Horizontal Torsion Research Articles

The primary stability of ultrashort residual proximal femur fixed with triangular fixation stem prosthesis: a comparative biomechanical study based on sawbones models.

Tumor resection near the proximal end of the femur and revision surgery of the distal femoral prosthesis may result in a very short bone segment remaining at the proximal end of the femur, known as ultrashort residual proximal femur (URPF). In this study, we propose a triangular fixation stem (TFS) prosthesis to improve the fixation of URPF. The aim of this research is to investigate the biomechanical properties of the TFS prosthesis and compare it with the conventional stem (CS) prosthesis through in vitro biomechanical experiments, providing preliminary biomechanical evidence for prosthetic fixation of URPF. A biomechanical study was conducted using Sawbones to explore initial stability. Twelve Sawbones were used to create a bone defect model, and prostheses were designed and fabricated to emulate TFS fixation and CS fixation structures. Axial compression and horizontal torsion experiments were performed on the fixed models using a mechanical testing machine, recording maximum displacement, maximum torque, and femoral strain conditions. Under an axial compressive load of 2800N, the overall displacement of the TFS group was 3.33 ± 0.58mm, which was significantly smaller than that of the CS group (4.03 ± 0.32mm, P = 0.029). The femoral samples of the TFS group demonstrated that the strain value alterations at the medial points 2, 3, 5, 6 and the lateral point 10 were conspicuously smaller than those of the conventional stem group (P < 0.05). Under torsional loads at levels of 1°, 3°, and 5°, the torques of the TFS group were 3.86 ± 0.69Nm, 3.90 ± 1.26Nm, and 4.39 ± 1.67Nm respectively, all of which were significantly greater than those of the CS group (1.82 ± 0.82Nm, P < 0.001; 2.05 ± 0.89Nm, P = 0.016; 1.96 ± 0.50Nm, P = 0.015 respectively). The TFS prosthesis improves fixation strength and reduces strain on the femur's proximal surface. Compared to CS fixation, it offers better resistance to compression and rotation, as well as improved initial stability.

The Performance Assessment of the Structural Bracing Model for Multi-Story Building

Earthquakes are a severe issue for construction. The building collapsed due to the earthquake because it could not bear the earthquake load. Even more so, it was constructed using outdated and different building regulations that do not comply with modern building codes that account for seismic loads. As a result, disaster mitigation methods, such as retrofitting, must be implemented. Retrofitting procedures are commonly used in many developed countries. The bracing system is a typical retrofitting method used on building structures. In this study, a retrofitting program was carried out on The State Finance Building II Semarang, which was built in the 1980s, one of the old buildings in Semarang City, using a reinforced portal structure. This study's bracing system is a Concentrically Brace Frame (CBF) with Inverted V Brace and V Brace variations. The structural analysis software ETABS V.18.2.0 analyzes the building's structure. The structural review includes story drift, the P-Delta effect, and horizontal torsion irregularities. According to the results, steel bracing can minimize the period and displacement associated with story drift, making the structure more stable, with a maximum displacement reduction of 59.66% for inverted V-type steel bracing. Aside from that, steel bracing also can minimize the occurrence of torsion in the building. As a result, steel braces can be used to strengthen the structure.

Seismic behavior of the brick masonry rural building strengthened with polypropylene grid cement mortar coating: Shaking table tests

Brick masonry structures are widely applied around the world, especially in Chinese rural areas, but their seismic performance is not satisfactory due to high brittleness of material and poor integrity of structure. Accordingly, a low-cost and highly efficient strengthening method for brick masonry structure is needed. This paper presents the shaking table tests for a 1/2-scale single-story brick masonry rural building strengthened with polypropylene grid cement mortar coating. The damage states of the test model under earthquake motions with different intensity were observed. The dynamic characteristics including natural frequency and damping ratio were discussed. The seismic response, such as acceleration, displacement, torsion angle, base shear and hysteretic energy dissipation, were analyzed. The results show that the weak areas of the test model were the corners of windows and door, the intersections between longitudinal wall and transverse wall and the top of longitudinal walls. With the input PGA of 1.0 g, the natural frequencies of the test model in the X and Y directions decreased to 93.1 % and 88.2 % of the initial values, respectively, the damping ratio in the X and Y directions increased to 2.56 and 1.61 times the initial values, respectively, and the maximum story drift and horizontal torsion angle were 1/122 and 0.0037 rad, respectively. The comparison between actual earthquake damage and test results showed that the use of polypropylene grid cement mortar coating to strengthen brick masonry rural building could result in good seismic behaviors.

Seismic behavior of RC-SMF and IMF corner beam–column connections subjected to unidirectional and bidirectional lateral loads

Failure of beam–column connections can lead to partial and complete building collapse during severe earthquakes. Corner beam–column connections may be more vulnerable during earthquakes because they must withstand bidirectional loading transferred from nearby beams and columns. Furthermore, horizontal torsion exacerbates the damage to corner beam–column connections compared with other components. The objective of this study is to explore the seismic performance of corner beam–column connections in reinforced concrete intermediate moment frames (IMFs) and special moment frames (SMFs). Four full-scale beam–column connection specimens are fabricated and tested under two different loading types (unidirectional and bidirectional loading). It is observed that the strength and deformation capacity of the specimens were strongly affected by the type of loading (unidirectional and bidirectional lateral loading) and the reinforcement details (SMF, IMF). All corner connection specimens failed by joint shear failure irrespective of loading type and reinforcement detail.

Numerical Study on the Effect of Water Waves and Depths on Inclined Braces with Respect to the Stability of VLFS Platforms in the Caspian Sea

Abstract Very large floating structures (VLFSs) have various applications, such as recreational applications, port facilities, etc. A surge in the population, the advantages of building floating structures compared to traditional methods of land extraction from the sea, and the development of construction technologies, have led to engineers paying attention to very large floating structures. Bracing systems are capable of controlling and reducing the horizontal responses of a floating platform, but they have no major impact on its vertical responses. In the present study, the semi-floating platform was numerically designed to be least affected by the three factors of wave force, horizontal torsion, and horizontal displacement. In order to optimize the design, the semi-floating platform was simulated and subjected to the three wave directions with collision angles of 40, 45 and 55 degrees in the environmental conditions of the Caspian Sea and by exerting the wave effect in a Flow-3D model. Examination of the platform’s movements has demonstrated that the arrangement of an eight-way restraint system with a 40-degree restraint angle responds better to the impact of waves and is more economical compared to other designs.

Research review of large deformation monitoring of rock and soil

Landslide is a kind of extremely harmful global geological disaster, which often cause serious property losses and casualties. Therefore, scientific and effective landslide monitoring is of great significance for disaster prevention and mitigation. This article introduces the status quo and development trend of landslide deformation monitoring technology in the form of a review. Firstly, the deformation monitoring technologies about rock and soil are summarized and evaluated from three aspects: air (GNSS technology, InSAR technology), sky (UAV technology, 3D laser scanning), and ground (MEMS and Optical fiber technology). Then, the article focuses on ground (deep inclinometer) of the above three aspects, mainly talks about some advanced monitoring technologies used in inclinometer such as fiber Bragg grating and MEMS. The research results show that the inclinometer based on fiber Bragg grating has high monitoring accuracy with 1 με, and the data can be transmitted in time without electromagnetic interference. The MEMS-based inclinometer can measure the vertical tilt angle and horizontal torsion angle, which can realize the three-dimensional deformation monitoring in space. The above research and development of the novel inclinometer provide an effective mean for rock and soil deformation monitoring. Finally, the article summarizes the realization of accurate and reliable monitoring of landslide deformation.

Analysis on dynamic eccentricity effect and torsional performance of steel reinforced concrete frame with special-shaped column

Based on the seismic simulation shaking table test of steel reinforced concrete frame model with special-shaped column, the lateral-torsional vibration response, dynamic eccentricity effect and nonlinear torsion response law of the model structure are studied. The results show that, under the action of three-way earthquake, the Y-direction and X-direction horizontal torsion coupling phenomena occur in the high-order vibration mode of the model structure, and the accidental eccentric torsion has a light influence on the seismic performance of the special-shaped column structure which does not exceed the height limit. The nonlinear torsion analysis shows that the inter-storey displacement angle of the model structure is affected by floor position, eccentricity and ground motion intensity. As the eccentricity and seismic intensity increases, the inter-storey torsion Angle of the model structure increases constantly. In case the relative eccentricity is less than or equal to 0.5 and the peak acceleration is less than or equal to 0.62g, then the amplitude of the inter-storey torsion Angle of the model increases slightly; In case the relative eccentricity is more than 0.5, then the lateral-torsional coupled effect of earthquake response of the structure is obvious, and the influence of eccentricity on torsion effect of the model structure is more obvious. The results show that steel reinforced concrete frame with special-shaped column has good ductility and torsion resistance.

Experimental Study of Seismic Isolated Structures with Sliding Implant-Magnetic Bearings

ABSTRACT Sliding implant-magnetic bearing (IMB) is a new type of seismic isolators that benefits from its adaptive energy-dissipation behavior. In order to assess the performance of the sliding IMB for seismic protection, a complete shaking table test on the base-isolated structure is reported in the present paper. Tri-directional-recorded earthquake ground motions and mono-directional artificial earthquake ground motions pertaining to both site classes II and III are employed to drive structural vibration in the laboratory experiment, respectively. Seismic mitigation of the base-isolated structure with respect to dynamic characteristics, story accelerations, inter-story drifts, horizontal torsions, and local strains is addressed. Experimental study shows expected results that the base-isolated structure with sliding IMBs attains more profitable mitigations on story accelerations and inter-story drifts under earthquake ground motions pertaining to the stiff soil site than those pertaining to the soft soil site. Significant mitigations on horizontal torsion of the structure and on local strain at the column bottom are attained as well. In addition, seismic performance of sliding IMBs during the shaking table test is assessed. It is revealed that the isolators exhibit satisfactory energy-dissipation capacity and excellent frictional behavior, and maintain good working state during the entire experimental test.

Effects of the Accidental Eccentricity on Regular and Irregular Buildings

The response of any building during seismic loading conditions might be affected by several factors, the horizontal torsion effect which generated by the eccentricity between centre of mass and centre of rigidity has conspicuous impact on the total response of building however, in many of the modern codes this influence is introduced by adopting the accidental eccentricity (AE) concept. In this paper analytical evaluation was done to assess the impact of the accidental torsion on high-rise structures with asymmetrical and symmetrical plan configurations in order to estimate the horizontal torsion effects for both regular and irregular structures during a high-intensity earthquake. The linear-static method, linear-dynamic (RS) method and time history method are the followed procedures for analysing the models, whilst the provisions of the considered codes are the Indian standard provisions and uniform building code 97 provisions, three different conditions were applied the first applying the seismic later load without accidental-eccentricity (AE), the second case is assuming %5 of (AE) which is worldwide presupposed value in many of seismic codes, where the third condition is adapting an accidental-eccentricity (AE) calculated according to the selected seismic codes. ETABS 2016 Software was utilized for analysing all models.

Connections on bundles of horizontal frames associated with contact sub-pseudo-Riemannian manifolds

Given a contact sub-pseudo-Riemannian manifold (M,H,g) we study connections on the bundle OH,g(M) of orthonormal horizontal frames attached to (M,H,g). We prove that there exist connections on OH,g(M) with vanishing horizontal torsion. All such connections induce a unique covariant derivation ∇:Sec(H)×Sec(H)⟶Sec(H) satisfying ∇g=0 and ∇XY−∇YX=P([X,Y]) for all X,Y∈Sec(H), where P:TM⟶H is the canonically defined projection. If we additionally assume that the Reeb vector field R is an infinitesimal isometry, then one can prove that there exists a unique connection on OH,g(M) with vanishing torsion. The induced covariant derivation ∇:Sec(TM)×Sec(H)⟶Sec(H) additionally satisfies the condition ∇RX=[R,X] for all X∈Sec(H). In the latter case, there exists a coframe on OH,g(M) which is invariant with respect to the isometries of (M,H,g), and which enables one to obtain the complete system of differential invariants of the metric (H,g).

Penetrating Keratoplasty for Keratoconus - Excimer Versus Femtosecond Laser Trephination.

Background:In case of keratoconus, rigid gas-permeable contact lenses as the correction method of first choice allow for a good visual acuity for quite some time. In a severe stage of the disease with major cone-shaped protrusion of the cornea, even specially designed keratoconus contact lenses are no more tolerated. In case of existing contraindications for intrastromal ring segments, corneal transplantation typically has a very good prognosis.Methods:In case of advanced keratoconus – especially after corneal hydrops due to rupture of Descemet’s membrane – penetrating keratoplasty (PKP) still is the surgical method of first choice. Noncontact excimer laser trephination seems to be especially beneficial for eyes with iatrogenic keratectasia after LASIK and those with repeat grafts in case of “keratoconus recurrences” due to small grafts with thin host cornea. For donor trephination from the epithelial side, an artificial chamber is used. Wound closure is achieved with a double running cross-stitch suture according to Hoffmann. Graft size is adapted individually depending on corneal size („as large as possible – as small as necessary“). Limbal centration will be preferred intraoperatively due to optical displacement of the pupil. During the last 10 years femtosecond laser trephination has been introduced from the USA as a potentially advantageous approach.Results:Prospective clinical studies have shown that the technique of non-contact excimer laser PKP improves donor and recipient centration, reduces “vertical tilt” and “horizontal torsion” of the graft in the recipient bed, thus resulting in significantly less “all-sutures-out” keratometric astigmatism (2.8 vs. 5.7 D), higher regularity of the topography (SRI 0.80 vs. 0.98) and better visual acuity (0.80 vs. 0.63) in contrast to the motor trephine. The stage of the disease does not influence functional outcome after excimer laser PKP. Refractive outcomes of femtosecond laser keratoplasty, however, resemble that of the motor trephine.Conclusions:In contrast to the undisputed clinical advantages of excimer laser keratoplasty with orientation teeth/notches in keratoconus, the major disadvantage of femtosecond laser application is still the necessity of suction and applanation of the cone during trephination with intraoperative pitfalls and high postoperative astigmatism.

PKP for Keratoconus - From Hand/Motor Trephine to Excimer Laser and Back to Femtosecond Laser

For patients with keratoconus, rigid gas-permeable contact lenses are the first line correction method and allow good visual acuity for quite some time. In severe stages of the disease with major cone-shaped protrusion of the cornea, even specially designed keratoconus contact lenses are no longer tolerated. If there are contraindications for intrastromal ring segments, corneal transplantation typically has a very good prognosis. In patients with advanced keratoconus - especially after corneal hydrops due to rupture of Descemet's membrane - penetrating keratoplasty (PKP) is still the first line surgical method. Non-contact excimer laser trephination seems to be especially beneficial for eyes with iatrogenic keratectasia after LASIK and for patients with repeat grafts due to "keratoconus recurrences" due to small grafts with thin host cornea. For donor trephination from the epithelial side, an artificial chamber is used. Wound closure is achieved with a double running cross-stitch suture according to Hoffmann. Graft size is adapted individually, depending on corneal size ("as large as possible - as small as necessary"). Limbal centration is preferred intraoperatively, due to optical displacement of the pupil. During the last 10 years, femtosecond laser trephination has been introduced from the USA as a potentially advantageous approach. Prospective clinical studies have shown that the technique of non-contact excimer laser PKP improves donor and recipient centration, reduces "vertical tilt" and "horizontal torsion" of the graft in the recipient bed, and thus results in significantly less "all-sutures-out" keratometric astigmatism (2.8 vs. 5.7 D), more regular topography (surface regularity index [SRI] 0.80 vs. 1.0) and better visual acuity (0.80 vs. 0.60), in comparison to the motor trephine. The stage of the disease does not influence functional outcome after excimer laser PKP. However, the refractive outcome of femtosecond laser keratoplasty resembles that with motor trephine. In contrast to the undisputed clinical advantages of excimer laser keratoplasty with orientation teeth/notches in keratoconus, the major disadvantage of femtosecond laser application is still the necessity of suction and applanation of the cone during trephination, with intraoperative disadvantages and high postoperative astigmatism.

TABU SEARCH ALGORITHM FOR OPTIMIZING PILE FOUNDATION LAYOUT ON FOOTING OF RESIDENTIAL HOUSE

In practice, positioning pile foundation on footing layout of a residential house is often based on empirical judgment and long working experiences of a designer. After the pile requirements calculated, some conditions like number of piles, spacing placement of all piles on the footing, and locations such as under columns, corner, or intersection have to be determined. Besides, the coincidence of shear and gravity centers is also another essential design consideration, which is often ignored in design practice. The present study is aimed at eliminating the horizontal torsion effects during the earthquakes occurrences by reducing the eccentricity distance between the centers of gravity and shear. The scope of present study excludes any foundation or structural related design and analysis. Recent advancement of computing capabilities of computers has made the structural analysis become a convenient tool at hand for designers. In this study, the Tabu Search algorithm was adopted as an optimization tool for pile placing on the footing of residential houses. Tabu Search algorithm was known as an efficient method for solving combinatorial optimization problems where it can find some quality solutions in relatively short running time without getting stuck in local optima. An example of footing layout design was demonstrated to show the effectiveness of the present study as a decision-making tool in design practice.

On the Trigonometric Correction of One Powerful Formula

An attempt is presented for the description of the magnitude of Newton’s gravitational force in the experiments with a horizontal torsion balance. There were developed many experimental arrangements in order to find experimentally the value of big G – the Newtonian gravitational constant – after the Michell-Cavendish experiment in 1798. The geometrical configurations of test and source masses play a very important role in these experiments. The old trigonometric function “sagitta” used by Johannes Kepler and Isaac Newton was newly employed as the trigonometric tool for the determination of the magnitude of Newton’s gravitational force between the source mass and the test mass. Based on the known experimental configurations with the horizontal torsion balance we have found that the “true” Michell-Cavendish configuration is not dependent on the space orientation. This “sagitta” function can be experimentally tested in the Karagioz-Izmailov configuration and the Karagioz-Izmailov-Gillies-Gershteyn configuration with the technology available at begin of our century. A proposal for the decomposition of the big G was presented. This concept could not be experimentally tested before the discoveries of the dipole in the cosmic microwave background radiation and the Pioneer anomaly.

Measuring hull girder deformations on a 9300 TEU containership

A 9300 TEU container carrier was equipped in 2006 with instrumentation aimed at wave induced accelerations, and motions. In 2010 the system was extended with strain sensors to include structural loads. Section loads for vertical bending could be readily obtained but the originally intended derivation of horizontal bending and torsion from the measured strains was found to be unreliable. This paper addresses an alternative approach that was adopted in the post processing of results. In particular the concept to use acceleration sensors to capture global hull deformations along the length of the hull, and the use of a data fusion procedure to obtain section loads from combined sensor data and finite element calculations. The approach is illustrated by comparison of actually measured accelerations and local strains with values obtained from the data fusion model. It is concluded that the approach is promising but in need of further validation and development. In particular the number and shapes of the modes used may not have been sufficient to represent the true deflection and thus strain distributions along the high loaded areas.

Excimer vs Femtosecond laser for nonmechanical keratoplasty – Where are the true benefits?

AbstractPurpose: To compare the intraoperative feasibility and postoperative outcome of the excimer (EXL) and femtosecond laser (FSL) for penetrating keratoplasty (PKP). Methods: Since 1989 more than 3500 non‐contact nonmechanical PKPs using the Zeiss‐Meditec MEL70® 193 nm EXL along metal masks with eight "orientation teeth/notches" (PKP) were performed. Since 2006 various groups applied the FSL for PKP with various 3D‐configurations. Results: The technique of EXL PKP may improve donor and recipient centration, reduce "vertical tilt" and "horizontal torsion" of the graft in the recipient bed, thus resulting in significantly less "all‐sutures‐out" astigmatism, higher regularity of the topography and better visual acuity. Clinical results of FSL PKP ‐ requiring variable amounts of applanation thus causing distortion of corneal tissue ‐ are still very limited and not yet finally convincing. Conclusions: Because of undisputed clinical advantages, especially in eyes with keratoconus, EXL trephination is still favoured in Homburg/Saar in daily practise. To determine potential benefits of FSL over EXL PKP, a prospective randomized study for keratoconus and Fuchs dystrophy is ongoing in Homburg/Saar.

REVIEW WORK ON ANALYSIS OF F1 CAR FRAME USING ANSYS

SAE Supra India organizes the undergraduate racing competition for 2013 in which teams are challenged to design considering the various circumstances and to fabricate the making a design in the campus itself. This paper’s sole focus is the design and analysis for a chassis which has to sustain the racing environment. As chassis plays a vital role in a race car and also it is the back bone of a good race car. Good designs allow a light, stiff and extremely safe chassis to be produced at. The work shown in this research paper was taken participation by Black Hawk SAE Supra team. This paper introduces several concepts of frame’s load distributions such a lateral, longitudinal vertical and horizontal torsion and consequent deformation modes. .Various studies were conducted upon the understanding the relation of the machine elements with the user according to Ergonomics consideration. Ergonomics considers factors such as Drivers visibility, seat inclination, thermal isolation etc. The chassis design was carried out on CAD software such as Pro-Engineers. Design model was prepared using anthropometric parameters of tallest driver as 95th percentile male was selected to SAE rules book. Static and dynamic load distributions were calculated analytically followed by extensive study of various boundary conditions to be applied during diverse FEA (Finite Element Analysis) test which was carried out in Ansys. Stress distributions, lateral displacements during static, dynamic and frequency modes were analyzed and found considerably high factor of safety as 3.85.

DALK und perforierende Laserkeratoplastik bei fortgeschrittenem Keratokonus

In cases of contact lens intolerance and/or central corneal scars, corneal transplantation is indicated for advanced keratoconus. This can be performed as deep anterior lamellar keratoplasty (DALK) or as penetrating keratoplasty (PKP). The German keratoplasty registry shows that the proportion of anterior lamellar grafts in Germany has remained stable at approximately 5 % in recent years. Up to now DALK has not been technically standardized but can result in a good visual acuity using the big bubble technique if Descemet's membrane is laid bare intraoperatively. In 10-20 % a conversion to PKP is required if perforation of Descemet's membrane occurs. In cases of advanced keratoconus PKP is still the method of first choice especially after corneal hydrops due to rupture of Descemet's membrane. Non-contact excimer laser trephination seems to be especially beneficial for eyes with iatrogenic keratectasia after LASIK and those with repeat grafts in cases of keratoconus recurrence due to the graft being too small. For donor trephination from the epithelial side, an artificial chamber is used. Wound closure is achieved by a double running cross-stitch suture according to Hoffmann. Graft size is adapted individually depending on corneal size (as large as possible and as small as necessary). Limbal centration is given priority intraoperatively due to optical displacement of the pupil. Prospective clinical studies have shown that the technique of non-contact excimer laser PKP improves donor and recipient centration, reduces vertical tilt and horizontal torsion of the graft in the recipient bed, thus resulting in significantly less all-sutures-out keratometric astigmatism (2.8D versus 5.7D), higher regularity of the topography (SRI 0.80 vs. 0.98) and better visual acuity (0.80 vs. 0.63) in contrast to the motor trephine. The stage of the disease does not influence functional outcome after excimer laser PKP. In cases with optimal course DALK achieves the same visual outcome as mechanical PKP but the healthy endothelium can be preserved and endothelial immune reactions are prevented in keratoconus. In contrast to the undisputed clinical advantages of excimer laser keratoplasty with orientation teeth/notches in keratoconus, the major disadvantage of femtosecond laser application is still the necessity of suction and applanation of the cone during trephination.

Prophylaxe und Management von Komplikationen bei perforierender Keratoplastik

Besides routine postoperative follow-up the prophylaxis of complications in penetrating keratoplasty (PKP) includes special preoperative and intraoperative aspects. Preoperative prophylaxis consists of the therapy of systemic diseases and eyelid abnormalities, determining individual optimal graft size, avoiding PKP in cases of uncontrolled intraocular pressure, avoiding PKP in cases of corneal hydrops, pretreatment of vascularized cornea, amniotic membrane transplantation before PKP in cases of ulcerative keratitis, quality controlled organ-cultured transplants and preoperative counselling by the surgeon to ensure patient compliance. Intraoperative prophylaxis consists of controlled arterial hypotension and complete relaxation during general anesthesia, avoidance of decentration, horizontal torsion and vertical tilt using a non-contact trephination technique (preferably excimer laser) with double-running cross-stitch sutures and application of Flieringa rings in aphakic vitrectomized eyes. Postoperatively, periodical control examinations using fluorescein and blue light are indispensable. All loose sutures have to be removed as early as possible. In cases of herpetic eye disease 2 × 400mg of oral acyclovir should be administered for at least 1 year. In cases of therapy-resistant epithelial defects 100 % autologous serum eyedrops or amniotic membrane patches are valid options. Immune reactions must be diagnosed and treated immediately with high doses of corticosteroids.

The Tibial Pilon Fractures: Are there Problems?

decade [2]. These fractures may be caused by falls, road accidents or sport injuries. TPF may be produced by two different dynamics: shear-stress injuries, which separate bone fragments, and compression injuries, which compress and impact bony matter. The mechanism is the implosion of the tibial plafond caused by axial compression between the talus and the distal tibial articular surface, with or without horizontal torsion [3]. It is often associated with significant degloving of the soft tissue surrounding the bone, while the skin, capsule and ligaments are partly spared. The aim of operative treatment is to anatomically reduce the fracture fragments to restore the congruity of the joint surface and promote bony union with minimal disruption of the soft tissue envelope [4]. So the TPF are always complex. Its complexity is related to the number of bone fragments, the decomposition of the bone fragments and the lesion of the neighboring soft tissues. Muller’s AO classification is the more complete and universally accepted system: it characterizes Type A (not articular), type B (partially articular) and type C (completely articular) fractures. TPF can also be classified by Ruedi and Allgower classification that includes three type of fracture depending on the displacement of articular surface, metaphyseal and injury extent of fractures [5]. The treatment of this type of fractures is a very timely topic, since there is no real consensus on the unique methods of treatment, which must take into account not only the stabilization of bone but also soft tissue which frequently leads to complications. Non operative management, such as cast immobilization, is reserved only for nondisplaced articular fractures, patients who have surgical controindications because of medical co-morbidities, or patients with low demand such as those who are nonambulatory. Surgical treatments are varied and different: minimally invasive osteosynthesis (MIO), open reduction and internal fixation (ORIF), minimally invasive plate osteosynthesis (MIPO), esternal fixation (EF), external fixator combined with limited invasive internal fixation (LIFEF), ilizarov treatment. Operative fixation of TPF has presented a significant challenge to the orthopaedic surgeon as the extensive soft tissue damage associated with such injuries makes surgical intervention hazardous. Advantages of minimally invasive osteosynthesis of pilon fractures compared to conventional open reduction and osteosynthesis, include protection of the soft tissue and no further disturbances of circulation-ideal prerequisites for undisturbed bone healing. Ruedi and Allogower [5] believed that anatomical restoration of the articular surface was fundamental surgical point. They considered essential: the restoration of the length and axis of fibula or tibia, the reconstruction of the distal end of the tibia, the filling of the defect resulting from im paction, using cancellous autografts, the support of the medial side of the tibia by plating to prevent a late varus deformity. White et al. say that provided surgery is performed expeditiously by experienced orthopedic trauma surgeons, most tibial pilon fractures can be stabilized by primary ORIF within a safe and effective operative window with relatively low rates of wound complications, a high quality of reduction, and functional outcomes that compare favorably with the published results for all other reported surgical treatments of these severe incurie [6]. A retrospective study by Watson et al. has shown that there is a significantly higher complication rate with the use of open plating techniques in AO type C fractures of the distal tibia, and this is probably related to the amount of dissection and stripping of soft tissues needed to achieve reduction and plate fixation [7].