Fractures occur commonly in veterinary medicine and are usually the result of vehicular trauma. Traditionally, comminuted mid-diaphyseal fractures are repaired with an interlocking nail, dynamic compression plate, or combination of a bone plate with an intramedullary pin. In recent years, the locking compression plate has gained popularity in human orthopedics due to its biomechanical characteristics and stability in osteoporotic or periprosthetic bone. In addition, the plate may be applied in a percutaneous manner, thereby allowing for biological osteosynthesis. This study evaluates the combination of a locking compression plate and an intramedullary pin in a Delrin rod gap model. Modalities tested include axial load to failure, torsion, and cyclic loading.

No description available.

Os materiais utilizados nas osteossínteses passam constantemente por avanços tecnológicos. Um dos mais recentes dispositivos é a chamada placa bloqueada, suas principais indicações são fraturas com alto grau de cominução, fraturas que não exigem uma redução anatômica, ossos osteopenicos, por exemplo, acometidos pela osteoporose, entre outras. Atualmente novos modelos de placas com bloqueio estão sendo desenvolvidos, onde a interface do parafuso e a placa são feito pela deformação do orifício, com a vantagem da instalação do parafuso em diversos ângulos. O presente projeto tem por objetivo estudar comparativamente a diferença entre os dois tipos de interface parafuso placa, como também realizar teste de quatro pontos comparando o sistema novo de bloqueio com o sistema convencional de bloqueio. Realizamos ensaios de arrancamento com sistema convencional de bloqueio (Synthes) e com o novo sistema de bloqueio (PAX) em parafusos 2,0mm; 2,4mm; 2,7mm e 3,5mm. Em todos os grupos testados o sistema convencional de bloqueio foi mais resistente e apresentou diferença significativa estatisticamente, teste de Mann- Witney (p< 0,05). Os valores de P obtidos foram: sistema 2.0mm p = 0,008; sistema 2.4 mm p= 0,008; sistema 2.7 mm p= 0,016; sistema 3.5 mm p= 0,008. No teste de 4 pontos utilizamos 20 placas da marca Synthes (sistema convencional de bloqueio) e 20 da marca PAX (novo sistema de bloqueio) e o sistema convencional de bloqueio se mostrou novamente mais resistente com diferença significativa. Os valores de P obtidos foram: sistema 2.0mm p = 0,008; sistema 2.4 mm p= 0,008; sistema 2.7 mm p= 0,008; sistema 3.5 mm p= 0,008. Conclui-se que o sistema convencional de bloqueio se mostrou mais resistente tanto no teste de arrancamento quanto no teste de flexão de quatro pontos. / The materials used in osteosynthesis constantly technological advances. One of the most recent devices is called the locking plate, its main indications are fractures with a high degree of comminution, fractures which do not require anatomical reduction, osteopenic bones, for example, affected by osteoporosis, among others. Currently new locking plate designs are being developed, where the screw interface and the plate are made by deformation of the hole, with the installation of the advantage screw at various angles. This study aims to compared the difference between the two types of interface screw - plate but also perform four-point test comparing the new locking system with the conventional system lock. Pullout tests conducted with conventional locking system (Synthes) and the new locking system (PAX) by screws 2.0mm; 2.4mm; 2.7mm and 3.5mm. In all groups tested the conventional system of blockade was stronger and showed a statistically significant difference, Mann-Witney test (p <0.05). P values were obtained: System 2.0mm P = 0.008; system 2.4 mm p = 0.008; System 2.7 mm p = 0.016; system 3.5 mm p = 0.008. In test points 4 used 20 Synthes plate mark (conventional blocking system) and 20 brand PAX (new locking system), the conventional locking system again showed a significant difference resistant. P values were obtained: System 2.0mm P = 0.008; system 2.4 mm p = 0.008; system 2.7 mm p = 0.008; system 3.5 mm p = 0.008. It follows that the conventional locking system has proved much more resistant peel test as in the four point bending test.

A utilização de placas bloqueadas e suas vantagens biomecânicas na redução de fraturas cominutivas de ossos longos em cães já foram descritas por diversos autores. O presente trabalho teve como objetivo avaliar diferentes configurações de placa bloqueadas submetidas a dois diferentes testes biomecânicos, um de flexão em quatro pontos para avaliar a influencia do preenchimento dos orifícios centrais na resistência a flexão da placa bloqueada com função de placa de apoio. O outro teste avaliou a força máxima ao arrancamento de dois diferentes tipos de placas, um com todos os orifícios perpendiculares e outro com os orifícios angulados alternadamente lateral e medialmente em relação ao eixo longitudinal da placa. Para cada teste formou-se dois grupos com dez corpos de prova cada. Não houve diferença estatística no resultado obtido no teste de flexão, a resistência a flexão do grupo com preenchimentos dos orifícios centrais foi maior em relação ao grupo sem preenchimento, porem sem significância. Já no teste de arrancamento o grupo de placas com orifícios angulados obteve um valor de forma máxima de arrancamento significantemente superior em relação ao grupo com orifícios perpendiculares em relação ao eixo longitudinal da placa. Concluiu-se que não há influencia na resistência da placa de apoio com o preenchimento dos orifícios centrais da placa bloqueada e que a configuração de placa com os orifícios angulados se mostrou mais resistente ao arrancamento. / The feasibility of locking plates and their biomechanical advantages in comminuted fractures are well known. The objective of this study was to evaluate different locking plate´s configurations submitted to a four point´s flexion test and pull out test. The flexion test evaluated the influence of screws in center position in bridging plate, the pull out test compared relative to pull out strength locking plates using parallel locking screws or angulated locking screws. For each biomechanical assay two groups of ten test materials were formed. The results found no statistical differences relative to flexion resistance in the groups with and without central screws. Relative to pull out test the group with angulated screws showed higher values of maximum pull out strength when compared with the perpendicular screws, the data were statistically significant. We concluded that there was no improvement in the resistance of bridging plate with the use of central screws, but the use of angulated screws showed a greater resistance to pull out when compared to parallel screws.

A utilização de placas bloqueadas e suas vantagens biomecânicas na redução de fraturas cominutivas de ossos longos em cães já foram descritas por diversos autores. O presente trabalho teve como objetivo avaliar diferentes configurações de placa bloqueadas submetidas a dois diferentes testes biomecânicos, um de flexão em quatro pontos para avaliar a influencia do preenchimento dos orifícios centrais na resistência a flexão da placa bloqueada com função de placa de apoio. O outro teste avaliou a força máxima ao arrancamento de dois diferentes tipos de placas, um com todos os orifícios perpendiculares e outro com os orifícios angulados alternadamente lateral e medialmente em relação ao eixo longitudinal da placa. Para cada teste formou-se dois grupos com dez corpos de prova cada. Não houve diferença estatística no resultado obtido no teste de flexão, a resistência a flexão do grupo com preenchimentos dos orifícios centrais foi maior em relação ao grupo sem preenchimento, porem sem significância. Já no teste de arrancamento o grupo de placas com orifícios angulados obteve um valor de forma máxima de arrancamento significantemente superior em relação ao grupo com orifícios perpendiculares em relação ao eixo longitudinal da placa. Concluiu-se que não há influencia na resistência da placa de apoio com o preenchimento dos orifícios centrais da placa bloqueada e que a configuração de placa com os orifícios angulados se mostrou mais resistente ao arrancamento. / The feasibility of locking plates and their biomechanical advantages in comminuted fractures are well known. The objective of this study was to evaluate different locking plate´s configurations submitted to a four point´s flexion test and pull out test. The flexion test evaluated the influence of screws in center position in bridging plate, the pull out test compared relative to pull out strength locking plates using parallel locking screws or angulated locking screws. For each biomechanical assay two groups of ten test materials were formed. The results found no statistical differences relative to flexion resistance in the groups with and without central screws. Relative to pull out test the group with angulated screws showed higher values of maximum pull out strength when compared with the perpendicular screws, the data were statistically significant. We concluded that there was no improvement in the resistance of bridging plate with the use of central screws, but the use of angulated screws showed a greater resistance to pull out when compared to parallel screws.

Stipinkaulio distalinės dalies lūžiai yra vienas iš dažniausių kaulų ir raumenų sistemos pažeidimų. Literatūroje nurodoma, kad distalinės stipinkaulio dalies lūžiai yra 1/10 visų lūžių, kuriuos patiria vyresni nei 35 metų amžiaus asmenys. Apie 3 % pacientų, po šios traumos išlieka ilgalaikė negalia. Siekiant optimizuoti stipinkaulio distalinės dalies lūžių gydymą, buvo atliktas tyrimas, kuriame buvo iškelti trys uždaviniai. Vertinome 2 savaičių imobilizacijos įtaką rankos funkcijai, po stipinkaulio distalinės dalies lūžio ir osteosintezės delnine rakinama plokštele. Taip pat vertinome,radiologinio lūžio tipo, pagal AO klasifikaciją, įtaką rankos funkcijai. Sugijus kaului, tirta metalinių konstrukcijų pašalinimo įtaka rankos funkcijai. Vertinant rezultatus, nustatyta, kad riešo judesių amplitudė ir rankos funkcija tarp pacientų, patyrusių stipinkaulio distalinės dalies lūžį su poslinkiu ir operuotų delnine rakinama plokštele, kuriems buvo taikyta pooperacinė 2 savaičių riešo imobilizacija ir kuriems pooperacinė riešo imobilizacija nebuvo taikyta, nesiskyrė. Tiriamiesiems, patyrusiems C tipo lūžį pagal AO radiologinę klasifikaciją nustatyta prastesnė funkcija. Riešo judesių amplitudė ir rankos funkcija po delninės rakinamos plokštelės pašalinimo nepakito. / Distal radius fracture is one of the most common injuries of the skeletal and muscular system. It has been reported in literature that distal radius fractures account for one-tenth of all the fractures experienced by people older than 35 years. Long-term disability remains in approximately 3% of patients after a distal radius fracture. In order to optimise treatment of distal radius fractures, a study with three objectives was performed. We evaluated the effect of immobilisation for the period of 2 weeks on the hand function after a distal radius fracture and osteosynthesis with a volar locking plate. The effect of the fracture type according to the AO classification on the hand function was also assessed. After the bone has healed, the effect of the removal of metal constructions on the hand function was evaluated. The analysis of the results demonstrated that there were no differences in the range of wrist motions and the hand functionbetween the patients after a displaced distal radius fracture operated with a volar locking plate and post-surgery immobilisation of the wrist applied for the period of 2 weeks and the patients who did not have post-surgery wrist immobilisation applied. A worse function was determined in the patients after type C fracture according to the AO radiological classification. The range of wrist motions and the hand function after the removal of a volar locking plate did not differ.

Os materiais utilizados nas osteossínteses passam constantemente por avanços tecnológicos. Um dos mais recentes dispositivos é a chamada placa bloqueada, suas principais indicações são fraturas com alto grau de cominução, fraturas que não exigem uma redução anatômica, ossos osteopenicos, por exemplo, acometidos pela osteoporose, entre outras. Atualmente novos modelos de placas com bloqueio estão sendo desenvolvidos, onde a interface do parafuso e a placa são feito pela deformação do orifício, com a vantagem da instalação do parafuso em diversos ângulos. O presente projeto tem por objetivo estudar comparativamente a diferença entre os dois tipos de interface parafuso placa, como também realizar teste de quatro pontos comparando o sistema novo de bloqueio com o sistema convencional de bloqueio. Realizamos ensaios de arrancamento com sistema convencional de bloqueio (Synthes) e com o novo sistema de bloqueio (PAX) em parafusos 2,0mm; 2,4mm; 2,7mm e 3,5mm. Em todos os grupos testados o sistema convencional de bloqueio foi mais resistente e apresentou diferença significativa estatisticamente, teste de Mann- Witney (p< 0,05). Os valores de P obtidos foram: sistema 2.0mm p = 0,008; sistema 2.4 mm p= 0,008; sistema 2.7 mm p= 0,016; sistema 3.5 mm p= 0,008. No teste de 4 pontos utilizamos 20 placas da marca Synthes (sistema convencional de bloqueio) e 20 da marca PAX (novo sistema de bloqueio) e o sistema convencional de bloqueio se mostrou novamente mais resistente com diferença significativa. Os valores de P obtidos foram: sistema 2.0mm p = 0,008; sistema 2.4 mm p= 0,008; sistema 2.7 mm p= 0,008; sistema 3.5 mm p= 0,008. Conclui-se que o sistema convencional de bloqueio se mostrou mais resistente tanto no teste de arrancamento quanto no teste de flexão de quatro pontos. / The materials used in osteosynthesis constantly technological advances. One of the most recent devices is called the locking plate, its main indications are fractures with a high degree of comminution, fractures which do not require anatomical reduction, osteopenic bones, for example, affected by osteoporosis, among others. Currently new locking plate designs are being developed, where the screw interface and the plate are made by deformation of the hole, with the installation of the advantage screw at various angles. This study aims to compared the difference between the two types of interface screw - plate but also perform four-point test comparing the new locking system with the conventional system lock. Pullout tests conducted with conventional locking system (Synthes) and the new locking system (PAX) by screws 2.0mm; 2.4mm; 2.7mm and 3.5mm. In all groups tested the conventional system of blockade was stronger and showed a statistically significant difference, Mann-Witney test (p <0.05). P values were obtained: System 2.0mm P = 0.008; system 2.4 mm p = 0.008; System 2.7 mm p = 0.016; system 3.5 mm p = 0.008. In test points 4 used 20 Synthes plate mark (conventional blocking system) and 20 brand PAX (new locking system), the conventional locking system again showed a significant difference resistant. P values were obtained: System 2.0mm P = 0.008; system 2.4 mm p = 0.008; system 2.7 mm p = 0.008; system 3.5 mm p = 0.008. It follows that the conventional locking system has proved much more resistant peel test as in the four point bending test.

The presented diploma thesis deals with stress-strain analysis of the intact human knee joint and the knee joint after reconstruction using fixation plate. Finite element method is used to determine the biomechanical response of the knee under loading with the FE software Ansys. The three-dimensional finite element model is consisted of bony structures (femur and tibia) which were created using computed tomography (CT) data, articular cartilages and both menisci. Model of the locking plate (LCP) was created based on producer's technical guide. Three models of the knee joint with LCP fixation plate are created for three different sizes of condylar fragment based on the intact model. On all variants is applied loading corresponding to maximum loading in a gait cycle. The results show that reconstruction of the knee joint with locking plate has no effect on changing in contact pressure on tibial plateau.

No description available.

Background: Open reduction and internal fixation with a plate is deemed to represent the gold standard of surgical treatment for displaced intra-articular calcaneal fractures. Standard plate fixation is usually placed through an extended lateral approach with high risk for wound complications. Minimally invasive techniques might avoid wound complications but provide limited construct stability. Therefore, 2 different types of locking nails were developed to allow for minimally invasive technique with sufficient stability. The aim of this study was to quantify primary stability of minimally invasive calcaneal interlocking nail systems in comparison to a variable-angle interlocking plate. Material and Methods: After quantitative CT analysis, a standardized Sanders type IIB fracture model was created in 21 fresh-frozen cadavers. For osteosynthesis, 2 different interlocking nail systems (C-Nail; Medin, Nov. Město n. Moravě, Czech Republic; Calcanail; FH Orthopedics SAS; Heimsbrunn, France) as well as a polyaxial interlocking plate (Rimbus; Intercus GmbH; Rudolstadt, Germany) were used. Biomechanical testing consisted of a dynamic load sequence (preload 20 N, 1000 N up to 2500 N, stepwise increase of 100 N every 100 cycles, 0.5 mm/s) and a load to failure sequence (max. load 5000 N, 0.5 mm/s). Interfragmentary movement was detected via a 3-D optical measurement system. Boehler angle was measured after osteosynthesis and after failure occurred. Results: No significant difference regarding load to failure, stiffness, Boehler angle, or interfragmentary motion was found between the different fixation systems. A ignificant difference was found with the dynamic failure testing sequence where 87.5% of the Calcanail implants failed in contrast to 14% of the C-Nail group (P < .01) and 66% of the Rimbus plate. The highest load to failure was observed for the C-Nail. Boehler angle showed physiologic range with all implants before and after the biomechanical tests. Conclusion: Both minimally invasive interlocking nail systems displayed a high primary stability that was not inferior to an interlocking plate. Clinical relevance: Based on our results, both interlocking nails appear to represent a viable option for treating displaced intra-articular calcaneal fractures.