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Bone problems are highly prevalent in laying hens. These problems affect the welfare, production and economic losses. Bone development begins in the embryonic period, and if the skeletal system develops well at that time, the subsequent production period can be affected positively. The present experiment aimed to investigate the effect of genotype on biomechanical parameters and composition of bone in the laying hen embryos. For this purpose, 360 fertilized eggs were obtained from two brown (Atak-S and Brown Nick) and two white (Atabey and Nick) layer breeders and incubated. Metatarsus, tibia and femur properties were examined on the embryonic d 19 and 21. Results showed that genotype played an important role in determining the biomechanical properties and mineral composition of the metatarsus, tibia and femur in the embryonic period. Examined bone characteristics improved with embryonic age. The least mineralization was observed in the metatarsus bone. In conclusion, bone properties were influenced from the genotype. However these differences were not related with laying hens being white or brown. The effect of the interaction between genotype and embryonic age on the bone properties should be considered., Yumurtacı tavuklarda kemik sorunları oldukça yaygındır. Bu sorunlar refahı, üretimi ve ekonomik kayıpları etkiler. Kemik gelişimi embriyonik dönemde başladığından bu dönemde iskelet sistemi iyi gelişirse, sonraki üretim periyodu olumlu yönde etkilenebilir. Bu çalışmada genotipin yumurtacı tavuk embriyolarında kemiğin biyomekanik özellikleri ve bileşimine etkisini incelemek amaçlanmıştır. Bu amaçla iki kahverengi (Atak-S ve Kahverengi Nick) ve iki beyaz (Atabey ve Nick) yumurtacı damızlıklardan elde edilen 360 adet döllü yumurta toplanmış ve inkübe edilmiştir. Embiyonik dönemin 19 ve 21. günlerinde metatarsus, tibia ve femur özellikleri incelenmiştir. Sonuçlar, embriyonik dönemde genotipin metatarsus, tibia ve femurun biyomekanik özellikleri ve mineral bileşiminde önemli bir rol oynadığını göstermiştir. Embriyonik yaşın artmasıyla incelenen kemik özellikleri iyileşmiştir. En az minerilizasyon metatarsus kemiğinde gözlenmiştir. Sonuç olarak, kemik özellikleri genotipten etkilenmiştir. Fakat bu farklılıklar beyaz veya kahverengi yumurtacı tavuk olmasıyla ilişkili değildir. Genotip ve embriyonik yaş arasındaki etkileşimin kemik özellikleri üzerindeki etkisi dikkate alınmalıdır.

This study evaluated the effects of a graded concentration of dietary calcium soaps of tallow (CST) supplementation on broiler performance, carcass characteristics, abdominal fat fatty acid profile, bone biomechanical properties, and bone mineral composition. One hundred and forty 11-d-old male broiler chickens were randomly allocated to 4 experimental groups with 5 replicate pens containing 7 birds per each. The birds received cornsoybean meal based diet and CST (CST0, CST10, CST20, and CST30, respectively) was included in the grower (0, 10, 20, and 30 g/kg) and finisher (0, 15, 30, and 45 g/kg) diet at the expense of vegetable acid oil and limestone. Dietary supplementations had no significant effect on BWG and FI during the entire experimental period. However, FCR was improved in CST0 and CST10 groups in comparison to those of the CST20 group from d 11 to d 42. According to the present study result, dietary supplementation of low level of CST significantly influenced intestinal microarchitecture of the jejunum and ileum by improving villus height/crypt ratio and villus height, respectively. Femur (P=0.001) and tibia (P=0.020) stiffness increased linearly with the increasing level of dietary CST. Tibia Ca (P=0.009) and P (P=0.009) concentration of CST10 and CST30 groups were lower than the CST0 group. Increasing levels of CST in diets significantly reduced the Fe and Mn concentrations in tibia samples. In conclusion, supplementation of CST has no detrimental effect on broiler performance parameters and might be used as an alternative dietary fat source in the broiler industry.

Objective Cephalomedullary nails are tools commonly used for surgical fixation in proximal femoral fractures. The most common complications in their use are varus collapse and screw cutout of the femoral head. The objective of this study is to examine the effects of intramedullary nail movement on varus collapse and screw cutout. Materials and methods The study was conducted on 70 composite femur models treated with PFNA. We divided the femurs into 4 groups based on the differences in nail diameter, fracture type and filling of the distal intramedullary area. All femurs were exposed to axial cyclic loading. Each femur was examined in terms of intramedullary nail movement and amount of erosions in femoral medulla [amount of erosion in femoral head (FT distance), amount of erosion in femoral neck (FB distance), amount of erosion in trochanteric major (TB distance) and expansion of trochanter tip (TT distance)]. Results We found that degree of nail movement in the intramedullary region was inversely correlated with nail diameter and directly correlated with instability of fracture. One of the parameters used to evaluate varus development, FB distance, was affected by the degree of intramedullary nail movement and fracture type. TB distance was affected by nail diameter. Conclusions Nail diameter and fracture type are effective in intramedullary nail movement. Varus collapse progress is accelerated by the increase in nail movement in the intramedullary region. Thus, we conclude that it is important to strengthen diaphyseal adherence, which decreases intramedullary movement of the nail. Level of evidence III; well-design case control study.

BACKGROUND The purpose of open reduction and internal fixation of acetabulum posterior wall fractures is to restore anatomical structure and stability of the hip joint, in order to start weight bearing as soon as possible and prevent hip arthrosis; restoration of the anatomy should preserve function of the joint as well. Although "special shaped precontoured plates" have been developed in recent years for surgical treatment of this region, studies comparing the traditional plates with the newly designed precontoured plates are lacking. AIM To evaluate the biomechanical properties of precontoured anatomic buttress and conventional curved reconstruction plates (CCRPs) for posterior wall acetabulum fracture treatment. METHODS Twelve pelvis models were created for testing plate treatment of fracture in the posterior wall of the acetabulum. These 12 pelvis models were used to create 24 hemipelvis models (experimental) by cutting from the sagittal plane and passing over the center of gravity, after which the posterior wall acetabular fractures (of similar type and size) were created. In these experimental models, the right acetabulum was fixed with a 5-hole CCRP, while the left was fixed with a precontoured anatomic buttress plate (PABP). Samples were placed through the test device and were subjected to static load testing, with a constant testing velocity of 2 mm/min until the load reached 2.3 kN or the acetabular fixation failed. Dynamic tests were also performed with sinusoidal wave load, with a maximal load of 2.3 kN and a load ratio of 0.1. RESULTS The average stiffness values were 460.83 +/- 95.47 N/mm for the PABP and 291.99 +/- 118.58 N/mm for the 5-hole CCRP. The precontoured anatomic acetabulum buttress plates had significantly higher rigidity than the CCRPs (P = 0.022). There was a statistically significant difference between the unloaded and 2.3 kN-loaded values of AL (posterosuperior fracture line vertical to the ground surface) and CL (posteroinferior fracture line vertical to the ground surface) parameters for both the PABPs and the 5-hole CCRPs (P = 0.036 and P = 0.045, respectively). According to the static tests, the amount of total displacement was significantly less in the PABPs than in the CCRPs. Comparative analysis of the displacement in the BL (posterior wall fracture line horizontal to the ground) parameter yielded no statistically significant differences between the PABP and the 5-hole CCRPs (P = 0.261). CONCLUSION PABP provides more stable fixation in acetabulum posterior wall fractures than 5-hole CCRP, allowing for proximal or distal fracture line screw application without reshaping.

Additively manufactured polymer composites have advantages over those fabricated traditionally due to their improved design flexibility, short time frame of design-to-manufacturing process and reduced material waste and investment cost. Additive manufacturing of short fiber reinforced thermoplastic composites has been well investigated recently, and their mechanical performance has been well characterized. Additive manufacturing of thermoplastic composites, however, has unresolved, high porosity and low mechanical performance issues. In this study, we investigated the feasibility of using of a customized, vibration-integrated, direct write additive manufacturing setup to fabricate short Kevlar reinforced epoxy composites. Highly viscous composite inks (max. of 6.3% Kevlar fiber) were successfully extruded and 3D-printed on a print bed, at room temperature. The mechanical performance of the printed composites was examined and compared to that of unreinforced base ink specimens by performing static and dynamic 3-point bending experiments. It was observed that additively manufactured, thermoset-based, short Kevlar fiber reinforced composites possess the mechanical performance surpassing the previously reported short Kevlar fiber reinforced thermoplastic composites and near to that of continuous fiber reinforced composites. Considering their high mechanical performance in addition to low weight, and high ductility, these composite materials have a great potential to find novel structural applications in the near future.