissue-engineered cartilage to prevent excessive and focal concentration of stress, while avoiding interference with substance exchange as much as possible. Firstly, we investigated the preparation at 1% - 4% agarose concentrations. Since the mechanical strength was insufficient at 1%, 2% was regarded as appropriate. Using 2% agarose, we prepared a mold with a 5 × 5 × 5 mm concavity to accommodate tissue-engineered cartilage (5 × 5 × 5 mm mixture of 1.5 × 107 cells and collagen gel), and stored the regenerative cartilage in it for 2 and 24 hours. On comparison with storage in a plastic mold with the same shape in which substance exchanged from side and bottom was impossible, although no significant differences were noted in the number or viability of cells after 2 hours, these were markedly reduced in the plastic mold after 24 hours. It was confirmed that favorable cell numbers and viability were maintained by immediately retaining the regenerative cartilage in the culture medium in the agarose mold and keeping the temperature at 37°C. Since this agarose mold also buffers against mechanical forces loaded on the three-dimensional regenerative tissue, it may be useful as a container for storage and transport of large-sized three-dimensional regenerative tissue.

杂交鲟(Sturgeon cartilage)软骨中硫酸软骨素的提取方法及分析鉴定

采用稀碱浸提、蛋白酶水解与三氯乙酸沉淀相结合脱蛋白的工艺,对杂交鲟软骨提取琉酸软骨素的方法进行了较系统的研究。综合考察各种影响因素,设计了正交试验对提取工艺参数进行了优化,并对产品的质量指标进行了检验。结果表明,最佳提取工艺参数为:碱提取时料液比为1:2.0,碱浓度为4%,碱提温度为40℃;胰蛋白酶的酶解温度为55℃,酶量为2%,酶解时间为10h,制备的硫酸软骨素为白色粉末,得率为28.9%,纯度为92.3%,蛋白质含量为2.59%,各项质量指标完全符合标准要求。与目前已报道的其他软骨素制备工艺相比较,该方法具有工艺简便,提取率高,产品纯度高的特点。光谱分析法结构鉴定结果表明它是一种软骨素肽,其主要成分为硫酸软骨素C。

Use of bone morphogenetic proteins in mesenchymal stemcell stimulation of cartilage and bone repair

The extracellular matrix-associated bone morphogenetic proteins(BMPs) govern a plethora of biological processes. The BMPs are members of the transforming growth factor-β protein superfamily, and they actively participate to kidney development, digit and limb formation, angiogenesis, tissue fibrosis and tumor development. Since their discovery, they have attracted attention for their fascinating perspectives in the regenerative medicine and tissue engineering fields. BMPs have been employed in many preclinical and clinical studies exploring their chondrogenic or osteoinductive potential in several animal model defects and in human diseases. During years of research in particular two BMPs, BMP2 and BMP7 have gained the podium for their use in the treatment of various cartilage and bone defects. In particular they have been recently approved for employment in non-union fractures as adjunct therapies. On the other hand, thanks to their potentialities in biomedical applications, there is a growing interest in studying the biology of mesenchymal stem cell(MSC), the rules underneath their differentiation abilities, and to test their true abilities in tissue engineering. In fact, the specific differentiation of MSCs into targeted celltype lineages for transplantation is a primary goal of the regenerative medicine. This review provides an overview on the current knowledge of BMP roles and signaling in MSC biology and differentiation capacities. In particular the article focuses on the potential clinical use of BMPs and MSCs concomitantly, in cartilage and bone tissue repair.

Mesenchymal stem cells as a potent cell source for articular cartilage regeneration

Since articular cartilage possesses only a weak capac-ity for repair, its regeneration potential is considered one of the most important challenges for orthopedic surgeons. The treatment options, such as marrow stimulation techniques, fail to induce a repair tissue with the same functional and mechanical properties of native hyaline cartilage. Osteochondral transplantation is considered an effective treatment option but is as-sociated with some disadvantages, including donor-site morbidity, tissue supply limitation, unsuitable mechani-cal properties and thickness of the obtained tissue. Although autologous chondrocyte implantation results in reasonable repair, it requires a two-step surgical pro-cedure. Moreover, chondrocytes expanded in culture gradually undergo dedifferentiation, so lose morpho-logical features and specialized functions. In the search for alternative cells, scientists have found mesenchymal stem cells(MSCs) to be an appropriate cellular mate-rial for articular cartilage repair. These cells were origi-nally isolated from bone marrow samples and further investigations have revealed the presence of the cells in many other tissues. Furthermore, chondrogenic dif-ferentiation is an inherent property of MSCs noticedat the time of the cell discovery. MSCs are known to exhibit homing potential to the damaged site at which they differentiate into the tissue cells or secrete a wide spectrum of bioactive factors with regenerative proper-ties. Moreover, these cells possess a considerable im-munomodulatory potential that make them the general donor for therapeutic applications. All of these topics will be discussed in this review.

Benefits of Ilizarov automated bone distraction for nerves and articular cartilage in experimental leg lengthening

AIM To determine peculiarities of tissue responses to manual and automated Ilizarov bone distraction in nerves and articular cartilage.METHODS Twenty-nine dogs were divided in two experimental groups: Group M-leg lengthening with manual distraction(1 mm/d in 4 steps), Group A-automated distraction(1 mm/d in 60 steps) and intact group. Animals were euthanized at the end of distraction, at 30 th day of fixation in apparatus and 30 d after the fixator removal. M-responses in gastrocnemius and tibialis anterior muscles were recorded, numerical histology of peronealand tibialis nerves and knee cartilage semi-thin sections, scanning electron microscopy and X-ray electron probe microanalysis were performed.RESULTS Better restoration of M-response amplitudes in leg muscles was noted in A-group. Fibrosis of epineurium with adipocytes loss in peroneal nerve, subperineurial edema and fibrosis of endoneurium in some fascicles of both nerves were noted only in M-group, shares of nerve fibers with atrophic and degenerative changes were bigger in M-group than in A-group. At the end of experiment morphometric parameters of nerve fibers in peroneal nerve were comparable with intact nerve only in A-group. Quantitative parameters of articular cartilage(thickness, volumetric densities of chondrocytes, percentages of isogenic clusters and empty cellular lacunas, contents of sulfur and calcium) were badly changed in M-group and less changed in A-group.CONCLUSION Automated Ilizarov distraction is more safe method of orthopedic leg lengthening than manual distraction in points of nervous fibers survival and articular cartilage arthrotic changes.