Reconstruction with Unconventional Endoprostheses after Resection of Primary Distal Femoral Bone Tumors: Implant Survival and Functional Outcomes / Reconstrução com endoprótese não convencional após ressecção de tumores ósseos primários de fêmur distal: sobrevida do implante e resultados funcionais

Abstract Objective To evaluate the survival time, the failure rate and its causes, and the functional results of cemented endoprostheses, with a polyethylene body, used after resection of primary bone tumors of the distal femur. Methods A retrospective study including 93 primary and 77 review procedures performed between 1987 and 2014. Survival was obtained by the Kaplan Meyer analysis, and the risk factors for implant failure were assessed through the Cox proportional risk model. The causes of endoprosthesis failure were classified according to Henderson et al. into five types: soft-tissue failure, aseptic loosening, structural fracture, infection, and tumor recurrence. The functional evaluation was performed using the functional classification system of the Musculoskeletal Tumor Society (MSTS) of bone sarcomas of the lower extremity, Brazilian version (MSTS-BR). Results Osteosarcoma was the most common diagnosis; 64.5% of the patients were younger than 20 years of age; the mean follow-up was of 124.3 months. The failure rate of the primary implant was of 54.8%, and the mean survival was of 123 months. The estimated survival of the primary implant was of 63.6%, 43.5%, 24.1%, and 14.5% in 5, 10, 15, and 20 years respectively. The most common cause of failure was type 2 (37.3%). Age ≤ 26 years and right side were risk factors for failure. The mean MSTS-BR score was of 20.7 (range: 14 to 27). Conclusion The results obtained for the failure rate and survival of the implant are in accordance with those of the literature, so the procedure herein studied is adequate and yields satisfactory functional results, even in the long term.

Resumo Objetivo Avaliar o tempo de sobrevida, a taxa de falha e suas causas, e os resultados funcionais de endopróteses cimentadas, com corpo em polietileno, empregadas após ressecção de tumores ósseos primários do fêmur distal. Métodos Estudo retrospectivo, que incluiu 93 procedimentos primários e 77 de revisão, realizados entre 1987 e 2014. A sobrevida foi obtida pela análise de Kaplan Meyer, e os fatores de risco para falha do implante foram avaliados por meio do modelo de riscos proporcionais de Cox. As causas de falha da endoprótese foram classificadas segundo Henderson et al. em cinco tipos: falha de partes moles, soltura asséptica, fratura estrutural, infecção e recorrência do tumor. A avaliação funcional foi realizada por meio do sistema de classificação funcional da Musculoskeletal Tumor Society (MSTS) para sarcomas ósseos da extremidade inferior, versão brasileira (MSTS-BR). Resultados Osteossarcoma foi o diagnóstico mais comum; 64,5% dos pacientes tinham menos de 20 anos; e o seguimento médio foi de 124,3 meses. A taxa de falha do implante primário foi de 54,8%, e a sobrevida média foi 123 meses. A estimativa de sobrevida do implante primário foi de 63,6%, 43,5%, 24,1%, 14,5% em 5, 10, 15 e 20 anos, respectivamente. A causa de falha mais comum foi a do tipo 2 (37,3%). Idade ≤ 26 anos e lado direito foram fatores de risco para falha. A pontuação média no MSTS-BR foi de 20,7 (variação: 14 a 27). Conclusão Os resultados obtidos para a taxa de falha e o tempo de sobrevida do implante estão de acordo com os da literatura, de forma que o procedimento estudado é adequado e apresenta resultados funcionais satisfatórios, inclusive em longo prazo.

Effects of different swimming intensities on the bone properties of the tibia and femur of Wistar Rats in which knee rheumatoid arthritis was induced / Efectos de las diferentes intensidades de la natación en las propiedades óseas de la tibia y fémur de Ratas Wistar con artritis reumatoide inducida en rodillas

Rheumatoid arthritis (RA) is a disease triggered by environmental and genetic factors. Research suggests that physical exercise has benefits such as delaying functional disability. In vivo studies using experimental models of arthritis can provide useful information about these benefits. to analyze the effects that different intensities of aquatic physical exercise have on the proprieties of the bones in induced arthritis in knees of Wistar rats. Male Wistar adults rats (n=20) were divided into 5 groups: Group Control Arthritis (GCA) n=4, Group control Placebo (GCP) n=4, Group Low Physical Activity (GB) n=4, Group Moderate Physical Activity (GM) n=4 and Group Intense Physical Activity (GI) n=4. The physical activity groups got an intra-articular injection of Zymosam on the right knee; the GCA received saline solution in the right knee; the GCP was submitted to the stress of the needle. The animals were submitted to aquatic activity for 30 minutes, 4 times a week for 5 weeks, and the intensity of the exercise was determined by a weight placed on their back: GB=1 %, GM=5 %, GI=15 % of their body weight. It was observed that the group GB, and the groups that did not exercise GCA and GCP, gained more weight compared to the group GM. In relation to the bone mineral content of the tibia, there was a decrease in the GM group when compared to the GCP group, whereas in the tibial bone mineral density there was a decrease in the GM group compared to the GCP, GCA, GB. As for the area of the femur, the GI group presented an increase of it compared to the GB and GM groups. It is concluded that the high intensity exercises promote better results in bone properties.

La investigación sugiere que el ejercicio físico tiene beneficios como retrasar la discapacidad funcional de la artritis reumatoide. Los estudios in vivo que utilizan modelos experimentales de artritis pueden proporcionar información útil sobre estos beneficios. Se analizaron los efectos de las intensidades del ejercicio físico acuático sobre las propiedades de los huesos, en la artritis inducida en las rodillas de ratas Wistar. Las ratas Wistar macho adultas (n = 20) se dividieron en 5 grupos: grupo de control artritis (ACG) n = 4, grupo control placebo (CGP) n = 4, grupo de actividad física baja (GB) n = 4, grupo de actividad física moderada (GM) n = 4 y grupo de actividad física intensa (GI) n = 4. Los grupos de actividad física recibieron una inyección intraarticular de Zymosam en la rodilla derecha; el GCA recibió solución salina en la rodilla derecha; el CGP fue sometido a la tensión de una aguja. Los animales fueron sometidos a actividad acuática durante 30 minutos, 4 veces a la semana durante 5 semanas, y la intensidad del ejercicio se determinó mediante un peso colocado sobre su espalda: GB = 1 %, GM = 5 %, GI = 15 % de su peso corporal. Se observó que el grupo GB, y los grupos que no ejercitaron GCA y CGP, ganaron más peso en comparación con el grupo GM. En relación con el contenido mineral óseo de la tibia, hubo una disminución en el grupo GM en comparación con el grupo GCP, mientras que en la densidad mineral del hueso tibial hubo una disminución en el grupo GM en comparación con el GCP, GCA, GB. En cuanto al área del fémur, el grupo GI presentó un aumento en comparación con los grupos GB y GM. En conclusión el ejercicio de alta intensidad promueve mejores resultados en las propiedades óseas.

Efectos del ranelato de estroncio sobre la densidad mineral ósea en hombres / Effect of strontium ranelate on bone mineral density in men

La osteoporosis afecta al 6-7% de la poblaciónmasculina. Es alta la proporción de pacientes confractura osteoporótica sin diagnóstico previo de estaenfermedad. La mortalidad luego de una fracturaes mayor en hombres que en población femenina;a pesar de esto, la mayoría de los pacientes no reciben tratamiento. Los fármacos aprobados, en nuestro medio, para tratar la osteoporosis masculina son:bifosfonatos, teriparatida y ranelato de estroncio. Elobjetivo de este estudio fue evaluar el efecto del ranelato de estroncio sobre la densidad mineral ósea enhombres después de 1 año de tratamiento. Se incluyeron los registros de 20 hombres de 67.8±3.0 años,tratados con ranelato de estroncio (2 g/día) durante 1año. Todos los pacientes presentaban un T-score inferior a -2.5 en cadera o columna vertebral o un T-scoreinferior a -2.0 y factores de riesgo de fractura. Nohubo modificación de parámetros de laboratorio luego del tratamiento (calcemia, calciuria, fósforo sérico,parathormona, 25(OH)vitamina D, fosfatasa alcalinay desoxipiridinolina). Luego de 1 año de tratamiento con ranelato de estroncio se observó incrementode la densidad mineral ósea en columna lumbar:0.953±0.029 versus 0.997±0.030 g/cm2 (p=0.0068),cuello femoral: 0.734±0.013 versus 0.764±0.016 g/cm2 (p=0.0084) y cadera total: 0.821±0.02 versus0.834±0.02 g/cm2 (p=0.0419). Conclusión: luego de1 año de tratamiento el ranelato de estroncio produjoun incremento significativo de la densidad mineralósea en columna lumbar y fémur proximal en hombres con osteoporosis (AU)

Osteoporosis affects 6-7% of the male population. The proportion of patients with fragility fractures but without diagnosis of the disease is high. Mortality after hip fracture is higherin men than in women; in spite of this, mostpatients are left without treatment for osteoporosis. Drugs approved, for the treatment ofosteoporosis in our country are bisphosphonates, teriparatide, and strontium ranelate (SrR).The objective of this study was to evaluate theeffect of SrR on axial BMD in men after one yearof treatment. We obtained pertinent data frommedical registries of 20 men aged 67,8±3,0 years,treated with oral SrR (2 g/day) for 12 months. All patients had a T-score below -2,5 at the hipor the lumbar spine, or a T-score below -2,0and one or more risk factors for fracture. Thelevels of serum calcium, phosphate, alkalinephosphatase, 25-hydroxyvitamin D, or PTH,or urinary calcium and desoxipyridinoline remained unchanged following SrR administration. After treatment with SrR there weresignificant increases in BMD at the lumbarspine: 0,953±0,029 versus 0,997±0,030 g/cm2(p=0,0068), femoral neck: 0,734±0,013 versus 0,764±0,016 g/cm2 (p=0.0084), and total hip: 0,821±0,02 versus 0,834±0,02 g/cm2(p=0,0419). Conclusion: in osteoporotic men,treatment with SrR significantly increases BMDin the lumbar spine and the proximal femur (AU)

The cortical matrix of femur in adult-aged Wistar rats is critically affected by maternal malnutrition during lactation period / La matriz cortical del fémur en ratas Wistar de edad adulta se ve críticamente afectada por la malnutrición materna durante el período de lactancia

Osteoporosis is associated with poor dietary habits. Malnutrition is characterized as a deficit on the intake of necessary nutrients that are essential for optimal health maintenance. It is known that malnutrition during the lactation period can affect the offspring. The present study aims to evaluate the chronic effects caused by maternal energy-protein restriction during lactation period in the offspring. At parturition, Wistar rat dams were divided in three groups: (1) Control group (C) - which received a 23 % protein diet without restrictions; (2) Protein-Energy restriction group (PER)- which received a 8 % protein diet; (3) Energy restriction group (ER) which received a 23 % protein diet in limited amounts, according to the ingestion of the second group. Each group had 12 pups. After weaning, all pups received free access to a 23 % protein diet until 180 days and then were euthanized. Their femur was excised, decalcified, histologically processed and analyzed under a microscope. The measurements of the osteon lacunae on the C, ER and PER groups were, respectively: 2.1 µm, 10.9 µm and 14.7 µm (p<0.05). A poor ingestion of proteins and calories during lactation period provoked critical and permanent changes on the bone matrix of the femur, which simulated osteoporosis.

La osteoporosis se asocia con malos hábitos alimenticios. La desnutrición se caracteriza como un déficit en la ingesta de los nutrientes necesarios que son esenciales para un mantenimiento óptimo de la salud. Se sabe que la malnutrición durante el período de lactancia puede afectar a la descendencia. El presente estudio tiene como objetivo evaluar los efectos crónicos causados por la restricción energética-proteína materna durante el período de lactancia en la descendencia. En el parto, las hijas de rata Wistar se dividieron en tres grupos: (1) grupo control (C) - que recibió una dieta con 23 % de proteína sin restricciones; (2) Grupo restricción de energía de proteína (PER) - que recibió una dieta con 8 % de proteína; (3) Grupo restricción de energía (ER) - que recibió una dieta de 23 % de proteína en cantidades limitadas, de acuerdo con la ingestión del segundo grupo. Cada grupo tenía 12 crías. Después del destete, todas las crías recibieron acceso libre a una dieta con 23 % de proteína hasta 180 días y luego fueron sacrificadas. Su fémur fue extirpado, descalcificado, procesado histológicamente y analizado bajo un microscopio. Las mediciones de las lagunas de osteón en los grupos C, ER y PER fueron, respectivamente: 2,1 mm, 10,9 mm y 14,7 mm (p <0,05). Una mala ingesta de proteínas y calorías durante el período de lactancia provocó cambios críticos y permanentes en la matriz ósea del fémur, que simulaba osteoporosis.

Caso Clínico: Uso de Aloinjerto Óseo Estructural en Tumor de Células Gigantes de Fémur / Case Report: Use Of Structural Bone Allograft In Giant Cell Tumor Of The Femur

INTRODUCCIÓN: El tumor de células gigantes óseo es muy raro y controversial en su comportamiento por lo que es predecible. El diagnóstico requiere biopsia previa antes de proceder al tratamiento.CASO CLÍNICO: Paciente masculino de 43 años de edad, mestizo, sin antecedentes personales o familiares de relevancia. Acude a consulta externa de ortopedia oncológica por presentar masa dura y dolorosa con aumento gradual de tamaño a nivel de rodilla derecha, deformidad, limitación funcional y crepitación. EVOLUCIÓN: El paciente fue sometido a biopsia de lesión a nivel de fémur distal derecho con reporte de anatomía patológica de tumor de células gigantes. Se realizó una resección ósea a nivel de tumor y tratamiento mediante colocación de aloinjerto estructural óseo, con un seguimiento de 2 años y obteniendo como resultado funcional una puntuación de 14/15 según la escala de Makin, se evidencio además osteointegración del injerto al hueso autógeno a los 15 meses. No presento infección, ni reabsorción del injerto, ni fatiga del material.CONCLUSIÓN: La cirugía de conservación de la extremidad utilizando los aloinjertos estructurales es una técnica favorable con funcionalidad y osteointegración adecuada, aumentando las expectativas y calidad de vida. Evitando amputaciones, artrodesis o prótesis tumorales cuyo costo beneficio con los años subsecuentes terminan siendo altos y deteriorando al paciente.

BACKGROUND: Bone giant cell tumor (GCT) is one of the least frequent, most controversial and least predictable tumors in its behavior. We present a case of GCT in the lower limb, which implied the distal femur. The diagnosis required a previous biopsy before proceeding with its en bloc resection, and treatment based on bone allograft. CASE REPORT: Male patient of 43 years of age, mestizo, with no relevant personal or family history. He went to the oncology orthopedics outpatient clinic for presenting a hard and painful mass with gradual increase in size at the level of the right knee, deformity, functional limitation and crepitus in that region, which is why he attends his assessment. EVOLUTION:The patient underwent a lesion biopsy at the level of the distal femur with a pathological anatomy report of giant cell tumor. Bone resection was performed at the tumor level and treatment was performed by allografting the bone structural allograft. A 2-year follow-up was performed and a score of 14/15 according to the Makin scale was obtained as functional results. Osteointegration of the graft to autogenous bone was also evidenced. Excellently at 15 months. We did not find infection, graft resorption or fatigue of the material. CONCLUSIONS: Limb preservation surgery represented by structural allografts is a favorable technique with adequate functionality and osteoingration, increasing the life expectancy of our patients and future revision possibilities. Avoiding amputations, arthrodesis or tumor prosthesis whose cost benefit with the subsequent years end up being high and deteriorating the quality of life in the patient.

Alendronato administrado en el foco de fractura: Estudio experimental en conejos / Alendronate administered at the fracture site. Experimental study in rabbits

Introducción: El objetivo de este estudio experimental fue evaluar el resultado radiológico e histológico del empleo de alendronato colocado localmente en el foco de fracturas de fémur en conejos. Materiales y Métodos: Se utilizaron 30 conejos a los cuales se les fracturó el fémur derecho y se los dividió en tres grupos de 10 animales cada uno. A los conejos del grupo 1 se les colocó una solución con alendronato en el foco de fractura; los del grupo 2 fueron sometidos al mismo procedimiento a los siete días de la fractura y el grupo 3 era de control. Se realizó la evaluación radiográfica en el momento de la fractura y a los 42 días del procedimiento. Se evaluaron las características del callo óseo mediante anatomía patológica, radiología y tomografía computarizada. Resultados: Se evaluaron 24 conejos (2 conejos del grupo 2 y 4 del grupo 3 murieron). El análisis histológico reveló moderada formación ósea en los tres grupos, sin diferencias estadísticamente significativas (p = 0,8336). Según los resultados de los estudios por imágenes, no existieron diferencias estadísticamente significativas en el tamaño del callo óseo entre los grupos para los dos estudios (radiografía: p = 0,777 y tomografía: p = 0,349). Conclusión: El alendronato colocado localmente en el foco de fractura, en la etapa aguda y luego de una semana, no alteró, de manera estadísticamente significativa, el proceso normal de consolidación, determinado por anatomía patológica y radiología, a las seis semanas de la fractura de fémur en conejos. Nivel de Evidencia: II

Introduction: The aim of this experimental study was to evaluate the radiologic and histological results of the use of alendronate administered locally at the fractures site in rabbits. Methods: The fractured right femur of 30 rabbits was used for evaluation. The animals were distributed in three groups of 10 rabbits each. A solution with alendronate was placed at the fracture site in group 1; the same procedure was performed 7 days after the fracture in group 2, and group 3 functioned as control. Radiographic evaluation was performed at the time of the fracture and at day 42. Radiological, PA and CT-scan evaluations of bone callus characteristics in each rabbit were performed. Results: Twenty-four rabbits were evaluated (2 rabbits in group 2 and 4 in group 3 died). Histological evaluation evidenced moderate bone formation in the three groups without statistically significant differences (p=0.8336). Concerning imaging studies, there were no statistically significant differences in the size of bone callus among groups for both studies (X-rays: p=0.777 and CT: p=0.349). Conclusion: The use of alendronate administered locally at the fracture site, in the acute period and after one week, did not alter the normal consolidation process determined by PA and radiology, six weeks after femur fracture in rabbits. Level of Evidence: II

Effects of continual intermittent administration of parathyroid hormone on implant stability in the presence of osteoporosis: an in vivo study using resonance frequency analysis in a rabbit model

Abstract Objective: This study aimed to evaluate the effects of continual intermittent administration of parathyroid hormone (PTH) on implant stability in the presence of osteoporosis, using rabbit models. Material and Methods: Fifteen female New Zealand white rabbits underwent ovariectomy and were administered glucocorticoids to induce osteoporosis, following which they were divided into three groups. The first group received intermittent subcutaneous PTH for 4 weeks until implant placement (PTH1), while the second and third groups received PTH (PTH2) and saline (control), respectively, for 4 weeks before and after implant placement. After intermittent administration of PTH or saline, titanium implants were inserted into the left femoral epiphyses of all animals, and the implant stability quotient (ISQ) was measured immediately after placement to assess the primary stability and at 2 and 4 weeks after implant placement to assess osseointegration. At 4 weeks after implant placement, histological and histomorphometric evaluations were conducted and the bone area around the implant socket was measured as a ratio of the total bone area to the total tissue area. Results: Regarding primary stability, the ISQ values for the PTH1 and PTH2 groups were significantly higher than those for the control group (p<0.05). Concerning osseointegration, the ISQ values at 2 and 4 weeks were significantly higher for the PTH2 group than for the PTH1 and control (p<0.05) groups. Histological assessments showed a thicker and more trabecular bone around the implant sockets in the PTH2 specimens than in the PTH1 and control specimens. The bone area around the implant socket was significantly greater in the PTH2 group than in the PTH1 and control groups (p<0.05). Conclusions: Our results suggest that continual intermittent PTH administration before and after dental implant placement is effective for the achievement of favorable stability and osseointegration in the presence of osteoporosis.

Influence of ß-tricalcium phosphate of different geometric shape on the morphology of regeneration of experimental defect of compact bone tissue / Influencia del fosfato ß-tricálcico de diferentes formas geométricas en la morfología de la regeneración del defecto experimental del tejido óseo compacto

Purpose: to compare the healing process of a defect of compact bone tissue after the implantation of osteoplastic materials based on ß-tricalcium phosphate ("ChronOS™" and "Calc-i-oss®"), which differ by manufacturer, geometrical shape and microscopic structure. Methods: the experiment was performed on 48 white male Wistar rats. In the middle third of the diaphysis of the femur we produced a perforated defect of 2.5 mm diameter in the medullary canal, which in the animals of the first group was filled with the osteoplastic material "ChronOS™" (block, Synthes, Switzerland), and in the animals of the second group with "Calc-i-oss®" (granules, «Degradable Solutions Dental¼, Switzerland). Fragments of the injured bones were studied on the 60th and 120th day by light microscopy with morphometry and by scanning electron microscopy. Results: it was found that regardless the geometric shape and the microscopic structure, both osteoplastic materials show high biocompatibility, osteoconductive properties, good integration with bone tissue of the regenerate, and that the microscopic structure of ß-tricalcium phosphate ("ChronOS™") may significantly affect the microscopic structure of bone tissue of the regenerate, which manifests itself in the specificity of its geometric shape. It was noticed that osteoplastic materials "ChronOS™" and "Calc-i-oss®" almost at the same rate were subjected to resorption and replacement by the bone tissue, the ratio of which was 22.55±1.25 to 77.45±1.25 and 25.72±2.06% to 74.28±2.06% on the 60th day of the experiment, and 17.65±1.09 to 82.35±1.09 and 18.31±1.54% to 81.69±1.54% on the 120th day. (AU)

Objetivo: Comparar el proceso de cicatrización de un defecto del tejido óseo compacto tras la implantación de materiales osteoplásticos a base de fosfato ß-tricálcico («ChronOS™¼ and «Calc-i-oss®¼) que difieren según el fabricante en la forma geométrica y estructura microscópica. El estudio fue realizado en 48 ratas Wistar machos en los cuales se produjo, en el tercio medio de la diáfisis del fémur, un defecto perforado de 2,5 mm de diámetro, el cual fue llenado con el material «ChronOS™¼ (block, Synthes, Switzerland) en un grupo y con «Calc-i-oss®¼ (granules, «Degradable Solutions Dental¼, Switzerland) en el segundo grupo. El sector del defecto fue evaluado en los días 60 y 120 por microscopía óptica y por microscopía electrónica de barrido. Resultados: independientemente de la forma geométrica y la estructura microscópica, ambos materiales osteoplásticos mostraron alta biocompatibilidad, propiedades osteoconductivas y buena integración con el tejido óseo regenerado. La estructura microscópica del fosfato ß-tricálcico («ChronOS™¼) puede afectar significativamente a la estructura microscópica del tejido óseo regenerado, que se manifiesta en su forma geométrica. Adicionalmente, se observó que ambos materiales osteoplásticos «ChronOS™¼ y «Calc-i-oss®¼ mostraron valores similares de resorción y reemplazo por tejido óseo, cuya relación al 60º día del experimento fue de 22,55±1,25 a 77,45±1,25 y 25,72±2,06% a 74,28±2,06%, y a los 120 días de 17,65±1,09 a 82,35±1,09 y de 18,31±1,54% a 81,69±1,54% respectivamente. (AU)

Repair of bone defects using adipose-derived stem cells combined with alpha-tricalcium phosphate and gelatin sponge scaffolds in a rat model

Abstract Objectives This study aimed to evaluate the potential of adipose-derived stem cells (ASCs) combined with a modified α-tricalcium phosphate (α-TCP) or gelatin sponge (GS) scaffolds for bone healing in a rat model. Material and Methods Bone defects were surgically created in the femur of adult SHR rats and filled with the scaffolds, empty or combined with ASCs. The results were analyzed by histology and histomorphometry on days seven, 14, 30, and 60. Results Significantly increased bone repair was observed on days seven and 60 in animals treated with α-TCP/ASCs, and on day 14 in the group treated with GS/ASCs, when compared with the groups treated with the biomaterials alone. Intense fibroplasia was observed in the group treated with GS alone, on days 14 and 30. Conclusions Our results showed that the use of ASCs combined with α-TCP or GS scaffolds resulted in increased bone repair. The higher efficacy of the α-TCP scaffold suggests osteoconductive property that results in a biological support to the cells, whereas the GS scaffold functions just as a carrier. These results confirm the potential of ASCs in accelerating bone repair in in vivo experimental rat models. These results suggest a new alternative for treating bone defects.

Functional investigation of bone implant viability using radiotracers in a new model of osteonecrosis

OBJECTIVES: Conventional imaging methods are excellent for the morphological characterization of the consequences of osteonecrosis; however, only specialized techniques have been considered useful for obtaining functional information. To explore the affinity of radiotracers for severely devascularized bone, a new mouse model of isolated femur implanted in a subcutaneous abdominal pocket was devised. To maintain animal mobility and longevity, the femur was harvested from syngeneic donors. Two technetium-99m-labeled tracers targeting angiogenesis and bone matrix were selected. METHODS: Medronic acid and a homodimer peptide conjugated with RGDfK were radiolabeled with technetium-99m, and biodistribution was evaluated in Swiss mice. The grafted and control femurs were evaluated after 15, 30 and 60 days, including computed tomography (CT) and histological analysis. RESULTS: Radiolabeling achieved high (>95%) radiochemical purity. The biodistribution confirmed good blood clearance 1 hour after administration. For 99mTc-hydrazinonicotinic acid (HYNIC)-E-[c(RGDfK)2, remarkable renal excretion was observed compared to 99mTc-methylene diphosphonate (MDP), but the latter, as expected, revealed higher bone uptake. The results obtained in the control femur were equal at all time points. In the implanted femur, 99mTc-HYNIC-E-[c(RGDfK)2 uptake was highest after 15 days, consistent with early angiogenesis. Regarding 99mTc-MDP in the implant, similar uptake was documented at all time points, consistent with sustained bone viability; however, the uptake was lower than that detected in the control femur, as confirmed by histology. CONCLUSIONS: 1) Graft viability was successfully diagnosed using radiotracers in severely ischemic bone at all time points. 2) Analogously, indirect information about angiogenesis could be gathered using 999mTc-HYNIC-E-[c(RGDfK)2. 3) These techniques appear promising and warrant further studies to determine their potential clinical applications.

Maternal malnutrition diet during lactation period leads to incomplete catch-up growth in femur of the pups at adulthood / Restricción alimentaria materna durante la lactancia conduce a la recuperación del crecimiento incompleto en el fémur de las crías en la edad adulta

The aim of this study was to evaluate the effects of maternal protein and energy restriction during lactation, analyzing on morphological dimensions whether there was catch-up growth through normative nutrition restored, as well as on mechanical axis of femur of the offspring at adulthood. At parturition, Wistar rat dams were randomly assigned to the following groups: 1) control group (C) - free access to a standard laboratory diet containing 23 % protein, 2) protein-energy restricted group (PER) - free access to an isoenergetic, protein-restricted diet containing 8 % protein, and 3) energy-restricted group (ER) ­ fed with restricted amounts of a standard laboratory diet. At weaning, all pups were separated of dams and received free access to a standard laboratory diet containing 23 % protein until 180 days, when the rats were anesthetized and sacrificed. The dimensions of excised pup femur were measured directly using pre-established anatomical points. Morphometric analysis of the femur (macroscopic) showed that most of the measurements in the ER and PER groups were significantly lower than in the control group, with the greatest reductions occurring in the PER group and several structural abnormalities. Our results show that protein and energy restriction during lactation leads to an incomplete catch-up growth in adulthood. The femur showed significant reduction in most of the parameters in the two treated groups, particularly the PER group, when compared to the control group.

El objetivo de este estudio fue evaluar los efectos de la restricción de la proteína materna y de energía durante la lactancia, y analizar las dimensiones morfológicas si hubo recuperación del crecimiento a través de la nutrición normativa restaurada, así como en el eje mecánico del fémur de la descendencia en la edad adulta. En el parto, las crías de ratas Wistar fueron agrupadas aleatoriamente en los siguientes grupos: 1) control (C) - con acceso libre a una dieta estándar del laboratorio, que contenía 23 % de proteínas; 2) con restricción de proteínas y energía (PER) - acceso libre a una dieta isoenergética, con restricción de proteínas, conteniendo un 8 % de éstas y 3) grupo con restricción de energía, alimentado con restricción en la cantidad de alimento de la dieta estándar del laboratorio (ER). Al destete, todas las crías fueron separadas y recibieron las dietas establecidas hasta los 180 días (d180), luego fueron anestesiadas y sacrificadas. Las mediciones de los fémures de las crías de rata fueron obtenidas por puntos anatómicos preestablecidos. El análisis morfométrico de fémur demostró que la mayoría de las mediciones en los grupos ER y PER eran significativamente menores que las del grupo control, con mayores reducciones en el grupo PER. Nuestros resultados muestran que las restricciones de energía y proteínas durante la lactancia conducen a una recuperación del crecimiento incompleto en la edad adulta. El fémur mostró una reducción significativa en la mayoría de los parámetros en los dos grupos tratados, en particular el grupo de PER, en comparación con el grupo control.

High-impact exercise in rats prior to and during suspension can prevent bone loss

High-impact exercise has been considered an important method for treating bone loss in osteopenic experimental models. In this study, we investigated the effects of osteopenia caused by inactivity in femora and tibiae of rats subjected to jump training using the rat tail suspension model. Eight-week-old female Wistar rats were divided into five groups (n=10 each group): jump training for 2 weeks before suspension and training during 3 weeks of suspension; jump training for 2 weeks before suspension; jump training only during suspension; suspension without any training; and a control group. The exercise protocol consisted of 20 jumps/day, 5 days/week, with a jump height of 40 cm. The bone mineral density of the femora and tibiae was measured by double energy X-ray absorptiometry and the same bones were evaluated by mechanical tests. Bone microarchitecture was evaluated by scanning electron microscopy. One-way ANOVA was used to compare groups. Significance was determined as P<0.05. Regarding bone mineral density, mechanical properties and bone microarchitecture, the beneficial effects were greater in the bones of animals subjected to pre-suspension training and subsequently to training during suspension, compared with the bones of animals subjected to pre-suspension training or to training during suspension. Our results indicate that a period of high impact exercise prior to tail suspension in rats can prevent the installation of osteopenia if there is also training during the tail suspension.

Osteosarcoma con presentación atípica en tercio medio de diáfisis de fémur. Reporte de un caso clínico y revisión de la literatura / Atipic osteosarcoma in the femoral shaft case report and review of the literature

Resumen: El osteosarcoma es el tumor maligno primario más frecuente del hueso. Se caracteriza por la formación de osteoide por las células tumorales. Su localización más frecuente es en las metáfisis de los huesos largos; sin embargo, la presentación puramente diafisaria se reporta en 10% de los casos. Se expone el caso de paciente del género femenino de 25 años que inició padecimiento cuatro meses previos a nuestra valoración al presentar dolor y aumento de volumen en tercio medio de muslo derecho, sin causa aparente. Las radiografías del fémur revelaron un tumor en la diáfisis del mismo. La resonancia magnética mostró extensión a partes blandas, sin compromiso del paquete neurovascular. Se tomó biopsia incisional con reporte histopatológico de osteosarcoma osteoblástico y condroblástico. Se clasificó como Enneking IIB, AJCC IIB. Inició tratamiento con tres ciclos de quimioterapia neoadyuvante y posteriormente se le realizó resección intercalar de fémur más reconstrucción con clavo centromedular y espaciador diafisario. El reporte histopatológico evidenció necrosis de 95% (Huvos grado III). Se continuó con tres ciclos de quimioterapia adyuvante. A 18 meses de concluida la quimioterapia adyuvante la paciente se encuentra sin datos de actividad tumoral local o a distancia, tolerando la deambulación sin auxiliares de la marcha. A pesar de que el osteosarcoma no se presenta de forma habitual en el tercio medio de la diáfisis de los huesos largos, debe siempre tomarse en cuenta como un diagnóstico diferencial con otras patologías de localización más frecuente en dicha región. Esta localización nos permite una amplia gama de alternativas quirúrgicas con la preservación de las articulaciones adyacentes.

Abstract: Osteosarcoma is the most frequent primary malignant bone tumor. It is characterized by osteoid production by tumor cells. Its most frequent location is in the metaphyses of long bones, but a purely diaphyseal presentation is reported in 10% of cases. We report the case of a female 25 year-old patient whose symptoms of pain and swelling of the right mid thigh started four months before, without an apparent cause. Femur X-rays showed a tumor in the femoral shaft. The MRI showed extension to soft tissues with no compromise of the neurovascular bundle. The histopathologic report of the incisional biopsy was osteoblastic and chondroblastic osteosarcoma, classified as Enneking IIB, AJCC IIB. Treatment consisted of three cycles of neoadjuvant chemotherapy. Then intercalary femur resection plus reconstruction with centromedullary nailing and a diaphyseal spacer were performed. The histopathologic report was 95% necrosis (Huvos grade III). Three cycles of adjuvant chemotherapy were given and now, 18 months after completing the latter, the patient has no signs of local or distant tumor activity, and she can walk unassisted. Despite the fact that osteosarcoma does not occur usually in the mid shaft of long bones, we should always bear it in mind as part of the differential diagnosis for other conditions that occur more frequently in that region. Such location allows for a broad gamut of surgical approaches that spare the adjacent joints.

Morphological features of healing of experimental defect of long bones diaphysis under the conditions of implantation of biphasic osteoplastic material / Características morfológicas del proceso de reparación de un defecto experimental en diáfisis de huesos largos postimplantación de material bifásico osteoplástico

Purpose: to study the healing process of a defect of the compact bone tissue after the implantation of osteoplastic material «easygraft CRYSTAL¼. Methods: the experiment was conducted on 24 Wistar rats. In the middle third of the diaphysis of the femur we created a perforated defect of 2.5 mm diameter in the medullary canal, which was filled with osteoplastic material «easy-graft CRYSTAL¼. Fragments of the injured bones were studied on the 60th and 120th days by light microscopy with morphometry and scanning electron microscopy. Results: it was found that in the area of the defect of the compact bone tissue «easy-graft CRYSTAL¼ shows high biocompatibility, osteoconductive properties and provides stability to the volume of the defect due to good integration with the bone tissue of regenerate and absence of signs of resorption of osteoplastic material throughout the period of experiment. (AU)

Objetivo: estudiar el proceso de reparación de un defecto del tejido óseo compacto después de la implantación de material osteoplástico (easy-graft CRYSTAL). Métodos: el experimento se realizó en 24 ratas Wistar. Se realizó en el tercio medio de la diáfisis del fémur un defecto de 2,5 mm de diámetro en el canal medular que se rellenó de material de osteoplástico (easy-graft CRYSTAL). Los huesos lesionados fueron estudiados en los días 60ª y 120ª mediante microscopía óptica y microscopía electrónica de barrido. Resultados: se encontró que en la zona del defecto del tejido óseo compacto el injerto mostró alta biocompatibilidad y propiedades osteoconductivas y proporcionó estabilidad al volumen del defecto debido a la buena integración con el tejido óseo y ausencia de signos de resorción de material osteoplástico durante todo el período experimental. (AU)

A comparative study of the areas of osteochondral defects produced in femoral condyles of rabbits treated with sugar cane biopolymer gel

PURPOSE: To assess the histological response of damaged osteochondral tissue in the femoral condyles of rabbits after repairing the wounds with sugar cane biopolymer gel - compared to the control group. METHODS: The study investigated 16 New Zealand rabbits, at 90, 120 and 180 days after surgery. In all the animals, a lesion of 3.2 mm in diameter and 4 mm deep was induced in each right and left femoral condyle. Each animal has provided both knees, divided into medial and lateral condyle, resulting in 64 samples. 32 knees were divided into two groups: Right knee, medial and lateral condyles, filled with biopolymer; Left knee, medial and lateral condyles, unfilled. The anatomical specimens were removed, and subjected to histological techniques and morphometric and statistical analysis. RESULTS: In all the periods of the group under study an inflammatory reaction mediated by giant cells and mononuclear cells was found, while in the control group there was early healing produced by fibroblasts and few mononuclear cells with statistical significance between groups. CONCLUSION: The biopolymer gel caused an inflammatory reaction mediated by giant cells and mononuclear cells while the control group there was cicatrization mediated by fibroblasts.

Biocompatibility and osteogenesis of the castor bean polymer doped with silica (SiO2) or barium titanate (BaTiO3) nanoparticles

PURPOSE: To evaluate the biocompatibility and osteogenesis of castor oil polymer doped with SiO2 or BaTiO3 nanoparticles. METHODS: Twenty four male rats Wistar were submitted to bone defect filled with castor oil polymer. The animals were distributed in two experimental groups had been formed with 12 animals each: Group 1 - Castor oil polymer doped with 0.30 grams of SiO2 replacing 0.30 grams of CaCO3. Group 2 - Castor oil polymer doped with 0.30 grams of BaTiO3 replacing 0.30 grams of CaCO3. Euthanasia occurred 30 and 60 days after surgery and the femurs were sent to histological analysis and MEV. RESULTS: The implants were biocompatible and allowed for progressive osteogenesis through osteoconduction in both observation periods. There was significant bone neoformation at 30 and 60 days in both groups within the histomorphometric evaluation, but group 1's osteogenesis was lesser in the 30 and 60-day periods observed when compared to the animals of group 2. The MEV morphometric evaluation evidenced a lesser percentage of osseous tissue filling within the BaTiO2-doped polymer. CONCLUSION: The castor oil polymer doped with SiO2 or BaTiO3 remained biocompatible and allowed for progressive osteogenesis in both observation periods. .

Calcar Preservation Arthroplasty for Unstable Intertrochanteric Femoral Fractures in Elderly

BACKGROUND: The treatment of unstable intertrochanteric fractures in elderly is still controversial. The purpose of this study is to present treatment strategies for unstable intertrochanteric fractures with hemiarthroplasty using standard uncemented collared femoral stems and at the same time preserving the fractured calcar fragment. METHODS: Fifty-four patients aged 75 years or older with unstable intertrochanteric fractures were included in this prospective cohort study. All patients were treated with calcar preserving hemiarthroplasty using cementless collored femoral stems. Fractured calcar fragment was stabilized either by compaction between the implant and femur or fixed with cable grip system. Follow-up evaluations were performed at least 24 months and later. Palmer and Parker mobility score and visual analogue scale (VAS) pain score were assessed. We also analyzed radiographs of the operated hip at each follow-up visit. RESULTS: The patients were 15 males and 39 females with a mean age of 81.3 years (range, 75 to 93 years). The average operative time was 86.6 minutes. The mean transfused blood units were 1.2 units. The average duration of hospital stay was 5.3 days. The preoperative mean mobility score was 6.20. This score was found to be 4.96 on postoperative third day and 5.90 at 24 months postoperatively. The results of the statistical analysis revealed significant increase in the mobility scores at each follow-up after three days. Radiological interpretation revealed no loosening in the cable-grip systems, and no significant subsidence (> 5 mm) of prosthesis was observed. CONCLUSIONS: Calcar preservation arthroplasty is a good option for elderly patients with severe osteoporosis, frail constitution and the patients who are at higher risk for second operation due to unstable intertrochanteric fractures.

Remodelación y deterioro en epifisiolisis de cadera después de la fijación in situ. Resultados preliminares / Slipped capital femoral epiphysis remodeling and deterioration after in situ fixation. Preliminary results

Introducción: Una vez detenida la progresion del deslizamiento, las caderas experimentan un fenomeno complejo de remodelacion. Mientras tanto, el choque femoro-acetabular provoca daño irreversible del cartilago articular. El proposito del trabajo es determinar si la remodelacion es suficiente para impedir el deterioro articular en el corto plazo. Materiales y Métodos: Se diseñó un estudio de cohorte retrospectivo de pacientes con deslizamientos moderados y graves, que recibieron como tratamiento la fijacion in situ. Se evaluó la capacidad de remodelación con el ángulo de Southwick y el ángulo alfa. El deterioro funcional se evaluó con el puntaje de Harris y el radiologico, con la escala de Tonnis. Seguimiento minimo: 4 años. Resultados: Diecisiete pacientes, mediana de seguimiento: 63 meses (Ri 55-81). El angulo de Southwick prequirurgico 57o (Ri 50-72) versus el posquirurgico 48o (Ri 45-74) disminuyó significativamente (p 0,023). lo mismo ocurrio con el angulo alfa complementario. El deterioro radiologico evaluado con la escala de Tonnis fue estadisticamente significativo (p 0,012). los resultados funcionales, cuantificados con el puntaje de Harris no mostraron diferencias estadisticamente significativas (p 0,49). Conclusiones: En esta serie, las epifisiolisis moderadas y graves fijadas in situ presentaron deterioro radiologico en 63 meses de seguimiento promedio. Sin embargo, la funcionalidad no se deterioro con la misma rapidez. Nivel de Evidencia: IV.

Background: After stopping the slip progression, hips undergo a remodeling complex phenomenon. Meanwhile femoro-acetabular shock causes irreversible joint cartilage damage. The purpose of the study is to determine if remodeling is sufficient to prevent joint deterioration in the short-term. Methods: a retrospective cohort study of patients with moderate and severe landslides, treated with in situ fixation was designed. Remodeling capacity was evaluated with Southwick angle and alpha angle. Functional and radiological impairment was evaluated with the Hip Harris Score and Tonnis scale, respectively. Minimum follow-up: 4 years. Results: Seventeen patients, median follow-up 63 months (iR 55-81). The pre-surgical Southwick angle 57o (iR 50-72) versus the postoperative one 48o (iR 45-74) significantly decreased (p 0.023). The same happened with the complementary angle alpha. The radiological deterioration was statistically significant (p 0.012). Functional results showed no statistically significant differences (p 0.49). Conclusions: in this series, moderate and severe slipped capital femoral epiphysis fixed in situ showed radiological deterioration during a 63-month follow-up. However, the functionality is not deteriorating as quickly. Level of Evidence: IV.

New Bone Formation around Implants Inserted on Autologous and Xenografts Irradiated or not with IR Laser Light: A Histomorphometric Study in Rabbits

Use of biomaterials and light on bone grafts has been widely reported. This work assessed the influence of low-level laser therapy (LLLT) on bone volume (BV) and bone implant contact (BIC) interface around implants inserted in blocks of bovine or autologous bone grafts (autografts), irradiated or not, in rabbit femurs. Twenty-four adult rabbits were divided in 8 groups: AG: autograft; XG: xenograft; AG/L: autograft + laser; XG/L: xenograft + laser; AG/I: autograft + titanium (Ti) implant; XG/I: xenograft + Ti implant; AG/I/L: autograft + Ti implant + laser; and XG/I/L: xenograft + Ti implant + laser. The animals received the Ti implant after incorporation of the grafts. The laser parameters in the groups AG/L and XG/L were λ=780 nm, 70 mW, CW, 21.5 J/cm 2 , while in the groups AG/I/L and XG/I/L the following parameters were used: λ=780 nm, 70 mW, 0.5 cm 2 (spot), 4 J/cm 2 per point (4), 16 J/cm 2 per session, 48 h interval × 12 sessions, CW, contact mode. LLLT was repeated every other day during 2 weeks. To avoid systemic effect, only one limb of each rabbit was double grafted. All animals were sacrificed 9 weeks after implantation. Specimens were routinely stained and histomorphometry carried out. Comparison of non-irradiated and irradiated grafts (AG/L versus AG and XG/L versus XG) showed that irradiation increased significantly BV on both grafts (p=0.05, p=0.001). Comparison between irradiated and non-irradiated grafts (AG/I/L versus AG/I and XG/I/L versus XG/I) showed a significant (p=0.02) increase of the BIC in autografts. The same was seen when xenografts were used, without significant difference. The results of this investigation suggest that the use of LLLT is effective for enhancing new bone formation with consequent increase of bone-implant interface in both autologous grafts and xenografts.

O uso de biomateriais e luz em enxertos ósseos têm sido relatados. Esse trabalho avaliou a influência do laser baixa potência - LBP no volume ósseo (VO) e superfície de contato osso-implante (COI) ao redor de implantes dentários inseridos em blocos de enxerto bovino ou autólogos incorporados, irradiados ou não, em fêmures de coelho. Vinte e quatro coelhos adultos foram divididos em 8 grupos: EA: enxerto autólogo; EX: enxerto xenógeno; EA/L: enxerto autólogo + laser; EX/L: enxerto xenógeno + laser; EA/I: enxerto autólogo + implante; EX/I: enxerto xenógeno + implante; EA/I/L: enxerto autólogo + implante de titânio + laser; EX/I/L: enxerto xenógeno + implante de titânio + laser. Os animais receberam um implante de titânio após a incorporação dos enxertos. Os parâmetros de laser nos grupos EA/L e EX/L foram λ =780 nm, 70 mW, CW, 21,5 J/cm 2 ), enquanto que nos grupos EA/I/L e EX/I/L os seguintes parâmetros de laser foram utilizados: λ =780 nm, 70 mW, 0,5 cm 2 (spot), 4 J/cm 2 por ponto (4), 16 J/cm 2 por sessão, intervalo de 48 h × 12 sessões, CW, modo contato. O LBP foi repetido a cada 48 h (2 semanas). Para evitar efeito sistêmico apenas um membro de cada coelho foi duplamente enxertado. Todos os animais foram sacrificados 9 semanas após o implante. Os espécimes foram corados rotineiramente e histomorfometria foi realizada. A comparação dos enxertos não-irradiados e irradiados (EA/L versus EA e EX/L versus EX) mostrou que a irradiação aumentou significantemente (p=0,02) o VO para ambos os tipos de enxertos (p=0,05, p=0,001). A comparação dos enxertos não-irradiados e irradiados (EA/I/L versus EA/I e EX/I/L versus EX/I) mostrou um aumento significante (p=0,02) do COI nos enxertos autólogos e xenógenos sem diferença estatística. Os resultados desta investigação sugerem que o uso de LBP é efetivo para aumentar a neoformação óssea com consequente aumento do COI em enxertos autólogos e xenógenos.