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OBJECTIVES: Tissue scaffolds are usually rigid structures made of polymeric materials. Biocompatibility and biodegradability are important properties for scaffold materials to possess, ensuring they support for cell growth and are extremely useful in in vitro 3D cell cultures.2D in vitro studies do not provide the desired success in in vivo applications. Tissue scaffolds are 3Dcell culture systems that eliminate this problem with breast cancer cell culture. The main objective of this study was to produce biocompatible and suitable porosity scaffolds from PLA and PCL materials, which enables MCF-7breast cancer cells to proliferate in 3D MATERIAL&METHODS: A custom 3Dprinter and 1.75 mm PCL and PLA filaments were used for the production of tissue scaffolds. Tissue scaffolds are produced with two different filling rates (20% and 40%).The design and production parameters of the scaffolds are defined and optimized by SolidWorks and Slic3r softwares to set the correct printing procedure. Biomechanical tests for mechanical characterization of all scaffolds were performed.MCF-7 breast cancer cell line was used to evaluate tissue scaffolds for 3Dcell culture. The ability of the cells to adhere to the scaffold surface was determined by crystal violet fixation and staining method used to detect viable cells RESULTS: 3Dcell culture with PCL and PLA tissue scaffolds is useful to improve cancer cell culture applications and enhance cell proliferation.3D tissue scaffolds have shown that MCF-7 cells are more compatible with surface adhesion than 2Dcultures CONCLUSIONS: The data obtained show that porous PLA and PCL tissue scaffolds are supportive for the 3Dculture and proliferation of MCF-7 breast cancer cells by providing a micro-environment in vivo mimic. [ABSTRACT FROM AUTHOR]

Background: Distal tibial fractures remains a significant challenge in orthopedic trauma surgery. As the fracture level approaches the joint, alternative fixation options instead of intramedullary nailing (IMN) come to the fore. The present study aimed to assess the biomechanical stability of IMN at different distal tibial fracture levels and the number of locking screws required., Methods: Using a total of 21 sawbone models, 3 different tibial fracture levels (3, 4.5, and 6 cm proximally to the talocrural joint) were created and the fractures were fixed using 2, 3, or 4 distal locking screws. A single compression force at a speed of 30 mm/min with a maximum force of 800 Newton and a cyclic compression force of 60 cycles at a speed of 60 mm/min was applied to all tibia models. The applied weight and displacements from the fracture lines were recorded and evaluated., Results: There was no statistically significant difference in fixation with 2 distal locking screws in groups 1, 2, and 3 (single test P =.9689) (cyclic test P =.8050). Therefore, if 2 distal screws are used, the fracture level does not affect the strength of fixation. In fractures located 6 cm proximal to the talocrural joint, all 4 holes of the nail can be used to insert screws, which provides a stronger fixation. When 2 screws are used, a statistically weaker fixation is obtained than with 3 or 4 screws. However, there is no significant difference between using 3 or 4 screws., Conclusion: Our findings support the use of IMN with 2 distal locking screws as a viable option for the management of distal tibial fractures. We found that it provides sufficient fixation regardless of the fracture level, suggesting that there is no need to choose an alternative fixation technique due to concerns of inadequate fixation as the fracture line moves distally. In cases where more stable fixation is desired, an additional locking screw can be used, but the potential increase in procedure and fluoroscopy time should be considered., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Regeneration of osteochondral tissue with its layered complex structure and limited self-repair capacity has come into prominence as an application area for biomaterial design. Thus, literature studies have aimed to design multilayered scaffolds using natural polymers to mimic its unique structure. In this study, fabricated scaffolds are composed of transition layers both chemically and morphologically to mimic the gradient structure of osteochondral tissue. The aim of this study is to produce gradient chitosan (CHI) scaffolds with bioactive snail ( Helix aspersa ) mucus (M) and slime (S) extract and investigate the structures regarding their physicochemical, mechanical, and morphological characteristics as well as in vitro cytocompatibility and bioactivity. Gradient scaffolds (CHI-M and CHI-S) were fabricated via a layer-by-layer freezing and lyophilization technique. Highly porous and continuous 3D structures were obtained and observed with SEM analysis. In addition, scaffolds were physically characterized with water uptake test, micro-CT, mechanical analysis (compression tests), and XRD analysis. In vitro bioactivity of scaffolds was investigated by co-culturing Saos-2 and SW1353 cells on each compartment of gradient scaffolds. Osteogenic activity of Saos-2 cells on extract loaded gradient scaffolds was investigated in terms of ALP secretion, osteocalcin (OC) production, and biomineralization. Chondrogenic bioactivity of SW1353 cells was investigated regarding COMP and GAG production and observed with Alcian Blue staining. Both mucus and slime incorporation in the chitosan matrix increased the osteogenic differentiation of Saos-2 and SW1353 cells in comparison to the pristine matrix. In addition, histological and immunohistological staining was performed to investigate ECM formation on gradient scaffolds. Both characterization and in vitro bioactivity results indicated that CHI-M and CHI-S scaffolds show potential for osteochondral tissue regeneration, mimicking the structure as well as enhancing physical characteristics and bioactivity.

The meniscus is a fibrocartilaginous tissue that is very important for the stability of the knee joint. However, it has a low ability to heal itself, so damage to it will always lead to articular cartilage degeneration. The goal of this study was to make a new type of meniscus scaffold made of chitosan, loofah mat, and PHBV nanofibers, as well as to describe hydrogel composite scaffolds in terms of their shape, chemical composition, mechanical properties, and temperature. Three different concentrations of genipin (0.1, 0.3, and 0.5 %) were used and the optimal crosslinker concentration was 0.3 % for Chitosan/loofah (CL) and Chitosan/loofah/PHBV fiber (CLF). Scaffolds were seeded using undifferentiated MSCs and incubated for 21 days to investigate the chondrogenic potential of hydrogel scaffolds. Cell proliferation analyses were performed using WST-1 assay, GAG content was analyzed, SEM and fluorescence imaging observed morphologies and cell attachment, and histological and immunohistochemical studies were performed. The in vitro analysis showed no cytotoxic effect and enabled cells to attach, proliferate, and migrate inside the scaffold. In conclusion, the hydrogel composite scaffold is a promising material for engineering meniscus tissue., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier B.V. All rights reserved.)

The main goal of the study was to produce chitosan-collagen hydrogel composite scaffolds consisting of 3D printed poly(lactic acid) (PLA) strut and nanofibrous cellulose for meniscus cartilage tissue engineering. For this purpose, first PLA strut containing microchannels was incorporated into cellulose nanofibers and then they were embedded into chitosan-collagen matrix to obtain micro- and nano-sized topographical features for better cellular activities as well as mechanical properties. All the hydrogel composite scaffolds produced by using three different concentrations of genipin (0.1, 0.3, and 0.5%) had an interconnected microporous structure with a swelling ratio of about 400% and water content values between 77 and 83% which is similar to native cartilage extracellular matrix. The compressive strength of all the hydrogel composite scaffolds was found to be similar (∼32 kPa) and suitable for cartilage tissue engineering applications. Besides, the hydrogel composite scaffold comprising 0.3% (w/v) genipin had the highest tan δ value (0.044) at a frequency of 1 Hz which is around the walking frequency of a person. According to the in vitro analysis, this hydrogel composite scaffold did not show any cytotoxic effect on the rabbit mesenchymal stem cells and enabled cells to attach, proliferate and also migrate through the inner area of the scaffold. In conclusion, the produced hydrogel composite scaffold holds great promise for meniscus tissue engineering.

The present study aims to investigate the effect of amount of lateralization and/or anteversion of the point where the iliac cut meets with the posterior column cut of periacetabular osteotomy (PAO), on X-ray parameters such as Center of edge (CE) angle, retroversion index (RVI) and sharp angle. Fourteen patients with symptomatic hip dysplasia (CE° < 20°) were included. Pelvis Computerized tomography (CT) sections were used for 3D printing. PAO was then performed on these models. The point (A), 1 cm lateral to the pelvic brim, is marked where the iliac cut intersects the posterior column cut. In Group I (1.5-0), point A is lateralized parallel to the osteotomy line for 1.5 cm. In Group II (1.5-0.5), it is additionally anteverted for 0.5 cm. In Group III (3-0), point A is lateralized for 3 cm and then additionally anteverted for 1 cm (Group IV: 3-1). Radiographs were taken in each stage. The lateral CE angle, RVI and sharp angle were measured. All had an increase in the CE angle and RVI and a decrease in the sharp angle compared to the control group ( P  < 0.05). The amount of CE angle (ΔCE) or RVI increase (ΔRV) was as follows: 3-1(38°, 0.3) > 3-0(27°, 0.2) and 1.5-0.5(25°, 0.1) > 1.5-0(17°, 0.07) ( P  < 0.05) (with no difference between groups 1.5-0.5 and 3-0, P  = 0.7). The amount of sharp angle decrease was as follows: 3-1(20°), 3-0(18°) < 1.5-0.5(11°) < 1.5-0(8°) ( P  < 0.05). The lateralization of the intersection point where the iliac wing cut meets with the posterior column cut along the cut surface led to an increase of lateral cover and focal retroversion. Additional anteversion leads to further increases in those parameters, while groups 1.5-0.5 and 3-0 did not differ between., (© The Author(s) 2022. Published by Oxford University Press.)

Biobased extracts comprise various bioactive components and they are widely used in tissue engineering applications to increase bioactivity as well as physical characteristics of biomaterials. Among animal sources, garden snail Helix aspersa has come into prominence with its antibacterial and regenerative extracts and show potential in tissue regeneration. Thus, in this study, bioactive H. aspersa extracts (slime, mucus) were loaded in chitosan (CHI) matrix to fabricate porous scaffolds for hard tissue regeneration. Physical, chemical properties, antimicrobial activity was determined as well as in vitro bioactivity for bone and cartilage regeneration. Mucus and slime incorporation enhanced mechanical properties and biodegradation rate of CHI matrix. Scanning electron microscopy images showed that the average pore size of the scaffolds decreased with higher extract content. Mucus and slime extracts showed antimicrobial effect on two bacterial strains. In vitro cytotoxicity, osteogenic and chondrogenic activity of the scaffolds were evaluated with Saos-2 and SW1353 cell lines in terms of Alkaline phosphatase activity, biomineralization, GAG, COMP and hydroxyproline content. Cell viability results showed that extracts had a proliferative effect on Saos-2 and SW1353 cells when compared to the control group. Mucus and slime extract loading increased osteogenic and chondrogenic activity. Thus, the bioactive extract loaded CHI scaffolds showed potential for bone and cartilage regeneration with enhanced physical properties and in vitro bioactivity., (© 2021 IOP Publishing Ltd.)

Tissue engineering approaches which include a combination of cells and scaffold materials provide an alternative treatment for meniscus regeneration. Decellularization and recellularization techniques are potential treatment options for transplantation. Maintenance of the ultrastructure composition of the extracellular matrix and repopulation with cells are important factors in constructing a biological scaffold and eliminating immunological reactions.The aim of the study is to develop a method to obtain biological functional meniscus scaffolds for meniscus regeneration. For this purpose, meniscus tissue was decellularized by our modified method, a combination of physical, chemical, and enzymatic methods and then recellularized with a meniscal cell population composed of fibroblasts, chondrocytes and fibrochondrocytes that obtained from mesenchymal stem cells. Decellularized and recellularized meniscus scaffolds were analysed biochemically, biomechanically and histologically. Our results revealed that cellular components of the meniscus were successfully removed by preserving collagen and GAG structures without any significant loss in biomechanical properties. Recellularization results showed that the meniscal cells were localized in the empty lacuna on the decellularized meniscus, and also well distributed and proliferated consistently during the cell culture period (p < 0.05). Furthermore, a high amount of DNA, collagen, and GAG contents (p < 0.05) were obtained with the meniscal cell population in recellularized meniscus tissue.The study demonstrates that our decellularization and recellularization methods were effective to develop a biological functional meniscus scaffold and can mimic the meniscus tissue with structural and biochemical features. We predict that the obtained biological meniscus scaffolds may provide avoidance of adverse immune reactions and an appropriate microenvironment for allogeneic or xenogeneic recipients in the transplantation process. Therefore, as a promising candidate, the obtained biological meniscus scaffolds might be verified with a transplantation experiment.

Background: Distraction osteogenesis to correct deformity and limb-length discrepancy was defined by Ilizarov. Traditional distraction osteogenesis was made with circular external fixators or monolateral fixators commonly for deformity, and external fixators was related with pin site infections and pain due to soft-tissue transfixation. Nowadays, bone lengthening method is used with different intramedullary nail systems for cosmetic purposes., Methods: From 2011 until 2018, a total of 9 patients (6 males and 3 females:16 femoral, 2 tibial), with constitutional short stature, to whom the intramedullary nail lengthening technique for cosmetic purposes had been applied, were retrospectively reviewed. The mean age was 28.3 while the mean height before the lengthening was 151 cm., Result: The mean lengthening gained in all patients were 8.7 cm. The mean follow-up period was 22 ± 11 months while the healing index with normal bone healing was 46.8 ± 16 months/cm. Complications that we noted were; insufficient bone regeneration (n = 2), quadriceps contracture (n = 1), proximal locking screw runaway (n = 1)., Conclusion: Bone lengthening for aesthetic purposes with different nail systems can be very safe and beneficial to the patients improving their social capabilities and self-confidence. Yet, patients should be well informed about the complications and risks of the lengthening surgery., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2020 Professor P K Surendran Memorial Education Foundation. Published by Elsevier B.V. All rights reserved.)

Objective: The aim of this study was to investigate the biomechanical differences between human dura mater and dura mater substitutes to optimize biomimetic materials., Methods: Four groups were investigated. Group I used cranial dura mater (n=10), group II used Gore-Tex® Expanded Cardiovascular Patch (W.L. Gore & Associates Inc., Flagstaff, AZ, USA) (n=6), group III used Durepair® (Medtronic Inc., Goleta, CA, USA) (n=6), and group IV used Tutopatch® (Tutogen Medical GmbH, Neunkirchen am Brand, Germany) (n=6). We used an axial compression machine to measure maximum tensile strength., Results: The mean tensile strengths were 7.01±0.77 MPa for group I, 22.03±0.60 MPa for group II, 19.59±0.65 MPa for group III, and 3.51±0.63 MPa for group IV. The materials in groups II and III were stronger than those in group I. However, the materials in group IV were weaker than those in group I., Conclusion: An important dura mater graft property is biomechanical similarity to cranial human dura mater. This biomechanical study contributed to the future development of artificial dura mater substitutes with biomechanical properties similar to those of human dura mater.

Background: High-energy traumas are common occurrences worldwide. The rate of overlooked neck fractures in polytrauma cases is also high. Previous studies have shown that articular hip pathologies, particularly neck fractures, are associated with fractures of the femoral shaft. This study sets out to describe cases of intra-articular hip pathology following traumatic femoral shaft fracture. Thus, the present study aims to investigate the relationship between ipsilateral hip pain and femoral shaft fractures., Methods: Patients who were diagnosed with a fracture of the femur shaft and who were operated on (intramedullary fixation or plate) were included in this study. Patients with pathologic fractures, femoral neck fractures, femoral intertrochanteric fractures, or pelvic fractures were excluded. Patients with at least six months of follow-up and who were capable of independent walking without support were grouped according to AO/OTA fracture classification. Patients were questioned for deep anterior groin pain, and physical examination tests and hip imaging (X-ray and MR arthrography) were performed by calling patients with the indicated complaints., Results: The presence of labral tears were noted in two patients. The incidence of osseous bump of the femoral neck identified by MR arthrography (MRA) was found in three of 16 hips. Assessment of the presence of gluteal tendinosis or tear and herniation pit identified three of 16 hips. The presence of osteophytes was noted in one patient. MRA identified three of 16 hips with more than one type of intra-articular pathology. Two patients with an osseous bump of the femoral neck were also diagnosed with additional hip pathology as herniation pit., Conclusion: Anterior groin pain in patients with a history of femoral shaft fracture is not always related to implants. Orthopedic surgeons should become suspicious in cases of intra-articular hip pathology in patients who have persistent hip pain after severe lower extremity trauma.

Recently, biologically active natural macromolecules have come into prominence to be used as potential materials in scaffold design due to their unique characteristics which can mimic the human tissue structure with their physical and chemical similarity. Among them, fish scale (FS) is a biologically active material with its structural similarity to bone tissue due to including type I collagen and hydroxyapatite and also have distinctive collagen arrangement. In the present study, it is aimed to design a novel composite scaffold with FS incorporation into chitosan (CH) matrix for bone tissue regeneration. Therefore, two biological macromolecules, fish scale and chitosan, were combined to produce bio-composite scaffold. First, FS were decellularized with the chemical method and disrupted physically as microparticles (100 μm), followed by dispersal in CH with ultrasonic homogenisation, CH/FS scaffolds were fabricated by lyophilization technique. Scaffolds were characterized physically, chemically, mechanically, and morphologically. SEM and porosity results showed that CH/FS scaffolds have uniform pore structure showing high porosity. Mechanical properties and degradation rate are enhanced with increasing FS content. In vitro cytotoxicity, proliferation and osteogenic activity of the scaffolds were evaluated with SaOS-2 cell line. CH/FS scaffolds did not show any cytotoxicity effect and the cells were gradually proliferated during culture period. Cell viability results showed that, FS microparticles had a proliferative effect on SaOS-2 cells when compared to control group. ALP activity and biomineralization studies indicated that FS microparticle reinforcement increased osteogenic activity during culture period. As a biological macromolecule with unique characteristics, FS was found as cytocompatible and provided promising effects as reinforcement agents for polymeric scaffolds. In conclusion, fabricated CH/FS bio-composites showed potential for bone tissue engineering applications., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Osteochondral tissue is hard to regenerate after injuries or degenerative diseases. Traditional treatments still have disadvantages, such as donor tissue availability, donor site morbidity, implant loss, and limited durability of prosthetics. Thus, recent studies have focused on tissue engineering strategies to regenerate osteochondral defects with different scaffold designs. Scaffolds have been developed from monolayer structures to bilayer scaffolds to repair the cartilage-bone interface and to support each tissue separately. In this study, Si-substituted nanohydroxyapatite particles (Si-nHap) and silica-based POSS nanocages were used as reinforcements in different polymer layers to mimic a cartilage-bone tissue interface. Chitosan and zein, which are widely used biopolymers, are used as polymer layers to mimic the structure. This study reports the development of a bilayer scaffold produced via fabrication of two different nanocomposite layers with different polymer-inorganic composites in order to satisfy the complex and diverse regenerative requirements of osteochondral tissue. The chitosan/Si-nHap microporous layer and the zein/POSS nanofiber layer were designed to mimic a bone-cartilage tissue interface. Bilayer scaffolds were characterized with SEM, compression, swelling, and biodegradation tests to determine morphological, physical, and mechanical properties. The results showed that the bilayer scaffold had a structure composed of microporous and nanofiber layers joined at a continuous interface with appropriate mechanical properties. Furthermore, in vitro cell culture studies have been performed with LDH, proliferation, fluorescence imaging, and ALP activity assays using osteosarcoma and chondrosarcoma cell lines. ALP expression levels provide a good illustration of the improved osteogenic potential of a porous chitosan/Si-nHap layer due to the Si-doped nHap incorporation. Histological data showed that both fiber and porous layers that mimic the cartilage and bone sections exhibit homogeneous cell distribution and matrix formation. Histochemical staining was used to determine the cell proliferation and ECM formation on each layer. In vitro studies indicated that zein-POSS/chitosan/Si-nHap nanocomposite bilayer scaffolds showed promising results for osteochondral regeneration.

We report the treatment process of a pediatric patient with deformity and shortening in the arm after a recurrent aggressive aneurysmal bone cyst (ABC) in the proximal humerus. The patient was treated with curettage of the lesion and lengthening on an intramedullary nail following an osteotomy just distal to the ABC. The period of lengthening was approximately 50 days. At the end of the treatment the lengthening goal was achieved without any neurovascular complication. There was a minimal loss in shoulder hyperabduction due to the deformity of the humeral head., (Copyright © 2017 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.)

To date, all the authors who have recommended external rotation osteotomy (ERO) in the late treatment of obstetrical brachial plexus palsy (OBPP), have neglected upper limb length discrepancy, which is an another sequelae of OBPP. In this paper, a new technique is reported for the late treatment of OBPP patients with upper limb length discrepancy, in which both humeral external rotation osteotomy (ERO) and lengthening are applied with an intramedullary elongation nail. With this technique, upper limb function is improved through re-orientation of the shoulder arc to a more functional range, and further improvements will be seen in the appearance of the upper limb with the elimination of length discrepancy. It is also advocated that there is a potentiating effect of the humeral lengthening on shoulder movements gained by ERO when the osteotomy is applied above the deltoid insertion, as this allows more lateralized placement of the deltoid insertion., (Copyright © 2017 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.)

The current study reports the biocompatibility and biomechanical characteristics of loofah-based scaffolds combined with hydroxyapatite (HA), cellulose, poly-l-lactic acid (PLLA) with chondrocytes-like cells. Scanning electron microscope (SEM) micrographs of the scaffolds showed that the addition of PLLA usually resulted in an increase in cell's attachment on scaffolds. Mechanical and elemental analyzes were assessed using tensile test and Energy Dispersive X-ray spectrometry (EDS), respectively. In summary, we showed that the loofah+PLLA+HA scaffolds perform significantly better than other loofah-based scaffolds employed in terms of increasing a diversity of mechanical properties including tensile strength and Young's modulus. Based on the analysis of the differential scanning calorimetry (DSC) thermograms and EDS spectrums that give an idea about the calcium phosphate (CaP) ratios, the improvement in the mechanical properties could principally be recognized to the strong interaction formed between loofah, PLLA and HA. The viability of chondrocytes on loofah-based scaffolds was analyzed by XTT tests. However, none of the scaffolds have proved to be toxic in metabolic activity. The histological evaluation obtained by hematoxylin and eosin (H&E), Masson trichrome, toluidine blue and immunohistochemistry methods showed that cells in all scaffolds produced extracellular matrix that defined proteoglycan and type I-II collagens. The results of this study suggest that the loofah-based scaffold with desirable properties can be considered as an ideal candidate for cartilage tissue engineering applications., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Introduction: Locking compression plate (LCP) system was designed to provide bone stability and to enhance bone healing. However, implant failure, nonunion and instability are still frequently encountered complications. The purpose of this study was to assess and compare the biomechanical characteristics of a novel adjustable dynamic plate (ADP) with the commonly used LCP., Materials and Methods: Twelve 4th generation composite artificial femoral bones were used. Transverse fracture was created in all bones, 6 femurs were fixated using the novel ADP, whereas the other 6 femurs were fixated using the traditional LCP. All samples had undergone a non-destructive repetitive different forces (axial compression, bending and torsion), to evaluate the biomechanical differences between the two plating systems., Results: Under axial load the mean stiffness value was 439.0 N/mm for the ADP and 158.9 N/mm for the LCP, ADP showed a statistically significant stiffness value than LCP with a P value of 0.004. There was no significant difference in flexion/extension bending strain values between ADP and LCP. However LCP provided significantly stiffer fixation in medial and lateral bending tests than ADP ( P  = 0.037) and ( P  = 0.016) respectively. But no significant difference was detected between the two plating system in the applied torsional stress., Conclusion: These results do not show any significant biomechanical difference in the applied torsional and bending stresses between LCP and ADP. However the remarkably increased persistent compression effect of the ADP created a considerable stress on fracture edges which may accelerate bone healing.

Objective: The role of plate configuration was found inconclusive on the biomechanical effects of the plate size and hole number for dual plate constructions in humeral shaft fractures. The purpose of this study was to test the biomechanical stability of various dual plate constructions., Methods: Twenty-four left humeri (4th Generation Composite Humerus, Sawbones, Malmö, Sweden) with comminuted midshaft humeral fracture were used. Four groups of plate constructs were tested: laterally fixed 8-hole locking plate and screws were combined with anteriorly locking plates containing 0, 4, 6, or 8 holes in groups I, II, III, and IV, respectively. The alterations in axial, bending, and torsional angles were recorded., Results: There were no fixation failures during axial, bending, or torsional stiffness testing within the elastic behavior limits. Axial stiffness was highest in Group IV. Torsional stiffness, posterior-to-anterior bending stiffness, lateral-to-medial bending stiffness, and medial-to-lateral bending stiffness were lowest in Group I., Conclusion: The similar stiffness values for the 8-to-4 hole and 8-to-6 hole plate constructions indicate that the 8-to-4 hole construction is an option in young adults, while the stiffest 8-to-8 hole combination may be an option for osteoporotic patients., (Copyright © 2016 Turkish Association of Orthopaedics and Traumatology. Production and hosting by Elsevier B.V. All rights reserved.)

Patients with cerebral palsy (CP) disorder often develop rotational hip deformity. Increasing deformities impair already diminished walking abilities; femoral osteotomies are often performed to maintain and improve walking abilities. Fixation of osteotomies with condylar plates has been used successfully, but does not often enable immediate postoperative full weight-bearing. To avoid considerable postoperative rehabilitation deficit and additional bone loss because of inactivity, a postoperative treatment with full weight-bearing, is therefore, desirable. Self-tapping Schanz screws with a unilateral external fixator crossing the knee joint providing stronger anchoring in osteopenic bone might fulfill these demands. A retrospective study was carried out on 27 ambulatory CP patients, mean age 17.5 years (range 9-22 years); 11 patients with bilateral severe intoeing deformities underwent a supracondylar femoral osteotomy between September 2008 and April 2012. All patients were allowed to bear their full weight postoperatively. The aim of this study was to describe the technique, the results of this technique, to evaluate the time required for bone healing, and the type of complications associated with a distal derotational femoral osteotomy fixed with a uniaxial external fixator crossing the knee joint. A total of 27 patients were studied [mean weight 48.8 kg (range 29.8-75 kg)]. The mean preoperative rotation included internal rotation of 69° and external rotation of 17°. All patients were evaluated clinically and radiographically for a minimum of 1 year after surgery. There was a significant decrease in the mean medial rotation from 69° to 32° (P=0.00034). The lateral rotation increased significantly from preoperative 17° to postoperative 45° (P=0.0011). The femoral anteversion decreased significantly from a mean of 55° preoperatively to a mean 17° postoperatively (P=0.030). All patients, except one, achieved solid fusion uneventfully. One patient was a 16-year-old female who had sustained a knee flexion contracture of 30° because of a delay in the physiotherapy program. One 13-year-old female patient with a bilateral osteotomy had a nondisplaced fracture in her right femur after a direct trauma 2 weeks after removal of an external fixator, and was treated by a cast. Another 17-year-old male patient developed a nonunion because of loosening of two pins and achieved solid union after revision by dynamic compression plate plating. Besides four cases with superficial pin-tract infection, no other complications were documented. Minimally invasive supracondylar femoral derotational osteotomy fixed with a unilateral external fixators crossing the knee joint is a reliable procedure in CP patients. Most patients can be treated with early postoperative full weight-bearing. However, removal of the knee joint crossing fixator should be performed as early as possible to achieve a full range of motion.

For talar neck fractures, open reduction and internal fixation have been thought to facilitate revascularization and prevent osteonecrosis. Newer screw systems allow for placement of cannulated headless screws, which provide compression by virtue of a variable pitch thread. The present study compared the biomechanical fixation strength of cannulated headless variable-pitch screw fixation and locking plate fixation. A reproducible talar neck fracture was created in 14 fresh cadaver talar necks. Talar head fixation was then performed using 2 cannulated headless variable-pitch 4-mm/5-mm diameter (4/5) screws (Acutrak; Acumed, Hillsboro, OR) and locking plate fixation. Headless variable-pitch screw fixation had lower failure displacement than did locking plate fixation. No statistically significant differences were found in failure stiffness, yield stiffness (p = .655), yield load (p = .142), or ultimate load between the 2 fixation techniques. Cannulated headless variable-pitch screw fixation resulted in better failure displacement than locking plate fixation in a cadaveric talus model and could be considered a viable option for talus fracture fixation. Headless, fully threaded, variable-pitch screw fixation has inherent advantages compared with locking plate fixation, because it might cause less damage to the articular surface and can compress the fracture for improved reduction. Additionally, plate fixation can increase the risk of avascular necrosis owing to the wider incision and dissection of soft tissues., (Copyright © 2015 American College of Foot and Ankle Surgeons. Published by Elsevier Inc. All rights reserved.)

Purpose: In this study, osteoblast-like MG-63 cells were cultured on 3 different scaffold types composed of (a) collagen + poly-L-lactic acid (PLLA), (b) collagen + hydroxyapatite (HA; 30ºC) or (c) collagen + hydroxyapatite (HA; 37ºC) and produced with different porosities., Methods: Biomechanical properties of the scaffolds were characterized by tensile strength measurements. Properties of the cell-seeded scaffolds were evaluated with scanning electron microscopy (SEM). Cell adhesion and proliferation capacities were evaluated. Alkaline phosphatase (ALP) levels in media were measured. Transmission electron microscopy (TEM) and histological analyses were used to assess morphological characteristics., Results: Our results showed that collagen-based PLLA and HA scaffolds have good cell biocompatibility. MTT test showed that the scaffolds exhibited no cytotoxicity. According to the force and displacement data, collagen + HA at 37ºC showed the highest mechanical strength and displacement., Conclusion: The results suggest that collagen-based PLLA and HA scaffolds might improve osteoblastic growth in vitro and have biomaterial integration potential in possible therapeutic approaches for future clinical studies.

Aim: Pseudomyogenic (epithelioid sarcoma-like) hemangioendothelioma is a rare local aggressive vascular tumor. Herein we present a 54-year-old male patient with a tumor on his index finger., Case: The patient presented with a 1-year history of pain and swelling that progressively exacerbated. Bone invasion was observed on the middle phalanx via direct radiography. Histopathological examination findings were compatible with epithelioid sarcoma-like hemangioendothelioma., Conclusion: To the best of our knowledge is the first case report of epithelioid sarcoma-like hemangioendothelioma with bone invasion.

Total ankle replacement (TAR) is a relatively new concept and is becoming more popular for treatment of ankle arthritis and fractures. Because of the high costs and difficulties of experimental studies, the developments of TAR prostheses are progressing very slowly. For this reason, the medical imaging techniques such as CT, and MR have become more and more useful. The finite element method (FEM) is a widely used technique to estimate the mechanical behaviors of materials and structures in engineering applications. FEM has also been increasingly applied to biomechanical analyses of human bones, tissues and organs, thanks to the development of both the computing capabilities and the medical imaging techniques. 3-D finite element models of the human foot and ankle from reconstruction of MR and CT images have been investigated by some authors. In this study, data of geometries (used in modeling) of a normal and a prosthetic foot and ankle were obtained from a 3D reconstruction of CT images. The segmentation software, MIMICS was used to generate the 3D images of the bony structures, soft tissues and components of prosthesis of normal and prosthetic ankle-foot complex. Except the spaces between the adjacent surface of the phalanges fused, metatarsals, cuneiforms, cuboid, navicular, talus and calcaneus bones, soft tissues and components of prosthesis were independently developed to form foot and ankle complex. SOLIDWORKS program was used to form the boundary surfaces of all model components and then the solid models were obtained from these boundary surfaces. Finite element analyses software, ABAQUS was used to perform the numerical stress analyses of these models for balanced standing position. Plantar pressure and von Mises stress distributions of the normal and prosthetic ankles were compared with each other. There was a peak pressure increase at the 4th metatarsal, first metatarsal and talus bones and a decrease at the intermediate cuneiform and calcaneus bones, in prosthetic ankle-foot complex compared to normal one. The predicted plantar pressures and von Misses stress distributions for a normal foot were consistent with other FE models given in the literature. The present study is aimed to open new approaches for the development of ankle prosthesis.

Objectives: Diagnosis of low-grade chondrosarcoma, especially discrimination between enchondroma and low-grade chondrosarcoma, may be difficult pathologically. The aim of this study was to evaluate the value of thallium-201 (Tl-201) scintigraphy in the diagnosis of chondrosarcoma and to investigate whether there was a correlation between Tl-201 uptake and tumor grade., Methods: We retrospectively evaluated 121 patients with pathologically proven bone and soft tissue tumors diagnosed between the years 1999 and 2007. All patients were followed by the Bone and Soft Tissue Tumor Working Group in our hospital. Twenty-three patients, mean age 44 +/- 15 (range 17-72) years, with a diagnosis of cartilaginous tumors were included. Increased Tl-201 uptake at the lesion sites greater than background was evaluated as malignant tumor. For the pathologic classification, a grading system (grade 1-3) based on the histopathologic findings was used. Pearson correlation coefficient was used to determine whether there was any correlation between Tl-201 uptake and tumor grade in chondrosarcoma., Results: There were 7 enchondromas and 16 chondrosarcomas. Four of 16 patients with chondrosarcoma had lesions pathologically classified as grade 3, 5 as grade 2, and 7 had grade 1 chondrosarcoma. Increased Tl-201 uptake was observed in all patients with grade 3 chondrosarcoma and 2 patients with grade 2 chondrosarcoma. Of 10 patients with chondrosarcoma, 3 grade 2 chondrosarcomas and 7 grade 1 chondrosarcomas, there was no Tl-201 uptake in the tumor region. A significant correlation was found between Tl-201 uptake and tumor grade in chondrosarcoma (p = 0.002, r = 0.71). Only a few reports in literature have demonstrated false negative results in low-grade chondrosarcoma., Conclusion: Tl-201 uptake was related to tumor grade in chondrosarcoma. If there is a possibility of chondrosarcoma, Tl-201 scintigraphy should be reported with caution.

Introduction: Commonly used headless design screws such as Acutrak and Herbert screws have limited compressive effect on short fragment fixation. Therefore, we investigated whether preloaded compression techniques could be helpful in improving the compression effect., Method: A prototype of interfragmentary compression screw was designed with a constant pitch to avoid self-compressive effect. Preloaded compression was achieved with a sleeve device before the insertion of the trailer side (the leading side was inserted). Prototype screw test results were compared with those of Acutrak and Herbert screws. Eight pullout and eight compression tests were performed for each of the three screws using homogenous synthetic bone blocks., Results: The mean pullout forces of the Acutrak, Herbert and prototype screws were 67.21, 45.90 and 61.88 N, respectively. Preloaded compression (18.15 N) was higher than the compression produced by Acutrak (15.27 N) and Herbert (15.11 N) screws (p < 0.05). However, at the end of full insertion, half of the power obtained by preloaded compression was lost., Conclusion: Preloaded compression technique was successful in attaining maximum compression rate. During trailing-side insertion, constant pitch design failed to keep compression rate. Variable pitches can be useful to preserve or increase compression rate. In addition, sleeve usage may be more advantageous in thin fragment fixation.

Objective: Prediction of diabetic foot ulcer outcome may be helpful for clinicians in optimizing and individualizing management strategy. The aim of the present study was to examine the possibility of predicting the outcome of patients with diabetic foot ulcers by using easily assessed clinical and laboratory parameters at baseline., Design: In this observational study, data were collected prospectively in 670 consecutive diabetic foot ulcer episodes in 510 patients examined between January 1999 and June 2008 and were used to evaluate potential predictors of amputation retrospectively. After exclusion of patients who did not come to the hospital for follow-up for a minimum of six months, data of 574 foot ulcer episodes were evaluated., Results: Limb ischemia, osteomyelitis and presence of gangrene and ulcer depth, determined by the Wagner classification system, were the major independent predictors of overall and major amputations. Older age, presence of coronary artery disease, smoking and ulcer size were found to be associated with either overall or major amputations. Baseline levels of acute phase reactants (white blood cell count, polymorphonuclear leukocyte count, platelet count, erythrocyte sedimentation rate (ESR), serum C-reactive protein (CRP) and albumin) and decreased hemoglobin levels were associated with amputation risk. Multivariate analysis showed that one standard deviation increase in baseline CRP and ESR levels were independent predictors of overall and major amputations, respectively., Conclusions: The presence of limb ischemia, osteomyelitis, local and diffuse gangrene and ulcer depth were independent predictors of amputation. Baseline levels of ESR and CRP appeared to be helpful for clinicians in predicting amputation.

The use of hybrid Ilizarov models around femoral area is gaining clinical popularity lately. Hybrid systems show different mechanical properties. The purpose of this report is to examine the stiffness characteristics of the C-arch and half-pins on the hybrid Ilizarov fixators. Eight models that included standard Ilizarov and hybrid models were applied to six femoral sawbones. The distal part of fixation was composed of a two-ring frame applied identically to all bones. The difference of the configuration was at the proximal part, where half-pins with or without C-arches were either added to the proximal two-ring frame or replaced the proximal one- or two-ring frame. Osteotomy was performed in the femoral diaphysis and the bone was distracted 2cm. The stability of the system was tested with the axial compression testing machine. Displacements between the adjacent fracture sides were measured with the video extensometer in three dimensions. We found that proximal half-pin applications alone had less stiffness, but half-pins with C-arch had more stiffness than the model including only half-pins. Additional half-pins onto one- or two-ring frames had more longitudinal stiffness, but this system showed weak resistance against transverse displacement.

Background/purpose: Investigations on the mechanical properties of human hair are inadequate. This research explores the break force of anagen hair by forming criteria according to the diameter of hair, gender, age, strain, use of drugs and hair dyes and how these criteria affect the mechanical resistance of hair., Methods: The resistances of anagen hair of 120 volunteers were investigated in our biomechanics laboratory. The relationship between the value of break force of hair and hair diameter, gender, age, strain, use of drugs and hair dyes was examined. Tensile tests were applied to each hair with a 50 N load cell device., Results: The statistical evaluation demonstrated a significant difference between the break forces of hairs with different hair diameters. The hairs with a diameter of 51 mum and above had a significantly higher break force than those of 50 mum and below (P=0.000). An insignificant correlation was observed between break force and strain (P=0.554, r=-0.055) whereas the correlation between diameter and strain was statistically significant (P=0.000, r=0.361)., Conclusion: The break force of hairs did not show any significant dependency on age, presence of hair dyes, gender and usage of drugs. Yet, a statistically significant difference was observed between the break forces of hairs when compared according to their diameters and strain. More research on the mechanical properties of human hair consistent with biological properties like protein structure, alpha keratin fibers and microfibril-matrix composite behaviors would guide dermatologists for diagnostic symptoms.

The authors describe a 38-year-old man who was referred to the nuclear medicine department because of pain and swelling of his fingers in both hands. Tc-99m MDP and Tl-201 scans were performed to evaluate the lesions. A Tc-99m MDP bone scan showed hyperemia and increased uptake in the lesions. A Tl-201 scan showed marked uptake in both early and delayed images in the lesions of his fingers. Bone biopsy and histologic examination confirmed sarcoidosis. This case indicates that Tl-201 uptake can be seen in bone lesions resulting from sarcoidosis.