3D Foot Anthropometric Measurements Under Two Weight- Bearing Conditions for Ergonomic Design of Foot-Related Products / Mediciones Antropométricas del Pie en 3D Bajo Dos Condiciones de Soporte de Peso para el Diseño Ergonómico de Productos Relacionados con los Pies

SUMMARY: This study collected 3D models of the left and right feet from 317 Chinese youth (155 females and 162 males) under half weight-bearing and no weight-bearing conditions. Thirteen dimensions and one angle were taken for each sample. By measuring 13 foot dimensions and 1 angle, this study comprehensively investigated the differences in foot shape between genders and the bilateral differences, as well as the foot shape differences under different conditions. The results showed that regardless of the condition, male foot dimensions were significantly larger than those of females. However, female foot shape was not simply a scaled-down version of male foot shape. On the contrary, the average angle of female feet was greater than that of males under both conditions, indicating a higher prevalence of hallux valgus in females. Both males and females exhibited significant correlation in foot dimensions between the left and right feet, with minimal differences. Under the half weight-bearing condition, the average foot length, width, and circumference were significantly larger than the corresponding measurements under the no weight-bearing condition, while the average height and angle were significantly smaller. Therefore, when designing footwear and foot-related medical rehabilitation aids, it is important to consider foot shape and dimensions under different conditions as a reference. The results of this study provide manufacturers of foot- related products with more detailed data support and are of significant value to the field of medical foot morphology research.

Este estudio recolectó modelos 3D de los pies izquierdo y derecho de 317 jóvenes chinos (155 mujeres y 162 hombres) en condiciones de carga media de peso y sin carga de peso. Para cada muestra se tomaron trece dimensiones y un ángulo. Al medir 13 dimensiones del pie y 1 ángulo, se investigó exhaustivamente las diferencias en la forma del pie entre ambos sexos y sus diferencias bilaterales, así como las diferencias en la forma del pie en diferentes condiciones. Los resultados mostraron que, independientemente de la condición, las dimensiones del pie de los hombres, estos eran significativamente más grandes que los de las mujeres. Sin embargo, la forma del pie femenino no era simplemente una versión reducida de la forma del pie masculino. Por el contrario, el ángulo promedio de los pies de las mujeres fue mayor que el de los hombres en ambas condiciones, lo que indica una mayor prevalencia de hallux valgus en las mujeres. Tanto hombres como mujeres exhibieron una correlación significativa en las dimensiones del pie, entre el pie izquierdo y el derecho, con diferencias mínimas. Bajo la condición de medio soporte de peso, la longitud, el ancho y la circunferencia promedio del pie fueron significativamente mayores que las medidas correspondientes bajo la condición sin soporte de peso, mientras que la altura y el ángulo promedio fueron significativamente más pequeños. Por lo tanto, al diseñar calzado y dispositivos médicos de rehabilitación relacionados con los pies, es importante tener en consideración la forma y las dimensiones del pie en diferentes condiciones como referencia. Los resultados de este estudio, brindan a los fabricantes de productos relacionados con los pies un soporte de datos más detallado y son de gran valor para el campo de la investigación médica de la morfología del pie.

Osteotomy of non-core weight-bearing area of the lateral tibial plateau, reduction, and internal fixation in treatment of tibial plateau fractures involving posterolateral column collapse / 中国修复重建外科杂志

OBJECTIVE@#To investigate the effectiveness of osteotomy of non-core weight-bearing area of the lateral tibial plateau, reduction, and internal fixation in the treatment of tibial plateau fractures involving posterolateral column collapse.@*METHODS@#A clinical data of 23 patients with tibial plateau fractures involving posterolateral column collapse, who had undergone osteotomy of non-core weight-bearing area of the lateral tibial plateau, reduction, and internal fixation between January 2015 and June 2021, was retrospectively analyzed. There were 14 males and 9 females with an average age of 42.6 years ranging from 26 to 62 years. The causes of injury included traffic accident in 16 cases, falling from height in 5 cases, and other injuries in 2 cases. According to Schatzker classification, there were 15 cases of type Ⅴ and 8 cases of type Ⅵ. The time from injury to operation was 4-8 days with an average of 5.9 days. The operation time, intraoperative blood loss, fracture healing time, and complications were recorded. The depth of articular surface collapse of posterolateral column and posterior inclination angle (PSA) of the tibial plateau were compared before operation and at 2 days and 6 months after operation; fracture reduction of tibial plateau fracture was evaluated by Rasmussen anatomic score. The recovery of knee function was evaluated by Hospital for Special Surgery (HSS) score at 2 days and 6 months after operation.@*RESULTS@#All 23 patients were completed the operation successfully. The operation time was 120-195 minutes, with an average of 152.8 minutes; the intraoperative blood loss was 50-175 mL, with an average of 109.5 mL. All patients were followed up 12-24 months, with an average of 16.7 months. One patient had superficial wound infection after operation, and the incision healed after dressing change; primary healing of incision of other patients was obtained. The fracture healing time was 12-18 weeks, with an average of 13.7 weeks. No failure of internal fixation, varus and valgus deformity of the knee joint, and instability of the knee joint was found at last follow-up. One patient developed joint stiffness and the range of motion of the knee joint was 10°-100°; the range of motion of the knee joint of other patients was 0°-125°. At 2 days and 6 months after operation, the depth of articular surface collapse of posterolateral column, PSA, and Rasmussen anatomic scores significantly improved when compared with those before operation ( P<0.05). There was no significant difference between the two postoperative time points ( P>0.05). The HSS score at 6 months after operation was significantly higher than that at 2 days after operation ( P<0.05).@*CONCLUSION@#For tibial plateau fractures involving posterolateral column collapse, reduction and internal fixation through osteotomy of non-core weight-bearing area of the lateral tibial plateau has the advantages of fully expose the posterolateral column fragment, good articular surface reduction, sufficient bone grafting, and fewer postoperative complications. It is beneficial to restore knee joint function and can be widely used in clinic.

Design and validation of a novel knee biomechanical test method / 生物医学工程学杂志

A novel structural dynamics test method and device were designed to test the biomechanical effects of dynamic axial loading on knee cartilage and meniscus. Firstly, the maximum acceleration signal-to-noise ratio of the experimental device was calculated by applying axial dynamic load to the experimental device under unloaded condition with different force hammers. Then the experimental samples were divided into non-specimen group (no specimen loaded), sham specimen group (loaded with polypropylene samples) and bovine knee joint specimen group (loaded with bovine knee joint samples) for testing. The test results show that the experimental device and method can provide stable axial dynamic load, and the experimental results have good repeatability. The final results confirm that the dynamic characteristics of experimental samples can be distinguished effectively by this device. The experimental method proposed in this study provides a new way to further study the biomechanical mechanism of knee joint structural response under axial dynamic load.

Influence of abutment angulation on implant failure in immediately placed and restored implants in the esthetic zone: a randomized clinical trial

Background: Tooth extraction socket in the aesthetic area is a major indication for immediate implant placement greatly improving patient satisfaction and preserving the alveolar ridge. However, the effect of non-axial force on the peri-implant bone with subsequent early implant failure remains unclear. Objective:Evaluate the prognosis of tilted implants immediately placed and restored with angled abutments in comparison to straight implants restored with straight abutments in the esthetic area (anterior or premolars) using computer-aided surgical guides. Material and methods: Badly decayed non-restorable teeth in the aesthetic zone (anterior or premolars) were extracted atraumatically. Immediately after guided implant insertion, the abutments were adjusted and placed according to the allocation group (0, 15, or 25-degree angle) then a temporary crown was performed out of occlusion in centric and eccentric relation. Early implant failure was assessed at three and six months. Results:There was no statistically significant difference between the two groups (P=0.305). Straight and angled abutment groups showed 6 (14.3%) and 8 (20%) failed cases, respectively. The post-hoc subgroup analysis showed no statistically significant difference between angle 15 and angle 25 degree groups where (P=0.686) or between Anterior and Premolar groups (P=0.853). Conclusion: There was no statistically significant difference in the failure rate when comparing angled to straight immediately placed & restored implants. This applies to both anterior and premolar implants

Zygomatic implants in intra-sinus versus extra-maxillary approaches for prosthetic rehabilitation in severely atrophic maxillae: finite element analysis / Implantes cigomáticos en abordajes intra sinusal versus extra maxilar para rehabilitación protésica en maxilares severamente atróficos: análisis de elementos finitos

Objetive: To compare the stresses and deformations generated on the surrounding bone of the zygomatic implants when using an intra sinusal and extra-maxillary approach, through the finite element method. Material and Methods: Computer aided designs (CADs) were constructed using SolidWorks Software of a skull with bone resorption to be rehabilitated through a fixed hybrid prosthesis using two zygomatic and two conventional straight implants. For the boundary conditions (load conditions), symmetry in the sagittal plane was assumed and that all the materials were isotropic, homogeneous and linearly elastic. Two zygomatic implantation techniques were simulated: intra sinusal (Is) and extra maxillary (Em). Vertical and lateral loads of 150 N and 50 N were applied to the finite element models to obtain Von Mises equivalent stress and strain (displacement). Results: The average measurement of the Von Mises stress (MPa) recorded were as follows: Approach of the implant body (Is: 0.24- Em: 0.28,) effort of implant body with vertical load: Is: 0.69 - Em: 0.96; effort of peri-implant surface under horizontal load: Is: 2.11 - Em: 0.94. Average displacement under vertical load of peri-implant surface Is: 0.35 - Em: 0.40, and of implant body Is: 1.34 - Em: 2.04. Average total deformation in approach Is: 2.23 mm - Em: 0.80mm, and average total deformation in the implant body under horizontal load was Is: 0.14 - Em: 0.21. Conclusion: The results of this study indicate that despite the differences that occurred in both stress and strain (displacement) between the intra-sinus and extra-maxillary approaches, the static strength of the bone, which is approximately 150 MPa in tension and 250 MPa in compression was not exceeded. Considering the limitations of finite element analysis, there seems to be no biomechanical reason to choose one approach over the other.

Objetivo: Comparar por el método de elementos finitos los esfuerzos y deformaciones generados sobre el hueso circundante de implantes cigomáticos tratados con un abordaje intra sinusal y extra maxilar. Material y Métodos: Se construyeron los diseños asistidos por computadora (CAD) utilizando el Software SolidWorks de un cráneo con una reabsorción ósea para ser rehabilitado, a través de una prótesis híbrida fija, mediante dos implantes cigomáticos y dos rectos convencionales. Para las condiciones de frontera (condiciones de carga) se asumió simetría en el plano sagital y que todos los materiales eran isotrópicos, homogéneos y linealmente elásticos. Se simularon dos técnicas de implantación cigomática: una intra sinusal (Is) y otra extra maxilar (Em). Se aplicaron cargas verticales y laterales de 150 N y 50 N a los modelos de elementos finitos para obtener el esfuerzo equivalente de Von mises y la deformación (desplazamiento). Resultados: La medición promedio del esfuerzo de Von Mises (MPa) registró: abordaje del cuerpo de implante (Is: 0.24-Em: 0.28) esfuerzo del cuerpo de implante con carga vertical: (Is:0.69 ­ Em: 0.96); esfuerzo de la superficie peri implantar ante carga horizontal (lateral):( Is:2.11 ­ Em:0.94). Desplazamiento promedio ante carga vertical de la superficie peri implantar (Is:0.35 ­ Em:0.40) y del cuerpo del implante (Is:1.34 ­ Em:2.04). Deformación total promedio en mm en abordaje (Is: 2.23 ­ Em:0.80) y deformación total promedio en el cuerpo del implante ante carga horizontal (Is:0.14 ­ Em:0.21). Conclusión: Los resultados de este estudio indican que a pesar de las diferencias que se presentaron tanto en el esfuerzo como en la deformación (desplazamiento) entre los abordajes intra sinusal y extra maxilar, la resistencia estática del hueso, que es de aproximadamente 150 MPa en tensión y 250 MPa en compresión no se superó. Considerando las limitaciones de los AEF, parece no haber razones biomecánicas para elegir uno u otro enfoque.

Weight Discharge in Postoperative of Plateau Fracture Tibialis: Systematic Review of Literature / Descarga de peso no pós-operatório de fratura de planalto tibial: Revisão sistemática da literatura

Abstract Tibial plateau fractures are a risk to the functional integrity of the knee, affecting the axial alignment and capable of leading to pain and disability of the individual. Early weight bearing and joint mobilization can prevent these functional deficits. the goal of the present study was to conduct a systematic review of the literature about studies that quote the beginning, evolution, and progression criteria for weight-bearing in postoperative period of tibial plateau fractures. We selected articles published in the last 12 years, in Portuguese and English, that described the time of onset and progression of weight-bearing, considering the severity of the fracture. Thirty-six articles were selected. There is no consensus in the literature as to the beginning and evolution of weight-bearing in the postoperative period of tibial plateau fractures; however, a relationship between the severity of the fracture and the fixation method has been observed.

Resumo As fraturas do planalto tibial constituem risco à integridade funcional do joelho, afetando o alinhamento axial e podendo levar à dor e à incapacidade do indivíduo. O suporte de carga e a mobilização articular precoce podem prevenir esses déficits e acelerar o processo de reabilitação. O objetivo do presente trabalho foi realizar uma revisão da literatura sobre estudos que citam o início, evolução e critérios de progressão do suporte de carga no pós-operatório das fraturas de planalto tibial. Foram selecionados artigos publicados nos últimos 12 anos, nos idiomas português e inglês, que descrevessem o tempo de início e progressão do suporte de carga, considerando a gravidade da fratura. Foram selecionados 36 artigos na literatura. Não há consenso na literatura quanto ao início e evolução do suporte de carga no pós-operatório das fraturas do planalto tibial. Contudo, observa-se relação entre a gravidade da fratura e o tempo de início da carga.

Complex Fractures of the Sacrum with Spinopelvic Dissociation Treated Surgically with Iliolumbar Fixation / Fraturas complexas do sacro com dissociação espinopélvica tratadas cirurgicamente com fixação iliolombar

Abstract Objective To analyze a series of cases of complex fractures of the sacrum with spinopelvic dissociation surgically treated with iliolumbar fixation, and to review the existing medical literature. Methods For the analysis, the medical records of the cases operated using the Schildhauer et al technique for fixation were retrospectively evaluated, and followed up for at least 12 months. The functional results were assessed using the visual analog scale (VAS) for pain and the Oswestry disability index, version 2.0. The data were compared with those of the existing medical literature. Results Six cases were analyzed, four of which evolved with moderate disability, one, with minimal disability, and one, with severe disability. Three cases that presented neurological deficits obtained significant improvement. Only one case evolved with pulmonary thromboembolic complications. Conclusion The Schildhauer et al technique is an efficient technique for the fixation of complex sacral fractures with spinopelvic dissociation. The patients evolved with good functional results. Early weight-bearing has been shown to be safe with the use of this treatment.

Resumo Objetivo Analisar uma série de casos de fraturas complexas do sacro com dissociação espinopélvica tratados cirurgicamente com fixação iliolombar, e revisar a literatura médica existente. Métodos Para a análise, foram avaliados retrospectivamente os prontuários médicos de casos operados utilizando a técnica de Schildhauer et al para fixação. O período de acompanhamento foi de pelo menos 12 meses. Os resultados funcionais foram avaliados por meio da escala visual analógica (EVA) de dor e do índice de incapacidade de Oswestry, versão 2.0. Os dados foram comparados com os da literatura médica existente. Resultados Seis casos foram analisados, sendo que quatro evoluíram com incapacidade moderada, um, com incapacidade mínima, e um, com incapacidade grave. Três casos que apresentavam déficit neurológico obtiveram melhora significativa. Apenas um caso evoluiu com complicação tromboembólica pulmonar. Conclusão A técnica de Schildhauer et al é eficiente para a fixação de fraturas complexas de sacro com dissociação espinopélvica. Os pacientes evoluíram com bons resultados funcionais. A liberação precoce de sustentação de carga demonstrou-se segura com o uso deste tratamento.

Influência do arco longitudinal medial na distribuição plantar e na flexibilidade posterior / La influencia del arco longitudinal medial en la distribución plantar y la flexibilidad posterior / The influence of medium longitudinal arch on plant distribution and posterior pliability

RESUMO O objetivo deste estudo foi verificar se a formação do arco longitudinal do pé interfere na distribuição da pressão plantar e na flexibilidade dos músculos posteriores da coxa. O método de estudo foi transversal e as impressões plantares foram obtidas usando o plantígrafo e analisadas segundo o método Viladot. A distribuição plantar e a flexibilidade foram avaliadas pela baropodometria e pelo banco de Wells, respectivamente. Foi observado que crianças com pés cavos apresentam maior flexibilidade quando comparadas às que têm o pé normal (p=0,02); e também que pés cavos apresentam maior pressão, ou seja, maior sobrecarga em calcâneo quando comparados àqueles com o arco plantar normal (p=0,02 membro inferior direito e p=0,03 membro inferior esquerdo). A avaliação do arco longitudinal medial mostra que crianças com pés cavos apresentam maior flexibilidade dos músculos posteriores de membro inferior. Os pés cavos também estão associados com maior descarga de peso em região de calcâneo.

RESUMEN El objetivo de este estudio fue verificar si la formación del arco longitudinal del pie interfiere con la distribución de la presión plantar y la flexibilidad de los músculos posteriores del muslo. El método de estudio fue transversal y las huellas plantar se obtuvieron utilizando el plantigraph y se analizaron según el método de Viladot. La distribución plantar y la flexibilidad se evaluaron mediante baropodometría y el banco de Wells, respectivamente. Se observó que los niños con pies huecos tienen mayor flexibilidad en comparación con aquellos con pies normales (p=0,02); y también que los pies huecos tienen una mayor presión, es decir, una mayor sobrecarga del talón en comparación con aquellos con arco plantar normal (p=0,02 miembro inferior derecho y p=0,03 miembro inferior izquierdo). La evaluación del arco longitudinal medial muestra que los niños con pies huecos tienen una mayor flexibilidad en los músculos posteriores de la extremidad inferior. Los pies huecos también están asociados con una mayor descarga de peso en la región del talón.

ABSTRACT Objective: To evaluate whether the formation of the longitudinal arch of the foot interferes with the distribution of plantar pressure and the pliability of the posterior thigh muscles. Methodology: a cross-sectional study and the footprints were obtained using the footprinting mat and analyzed according to the Viladot method. Plantar distribution and pliability were assessed by baropodometry and Wells' bank, respectively. Results: It was observed that children with cavus feet present greater pliability when compared to those with normal feet (p=0.02). Also, the cavus feet exhibit higher pressure, that is, a greater heel overload compared to those with normal plantar arch (p=0.02 lower right limb and p=0.03 lower left limb). Conclusions: The evaluation of the medial longitudinal arch shows that children with cavus feet have greater pliability of the lower limb posterior muscles. The cavus feet are also associated with higher pressure in the calcaneal region.

Spatial variability of precompression stress and volumetric water content of a red-yellow latosol (Oxisol) / Variabilidade espacial da pressão de preconsolidação e da umidade volumétrica de um latossolo vermelho amarelo

The intensive agricultural machinery traffic to which soils under coffee crops are exposed may cause significant changes in soil structure. The goals of this study were to: a) characterize the spatial variability of precompression stress (σp) and volumetric water content (θ) of a Red-Yellow Latosol (Oxisol) and determine their spatially dependent structures using ordinary kriging semivariograms; b) using this date to construct a load-bearing capacity (LBC) map for the site, identifying the depth with higher ; and c) use the map as a decision support tool regarding agricultural machinery logistic management in coffee plantations. The research was conducted on an experimental farm of the Agricultural Research Company of Minas Gerais (Epamig), Patrocinio, MG, on a clayey Oxisol. Samples were collected from 2.0 × 1.5 m sampling pits at intersections of a rectangular 40 × 150 m grid, totaling 28 sampling points. The soil samples were collected with metal rings (0.0254 m in height and 0.0630 m in diameter) using an Uhland sampler. Sampling at each pit was at 3 layers: 0.00­0.03 m, 0.10­0.13 m, and 0.25­0.28 m, and seven samples arranged in a matrix form were collected at each layer, totaling 588 samples. The σp and θ showed a spatially dependent structure. The depth of 0.00­0.03 m showed higher LBC, indicating that this depth was more compacted compared to other depths. Based on the σp maps, the tractor and the combine should not traffic into the areas at water content of 0.45 m3 m-3, because the soil has a LBC of 200 kPa. If this condition is not respected, additional compaction will occur. Tractor traffic is permissible when the water content reaches values less than 0.36 m3 m-3, whereas for combine traffic, the water content values must be less than 0.30 m3 m-3.

O tráfego intenso de máquinas agrícolas sobre solos cultivados com cafeeiro pode causar alterações significativas na estrutura do solo. Os objetivos deste estudo foram: a) avaliar e identificar a variabilidade espacial da pressão de preconsolidação (σp) e a umidade volumétrica (θ) de um Latossolo Vermelho-Amarelo (LVA) e determinar a estrutura de dependência espacial através de semivariogramas utilizando a krigagem ordinária; b) verificar no mapa, a profundidade com maior capacidade de suporte de carga (CSC) do solo ; c) dar suporte a tomada de decisão no manejo do maquinário agrícola da cultura cafeeira e utilizar esses mapas para a logística de manejo de trafego de máquinas. O experimento foi conduzido num LVA textura muito argilosa na Fazenda da Epamig (Empresa de Pesquisa Agropecuária de Minas Gerais), em Patrocínio-MG. A amostragem foi realizada numa malha retangular (150 m x 40 m), onde foram coletadas amostras indeformadas em anéis metálicos de 0,0254 m de altura por 0,0630 m de diâmetro com auxílio do amostrador tipo Uhland em 28 trincheiras. Cada trincheira possui três degraus que correspondem às profundidades de (0.00-0.03; 0.10-0.13 e 0.25-0.28 m) e as dimensões dos degraus foram de 2,0 x 1,5 m, coletaram-se sete amostras (disposta em forma matricial) para cada degrau, totalizando 588 amostras. A σp e θ apresentaram estrutura de dependência espacial. A profundidade de 0.00-0.03m apresentou maior CSC indicando que esta profundidade está mais compactada em relação as demais profundidades. Com base nos mapas da σp, o trator e a colhedora não devem trafegar na área para umidade volumétrica igual a 0.45 m3 m-3, pois o solo possui CSC de 200 kPa. Se essa condição for desrespeitada, a compactação adicional poderá ocorrer. Para o tráfego do trator, deve-se esperar por um período, para que a θ atinja um valor menor que 0.36 m3 m-3, enquanto que para o tráfego da colhedora deve-se esperar a θ atingir valor menor que 0.30 m3 m-3.

A new type of adjustable weight bearing rehabilitation brace for lower limbs in postoperative rehabilitation of proximal femoral nail anti-rotation / 中国骨伤

OBJECTIVE@#To study and analyze the clinical effect of the self-developed new adjustable weight-bearing rehabilitation brace in the rehabilitation of the femoral intertrochanteric fracture after the operation of PFNA.@*METHODS@#From July 2015 to June 2017, 62 patients with typeⅡ (Evans-Jensen classification) intertrochanteric fracture of femur were treated with PFNA internal fixation. There were 11 males and 19 females in the routine rehabilitation group, with an average age of (70.73± 6.09) years;17 males and 15 females in the brace rehabilitation group, with an average age of (71.25±6.60) years. Among them, the patients in the routine rehabilitation group recovered according to the routine method, and the patients in the support rehabilitation group used the self-developed new adjustable weight-bearing rehabilitation support of lower limbs to assist the early rehabilitation. The pain intensity(VAS score), weight-bearing of affected limb, clinical healing time of fracture, Harris score and complications were recorded and analyzed.@*RESULTS@#Nine patients lost their visit half a year later, the other 53 patients were followed up for 9 to 18 months. The VAS score at 1, 3, 6 months after operation of brace rehabilitation group was lower than that of routine rehabilitation group(<0.05). The weight bearing of the limbs in the rehabilitation group was significantly higher than that in the conventional rehabilitation group(<0.05), but the clinical healing time of fracture in the brace rehabilitation group was shorter than that in the routine rehabilitation group(<0.05). In addition, the Harris score of the postoperativebrace rehabilitation group was better than that of the conventional rehabilitation group(<0.05). The incidence of complications was lower than that of the conventional rehabilitation group(=0.048).@*CONCLUSION@#In the rehabilitation of Evans Jensen typeⅡintertrochanteric fracture after PFNA internal fixation, the new self-developed adjustable weight-bearing rehabilitation brace can significantly relieve postoperative pain, regulate and moderately increase the stress stimulation at the fracture end, so as to promote fracture healing, accelerate the recovery of hip joint function, reduce the incidence of complications, and its clinical effect is safe and reliable.

Scanning electron microscopy assessment of the load-bearing capacity of cad/cam-fabricated molar crowns

Abstract Although fiber-reinforced composites are commonly used in dental practice, whether fiber-reinforced crowns and fixed partial dentures can be used as definitive prostheses remains to be determined. This study used scanning electron microscopy to evaluate the load-bearing capacity of non-reinforced and fiber-reinforced composite (FRC) molar crowns prepared by computer-aided design/computer-aided manufacturing (CAD/CAM). The crowns were fabricated from three empirical FRC blocks, one empirical composite block, and one commercial ceramic block. The FRC resin was prepared by mixing BaO silicate particles, E-glass fiber, and dimethacrylate resin. Specimens were divided into five groups (n = 10), differing in the amounts of filler, resin, and fiber. Crowns were statically loaded until fracture. One-way analysis of variance and Tukey's post hoc multiple comparison tests were used for statistical analyses. The groups showed significant differences in load-bearing capacity; empirical bidirectional FRC resin blocks had the highest capacity, while commercial ceramic blocks had the lowest capacity. Molar crowns formed from FRC resin blocks had higher load-bearing capacity compared to non-reinforced composite resin and ceramic blocks. These results show that fiber reinforcement increased the load-bearing capacity of molar crowns.

Surgically induced degenerative changes in the femorotibial joints by total medial meniscectomy in minipigs closely resemble late-stage osteoarthritis / 대한수의학회지

Animal models of osteoarthritis (OA) have played a key role in understanding the etiology of OA and in the development of new therapeutic strategies. Although pigs have an advantage as an animal disease model due to their similarity to humans, there are few studies on the induction of OA in minipigs. Therefore, this study aimed to characterize disease progression of OA in total medial meniscectomy (TMM)-operated skeletally mature minipigs, up to day 180 postoperatively. There were no significant alterations in vital signs or hematological indices throughout the observation period. However, clinical manifestations of OA in the medial femoral condyles of TMM-operated minipigs were progressive, depending on postoperative duration, with respect to osteophytes formation and roughened surfaces on radiological observation, cartilage erosion under macroscopic examination, and severe cartilage defects including fibrillation, vertical fissures, and cartilage denuding on histopathological observation, with the highest score indicating late-stage OA on day 180 and without indicating apparent variation between subjects. In particular, the lateral femoral condyles were also degenerated, possibly due to localization of weight-bearing from both menisci to the lateral meniscus. Therefore, TMM in minipigs is suitable for reproducible induction of degenerative changes in the femorotibial joints that closely resemble late-stage OA, and is suitable for use in further research.

Retroperitoneal Extrapleural Approach for Corpectomy of the First Lumbar Vertebra : Technique and Outcome

OBJECTIVE: Corpectomy of the first lumbar vertebra (L1) for the management of different L1 pathologies can be performed using either an anterior or posterior approach. The aim of this study was to evaluate the usefulness of a retroperitoneal extrapleural approach through the twelfth rib for performing L1 corpectomy.METHODS: Thirty consecutive patients underwent L1 corpectomy between 2010 and 2016. The retroperitoneal extrapleural approach through the 12th rib was used in all cases to perform single-stage anterior L1 corpectomy, reconstruction and anterior instrumentation, except for in two recurrent cases in which posterior fixation was added. Visual analogue scale (VAS) was used for pain intensity measurement and ASIA impairment scale for neurological assessment. The mean follow-up period was 14.5 months.RESULTS: The sample included 18 males and 12 females, and the mean age was 40.3 years. Twenty patients (67%) had sensory or motor deficits before the surgery. The pathologies encountered included traumatic fracture in 12 cases, osteoporotic fracture in four cases, tumor in eight cases and spinal infection in the remaining six cases. The surgeries were performed from the left side, except in two cases. There was significant improvement of back pain and radicular pain as recorded by VAS. One patient exhibited postoperative neurological deterioration due to bone graft dislodgement. All patients with deficits at least partially improved after the surgery. During the follow-up, no hardware failures or losses of correction were detected.CONCLUSION: The retroperitoneal extrapleural approach through the 12th rib is a feasible approach for L1 corpectomy that can combine adequate decompression of the dural sac with effective biomechanical restoration of the compromised anterior load-bearing column. It is associated with less pulmonary complication, no need for chest tube, no abdominal distention and rapid recovery compared with other approaches.

Native 1st Metatarso-Phalangeal Joint Infection: A Rare Case Report / 대한족부족관절학회지

Septic arthritis is a serious medical condition that can lead to significant complications if misdiagnosed or mismanaged. A rare case of a 1st metatarso-phalangeal joint septic arthritis in a native joint is presented in a patient with no significant risk factors. A 41-year-old patient was referred by his general practitioner owing to ongoing pain and swelling over his native 1st metatarso-phalangeal joint with difficulty on weightbearing for three months. After a series of investigations, including blood tests and a foot magnetic resonance imaging, which were inconclusive, the patient was led to the operating theatre for sampling and washout of his joint. The samples taken in the theatres revealed septic arthritis with Streptococcus mitis as the causative microorganism. The patient was treated with six weeks of oral antibiotics with a good functional outcome. This case report illuminates this rare condition and makes foot and ankle surgeons aware of its existence. A high suspicion for this condition can prevent misdiagnosis and mismanagement.

Retroperitoneal Extrapleural Approach for Corpectomy of the First Lumbar Vertebra : Technique and Outcome

OBJECTIVE: Corpectomy of the first lumbar vertebra (L1) for the management of different L1 pathologies can be performed using either an anterior or posterior approach. The aim of this study was to evaluate the usefulness of a retroperitoneal extrapleural approach through the twelfth rib for performing L1 corpectomy. METHODS: Thirty consecutive patients underwent L1 corpectomy between 2010 and 2016. The retroperitoneal extrapleural approach through the 12th rib was used in all cases to perform single-stage anterior L1 corpectomy, reconstruction and anterior instrumentation, except for in two recurrent cases in which posterior fixation was added. Visual analogue scale (VAS) was used for pain intensity measurement and ASIA impairment scale for neurological assessment. The mean follow-up period was 14.5 months. RESULTS: The sample included 18 males and 12 females, and the mean age was 40.3 years. Twenty patients (67%) had sensory or motor deficits before the surgery. The pathologies encountered included traumatic fracture in 12 cases, osteoporotic fracture in four cases, tumor in eight cases and spinal infection in the remaining six cases. The surgeries were performed from the left side, except in two cases. There was significant improvement of back pain and radicular pain as recorded by VAS. One patient exhibited postoperative neurological deterioration due to bone graft dislodgement. All patients with deficits at least partially improved after the surgery. During the follow-up, no hardware failures or losses of correction were detected. CONCLUSION: The retroperitoneal extrapleural approach through the 12th rib is a feasible approach for L1 corpectomy that can combine adequate decompression of the dural sac with effective biomechanical restoration of the compromised anterior load-bearing column. It is associated with less pulmonary complication, no need for chest tube, no abdominal distention and rapid recovery compared with other approaches.

Evidence-Based Physical Therapy for Anterior Cruciate Ligament Injury: Literature Review

Most athletes with anterior cruciate ligament (ACL) ruptures undergo a surgical ACL reconstruction (ACLR) and rehabilitation. On the other hand, controversy still exists because neither a reconstruction nor rehabilitation have been proven to be superior in the management of ACL injury. This study reviewed the success rates of interventions to provide recommendations for the optimal management after an ACL injury. One of the most important considerations after an ACL injury is the timing and type of intervention. At the early stages, which involve the loss of volume and strength of quadriceps femoral muscle, weight bearing (closed kinetic chain) exercises with pain management followed by high velocity resistance exercises in an open kinetic chain environment are recommended to improve the quadriceps function. After that, it is important to apply intensive isokinetic exercise with a lower extension rate. In this case, it is important to apply overload to the muscles and to simultaneously lead the co-contraction of the hamstrings. Standards are essential because the timing and type of interventions are crucial to prevent re-injury and complications, such as osteoarthritis, as well as to confirm the successful outcome of the treatment. Different interventions recommended for ACL damage have yet to reach consensus. Further studies will be needed to observe the effects of the intervention through multidisciplinary approaches.

Principles for Management of Periprosthetic Acetabular Fractures after Hip Arthroplasty

Periprosthetic acetabular fracture (PAF) is an uncommon complication following hip arthroplasty. However, as the number of people needing hip prostheses continues to rise, the absolute number of PAF is expected to increase as well. These fractures may occur either intraoperatively or postoperatively. Postoperative fractures can be caused by traumatic events or by pathologic conditions related to periacetabular osteolysis. The management of PAF usually depends on the degree of displacement and the stability of the acetabular component. While most of non-displaced fractures can be managed nonoperatively by protected weight bearing, displaced fractures with unstable implants require surgical intervention, which is often technically challenging. This review summarized the latest findings on the epidemiology, the diagnosis, the classification, and the treatment of PAF.

Percutaneous Iliosacral Screw Fixation with Cement Augmentation in Osteoporotic Sacral Fracture

PURPOSE: The prevalence of osteoporotic sacral fractures is increasing. Traditionally, conservative treatment is the 1st option, but it can increase the risk of comorbidity in the elderly. To reduce the complications and allow early mobility, iliosacral screw fixation with cement augmentation will be one of the treatment options for patients with osteoporotic sacral fractures. MATERIALS AND METHODS: This study reviewed 25 patients (30 cases) who had undergone percutaneous iliosacral screw fixation with cement augmentation for osteoporotic sacral fractures from July 2012 to December 2018 with a minimum follow up of six months. The clinical outcomes were assessed using the measures of pain (visual analogue scale [VAS] score), hospital stay and the date when weight-bearing started. All patients were evaluated radiologically for pull-out of screw, bone-union, and cement-leakage. RESULTS: Bone union was achieved in 30 cases (100%). The mean duration of the hospital stay was 24 days (4–66 days); weight-bearing was performed on an average nine days after surgery. The VAS scores immediately (3.16) and three months after surgery (2.63) were lower than that of the preoperative VAS score (8.3) (p<0.05). No cases of cement-leakage or neurologic symptoms were encountered. Two patients (6.7%) experienced a pulling-out of the screw, but bone-union was accomplished without any additional procedures. CONCLUSION: Percutaneous iliosacral fixation with cement augmentation will be an appropriate and safe surgical option for osteoporotic sacral fractures in the elderly in terms of early weight-bearing, pain reduction, and bone-union.

Effect of the restorative technique on load-bearing capacity, cusp deflection, and stress distribution of endodontically-treated premolars with MOD restoration

OBJECTIVES: To evaluate the influence of the restorative technique on the mechanical response of endodontically-treated upper premolars with mesio-occluso-distal (MOD) cavity. MATERIALS AND METHODS: Forty-eight premolars received MOD preparation (4 groups, n = 12) with different restorative techniques: glass ionomer cement + composite resin (the GIC group), a metallic post + composite resin (the MP group), a fiberglass post + composite resin (the FGP group), or no endodontic treatment + restoration with composite resin (the CR group). Cusp strain and load-bearing capacity were evaluated. One-way analysis of variance and the Tukey test were used with α = 5%. Finite element analysis (FEA) was used to calculate displacement and tensile stress for the teeth and restorations. RESULTS: MP showed the highest cusp (p = 0.027) deflection (24.28 ± 5.09 µm/µm), followed by FGP (20.61 ± 5.05 µm/µm), CR (17.72 ± 6.32 µm/µm), and GIC (17.62 ± 7.00 µm/µm). For load-bearing, CR (38.89 ± 3.24 N) showed the highest, followed by GIC (37.51 ± 6.69 N), FGP (29.80 ± 10.03 N), and MP (18.41 ± 4.15 N) (p = 0.001) value. FEA showed similar behavior in the restorations in all groups, while MP showed the highest stress concentration in the tooth and post. CONCLUSIONS: There is no mechanical advantage in using intraradicular posts for endodontically-treated premolars requiring MOD restoration. Filling the pulp chamber with GIC and restoring the tooth with only CR showed the most promising results for cusp deflection, failure load, and stress distribution.

An Instrumented Workstation to Evaluate Weight-Bearing Distribution in the Sitting Posture

BACKGROUND: Sitting posture may be related to risk factors, including inadequate weight-bearing support, particularly when maintained for long periods. Considering that body weight is loaded in a closed support system composed of the seat, backrest, floor and working surface, the aims of the present study were to describe the development of an ergonomic sitting workstation to continuously record weight-bearing at the seat, chair, backrest, work surface, and floor and to test its measurement properties: reproducibility, criterion-related validity, and sensitivity. METHODS: Rigid bodies (1 to 30 kg) and participant weights were recorded to evaluate the workstation measurement properties. RESULTS: Rigid body tests showed variation values less than 0.050 kg on reproducibility test and errors below 5% of measured value on criterion validity tests. Participant tests showed no statistically significant differences between repeated measures (p ≥ 0.40), errors were less than 2% of participant weights and sensitivity presented statistically significant changes (p = 0.007). CONCLUSION: The sitting workstation proposed showed to be reliable, valid and sensitive for use in future ergonomic studies to evaluate the sitting posture.