Effect of experimental pulmonary arterial hypertension on renal and bone parameters of rats submitted to resistance exercise training.

Pulmonary arterial hypertension (PAH) is characterized by right ventricular failure and diminished cardiac output, potentially leading to renal and bone impairments. In contrast, resistance exercise training (RT) offers cardiovascular and bone health benefits. This study aimed to assess the impacts of stable PAH induced by monocrotaline (MCT) and RT on renal morphometry, as well as bone morphometry and biomechanical properties in male Wistar rats. Four experimental groups, untrained control (UC, n=7), trained control (TC, n=7), untrained hypertensive (UH, n=7), trained hypertensive (TH, n=7), were defined. After the first MCT or saline injection (20 mg/kg), trained rats were submitted to a RT program (i.e., Ladder climbing), 5 times/week. Seven days later the rats received the second MCT or saline dose. After euthanasia, renal and femoral histomorphometry and femoral biomechanical properties were assessed. PAH reduced renal glomerular area and volume, which was prevented by the RT. While PAH did not harm the femoral morphometry, structural and mechanical properties, RT improved the femoral parameters (e.g., length, percentage of trabeculae and bone marrow, ultimte and yield loads). Experimental stable PAH promotes renal but not bone damages, whereas RT prevents renal deteriorations and improves the femoral morphological and biomechanical properties.

The Dejour classification for trochlear dysplasia shows slight interobserver and substantial intraobserver reliability.

PURPOSE: Trochlear dysplasia is one of the main risk factors for recurrent patellar dislocation. The Dejour classification identifies four categories that can be used to classify trochlear dysplasia. The purpose of this study is to evaluate the inter- and intraobserver reliability of the Dejour classification for trochlear dysplasia. The hypothesis was that both intra- and interobserver reliability would be at least moderate. METHODS: This is a cross-sectional, reliability study. Twenty-eight examiners from the International Patellofemoral Study Group 2022 meeting evaluated lateral radiographs of the knee and axial magnetic resonance images from 15 cases of patellofemoral instability with trochlear dysplasia. They classified each case according to Dejour's classification for trochlear dysplasia (A-D). There were three rounds: one with only computed radiograph (CR), one with only magnetic resonance imaging (MRI) and one with both. Inter- and intraobserver reliability were calculated using κ coefficient (0-1). RESULTS: The mean age of patients was: 14.6 years; 60% were female and 53% had open physis. The interobserver reliability κ probabilities were 0.2 (CR), 0.13 (MRI) and 0.12 (CR and MRI). The intraobserver reliability κ probabilities were 0.45 (CR), 0.44 (MRI) and 0.65 (CR and MRI). CONCLUSION: The Dejour classification for trochlear dysplasia has slight interobserver reliability and substantial intraobserver reliability. LEVEL OF EVIDENCE: Level I.

Esclerosis bilateral de huesos largos: enfermedad de Erdheim-Chester. Reporte de un caso / Bilateral long bone sclerosis: Erdheim-Chester disease. Case report

La enfermedad de Erdheim-Chester (EEC) es una patología poco frecuente, caracterizada por presentar infiltración xantogranulomatosa sistémica, con afección de diversos sistemas incluido el óseo. La EEC se encuentra descripta dentro de las enfermedades osteocon-densantes (EO), las cuales se reconocen por presentar aumento de la masa ósea y compromiso tanto de huesos largos como planos. La presentación clínica de la EEC es variada: puede presentar desde un curso indolente hasta manifestaciones multisistémicas. Las características radiológicas son de gran importancia para establecer su diagnóstico. Presentamos una paciente con EEC, con esclerosis bilateral de huesos largos, que exhibe algunas características diferenciales con relación a otros casos reportados: a) afectación exclusivamente ósea a 10 años de evolución, b) compromiso bilateral y simétrico de distinta magnitud, c) esclerosis cortical endóstica y perióstica, d) signos radiológicos sugestivos de periostitis, d) ausencia de compromiso metafisario, e) ausencia de actividad metabólica de las lesiones en las imágenes de 18F-FDG PET/CT.Conclusión: la presencia de lesiones osteocondensantes bilaterales exclusivamente en huesos largos deben hacer sospechar EEC. La ausencia de compromiso metafisario y de actividad metabólica en 18F-FDG PET/CT ha sido raramente descripta. (AU)

Erdheim - Chester disease (ECD) is a rare disease, characterized by systemic xanthogranulomatous infiltration, with involvement of various organs including bone. ECD is described within the sclerosing bone disorders, which are recognized for presenting increased bone mass and involvement of both long and flat bones. The clinical presentation of ECD is diverse, ranging from an asymptomatic course to multisystemic manifestations. Radiological features are of great importance to establish the diagnosis. We describe here a patient with ECD, with bilateral sclerosis of long bones that presents some differential characteristics in relation to other reported cases: a) exclusively bone involvement at 10 years of evolution, b) bilateral and symmetric involvement of different magnitude, c) endosteal and periosteal cortical sclerosis d) radiological signs suggestive of periostitis, d) absence of metaphyseal involvement, e) absence of metabolic activity of the lesions in 18F-FDG PET/CT.Conclusion: the presence of bilateral osteosclerosis exclusively in long bones should lead to suspect ECD. The absence of metaphyseal involvement and metabolic activity in 18F-FDG PET/CT have been rarely described. (AU)

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.

Laser-photobiomodulation on titanium implant bone healing in rat model: comparison between 660- and 808-nm wavelength.

Laser-photobiomodulation (L-PBM) has been widely studied and its biomodulatory effects have been established on irradiated cells, increasing viability and proliferation and on damaged tissues. In addition, L-PBM may reduce and modulate the inflammatory process. The effect of 660-nm and 808-nm laser-photobiomodulation on bone repair around titanium dental implants placed in rat's femur was evaluated by histomorphometry. Twenty-seven Wistar rats were divided into 3 groups of nine animals: group C - non-irradiated control; group R - λ=660nm irradiated; and group IR - λ=808nm irradiated. Each group was further divided in 3 subgroups of three animals each, according to histomorphometry analysis in 3 days, 7 days, and 14 days after irradiation. Histological H.E.-stained slides were photographed, and bone matrix measured in new-formed bone area. Bone matrix histomorphometry analysis indicates that at 7 days in the irradiated groups (R and IR), a bigger area matrix was observed in relation to control group (C) (p=0.04 and p=0.048 respectively). On the other hand, at 14 days, control group (C) presented a bigger area than infrared irradiated (IR) (p=0.001) and red irradiated group (R) also showed a bigger area than infrared irradiated group (IR) (p=0.019). Histological analysis indicates that irradiated groups (R and IR) exhibited a faster bone tissue matrix production than control group.

One-stage exchange should be avoided in periprosthetic joint infection cases with massive femoral bone loss or with history of any failed revision to treat periprosthetic joint infection.

AIMS: There is a paucity of long-term studies analyzing risk factors for failure after single-stage revision for periprosthetic joint infection (PJI) following total hip arthroplasty (THA). We report the mid- to long-term septic and non-septic failure rate of single-stage revision for PJI after THA. METHODS: We retrospectively reviewed 88 cases which met the Musculoskeletal Infection Society (MSIS) criteria for PJI. Mean follow-up was seven years (1 to 14). Septic failure was diagnosed with a Delphi-based consensus definition. Any reoperation for mechanical causes in the absence of evidence of infection was considered as non-septic failure. A competing risk regression model was used to evaluate factors associated with septic and non-septic failures. A Kaplan-Meier estimate was used to analyze mortality. RESULTS: The cumulative incidence of septic failure was 8% (95% confidence interval (CI) 3.5 to 15) at one year, 13.8% (95% CI 7.6 to 22) at two years, and 19.7% (95% CI 12 to 28.6) at five and ten years of follow-up. A femoral bone defect worse than Paprosky IIIA (hazard ratio (HR) 13.58 (95% CI 4.86 to 37.93); p < 0.001) and obesity (BMI ≥ 30 kg/m2; HR 3.88 (95% CI 1.49 to 10.09); p = 0.005) were significantly associated with septic failure. Instability and periprosthetic fracture were the most common reasons for mechanical failure (5.7% and 4.5%, respectively). The cumulative incidence of aseptic failure was 2% (95% CI 0.4 to 7) at two years, 9% (95% CI 4 to 17) at five years, and 12% (95% CI 5 to 22) at ten years. A previous revision to treat PJI was significantly associated with non-septic failure (HR 9.93 (95% CI 1.77 to 55.46); p = 0.009). At the five-year timepoint, 93% of the patients were alive (95% CI 84% to 96%), which fell to 86% (95% CI 75% to 92%) at ten-year follow-up. CONCLUSION: Massive femoral bone loss was associated with greater chances of developing a further septic failure. All septic failures occurred within the first five years following the one-stage exchange. Surgeons should be aware of instability and periprosthetic fracture being potential causes of further aseptic revision surgery. Cite this article: Bone Joint J 2021;103-B(7):1247-1253.

Is an anodizing coating associated to the photobiomodulation able to optimize bone healing in ovariectomized animal model?

This in vivo study investigated whether the bioactivity of anodizing coating, produced by plasma electrolytic oxidation (PEO), on mini-plate in femur fracture could be improved with the association of photobiomodulation (PBM) therapy. From the 20 ovariectomized Wistar female rats, 8 were used for model characterization, and the remaining 12 were divided into four groups according to the use of PBM therapy by diode laser (808 nm; power: 100 mW; energy: 6.0 J; energy density: 212 J/cm2; power density: 3.5 W/cm2) and the type of mini-plate surface (commercially pure titanium mini-plate -cpTi- and PEO-treated mini-plate) as follow: cpTi; PEO; cpTi/PBM; and PEO/PBM. After 60 days of surgery, fracture healing underwent microstructural, bone turnover, histometric, and histologic adjacent muscle analysis. Animals of groups with PEO and PBM showed greater fracture healing than cpTi control group under histometric and microstructural analysis (P < 0.05); however, bone turnover was just improved in PBM's groups (P < 0.05). there was no difference between cpTi and PEO without PBM (P > 0.05). Adjacent muscle analysis showed no metallic particles or muscle alterations in all groups. PEO and PBM are effective strategies for bone repair in fractures, however their association does not provide additional advantages.

Biomechanical and histological characterization of MPS I mice femurs.

Mucopolysaccharidosis type I (MPS I) is a lysosomal storage disorder characterized by alpha-L-iduronidase (IDUA) deficiency, an enzyme responsible for glycosaminoglycan degradation. Musculoskeletal impairment is an important component of the morbidity related to the disease, as it has a major impact on patients' quality of life. To understand how this disease affects bone structure, morphological, biomechanical and histological analyses of femurs from 3- and 6-month-old wild type (Idua +/+) and MPS I knockout mice (Idua -/-) were performed. Femurs from 3-month-old Idua -/- mice were found to be smaller and less resistant to fracture when compared to their age matched controls. In addition, at this age, the femurs presented important alterations in articular cartilage, trabecular bone architecture, and deposition of type I and III collagen. At 6 months of age, femurs from Idua -/- mice were more resistant to fracture than those from Idua +/+. Our results suggest that the abnormalities observed in bone matrix and articular cartilage in 3-month-old Idua -/- animals caused bone tissue to be less flexible and more likely to fracture, whereas in 6-month-old Idua -/- group the ability to withstand more load before fracturing than wild type animals is possibly due to changes in the bone matrix.

Pressão articular na osteoartrose femorotibial de cães (Canis lupus familiaris) - uma revisão sistemática / Intra-articular pressure in femorotibial osteoarthrosis in dogs (Canis lupus familiaris) - a systematic review / Presión intraarticular en la osteoartrosis femorotibial de perros (Canis lupus familiaris) - una revisión sistemática

Os principais sinais clínicos da osteoartrose incluem a claudicação e a diminuição da amplitude de movimento articular. A diminuição do espaço articular é uma característica importante e comum em osteoartrose femorotibial, podendo induzir ao aumento da pressão intra-articular dentro do espaço fascial ou osseofascial e desencadear a Síndrome Compartimental Articular, quer pela diminuição do tamanho do espaço intra-articular ou pelo acúmulo de líquido sanguinolento, seroma ou linfa. Essa síndrome pode resultar na inadequada perfusão sanguínea e causar isquemia local, e consequentemente, maior dano articular. Visto que a aferição da pressão intra-articular não é uma prática comum na Medicina Veterinária, o presente estudo teve como objetivo realizar uma revisão da literatura sobre a pressão intra-articular da articulação femorotibial de cães acometidos por osteoartrose.(AU)

The main clinical signs of osteoarthrosis includes lameness and decreased range of joint motion. The decreased joint space its an important and common feature in femorotibial osteoarthrosis of the and may induce an increased intra-articular pressure within the fascial or osteofascial space, triggering the Joint Compartment Syndrome, either by decreasing the size of the joint space or through the accumulation of bloody fluid, seroma or lymph. This Syndrome can result on inadequate blood flow and create an hypoxic joint, leading to greater joint damage. Since intra-articular pressure measurement is not a common practice in Veterinary Medicine, the present study aimed to review the literature on intra-articular femorotibial pressure in dogs with osteoarthrosis.(AU)

Las principales manifestaciones clínicas de osteoartrosis incluyen cojera y disminución de la amplitud del movimiento articular. El estrechamiento del espacio articular es una importante y común característica en la osteoartrosis femorotibial, y puede inducir una elevación de la presión dentro del espacio fascial u osofascial, con la consiguiente síndrome compartimental articular, ya sea decreciendo el tamaño del espacio intra articular o mediante acumulación de líquido sanguinolento, seroma o linfa. Esta síndrome puede provocar una perfusión sanguínea inadecuada y causar una isquemia articular, resultando en, un mayor daño articular. Dado que la medición de la presión sobre las articulaciones no es una práctica común en medicina veterinária, el presente estudio tuvo como objetivo revisar la literatura acerca de la presión de la articulación femorotibial de perros con osteoartrosis.(AU)

Intraoperative morphometric study of distal femur in Brazilian patients undergoing total knee arthroplasty.

BACKGROUND: Total knee arthroplasty (TKA) is the treatment option for patients with severe osteoarthritis (OA) of the knee whose symptoms are refractory to conservative management. Unfortunately, the level of patient dissatisfaction is high, reaching up to 25%. The reasons for this dissatisfaction are multifactorial, but bone-implant mismatch significantly increases the chance of pain and functional limitation. Sex-specific prosthesis designs have been developed to overcome this issue, but their use is still controversial. The primary objective of this study was to evaluate possible sex differences in the shape of the distal femur in patients with osteoarthritis. Secondary objectives were to investigate interpersonal variability of the distal femur and to determine the number of femoral implant sizes required to meet shape variations. METHODS AND FINDINGS: A cross-sectional observational study prospectively compared 294 knees of 293 patients with osteoarthritis according to sex (201 female/93 male). Six intraoperative measurements were performed on the distal femur (height and width of both lateral and medial condyles, total medial-lateral width of the femur, and intercondylar distance). Sex differences and interpersonal variability were analyzed by multiple linear regressions. Measurements were also correlated with patient height. An optimization analysis was used to estimate the number of femoral implant sizes required. There were significant sex differences in the distal femur, where men had higher values than women in all measurements. Great interpersonal variability was found. The height of the lateral condyle was correlated with patient height, but the correlation was not strong. Twenty-five femoral implant sizes were required to meet the shape variations in our sample. CONCLUSIONS: The shape of the distal femur in patients with osteoarthritis shows great interpersonal variability, with men showing significantly higher values than women. A total of 25 different implant sizes would be necessary to adequately meet the variations observed in our study population.

Pressão articular na osteoartrose femorotibial de cães (Canis lupus familiaris) - uma revisão sistemática / Intra-articular pressure in femorotibial osteoarthrosis in dogs (Canis lupus familiaris) - a systematic review / Presión intraarticular en la osteoartrosis femorotibial de perros (Canis lupus familiaris) - una revisión sistemática

Os principais sinais clínicos da osteoartrose incluem a claudicação e a diminuição da amplitude de movimento articular. A diminuição do espaço articular é uma característica importante e comum em osteoartrose femorotibial, podendo induzir ao aumento da pressão intra-articular dentro do espaço fascial ou osseofascial e desencadear a Síndrome Compartimental Articular, quer pela diminuição do tamanho do espaço intra-articular ou pelo acúmulo de líquido sanguinolento, seroma ou linfa. Essa síndrome pode resultar na inadequada perfusão sanguínea e causar isquemia local, e consequentemente, maior dano articular. Visto que a aferição da pressão intra-articular não é uma prática comum na Medicina Veterinária, o presente estudo teve como objetivo realizar uma revisão da literatura sobre a pressão intra-articular da articulação femorotibial de cães acometidos por osteoartrose.

The main clinical signs of osteoarthrosis includes lameness and decreased range of joint motion. The decreased joint space it’s an important and common feature in femorotibial osteoarthrosis of the and may induce an increased intra-articular pressure within the fascial or osteofascial space, triggering the Joint Compartment Syndrome, either by decreasing the size of the joint space or through the accumulation of bloody fluid, seroma or lymph. This Syndrome can result on inadequate blood flow and create an hypoxic joint, leading to greater joint damage. Since intra-articular pressure measurement is not a common practice in Veterinary Medicine, the present study aimed to review the literature on intra-articular femorotibial pressure in dogs with osteoarthrosis.

Las principales manifestaciones clínicas de osteoartrosis incluyen cojera y disminución de la amplitud del movimiento articular. El estrechamiento del espacio articular es una importante y común característica en la osteoartrosis femorotibial, y puede inducir una elevación de la presión dentro del espacio fascial u osofascial, con la consiguiente síndrome compartimental articular, ya sea decreciendo el tamaño del espacio intra articular o mediante acumulación de líquido sanguinolento, seroma o linfa. Esta síndrome puede provocar una perfusión sanguínea inadecuada y causar una isquemia articular, resultando en, un mayor daño articular. Dado que la medición de la presión sobre las articulaciones no es una práctica común en medicina veterinária, el presente estudio tuvo como objetivo revisar la literatura acerca de la presión de la articulación femorotibial de perros con osteoartrosis.

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.

Mechanical Vibration Associated With Intermittent PTH Improves Bone Microarchitecture in Ovariectomized Rats.

INTRODUCTION: Intermittent 1-34 parathyroid hormone (iPTH) administration, a bone-forming treatment, is widely used as a therapy for severe osteoporosis. It can only be used for a maximum of 24 mo and must be followed by an antiresorptive drug to retain the new formed tissue. Mechanical load, in the form of low-intensity and high-frequency vibration, has received considerable attention due to its ability to prevent bone loss. AIM: To investigate the ability of whole body mechanical vibration (MV) to potentiate the anabolic effects of iPTH and to inhibit bone resorption following discontinuation of iPTH treatment in estrogen-deficient rats. METHODOLOGY: Fifty-four 6-month-old female Wistar rats were ovariectomized (OVX) or sham-operated. After 5 mo, they were divided into 7 groups: Sham - non-OVX; Control - OVX, vehicle for 60 d; MV - OVX, submitted to MV for 60 d; PTH60d - OVX, injected with iPTH for 60 d; PTH+MV - OVX, injected with iPTH combined with MV for 60 d; PTH30d - OVX, injected with iPTH for 30 d, and untreated for 30 d; PTH30d/MV30d - OVX, injected with iPTH for 30 d, followed by MV for 30 d. Bone mineral density (BMD) and body composition (lean mass and fat) were evaluated at OVX (T0), the beginning (T1), and at the end (T2) of treatments by dual X-ray absorptiometry (DXA). Femurs were processed for histomorphometry (bone volume - BV/TV and cortical thickness - Ct.Th) and tibias for biomechanical test. RESULTS: Body composition and BMD were similar among the groups at T0. In T2, MV presented higher fat than other groups (except PTH60d) and PTH30d/MV30d showed greater lean mass than Control. At T1, Sham presented the highest BMD, but between T1 vs T2 there was an increase in all iPTH-treated groups. At T2, BMD was higher in PTH60d and PTH+MV than in the Control and MV groups. The highest BV/TV was observed in the PTH+MV group, followed by PTH60d. Cortical thickness was increased in PTH60d and PTH+MV compared to Sham. Vibration applied post-iPTH (PTH30d/MV30d) improved the force at failure in tibias when compared to Sham and Control groups. CONCLUSION: MV potentiated iPTH anabolic effects in cancellous bone; however, MV was unable to maintain bone mass after stopping iPTH in ovariectomized rats.

Extensive burn injury causes bone collagen network alteration and growth delay related to RANK-L immunoexpression change.

PURPOSE: Extensive burn injury mainly affects children, and hypermetabolic state can lead to growth delay. This study aimed to investigate bone histopathological and morphometric aspects, collagen fibers network and the immunoexpression of biological markers related to bone development in a young experimental model for extensive burn. MATERIALS AND METHODS: A total of 28 male Wistar rats were distributed into Control (C) and subjected to scald burn injury (SBI) groups. Sham or injured animals were euthanized 4 or 14 days post-lesion and proximal epiphyses of the femur were submitted to histological, morphometric (thickness epiphyseal plate), and RUNX-2 and receptor activator of nuclear factor kappa- ß ligand (RANK-L) immunoexpression methods. RESULTS: Histopathological femoral findings showed delayed appearance of the secondary ossification center in SBI, 14 days post-injury. Collagen fibers 4 days after injury were observed in articular cartilage as a pantographic network with a transversally oriented lozenge-shaped mesh, but this network was thinner in SBI. Fourteen days after the injury, the pantographic network of collagen presented square-shaped mesh in C, but this aspect was changed to a wider mesh in SBI. Morphometric analysis of epiphyseal plate revealed that the SBI group had less thickness than the respective controls (p<0.05). RUNX-2 showed no difference between groups, but RANK-L score was higher in all SBI groups. CONCLUSIONS: Extensive burn injury causes delayed bone growth and morphological changes. Alterations in collagen network and enhancement in immunoreactivity of RANK-L result in increased osteoclastogenesis.

Fibrosarcoma arising after femur osteosynthesis with pin and plate placement in a cat / Fibrossarcoma em sítio de osteossíntese de fêmur com pino e placa em um felino

A 6-year old spayed female Siamese cat was presented with a history of left limb acute lameness. Radiographic imaging revealed a complete comminuted diaphyseal femur fracture, which was corrected through intramedullary pin placement along with plate osteosynthesis. After two months the animal returned to the hospital presenting severe diffuse enlargement of the left hindlimb, characterized as a non-delimited, solid, and firm plaque-like mass surrounding the pin and bone, which extended from the femorotibiopatelar joint to the pelvis, and infiltrated the adjacent musculature. Incisional biopsy exam indicated a highly malignant sarcoma. The entire limb was surgically removed and sent to histopathological evaluation. Microscopically, the mass was composed of spindle shaped cells, displaying high pleomorphism and cellular atypia. Abundant collagen production was evidenced through Masson's trichrome stain and strong cytoplasmic staining for vimentin. These results were consistent with fibrosarcoma. The cat went through one session of chemotherapy; however, tumor recurrence occurred 20 days later, and the animal was submitted to euthanasia. This is the first description of fibrosarcoma arising in the vicinity of an intramedullary pin and plate in a cat.

Uma gata, castrada, 6 anos de idade, da raça Siamês, apresentou histórico clínico de claudicação aguda do membro pélvico esquerdo. O exame radiográfico revelou uma fratura completa cominutiva diafisária do fêmur, a qual foi corrigida através de osteossíntese pela implantação de um pino intramedular, além de placa metálica. Depois de dois meses, o felino retornou ao hospital apresentando aumento severo e difuso do membro pélvico, caracterizada por uma massa não delimitada, sólida, como uma placa, circundando o pino e o osso, a qual se estendia da articulação femorotibiopatelar até a pelve, e infiltrava a musculatura adjacente. A biópsia incisional indicou sarcoma de alta malignidade. O membro inteiro foi cirurgicamente removido e enviado para análise histopatológica. Microscopicamente, a massa era composta por células fusiformes, demonstrando alto pleomorfismo e atipia celular. Abundante produção de colágeno foi evidenciada através da técnica histoquímica de tricrômico de Masson e forte imunomarcação citoplasmática para vimentina. Esses resultados foram consistentes com fibrossarcoma. O felino foi submetido a uma sessão de quimioterapia, porém houve recorrência tumoral 20 dias após a sessão, e o paciente foi submetido a eutanásia. Essa é a primeira descrição de fibrossarcoma que surgiu em local próximo a implantação de pino intramedular e placa em um felino.

Fibrosarcoma arising after femur osteosynthesis with pin and plate placement in a cat / Fibrossarcoma em sítio de osteossíntese de fêmur com pino e placa em um felino

A 6-year old spayed female Siamese cat was presented with a history of left limb acute lameness. Radiographic imaging revealed a complete comminuted diaphyseal femur fracture, which was corrected through intramedullary pin placement along with plate osteosynthesis. After two months the animal returned to the hospital presenting severe diffuse enlargement of the left hindlimb, characterized as a non-delimited, solid, and firm plaque-like mass surrounding the pin and bone, which extended from the femorotibiopatelar joint to the pelvis, and infiltrated the adjacent musculature. Incisional biopsy exam indicated a highly malignant sarcoma. The entire limb was surgically removed and sent to histopathological evaluation. Microscopically, the mass was composed of spindle shaped cells, displaying high pleomorphism and cellular atypia. Abundant collagen production was evidenced through Masson's trichrome stain and strong cytoplasmic staining for vimentin. These results were consistent with fibrosarcoma. The cat went through one session of chemotherapy; however, tumor recurrence occurred 20 days later, and the animal was submitted to euthanasia. This is the first description of fibrosarcoma arising in the vicinity of an intramedullary pin and plate in a cat.(AU)

Uma gata, castrada, 6 anos de idade, da raça Siamês, apresentou histórico clínico de claudicação aguda do membro pélvico esquerdo. O exame radiográfico revelou uma fratura completa cominutiva diafisária do fêmur, a qual foi corrigida através de osteossíntese pela implantação de um pino intramedular, além de placa metálica. Depois de dois meses, o felino retornou ao hospital apresentando aumento severo e difuso do membro pélvico, caracterizada por uma massa não delimitada, sólida, como uma placa, circundando o pino e o osso, a qual se estendia da articulação femorotibiopatelar até a pelve, e infiltrava a musculatura adjacente. A biópsia incisional indicou sarcoma de alta malignidade. O membro inteiro foi cirurgicamente removido e enviado para análise histopatológica. Microscopicamente, a massa era composta por células fusiformes, demonstrando alto pleomorfismo e atipia celular. Abundante produção de colágeno foi evidenciada através da técnica histoquímica de tricrômico de Masson e forte imunomarcação citoplasmática para vimentina. Esses resultados foram consistentes com fibrossarcoma. O felino foi submetido a uma sessão de quimioterapia, porém houve recorrência tumoral 20 dias após a sessão, e o paciente foi submetido a eutanásia. Essa é a primeira descrição de fibrossarcoma que surgiu em local próximo a implantação de pino intramedular e placa em um felino.(AU)

Doxycycline reduces osteopenia in female rats.

Doxycycline, a member of the tetracycline family, is a drug used as an antibiotic (dosage of 100 mg/day) and as an anti-inflammatory drug on the dosage of 20 mg twice a day, this use has Matrix Metalloproteinases (MMP) inhibitor action. Doxycycline is a calcium chelator and therefore interferes in bone remodeling. The main objective of this study was to evaluate the action of the drug doxycycline in the control of osteopenia. Sixty three Wistars rats were divided into 9 groups with n = 7 each, as follow: the control group with doxycycline 10 mg/kg/day (C10), control with doxycycline 30 mg/kg/day (C30) and control (C), ovariectomized group with doxycycline 10 mg/kg/day (OVX10), ovariectomized with doxycycline 30 mg/kg/day (OVX30), and ovariectomized with water (OVX), sedentary group with 10 mg/kg/day (Se10), sedentary with doxycycline 30 mg/kg/day (Se30), and sedentary group with water (Se). Left femoral bone was used for bone densitometry, right femoral bone for histological analysis. The right tibia was intended for chemical quantifications, the total serum was used for cholesterol and calcium quantification. The length of the left femoral bone was measured after the densitometry analysis. Statistical analysis was performed using multivariate general linear model (ANOVA two factors with Bonferroni adjustment) and the TRAP analysis was subjected to normality test and then were subjected to nonparametric test, both with p < 0.05 significance. Statistically significant differences were found, with better results for the groups exposed to the medication (10 and 30 mg/kg/day): Se vs. Se10 and Se vs. Se30 for BMC, quantification of magnesium, amount of cancellous bone in the distal portion; OVX vs. OVX10 for BMC, BMD and calcium in serum; OVX vs. OVX10 and OVX30 for quantification in proximal and distal portion of cancellous bone; Se vs. Se30 and OVX vs. OVX30 for immunostaining for TRAP, all results with minimum of p ≤ 0.05. Doxycycline had a deleterious effect on control groups and positive action for bone organization on female rats affected by bilateral ovariectomy-induced osteopenia and sedentary lifestyle.

Interlocking nailing of femoral shaft fractures with an extremely narrow medullary canal is associated with iatrogenic fractures.

INTRODUCTION: Controversy exists regarding the use of reamed interlocking nailing in femoral shafts with extremely narrow medullary canals (diameter ≤ 9 mm). The aims of this study were to (1) investigate the association of age and sex on femoral canal diameter in patients with a simple femoral shaft fracture and (2) compare the outcomes and complications of interlocking nailing between wide and extremely narrow intramedullary canals. PATIENTS AND METHODS: For the purposes of this retrospective cohort study, consecutive patients with simple femoral shaft fractures were recruited between January 2009 and December 2016. The patient demographic data were analyzed. Then, fractures treated with interlocking nailing were divided into the wide group (canal diameter > 9 mm) and narrow group. The primary outcome was union rate, and the secondary outcomes were complications such as thermal necrosis, fat embolism syndrome, iatrogenic fracture, and implant failure. RESULTS: This study included 340 femoral shaft fractures. The average canal diameter was 9.97 ±â€¯1.79 mm, with significantly wider canals in men than in women. Overall, 289 of the patients had undergone interlocking nail fixation, and a similar union rate and complications were noted between the wide canal and narrow canal groups, with the exception of the incidence of iatrogenic fracture. CONCLUSIONS: Femoral shaft fractures associated with extremely narrow medullary canals are more common in women than in men. There was a similar union rate found when using interlocking nailing in a femoral shaft fracture in cases with extremely narrow and wider canals. Iatrogenic fracture is the only significant risk when using interlocking nailing in femoral shafts with extremely narrow canals.

Thyrotoxicosis Involves ß2-Adrenoceptor Signaling to Negatively Affect Microarchitecture and Biomechanical Properties of the Femur.

Background: Thyrotoxicosis increases bone turnover, resulting in net bone loss. Sympathetic nervous system (SNS) activation, via ß2-adrenoceptor (ß2-AR) signaling, also has osteopenic effects. Because thyroid hormones (TH) interact with the SNS to regulate several physiological processes, we hypothesized that this interaction also occurs to regulate bone mass. Previous studies support this hypothesis, as α2-AR knockout (KO) mice are less susceptible to thyrotoxicosis-induced osteopenia. Here, we evaluated whether TH-SNS interactions in bone involve ß2-AR signaling. Methods: Thyrotoxicosis was induced in 120-day-old female and male mice with ß2-AR gene inactivation (ß2-AR-/-) by daily treatment with supraphysiological doses of triiodothyronine (T3) for 12 weeks. The impact of thyrotoxicosis on femoral bone microarchitecture, remodeling, fracture risk, and gene expression of the receptor activator of nuclear factor-kappa-B (RANK)-RANK ligand (RANKL)-osteoprotegerin (OPG) pathway was evaluated. In addition, the effect of the ß2-AR-specific agonist clenbuterol (CL) on cAMP accumulation was determined in osteoblastic (MC3T3-E1) cells treated with T3 and/or 17ß-estradiol (E2). Results: Thyrotoxicosis negatively affected trabecular bone microarchitecture in wild-type (WT) females, but this effect was milder or nonexistent in ß2-AR-/- animals, whereas the opposite was seen in males. T3 treatment increased the femoral RANKL/OPG mRNA ratio and the endosteal perimeter and medullary area of the diaphysis in WT females and males, but not in ß2-AR-/- mice, suggesting that T3 promotes endosteal resorption in cortical bone, in a mechanism that involves ß2-AR signaling. T3 treatment increased endocortical mineral apposition rate only in WT females but not in ß2-AR-/- mice, suggesting that TH also induce bone formation in a ß2-AR signaling-dependent mechanism. T3 treatment decreased femoral resistance to fracture only in WT females, but not in KO mice. E2 and CL similarly increased cAMP accumulation in MC3T3-E1 cells; whereas T3 alone had no effect, but it completely blocked E2-stimulated cAMP accumulation, suggesting that some T3 effects on bone may involve E2/cAMP signaling in osteoblasts. Conclusions: These findings sustain the hypothesis that T3 interacts with the SNS to regulate bone morphophysiology in a ß2-AR signaling-dependent mechanism. The data also reveal sex as an important modifier of skeletal manifestations of thyrotoxicosis, as well as a modifier of the TH-SNS interactions to control bone microarchitecture, remodeling, and resistance to fracture.