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Aims The present study investigates the effectiveness of platelet-rich plasma (PRP) gel without adjunct to induce cartilage regeneration in large osteochondral defects in a rabbit model. Methods A bilateral osteochondral defect was created in the femoral trochlear groove of 14 New Zealand white rabbits. The right knees were filled with PRP gel and the contralateral knees remained untreated and served as control sides. Some animals were killed at week 3 and others at week 12 postoperatively. The joints were harvested and assessed by Magnetic Resonance Observation of Cartilage Repair Tissue (MOCART) MRI scoring system, and examined using the International Cartilage Repair Society (ICRS) macroscopic and ICRS histological scoring systems. Additionally, the collagen type II content was evaluated by the immunohistochemical staining. Results After 12 weeks post-surgery, the defects of the PRP group were repaired by hyaline cartilage-like tissue. However, incomplete cartilage regeneration was observed in the PRP group for three weeks. The control groups showed fibrocartilaginous or fibrous tissue, respectively, at each timepoint. Conclusion Our study proved that the use of PRP gel without any adjuncts could successfully produce a good healing response and resurface the osteochondral defect with a better quality of cartilage in a rabbit model. Cite this article: Bone Joint Res 2021;10(3):192–202.

In complex machines, the generation of a Disassembly Plan (DP) which allows a minimum change of disassembly tools and directions, and permits an easy dismounting of wear parts is the main requireme...

Congenital syndactylies are frequent congenital malformations of the hand. They can be an isolated finding or they can be found in association with other polymalformative syndromes. Several surgical techniques used to treat them have been described in the literature. The most used is the dorsal commissural omega-flap technique. We here report a study of 18 patients with congenital syndactyly, with multiple involvement in several cases, whose data were collected at the Department of Orthopedics and Traumatology of Sfax (Tunisia). All patients were operated using the dorsal commissural omega-flap technique. We operated 42 commissures in 18 patients. The average age of patients was 7 years. Only 3 patients had syndromic forms. Six of these patients were operated in two stages. For scar quality, mean OSAS score was 11.47 (11.35 for simple types and 12 for complex types). All patients with complex types had long-term complications (100%). Six patients with simple types out of 14 had complications (42.85%). The management of congenital syndactylies is surgical. It is important to provide parents with accurate information on the essential role of follow-up appointments in order to avoid complications in the short and the long term.

Background: The aim of this study was to assess the oncologic outcome of pelvic bone sarcomas (PBS) and to identify prognosis factors.Methods: We report a multicentric cohort of patients treated for a PBS from 2000 to 2020. Data from 12 hospitals were analysed. Patients treated for primary PBS were included. Alive patients with less than 6 months of follow up were excluded. The primary outcome was survival.Results: One hundred and fourteen patients (67 males and 48 females) were reviewed with a mean follow up of 32±46,5 (1 to 216) months. The mean patient and doctor diagnosis delays were respectively 8,5±10,2 (1 to 60) and 3±4,3 (0 to 24) months. Sixty-eight patients (59,6%) died after a mean time from diagnosis of 15,9±22,8 (1 to 120) months. The overall survival rates at 5 and 10 years were respectively 38,4% and 27,6%. Chondrosarcoma histological type (HR=3,64), metastasis (HR=3,55) and surgery (HR=0,12) were identified as significant survival factors. Surgery was also associated to a decreased risk of metastasis (OR=0,03, 95% CI: 0,01 – 0,1). Among the 76 patients (66,7%) who underwent surgery, local recurrence was observed in 19 patients (25%) with a mean time from surgery to onset of 11,05 (±17,5) months. Conclusions: This nation-wide20-year-cohort study shows that surgery is the most effective treatment option in PBS regardless the histological type of the tumour. Efforts have to be done to decrease the diagnosis delay in order to start treatment when surgery is still feasible.

Purpose Fluorapatite (Fap), an alumina (Al2O3) known for its excellent bio-inertia, can significantly increase the biocompatibility and bioactivity of biomaterials. This study is an investigation of the interface bone/Al2O3–Fap composite coatings implanted in the tibia of the rabbit. Methods Two techniques T1 and T2 were implemented on four rabbits, R1–R4 to assess the effect of the alumina (Al2O3)–Fap [Ca10(PO4)6F2] composite, coating for 316L stainless steel, on bone contact. The fluorapatite powder was synthesized using a wet-chemical method. The biocompatibility and the bioactivity of the Al2O3–Fap composite were evaluated by in vitro/in vivo tests. The characteristics of the bone/implant interface were investigated with scanning electron microscopy, radiology and 3D scanner. Results The results showed that T2 was more effective than T1, with a good contact between the implant/bone on the radiographs performed after 28 days. Implants coated with alumina did not show any integration signs with bone tissue. The addition of Fap to alumina coating would increase the adhesion of prosthesis on bone cells and guarantee a stable implantation. Conclusion Al2O3–Fap coating showed excellent behavior in vitro and in vivo tests revealing that the Fap is effective in improving biocompatibility and bioactivity.

In a complex mechanical product, the easy dismantling of wear parts is a main requirement to ensure an efficient design. In fact, the maintenance charge in the preventive or corrective case is remarkably expensive, which needs to anticipate the repair assignment in the design phase. Subsequently, considering the disassembly alan (DP) of wear parts, from the early design phase, is a first step in the implementation of the circular economy concept. In this paper, a new disassembly tool based on the wear parts priority concept is presented. A modular decomposition of the product mockup is firstly presented. Based on an extraction data module, a wear parts identification process is conducted. Then, a feasible DP of different modules, containing the identified wear parts, is generated. An evaluation of the generated DPs is performed based on the total disassembly time. The estimation time of different disassembly operations is obtained from industrial practices. An implementation of the proposed approach is detailed using an industrial gear box containing multiple wear parts. A comparative study with the literature highlighted the efficiency of the proposed approach.

La prise en charge de l´ostéomyélite aiguë devient plus délicate depuis l´émergence duStaphylocoque aureusrésistant à la méthicilline d´origine communautaire. Nous avons recueilli les cas d´ostéomyélite aiguë dues à ce germe sur une période de 21 ans (Janvier 1995-Décembre 2016) et nous avons essayé d´analyser les particularités de cette entité pathologique. Notre série comporte 15 enfants, d´âge moyen 9 ans. Le membre inférieur était atteint dans tous les cas. Une notion de traumatisme local a été signalée dans 8 cas et une porte d´entrée cutanée a été trouvée dans 4 cas. Le mode de début était aigu dans 12 cas avec un tableau de pseudo-paralysie du membre atteint. Une staphylococcie pulmonaire avec des signes septico-pyohémiques ont été notés dans un cas. L´hémoculture était positive dans 8 cas. La recherche par PCR de la leucocidine de Panton et Valentine était pratiquée dans 1 cas avec un résultat positif. Tous ces patients ont eu un débridement chirurgical et une antibiothérapie empirique secondairement adaptée. L´évolution était bonne dans 8 cas et mauvaise dans les autres cas avec passage à la chronicité dans 6 cas et un cas de décès. Une fracture pathologique a été signalée dans 3 cas. La survenue d´une ostéomyélite àStaphylocoque aureusrésistant à la méthicilline d´origine communautaire est péjorative. Connaitre ces infections en se basant sur des arguments cliniques et paracliniques est un enjeu important pour une prise en charge thérapeutique spécifique et rapide.

The generation of assembly sequences (AS) is a topical subject aimed to help designers for the determination and the simulation of the different stages of a mechanical product assembly. So, it is considered as an important step in the process of designing a new mechanical product. In addition, it allows minimizing the design cost and reducing the time of maintenance. For that, researches are developed several methods to optimize the determination of assembly sequences.

Humeral pseudarthrosis are common with a non-union rate after fracture between 8% and 13%. Several operative methods have been described for the treatment of humeral pseudarthrosis. The aim of this study was to assess a new approach based on compression using a monoplane external fixator without graft. This study was conducted in the Department of Orthopedic Surgery, and Traumatology of Habib Bourguiba University Hospital in Sfax-Tunisia between April 2009 and September 2018. Fifty-eight patients were operated on using a dynamic monoplane axial fixation device with continuous compression by manipulating the compression system of the fixator. All the cases were evaluated according to the modified Stewart and Hundley classification. The fracture was located in the middle third in 53.4% of the cases. The pseudarthrosis was hypertrophic in 34.5% of the cases. Fifty-four patients were treated with this method as a first cure of non-union and four patients had previously a first cure for their pseudarthrosis. We noted 11 septic pseudarthrosis. The average follow-up was 47.2 months. We obtained consolidation in 98% of the cases. The average consolidation time was 5.1 months. Based on the modified Stewart and Hundley criteria, 75.8% had very good results. This study highlights that a continuous external compression is effective in the treatment of non-unions, as it allows consolidation without opening the pseudarthrosis site and without bone grafting while having satisfactory anatomical and functional results.

With the new technologies of the product design, the assembly automation lines has expatriated to a new assembly strategy characterized by an assembly modularization. This strategy consists, in a first time, in preparing subassemblies on secondary lines and then assembled with each other on the main line in a second time. The choice has been made to automate certain sections of the main line and to leave the subassembly lines in a manual way. The aim of this work is to identify the subassemblies of a mechanical product from its CAD model in order to predict secondary’s assembly lines. For better discussing and explaining all the steps of the proposed approach a CAD assembly of an industrial complex product is presented in all sections of this paper.

Particles impact damping is one of the promising technologies used for the passive mitigation of vibrations. Through the dynamic impact and friction between particles, particles impact damper is able to reduce or eliminate vibratory energy under kinetic shape. Due to the simplicity of this type of damper and the operating frequency band, it is widely used in civil engineering. On the other hand it can operate in aggressive environments including high temperature or humidity. In this paper, the dynamic behaviour and efficiency of this process to reduce vibrations are highlighted. Using a simple analytical model, a clamped-free beam coupled to a particles impact damper, the influence of some system parameters is investigated. The proposed model is, then, validated through a comparison of simulated responses with experimental results established in a previous work. It is noticed that the nonlinear behaviour and the large number of their design parameters make the determination of its participation in damp very complicated. For this reason, it is crucial to seek optimal design parameters of the particles impact damper. In this context, an optimized method based on a genetic algorithm is proposed. The obtained results demonstrate the satisfactory side of this approach to identify the optimal parameters of the considered particles impact damper. Consequently, the developed approach may be constitutes an aid, for the engineer, to choose particles impact damper parameters according to the characteristics of the vibrating structure to be studied.

Assembly Sequence Planning (ASP) is one of the well-known optimization problems in the manufacturing industry. It represents a great deal of interest over the past three decades. This paper aims to present a method for generating ASP, taking into account the stability assignment during assembly’s operations. The developed method uses the topological and geometrical assembly constraints extracted and generated from CAD system (assembly constraints, mass and center of gravity of components, interference and contact matrices), to guarantee the generation of a feasible ASP. The main contribution of this research is the development of a method which respects the stability assignment of heavy machines during the assembly’s operations. Also, it reduces the design costs and minimizes the time of replacement or repair of failing components of industrial equipments, which has become complicated task given the complexity of today’s mechanisms. A validation example is used to highlight the advantages of the proposed approach.

Today, the assembly process is the least automated phase of production for mechanical products. The percentage of the automated assembly line operations of automobiles fluctuates between 10 and 20% according to manufacturers. The use of industrial robots in the assembly lines played a decisive role in the development of their activity despite the high cost. Indeed, this strategy is a key element that increases productivity. The use of robots in assembly tasks requires the trajectory determination of parts to be assembled from the design phase of the product. This problem is difficult if the part may interfere with other elements and requires combined trajectories to avoid the interference. Therefore, the simulation of part assembling trajectories from the design phase is an interesting and topical research issue. The main objective of this paper is to develop a new approach to generate multidirectional combined trajectories of parts. A mathematical formulation of the proposed approach is firstly proposed, being based on both the position matrix concept and the bounding box method. A didactic example is used to illustrate the different stages of the proposed approach. To highlight the computer implementation of the proposed method, an industrial case study is presented. This example was chosen to illustrate the effectiveness of the proposed approach such as the gain of assembly time, the reduction of costs by robotization of the work, and the programming assistance of these robots.

Le pied bot varus equin (PBVE) invetere est une attitude vicieuse du pied qui ne repose plus sur le sol par ses points d'appui normaux mais par son bord externe et sa pointe. Lorsque cette attitude vicieuse persiste longtemps, elle evolue vers des deformations osteoarticulaires importantes a l'âge adulte. Le PBVE fixe constitue une bonne indication d'arthrodese tibio-calcaneenne. Celle-ci permet dans la majorite des cas d'obtenir un appui plantigrade indolore et stable. Le but de ce travail est d'evaluer les resultats cliniques et radiologiques de l'astragalectomie avec adhese tibiocalcaneenne. Nous rapportons une serie de 3 cas d'arthrodese tibio-calcaneenne pour deformation grave de l'arriere-pied associant un varus et un equin important et genant chez l'adulte. Les resultats etaient juges satisfaisants avec un appui plantigrade indolore et stable. Avec fusion de l'arthrodese a 90 jours, sans inegalite pour le cas bilateral et un raccourcissement de 2cm compense par une semelle a droite pour le cas unilateral. Dans les deformations importantes et fixees de la cheville et du PBVE, l'arthrodese tibio-calcaneenne permet dans la majorite des cas d'obtenir un appui plantigrade indolore et stable sans risque vasculaire, ni cutane.

The Assembly or Disassembly Sequence Planning (ASP/DSP) remains an actual optimization problem in the manufacturing industry. It has represented a great deal of interest over the past three decades. Furthermore, given the complexity of today’s mechanisms, an optimal ASP/DSP can reduce the design costs and minimize the maintenance time of industrial equipment. Among the least used criteria in ASP/DSP generation, the stability criterion seems to be quite interesting especially for heavy mechanisms. This paper proposes an approach to generate feasible ASP based on the components’ stability during the assembly operations. The generation of feasible ASP was guaranteed using the geometrical and topological assembly constraints extracted from the CAD assembly. An example of a heavy machine is adopted to highlight the advantages of the proposed approach.

Disassembly sequence planning is considered an important research topic in the manufacturing automation field. In recent years, in close collaboration with manufacturers, many investigations have been conducted to design robust and profitable dismantling systems. Therefore, the designers of new products have to consider the disassembly constraints in the design phase of products. Moreover, considering the disassembly constraints is important not only in the context of life end of a product but also in its life cycle in order to reduce problems related to its exploitation and maintenance. Consequently, the optimization of the disassembly process of a product is a crucial task for improving the product design. This article presented an automated disassembly sequence planning approach based on ant colony algorithm. The developed method permits the generation of an optimal and feasible disassembly sequence planning of a product from its computer-aided design (CAD) model. Several criteria were introduced in this approach such as part volume, tool change, disassembly directions, and the maintainability of wearing part. A comparison between genetic and ant colony algorithms was conducted to reveal the effectiveness of the proposed approach. A case study is presented and an implemented tool was developed. The obtained results demonstrate the satisfactory side of the considered criterions to identify the feasible disassembly sequence plan.

For complex products, the generation of an assembly or disassembly plan becomes a difficult task as the assembly parts’ numbers increase. To bypass this problem, the use of a subassembly concept represents an original technique. It aims to organize the multipart assembly product into some subassembly encapsulation. Each subassembly contains, relatively, a small number of parts. As a result, the assembly or disassembly plan problem becomes between the identified subassemblies and, in that case, can be generated easily. Despite the attractiveness of the subassembly concept, the identification of subassemblies from the CAD model product remains a relevant research subject to be improved. In fact, the resolution of the precedence relation problem from the CAD model data constitutes the biggest difficulty of this technique. In this work, a novel disassembly plan approach based on a subassembly concept is presented. The proposed approach starts with the investigation of the CAD assembly data to extract a contact matrix. Then, the extracted matrix is enriched by assembling conditions in order to search the set of base parts initiating subassemblies. Once the subassemblies were recognized, a new subassembly interference matrix is regenerated. The disassembly plan is carried out, between the known subassemblies, using a simplification method of subassemblies interference matrix. An example of the CAD assembly product is treated during this paper to clarify the different steps of the proposed approach. The simulated results of both subassembly identification and disassembly plan were compared to examples given by the literature in order to validate the developed approach.

Assembly or disassembly sequence planning is a very hard combinatory problem while the assembly parts numbers become important. To reduce this difficulty, especially for the case of complex products, the subassembly identification concept can constitute an original way. It aims to decompose the complex assembly product into some subassembly entities containing a small number of parts. Consequently, the generation of assembly or disassembly sequence planning of parts becomes between the subassemblies and, in that case, can be determined relatively easily. Despite the prettiness of the subassembly method, the identification of subassembly from a computer-aided design (CAD) model remains a relevant research subject to be improved. In this paper, a subassembly identification approach is presented. The proposed approach begins with the exploration of the CAD assembly data to carry out an adjacency matrix. Then, to identify the subassemblies, the extracted matrix is transformed through three steps. The first step consists of idealizing this matrix by removing all connection parts identified by the Feature-Manager, which permits reducing its size. Afterward, based on the reduced matrix, an all-direction matrix is constructed to identify the base part of a subassembly. The third step consists of enriching the all-direction matrix by mounting conditions to construct the set of subassemblies. An example of a CAD assembly mechanism is presented in all sections of this paper in order to explain and discuss the steps of the proposed approach.

Over the last years, computer-aided design (CAD) has developed rapidly thanks to integrated applications. These applications, namely CAD-integrated applications, have the ability to resolve many industrial challenges related to the design process such as assembly/disassembly sequence planning or computer-aided process planning. The implementation of these applications depends essentially on data extracted from the CAD model. However, the accessibility to these data remains a complex task for CAD-integrated application developers. The aim of this work is modelling and implementing a CAD-integrated system named CADLAB $$^{\copyright }$$ which automatically identifies and generates a diversity of data from a CAD assembly model under exploitable forms. The modelling of this system is performed using MBSE tool which is systems modelling language. The computer implementation of CADLAB is carried out with several software packages such as Solidworks $$^{\copyright }$$ , Excel $$^{\copyright }$$ and MATLAB $$^{\copyright }$$ . With CADLAB system, the identifiable CAD data are the assembly components and constraints’ data. Whereas, the generated CAD data represent the assembly interference matrices as well as several assembly related matrices. The developed system was tested on several CAD examples and the obtained results were verified. The correctness of these results proves the efficiency of CADLAB to carry out CAD data extraction and then enhance the interoperability process between CAD system and CAE applications. The proposed method can help designers find the CAD assembly data in complex mechanical assembly model, facilitate the structuring of the useful designing data, and thereby improve the efficiency of product knowledge reuse.

Objective The purpose of this study was to investigate the effect of fresh human amniotic membrane (FHAM) as a substitute of periosteum to enhance bone regeneration in critical-sized defects. Methods Tibial diaphyseal bone defects were created in forty New Zealand white rabbits and treated with FHAM or left empty. Treatment groups consisted of: FHAM implanted in the place of removed periosteum (FHAMP group); FHFAM implanted to fill the entire defect (FHAMF group) compared to negative control group; empty defect with removing the periosteum (NC group) and positive control group; and empty defect without removing the periosteum (PC group). Bone regeneration was evaluated by radiographic, micro-computed tomography (μ-CT) and histological analyses at 4 and 8 weeks post-surgery. Results Radiographic and μ-CT analysis demonstrated clearly enhanced new bone formation in positive control group (PC) and FHAMP group compared to negative control group (NC) and FHAMF group. Histological staining exhibited remaining woven bones and cartilage matrix in the FHAMP group, immature lamellar bone with medellury cavity and marrow bone formation in PC group from 4 weeks post-operatively. For FHAMF group, a little new bone formation was detected only from 8 weeks post-operatively, and an absence of any sign of healing in NC group at both time points. Conclusion The results provide that FHAM increases bone regeneration in critical-sized defects when it is implanted in the place of the removed periosteum, but its additive effect does not have the same effect of the natural periosteum.

Les fractures-luxations anciennes de la base du cinquième métacarpien peuvent se compliquer d'une arthrose post-traumatique gênante sur le plan fonctionnel et de prise en charge difficile. La technique d'arthroplastie stabilisée comporte une résection arthroplastique de la base du cinquième métacarpien associée à une arthrodèse diaphyso-métaphysaire latérale entre le quatrième et le cinquième métacarpien. A travers deux observations, nous présentons les objectifs de cette technique d'arthroplastie stabilisée et ses particularités par rapport aux autres techniques destinées au traitement des séquelles des fractures-luxations de la base du M5.

Introduction : nous rapportons un cas de tuberculose de l’epiphyse femorale inferieure ayant un aspect radiographique caracteristique d’un chondroblastome. Methodes : il s’agissait d’un garcon de 8 ans qui a consulte pour gonalgies droites depuis 3 mois, avec notion de traumatisme du pied il y a 1 mois. A l’examen, ce garcon etait apyretique, il marchait avec discrete boiterie droite. Le genou n’avait pas de signes inflammatoires et pas de choc rotulien, sa mobilite etait normale et il y avait des douleurs moderees du bord interne du genou. Le bilan biologique a montre une VS a 14, fibrinemie a 2.2, CRP et Latex Waler-Rose negatifs. La radiographie a montre une lacune epiphysaire sous chondrale du condyle femoral interne. A l’IRM, elle faisait 16*11 mm, en hyposignal T1 et hypersignal T2 avec important œdeme perilesionnel qui prend le contraste. Le diagnostic de chondroblastome a ete evoque et une biopsie a ete realisee par un abord direct Trans-cartilagineux. Resultats : Le tissu preleve etait puriforme et le diagnostic d’osteomyelite subaigue etait evoque. L’examen anatomopathologique a confirme le diagnostic de tuberculose. Il n’y avait pas d’autres localisations tuberculeuses et l’enfant a ete mis sous antituberculleux. Au recul de 2 ans, l’enfant est asymptomatique et on a constate un comblement progressif de la lesion epiphysaire. Conclusion : La tuberculose doit etre evoquee devant toute lesion epiphysaire solitaire de l’enfant. Elle vient en 3eme position apres l’osteomyelite et le chondroblastome.

Introduction : les formes septicopyohemiques de l’osteomyelite aigue sont rares. Le but de notre travail est d’etudier les caracteristiques epidemiologiques, cliniques et evolutives de cette pathologie grave.

Introduction : la survenue d’une fracture sur osteomyelite aigue est une complication grave qui pose un probleme difficile de consolidation sur un os infecte et fragile. Notre but est de chercher les facteurs favorisant la survenue de cette complication afin de la prevenir et de d’ameliorer sa prise en charge. Methode : notre serie comporte 11 fractures pathologiques sur 118 osteomyelites aigues des os longs colligees sur une periode de 12 ans.

Introduction Arthrogryposis is a condition existing at birth, seen in different diseases that have in common the existence of multiple joint stiffness. The clinical presentation is diversified and the functional prognosis depends on the etiology, which makes therapeutic options different from one case to another. The objective of this study was to describe clinical manifestations observed in arthrogrypotic patients and show the different therapeutic methods and functional results. Methods This was a retrospective study over a period of 12 years from 2000 to 2012, based on clinical examinations of 23 patients with arthrogryposis. Results The mean age of the patients was 6.6 years. The four limbs were involved in 19 cases and only the lower limbs in four cases. The etiology was amyoplasia in nine patients, distal arthrogryposis in three, peripheral neuropathy in two, and muscular atrophy in one infantile patient. Foot deformities were observed in 22 cases, with 25 talipes equinovarus deformities (clubfoot), six convex feet, and five valgus feet. The Ponseti method was applied in 12 clubfeet with recurrence in eight cases. The other clubfeet had functional treatment and necessitated surgical release in 11 cases. Deformation of the knee was seen in 15 patients, flessum in 16 knees, restriction of flexion in eight cases, genu recurvatum in three, stiffness in extension in two, and agenesis of the patella in one case. Surgical treatment was carried out in only one case. Other cases of deformity of the knee were treated by rehabilitation with slight improvement. Deformation of the hip was seen in 15 patients, with 16 hips dislocated and four hips in flessum. The dislocation of the hip was treated orthopaedically in two cases and surgically in six cases, with reduction in all cases but persistence of stiffness. Involvement of the shoulders was observed in eight cases, the elbow in seven cases, the wrist in ten cases, and the fingers in 16 cases. The treatment was based on physical therapy and orthotics in all cases, and improvement was better in the wrist and fingers. Conclusion Arthrogryposis has different clinical presentations. Successful treatment is not constant. Multidisciplinary care is necessary and should be early and continued in order to gain the maximum autonomy and facilitate patients' social integration.

The assembly sequence plan (ASP) is a relatively new concept that has drawn the attention of many researchers over the last years. In spite of the enormous development of CAD Software in many aspects, the automatic generation of ASP from CAD assembly remains a subject to improve especially with the growing complexity of industrial products. This article presents an ASP generation approach based on CAD assembly data. To generate ASP, the developed method is composed of two mains steps. The first one is the extraction of the CAD assembly data. To identify all possible obstacles during the components’ displacement, an interference analysis process is performed in the second step. An illustrative example of the CAD assembly is detailed in the different stages of this article.

At present, Computer-Aided tools are at the heart of the product development cycle. These tools can accelerate and make more efficient the design and simulation tasks. However, there is no commercial aid tool for the assistance in the assembly/disassembly tasks. In this context, many approaches and methods are proposed in which feasible assembly/disassembly sequences can be generated. Amongst the limitations of those approaches is the considerable processing time. In this paper, we propose an approach for the simplification of the product CAD model in order to generate Assembly Sequences (AS). The developed approach, which is automatic and integrated to CAD system, begins by the identification and the elimination of standard components (such as screws, nuts, keys, etc.) present in the model. Then a simplified AS is carried out using a collision analysis. Finally, the global AS is obtained by inserting the eliminated elements into the final AS using a case-based algorithm which contains a census of the different standard component types. This developed case-based algorithm allows, according to the type, the identification of the assembly direction and the chronological order of the eliminated standard component.

Nowadays, mechanical products which respond to customer requirements become more and more complex. Concurrent engineering environment requires that various computer-aided tools be used concurrently for design, analysis, and validation of complex product. Computer-aided design (CAD) and computer-aided engineering (CAE) tools should have the capacity of integration or easy interoperability. However, many of them are often unconnected systems that are not intended for collaborative use. Engineering designers and analysts tend to use specific CAD software for design and other CAE software for analysis. Consequently, the triplet (Cost/Delay/Quality) of a complex product cannot be improved. In this paper, a disassembly plan (DP) generation based on a coupling between Solidworks and Matlab is detailed. Base on an encapsulation of parts into a subassemblies bloc, the proposed approach aims to automatically integrate the both softwares in a concurrent engineering context in order to identify and generate a feasible and optimal DP. A comparative example is presented in order to highlight the feasibility and efficiency of the proposed approach.

Recently, Disassembly Sequence Planning (DSP) plays an important role in the life cycle of mechanical products. Disassembly specification during the design phase of a product is considered as a great interest of engineers and designers. This paper presents an automated DSP based on Particle Swarm Optimization (PSO). First, the collision test is performed by the use of the interference test tool of the CAD software in order to identify all possible interferences during the components’ motion. Then interference matrices are generated to ensure the feasibility of disassembly operations. Next, a PSO algorithm, based on the regeneration of DSP, was performed to optimize the DSP using an objective function. Various criteria such as part volume, tools change, directions and maintainability of usury component are considered. Finally, to highlight the performance of the developed approach, an implemented tool is developed and an illustrative example is studied.

Les fractures-luxations anciennes de la base du cinquième métacarpien peuvent se compliquer d'une arthrose post-traumatique gênante sur le plan fonctionnel et de prise en charge difficile. La technique d'arthroplastie stabilisée comporte une résection arthroplastique de la base du cinquième métacarpien associée à une arthrodèse diaphyso-métaphysaire latérale entre le quatrième et le cinquième métacarpien. A travers deux observations, nous présentons les objectifs de cette technique d'arthroplastie stabilisée et ses particularités par rapport aux autres techniques destinées au traitement des séquelles des fractures-luxations de la base du M5.

Assembly sequence planning has drawn the attention of many researchers over the last years. Despite, the great development of CAD software in many aspects (simulation algorithms, interfaces, and ergonomics), automatic generation of assembly sequence planning from CAD assembly remains an issue to improve especially with the increasing complexity of industrial products. In this paper, an approach of assembly sequence planning generation from a CAD assembly model is presented. In order to generate feasible assembly sequence planning, the developed approach begins with the exploration of CAD assembly. Then, a collision analysis is performed to identify all possible obstacles during the components’ motion. An example of CAD assembly is presented in all sections of this paper in order to demonstrate the efficiency of the proposed approach.

Disassembly sequence planning is a relatively new subject and has only recently gained interest in the research literature. Disassembly simulations are important not only for improving product design, but also for maintaining an updated process plan, which becomes a tedious and complicated task given the complexity of today’s mechanisms. The crucial issue, in the generation of disassembly plans, is the rise in the amount of sequences, especially with the increase of the number of parts in the mechanism. For this reason, it is crucial to seek an optimal feasible method for the disassembly process. In this paper, an optimized disassembly process based on a genetic algorithm is proposed. The method takes into account several criteria such as maintainability of usury component, part volume, tools change and the change of disassembly directions. The results obtained demonstrate the satisfactory side of these criteria to identify a feasible disassembly sequence.

International audience; In this paper, an experimental characterisation of a particle impact damper (PID) under periodic excitation is investigated. The developed method allows the measurement of damping properties of PID without the supplementary use of a primary structure. The passive damping of PID varies with the excitation frequency and its design parameters. The nonlinear damping of PID is then interpreted as an equivalent viscous damping to be introduced in a finite element model of a structure to predict its dynamic response. The results of numerical simulations are in good agreement with those of experiment and show the relevance of the developed method to predict the dynamic behaviour of a structure treated by PID's.

Le syndrome du tunnel tarsien est une pathologie rare. Sa symptomatologie comporte des douleurs plantaires et des dysesthesies dans le territoire du nerf tibial posterieur. L’existence d’un Tinel sur le trajet du nerf tibial posterieur est le meilleur argument clinique en faveur de la compression. L’exploration electrophysiologique confirme le diagnostic. L’imagerie permet d’aider l’enquete etiologique a la recherche d’une lesion de la trame osseuse, des sequelles de fracture de l’arriere-pied, des troubles statiques du pied et de la presence d’eventuelles lesions expansives intracanalaires. Le traitement initial est toujours medical, il associe la prescription d’antalgiques, d’anti-inflammatoires. La reeducation sensitivomotrice est toujours indiquee. L’appareillage est indique en cas de troubles statiques du pied. La chirurgie est indiquee en cas d’echec du traitement conservateur ou en presence d’une lesion compressive intracanalaire. Elle est basee sur l’incision du retinaculum des flechisseurs, l’ouverture de l’aponevrose de l’abducteur de l’hallux et la neurolyse du nerf tibial posterieur. Le geste chirurgical doit liberer toutes ces structures pour avoir de bons resultats et eviter les recidives a long terme.

Seen the significant number of parts constituting a mechanism, assembly or disassembly sequence planning became a very hard problem. The subassembly identification concept can constitutes the most original way to solve this problem particularly for complex product. This concept aims to break down the multipart assembly product into particular number of subassemblies, and each subassembly is constituted by a small number of parts. Consequently the generation of assembly or disassembly sequence planning between parts can be determined relatively easily because it becomes between the subassemblies constituting the product. Then, each subassembly is assembled or disassembled using the same approach. In literature subassemblies identification approach from CAD model is not very developed and still a relevant research subject to be improved. In this paper, a novel subassemblies identification approach is presented. This proposed approach starts with the exploration of the CAD assembly data to get an adjacency matrix. Then, the extracted matrix is enriched by adding the contact in all directions in order to determine and to classify the base parts initiator of each subassembly. The next step is to identify subassemblies using a new matrix called sum matrix obtained from contact all direction matrix and fit matrix. For better discussing and explaining the stages of the proposed approach an example of CAD assembly product is presented in all sections of this paper.

In recent years, more and more research has been conducted in close collaboration with manufacturers to design robust and profitable dismantling systems. Thus, engineers and designers of new products have to consider constraints and disassembly specifications during the design phase of products not only in the context of the end of life but more precisely in the product life cycle. Consequently, optimization of disassembly process of complex products is essential in the case of preventive maintenance. In Fact, Disassembly Sequence Plan (DSP), which is among the combinatorial problems with hard constraints in practical engineering, becomes an NP-hard problem. In this research work, an automated DSP process based on a metaheuristic method named “Ant Colony Optimization” is developed. Beginning with a Computer Aided Design (CAD) model, a collision analysis is performed to identify all possible interferences during the components’ motion and then an interference matrix is generated to identify dynamically the disassembly parts and to ensure the feasibility of disassembly operations. The novelty of the developed approach is presented in the introduction of new criteria such as the maintainability of the usury component with several other criteria as volume, tools change and disassembly directions change. Finally, to highlight the performance of the developed approach, an implemented tool is developed and an industrial case is studied. The obtained results prove the satisfactory side of these criteria to identify a feasible DSP in a record time.

The performance of the porous glass ceramic doped with 10 wt% Zinc and 2 wt% TiN (46S6-10Zn), in the restoration of critical diaphyseal bone defect, was evaluated by several physicochemical methods and histological studies. The critical defect in rabbits was created and then filled with 46S6-10Zn. At different periods after implementation, animals were sacrificed. Samples were harvested for exploration. The nuclear magnetic resonance (MAS-NMR) of 31 P and 29 Si illustrates the progressive degradation of 46S6-10Zn in favor to of the formation and the development of biological apatite. Therefore, after one month of implementation, MAS-NMR 29 Si proves the presence of Q 2 (25%), Q 3 (73%) and Q 4 (2%). However, after six months, the disappearance of all these species was revealed and characterized by the 46S6-10Zn dissolution. Besides, MAS-NMR 31 P demonstrates the presence of Q C 0 (4%), Q HA 0 (55%) and Q a 0 (41%) after one month. Nevertheless, six months later, we observe the presence of Q HA 0 (80%) and Q a 0 (20%). Histological study demonstrates an intimate contact of 46S6-10Zn surrounding bone after one month of implantation. However, after four months, mature bone matrix became calcified and the implanted 46S6-10Zn began to be degraded. Moreover, nine months later, 46S6-10Zn was nearly resorbed and replaced by a calcified tissue in the periphery and an osteoid tissue in the middle of bone defects.

Apoptosis of skeletal muscle fibers is a well-known event occurring in patients suffering from muscular dystrophies. In this study, we hypothesized that functional polymorphisms in genes involved in the mitochondrial apoptotic pathway might modulate the apoptotic capacity underlying the muscle loss and contributing to intrafamilial and interfamilial variable phenotypes in LGMD2C (Limb Girdle Muscular Dystrophy type 2C) patients sharing the same c.521delT mutation in SGCG gene. Detection of apoptosis was confirmed on muscle biopsies taken from LGMD2C patients using the TUNEL method. We genotyped then ten potentially functional SNPs in TP53, BCL-2 and BAX genes involved in the mitochondrial apoptotic pathway. Potential genotype-dependent Bcl-2 and p53 protein expressed in skeletal muscle was investigated using western blot and ELISA assays. The result showed that muscle cells carrying the TP53-R72R and TP53-16 bp del/del genotypes displayed an increased p53 level which could be more effective in inducing apoptosis by activation of the pro-apoptotic gene expression. In addition, the BCL2-938 AA genotype was associated with increased Bcl-2 protein expression in muscle from LGMD2C patients compared to -938CC genotype, while there was no evidence of significant difference in the BAX haplotype. Our findings suggest that increased Bcl-2 protein expression may counteract pro-apoptotic pathways and thus reduce the muscle loss. To the best of our knowledge, this is a pioneer study evaluating the role of apoptotic BCL-2 and TP53 genes in contributing to the phenotypic manifestation of c.521delT mutation in LGMD2C patients. Larger studies are needed to validate these findings.

L’hemophilie type A est une maladie relativement rare. Elle est particulierement associee a un haut risque hemorragique en milieu chirurgical et pendant la periode peri-operatoire. Nous rapportons le cas d’un garcon de 10 ans, qui a developpe, suite a un traumatisme benin de l’avant-bras, une tension musculaire evoluant a bas bruit vers un syndrome de Volkmann, pour lequel une liberation type Page-Scaglietti-Gosset a ete indiquee. Nous insistons sur les difficultes de la prise en charge, essentiellement en periode peri-operatoire. Observation Il s’agit d’un garcon âge de 10 ans, hemophilique type A, victime d’un accident domestique lui occasionnant un traumatisme ferme de l’avant-bras gauche, sans lesion osseuse sous-jacente. Le tableau clinique a ete insidieux avec une tension musculaire moyenne et une douleur moderee. Le patient nous a ete adresse a 45 jours du traumatisme, au stade de syndrome de Volkmann. L’intervention de Page-Scaglietti-Gosset a ete indiquee necessitant alors une grande preparation peri-operatoire. Le protocole transfusionnel prevenant le risque hemorragique majeur a comporte deux transfusions quotidiennes de facteur VIII pendant 5 jours avant l’intervention, une transfusion 2 heures avant l’acte, une transfusion en peroperatoire. Le protocole postoperatoire a ete une transfusion a 2 heures apres l’acte, et une transfusion 2 heures avant chaque changement de pansement et avant tout acte comportant le moindre risque hemorragique. Cette prise en charge a ete tres lourde sur le plan economique vu le cout tres eleve de ces facteurs. Resultats L’intervention s’est tres bien deroulee, sans incidents. Les suites operatoires ont ete simples. Au recul de 6 mois, nous avons obtenu un resultat fonctionnel excellent. L’intervention de Page-Scaglietti-Gosset est une operation lourde et a un haut risque hemorragique. Le meilleur moyen de prevention en periode peri-operatoire reste le maintien du facteur deficitaire a une concentration suffisante par apport du facteur VIII. La surveillance de l’hemostase en perioperatoire est surtout clinique – champ operatoire, drain, plaie operatoire, points de ponction veineuse et couleur des urines. L’hemophilie, maladie de la coagulation relativement rare, est tres redoutee en periode perioperatoire pour ses risques hemorragiques. Poser le diagnostic et suivre l’evolution en peri-operatoire, instituer le traitement substitutif et appliquer les precautions liees au terrain a haut risque hemorragique – tels sont les problemes rencontres par le medecin.

Les traumatismes complexes du pouce peuvent entrainer des lesions complexes associes a des pertes de substances necessitant des reconstructions, parfois compliquees et en plusieurs temps. Une technique simple de compromis peut parfois apporter un resultat fonctionnel comparable a celui obtenu par des techniques compliquees essayant une reconstruction anatomique. Nous presentons un cas de reconstruction d’un pouce par un greffon osseux unique cortico-spongieux utilisant la technique de Masquelet. Patient âge de 48 ans, gaucher, menuisier, ampute deja du pouce droit, se presente suite accident de travail par toupie avec un traumatisme complexe de la main gauche. Le bilan lesionnel peroperatoire trouve un fracas ouvert du pouce avec perte de substance osseuse subtotale de P1 et P2 preservant la houppe, l’ongle et la pulpe avec delabrement important des parties molles et des pedicules, une amputation trans P1 du 2e et du 3e rayon, une amputation trans P2 du 4e et du 5e rayon. Un embrochage axial de sauvetage du pouce a ete realise ainsi qu’un embrochage M2-M1 ouvrant la premiere commissure. La PEC ulterieure consistait dans un premier temps a un comblement par du ciment pour preparation d’une membrane induite. Dans un 2e temps a un greffon cortico-spongieux monobloc a remplace le ciment. Au recul de 3 mois, bon etat local avec cicatrisation de la colonne du pouce et on a constate la creation d’une pseudarthrodese utile entre le greffon et la houppe restante de P2. Au recul de 6 mois, restitution d’une pince pollici-digitale permettant une fonction utile de la main. La main gauche, dont seul le pouce a ete reconstitue, a ete fonctionnellement plus utile que la main controlaterale, dont le pouce est ampute. La greffe osseuse par la technique de membrane induite est une alternative peu compliquee et interessante dans l’arsenal de reconstruction du pouce et a laquelle on doit penser devant toute perte de substance osseuse. Elle doit etre realisee en chirurgie differee, apres l’obtention d’une bonne cicatrisation, vu le risque infectieux. La perte du pouce est particulierement handicapante mais les progres de la chirurgie permettent aujourd’hui de le reconstruire. Tout doit etre tente pour reconstruire prioritairement ce doigt. La greffe osseuse par la technique de membrane induit est un procede peu complique mais peut donner dans certaines circonstances des resultats comparables a d’autres plus compliques et plus contraignants.