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Background: Increased posterior wall acetabular fractures among older adults, require precise treatment to restore stability to the joint, lower the risk of degenerative arthritis, and enhance overall functional recovery. The purpose of this study was to compare the fixation stability and mechanical characteristics of calcaneal buttress plate and conventional reconstruction plate under different loading condition. Methods: Typical acetabular posterior wall fractures were created on twenty synthetic hemipelvis models. They were fixed with calcaneus plate and reconstruction plate. Dynamic and static tests were performed. Displacements of fracture line and stiffness were calculated. Findings: After dynamic loading, calcaneus plate fixation has significantly less displacement than the reconstruction plate on the superior posterior wall. Under static loading condition, the calcaneus plate group has significantly less displacement than the reconstruction plate group on the inferior posterior part of the fracture. The average stiffness values of the calcaneus plate group and the reconstruction plate group were 265.16 +/- 53.98 N/mm and 167.48 +/- 36.87 N/mm, respectively and a statistically significant difference was found between the two groups. Interpretation: The calcaneal plate group demonstrated better stability along the fracture line after dynamic and static loading conditions. Especially when the fragment was on the acetabulum's superior posterior, inferior posterior, and inferior rim, Calcaneal buttress plates offer biomechanically effective choices., Manisa Celal Bayar University [2020-076], We want to thank Manisa Celal Bayar University (project number 2020-076) for funding this research.

Background: Increased posterior wall acetabular fractures among older adults, require precise treatment to restore stability to the joint, lower the risk of degenerative arthritis, and enhance overall functional recovery. The purpose of this study was to compare the fixation stability and mechanical characteristics of calcaneal buttress plate and conventional reconstruction plate under different loading condition. Methods: Typical acetabular posterior wall fractures were created on twenty synthetic hemipelvis models. They were fixed with calcaneus plate and reconstruction plate. Dynamic and static tests were performed. Displacements of fracture line and stiffness were calculated. Findings: After dynamic loading, calcaneus plate fixation has significantly less displacement than the reconstruction plate on the superior posterior wall. Under static loading condition, the calcaneus plate group has significantly less displacement than the reconstruction plate group on the inferior posterior part of the fracture. The average stiffness values of the calcaneus plate group and the reconstruction plate group were 265.16 +/- 53.98 N/mm and 167.48 +/- 36.87 N/mm, respectively and a statistically significant difference was found between the two groups. Interpretation: The calcaneal plate group demonstrated better stability along the fracture line after dynamic and static loading conditions. Especially when the fragment was on the acetabulum's superior posterior, inferior posterior, and inferior rim, Calcaneal buttress plates offer biomechanically effective choices., Manisa Celal Bayar University [2020-076], We want to thank Manisa Celal Bayar University (project number 2020-076) for funding this research.

To compare the amount of displacement and rigidity at the fracture line under static ; dynamic axial loading and torsional stress of conventional cannulated screw (CS), plate screw fixation including inter-fragmentary screw (PL), and talon cannulated compression device or talon screw in other words (TS) in posterior column fracture models. Synthetic hemipelvis bone models presenting a posterior column fracture were used in this study. Group PL, CS, and TS were created with ten bone models prepared for each group for dynamic and static loading tests and another ten for torsional tests. Rigidity and displacement amounts before and after loading were measured at the reference points AL, BL, and CL, located at the acetabulum's top, middle, and bottom, respectively. Torsional tests for each group were used to calculate torsional rigidity and maximum torque values. In dynamic axial loading tests, Group CS showed more displacement than PL at the BL point (p = 0,032) and Group TS at AL (p = 0,032) and CL (p = 0,004) points. In static axial loading tests, Group CS significantly displaced more than TS at AL and CL points (p = 0,05 and p = 0,014, respectively). Group PL and Group TS exhibited similar behavior in dynamic, static axial loading tests and torsional rigidity. The maximum torque that Group PL could withstand was statistically significantly higher than the other two groups (p 0,001). Talon cannulated screws had promising results in posterior column fractures of the acetabulum, which may decline the need for open surgery for stable fixation.

To compare the amount of displacement and rigidity at the fracture line under static ; dynamic axial loading and torsional stress of conventional cannulated screw (CS), plate screw fixation including inter-fragmentary screw (PL), and talon cannulated compression device or talon screw in other words (TS) in posterior column fracture models. Synthetic hemipelvis bone models presenting a posterior column fracture were used in this study. Group PL, CS, and TS were created with ten bone models prepared for each group for dynamic and static loading tests and another ten for torsional tests. Rigidity and displacement amounts before and after loading were measured at the reference points AL, BL, and CL, located at the acetabulum's top, middle, and bottom, respectively. Torsional tests for each group were used to calculate torsional rigidity and maximum torque values. In dynamic axial loading tests, Group CS showed more displacement than PL at the BL point (p = 0,032) and Group TS at AL (p = 0,032) and CL (p = 0,004) points. In static axial loading tests, Group CS significantly displaced more than TS at AL and CL points (p = 0,05 and p = 0,014, respectively). Group PL and Group TS exhibited similar behavior in dynamic, static axial loading tests and torsional rigidity. The maximum torque that Group PL could withstand was statistically significantly higher than the other two groups (p 0,001). Talon cannulated screws had promising results in posterior column fractures of the acetabulum, which may decline the need for open surgery for stable fixation.

Background: Achilles tendon (AT) midsubstance injuries may heal suboptimally, especially in athletes. Transforming growth factor-beta 3 (TGF-beta 3) shows promise because of its recently discovered tendinogenic effects. Using poly(lactic-co-glycolic acid)-b-poly(ethylene glycol) (PLGA-b-PEG) nanoparticles (NPs) may enhance the results by a sustained-release effect. Hypothesis: The application of TGF-beta 3 will enhance AT midsubstance healing, and the NP form will achieve better outcomes. Study Design: Controlled laboratory study. Methods: A total of 80 rats underwent unilateral AT transection and were divided into 4 groups: (1) control (C); (2) empty chitosan film (Ch); (3) chitosan film containing free TGF-beta 3 (ChT); and (4) chitosan film containing TGF-beta 3-loaded NPs (ChN). The animals were sacrificed at 3 and 6 weeks. Tendons were evaluated for morphology (length and cross-sectional area [CSA]), biomechanics (maximum load, stress, stiffness, and elastic modulus), histology, immunohistochemical quantification (types I and III collagen [COL1 and COL3]), and gene expression (COL1A1, COL3A1, scleraxis, and tenomodulin). Results: Morphologically, at 3 weeks, ChT (15 +/- 2.7 mm) and ChN (15.6 +/- 1.6 mm) were shorter than C (17.6 +/- 1.8 mm) (P = .019 and = .004, respectively). At 6 weeks, the mean CSA of ChN (10.4 +/- 1.9 mm(2)) was similar to that of intact tendons (6.4 +/- 1.1 mm(2)) (P = .230), while the other groups were larger. Biomechanically, at 3 weeks, ChT (42.8 +/- 4.9 N) had a higher maximum load than C (27 +/- 9.1 N; P = .004) and Ch (29.2 +/- 5.7 N; P = .005). At 6 weeks, ChN (26.9 +/- 3.9 MPa) had similar maximum stress when compared with intact tendons (34.1 +/- 7.8 MPa) (P = .121); the other groups were significantly lower. Histologically, at 6 weeks, the mean Movin score of ChN (4.5 +/- 1.5) was lower than that of ChT (6.3 +/- 1.8). Immunohistochemically, ChN had higher COL3 (1.469 +/- 0.514) at 3 weeks and lower COL1 (1.129 +/- 0.368) at 6 wee

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. © 2021 Elsevier Masson SAS

Background: Achilles tendon (AT) midsubstance injuries may heal suboptimally, especially in athletes. Transforming growth factor-beta 3 (TGF-beta 3) shows promise because of its recently discovered tendinogenic effects. Using poly(lactic-co-glycolic acid)-b-poly(ethylene glycol) (PLGA-b-PEG) nanoparticles (NPs) may enhance the results by a sustained-release effect. Hypothesis: The application of TGF-beta 3 will enhance AT midsubstance healing, and the NP form will achieve better outcomes. Study Design: Controlled laboratory study. Methods: A total of 80 rats underwent unilateral AT transection and were divided into 4 groups: (1) control (C); (2) empty chitosan film (Ch); (3) chitosan film containing free TGF-beta 3 (ChT); and (4) chitosan film containing TGF-beta 3-loaded NPs (ChN). The animals were sacrificed at 3 and 6 weeks. Tendons were evaluated for morphology (length and cross-sectional area [CSA]), biomechanics (maximum load, stress, stiffness, and elastic modulus), histology, immunohistochemical quantification (types I and III collagen [COL1 and COL3]), and gene expression (COL1A1, COL3A1, scleraxis, and tenomodulin). Results: Morphologically, at 3 weeks, ChT (15 +/- 2.7 mm) and ChN (15.6 +/- 1.6 mm) were shorter than C (17.6 +/- 1.8 mm) (P = .019 and = .004, respectively). At 6 weeks, the mean CSA of ChN (10.4 +/- 1.9 mm(2)) was similar to that of intact tendons (6.4 +/- 1.1 mm(2)) (P = .230), while the other groups were larger. Biomechanically, at 3 weeks, ChT (42.8 +/- 4.9 N) had a higher maximum load than C (27 +/- 9.1 N; P = .004) and Ch (29.2 +/- 5.7 N; P = .005). At 6 weeks, ChN (26.9 +/- 3.9 MPa) had similar maximum stress when compared with intact tendons (34.1 +/- 7.8 MPa) (P = .121); the other groups were significantly lower. Histologically, at 6 weeks, the mean Movin score of ChN (4.5 +/- 1.5) was lower than that of ChT (6.3 +/- 1.8). Immunohistochemically, ChN had higher COL3 (1.469 +/- 0.514) at 3 weeks and lower COL1 (1.129 +/- 0.368) at 6 wee

As most of the unenriched cages will soon switch to enriched cages, it is important to characterize all the effects in the laying hens for sustainable production. Laying hens can be used in several production periods by applying molting. The aim of this study was to determine the cage type (unenriched and enriched) on performance, welfare, and microbiological properties of laying hens during the molting period and the second production cycle. Overall, 840 brown laying hybrids were used in the experiment. Laying hens were reared on two different cage types (unenriched cage (UEC) and enriched cage (EC)) in the same poultry house. When the hybrids were 75 weeks old, they were subjected to force molting with whole grain barley. Performance, welfare, microbiological, and serological data of laying hens were obtained from 73 to 107 weeks of age. Egg production, egg weight, feed conversion ratio, breaking strength, albumen and yolk index, Haugh unit, feather condition, and breaking force of femur and metatarsus were better in the post-molting period. However, keel bone deformities and Newcastle disease virus antibody titers are the worst in the post-molting period. Stiffness of femur and metatarsus was increased with period. These results indicate that necessary precautions should be taken against the problems that may occur in the direction of bone and health. During the molting period, hens kept in EC had lower egg production but they returned to egg production at a high rate. EC type had a positive effect on egg production, feed conversion ratio, feather and foot condition, and breaking force of metatarsus.

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., 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.

As most of the unenriched cages will soon switch to enriched cages, it is important to characterize all the effects in the laying hens for sustainable production. Laying hens can be used in several production periods by applying molting. The aim of this study was to determine the cage type (unenriched and enriched) on performance, welfare, and microbiological properties of laying hens during the molting period and the second production cycle. Overall, 840 brown laying hybrids were used in the experiment. Laying hens were reared on two different cage types (unenriched cage (UEC) and enriched cage (EC)) in the same poultry house. When the hybrids were 75 weeks old, they were subjected to force molting with whole grain barley. Performance, welfare, microbiological, and serological data of laying hens were obtained from 73 to 107 weeks of age. Egg production, egg weight, feed conversion ratio, breaking strength, albumen and yolk index, Haugh unit, feather condition, and breaking force of femur and metatarsus were better in the post-molting period. However, keel bone deformities and Newcastle disease virus antibody titers are the worst in the post-molting period. Stiffness of femur and metatarsus was increased with period. These results indicate that necessary precautions should be taken against the problems that may occur in the direction of bone and health. During the molting period, hens kept in EC had lower egg production but they returned to egg production at a high rate. EC type had a positive effect on egg production, feed conversion ratio, feather and foot condition, and breaking force of metatarsus.

Introduction: Anchorage, which is defined as resistance against undesired tooth movements, is one of the most important factors in success of orthodontic treatment. In recent years, mini-implants have been used instead of uncomfortable headgears and Nance appliances. The pullout test is the most common method for measuring the anchorage capacity of mini-implants. The aim of this study was to investigate the effects of cortical bone thickness and cortical layer bone density on pullout strength of mini-implants. Methods: Mini-implants were placed in polyurethane foam blocks representing 3 different cortical thicknesses (1 mm, 2 mm, and 3 mm) and 3 different cortical bone densities (grade 40, grade 45, and grade 50). Pullout tests were performed with 5 mm/min loading rate. Load vs displacement values were recorded during the tests. Results: Comparing cortical thicknesses on the same bone densities, statistically significant differences were found between 1 mm, 2 mm, and 3 mm thicknesses. Likewise, comparing bone densities on the same cortical thicknesses, statistically significant differences were found among all groups. Spearman rank tests showed that both cortical thickness and cortical bone density are correlated with pullout strength (rs, 0.548; P0.001 and rs, 0.691; P0.001, respectively). Conclusions: Although both factors are positively correlated with pullout strength, the effect of cortical bone density was the dominant factor affecting primary stability.

Purpose To compare five different repair techniques for extensor tendon zone III modified Kessler (MK), double-modified Kessler (DMK), modified Kessler epitendinous (MKE), double-modified Kessler epitendinous (DMKE), and running-interlocking horizontal mattress (RIHM) in terms of shortening, stiffness, gap formation, and ultimate load to failure. Methods A total of 35 human cadaver fingers were randomly assigned to five suture techniques with 7 fingers each and were tested under dynamic and static loading conditions. Results DMK was found to be superior over MK in terms of ultimate load to failure (36 N vs. 24 N, respectively), shortening (1.75 vs. 2.20 mm, respectively) and gap formation. However, these two methods had similar characteristics in terms of stiffness. The addition of epitendinous sutures to the repair methods resulted in approximately 40% increase in ultimate load to failure, whereas epitendinous sutures had no effect on shortening. DMKE was found to be superior over MKE in terms of shortening (1.77 vs. 2.22 mm, respectively). However, these two methods had similar characteristics in terms of mean ultimate load to failure and stiffness. RIHM was found to be superior over the other four methods in terms of ultimate load to failure (89 N), stiffness, and shortening (0.75 mm). Conclusion RIHM was found to be stronger and more durable for extensor tendon zone III than the other techniques in terms of ultimate load to failure and stiffness.

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.

Purpose To compare five different repair techniques for extensor tendon zone III modified Kessler (MK), double-modified Kessler (DMK), modified Kessler epitendinous (MKE), double-modified Kessler epitendinous (DMKE), and running-interlocking horizontal mattress (RIHM) in terms of shortening, stiffness, gap formation, and ultimate load to failure. Methods A total of 35 human cadaver fingers were randomly assigned to five suture techniques with 7 fingers each and were tested under dynamic and static loading conditions. Results DMK was found to be superior over MK in terms of ultimate load to failure (36 N vs. 24 N, respectively), shortening (1.75 vs. 2.20 mm, respectively) and gap formation. However, these two methods had similar characteristics in terms of stiffness. The addition of epitendinous sutures to the repair methods resulted in approximately 40% increase in ultimate load to failure, whereas epitendinous sutures had no effect on shortening. DMKE was found to be superior over MKE in terms of shortening (1.77 vs. 2.22 mm, respectively). However, these two methods had similar characteristics in terms of mean ultimate load to failure and stiffness. RIHM was found to be superior over the other four methods in terms of ultimate load to failure (89 N), stiffness, and shortening (0.75 mm). Conclusion RIHM was found to be stronger and more durable for extensor tendon zone III than the other techniques in terms of ultimate load to failure and stiffness.

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.

Scoliosis is a spinal deformity caused by lateral curve on the frontal plane of the spine. Development and the treatment of the deformity varies with respect to the age. Scoliosis in patients with on going growth show rather more alteration compared to the adults. Because of the growth of the spine, the fixed segments need to be prolonged by surgical operation at periodic time intervals. Although posterior stabilization systems have been developed to facilitate lengthening for pediatric scoliosis, the treatment process is adversely affected because the correct time for elongation procedures can not be determined. With the smart implant rods produced within the scope of the thesis, stress and load between the two fixed vertebral segments in the treatment process can be tracked. First, sensors with the desired precision are produced and integrated into the bars. Smart implant rods were first subjected to mechanical tests individually according to the relevant standards of ASTM, and then vertebralctomy models were established for mechanical verification of the system and frequency values were measured by testing compression, tension, lateral bending and torsion tests. Frequency measurements were conducted under varying soft tissue thickness and effects were evaluated. Moreover, in order to determine the fatigue performances of the sensors, cyclic loads were applied and frequency measurements were recorded. System was tested on cadaviers under compression and tension tests. After mechanical modelling, animal model experiements were conducted. During the animal model experiments, transpedicular screws were inserted and attached with two rods on 15 sheeps. Sheeps were observed for a period of 6 months after the operation and frequency measurements were held once in a month from the sensors placed on the rods. In vertebrctomy models and cadaver tests, it was found that the increase in load under compression and lateral bending tests, increased the dielectric constant and c, Skolyoz, omurganın frontal düzlemde lateral sapma göstermesiyle oluşan spinal bir deformitedir. Hastalığın gelişimi ve tedavisi yaş aralıklarına göre farklılıklar göstermektedir. Büyüme süreci devam eden hastalarda görülen skolyoz, omurgadaki gelişim nedeniyle zamana bağlı olarak yetişkinlerde görülene kıyasla daha büyük değişiklikler gösterir. Omurgadaki büyüme nedeniyle, sabitlenmiş segmentlerin belirli zaman aralıklarında cerrahi müdahale ile uzatılması gerekmektedir. Pediatrik skolyoz için uzatma işlemini kolaylaştırıcı posterior stabilizasyon sistemleri geliştirilmiş olsa da tedavi süreci, uzama işlemleri için doğru zaman tespit edilemediğinden dolayı olumsuz yönde etkilenmektedir. Tez kapsamında üretilen akıllı implant çubuklar ile tedavi sürecinde sabitlenen iki omurga segmenti arasındaki gerilme ve yükleme takip edilebilecektir. İlk olarak istenilen hassasiyette sensörler üretilmiş ve çubuklara entegre edilmiştir. Akıllı implant çubuklar, ASTM' nin ilgili standartlarına göre önce tekil olarak mekanik testlere tabi tutulmuş sonrasında sistemin mekanik doğrulaması için vertebrektomi modeller kurulmuş ve basma, çekme, yana eğme ve burma yükleri altında test edilerek frekans değerleri ölçülmüştür. Farklı yumuşak doku kalınlıkları ile frekans ölçümleri yapılmış ve etkisi araştırılmıştır. Ayrıca sensörlerin yorulma performanslarının belirlenmesi için çevrimsel yük uygulanmış ve frekans ölçümleri alınmıştır. Sistem, kadavralarda basma ve çekme yükleri altında teste tabi tulumuştur. Mekanik modellemeden sonra canlı hayvan deneyleri gerçekleştirilmiştir. Canlı hayvan deneylerinde 15 koyuna bilateral transpediküler vida yerleştirilmiş ve iki adet rodla birleştirilerek tespit edilmiştir. Koyunlar ameliyat sonrası 6 ay süreyle gözlem altında tutulmuş ve ayda bir kez çubuklarda yer alan algılayıcılardan frekans ölçümleri alınmıştır. Vertebrektomi modellerde ve kadavrada yapılan testler sonucunda, basma ve yana eğme kuvvetleri altında yükün artması dielektrik katsayısı ve

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 fract

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 fract