Femur

A 20-year-old man with bilateral absence of patella, thinness of the left femoral neck, femoral and tibial shaft was reported. This clinical presentation has not been reported in the English language literature. We propose that the unusual association observed in our patient may represent a distinguishing clinical presentation from previously reported aplastic patella syndromes.

Osteoclast-mediated bone resorption plays an essential role in calcium homeostasis and lactation. The cytokine receptor activator of nuclear factor κB ligand (RANKL) is one of a number of factors that controls the production, survival, and activity of osteoclasts. Calciotropic hormones, such as PTH, control RANKL transcription in part via an enhancer known as the distal control region (DCR), and mice lacking this enhancer have fewer osteoclasts under normal physiological conditions. Here, we have addressed the role of the DCR in situations in which activation of the PTH receptor is thought to stimulate bone resorption via elevation of RANKL expression. Dietary calcium deficiency stimulated RANKL expression in the bone of young (1 month old) wild-type, but not DCR knockout (KO), mice. Consistent with this, the cancellous bone loss and the increase in osteoclasts caused by dietary calcium deficiency were blunted in young KO mice. DCR deletion also prevented the increase in RANKL expre...

El síndrome de pinzamiento femoroacetabular (SPFA) se caracteriza por un contacto anormal entre el fémur y el acetábulo al final de ciertos movimientos de la cadera, especialmente durante la flexión, la rotación interna y la externa. Ha sido propuesto recientemente como factor causal importante de osteoartritis temprana y de dolor de cadera en pacientes jóvenes. Es una entidad cuyo diagnóstico se basa en una buena historia clínica y en ayudas imagenológicas, como radiografías AP de pelvis, lateral verdadera de cadera o a través de la mesa (cross table) y artroresonancia magnética. El tratamiento se dirige hacia la corrección quirúrgica de la anormalidad anatómica que está desencadenando el cuadro y su éxito depende de una intervención temprana. El propósito de este artículo es brindar una aproximación a la patología, clínica, diagnóstico y tratamiento de este síndrome basado en el caso clínico de un paciente.

Non-enzymatic glycation (NEG) is an age-related process accelerated by diseases like diabetes, and causes the accumulation of advanced glycation end-products (AGEs). NEG-mediated modification of bone's organic matrix, principally collagen type-I, has been implicated in impairing skeletal physiology and mechanics. Here, we present evidence, from in vitro and in vivo models, and establish a causal relationship between collagen glycation and alterations in bone fracture at multiple length scales. Through atomic force spectroscopy, we established that NEG impairs collagen's ability to dissipate energy. Mechanical testing of in vitro glycated human bone specimen revealed that AGE accumulation due to NEG dramatically reduces the capacity of organic and mineralized matrix to creep and caused bone to fracture under impact at low levels of strain (3000-5000 μstrain) typically associated with fall. Fracture mechanics tests of NEG modified human cortical bone of varying ages, and their age-matched controls revealed that NEG disrupted microcracking based toughening mechanisms and reduced bone propagation and initiation fracture toughness across all age groups. A comprehensive mechanistic model, based on experimental and modeling data, was developed to explain how NEG and AGEs are causal to, and predictive of bone fragility. Furthermore, fracture mechanics and indentation testing on diabetic mice bones revealed that diabetes mediated NEG severely disrupts bone matrix quality in vivo. Finally, we show that AGEs are predictive of bone quality in aging humans and have diagnostic applications in fracture risk.

Bone cancer pain remains one of the most challenging cancer pains to fully control. In order to clarify bone cancer pain mechanisms and examine treatments, animal models mimicking the human condition are required. In our model of Walker 256 tumor cells implantation of the shaft of femur at the third trochanter level, the anatomical structure is relatively simple and the drilled hole is vertical and in the cortical bone only 1-2 mm in depth without injury of the distal femur. Pain behaviors and tumor growth were observed for 21 days. And neurochemical changes were further investigated in this model. The results showed that cancer-bearing rats demonstrated a decreased limb use score from day 14, an increased spontaneous flinching and guarding times from day 7 and a decreased withdrawal threshold from day 6. The tumor infiltration of bone was monitored by MRI and further verified by histological examination. C-fos and the capsaicin receptor (TRPV1) positive neurons were more expressed in cancer-bearing rats and the substance P expression has no difference, suggesting that neurons were activated in the model. Our animal model demonstrated time-dependent tumor growth and pain behaviors and will be a novel animal model of bone cancer pain in the future.

The aim of this study was to investigate the effects of low-level laser therapy (LLLT; infrared, 830 nm) on the bone properties and bone strength of rat femora after ovariectomy (OVX). Osteoporosis affects 30% of postmenopausal women, and it has been recognized as a major public health problem. Based on the stimulatory effects of LLLT on proliferation of bone cells, we hypothesized that LLLT would be efficient in preventing bone mass loss in OVX rats. Forty female rats were divided into four groups: sham-operated control (SC), OVX control (OC), sham-operated irradiated at a dose of 120 J/cm(2) (I120), and OVX irradiated at a dose of 120 J/cm(2) (O120). Animals were operated at the age of 90 days. Laser irradiation was initiated 1 day after the operation and was performed three times a week, for 2 months. Femora were submitted to a biomechanical test and a physical properties evaluation. Maximal load of O120 was higher than in control groups. Wet weight, dry weight, and bone volume of O120 did not show any difference when compared with SC. The results of the present study indicate that LLLT was able to prevent bone loss after OVX in rats. However, further studies are needed to investigate the effects of different parameters, wavelengths, and sessions of applications on OVX rats.

The aim of this study was to investigate the effects of photoradiation--infrared at 830 nm--used in two doses, on femora of osteopenic rats. Osteoporosis has recently been recognized as a major public health problem. Based on stimulatory effects of photoradiation on the proliferation of bone cells, we hypothesized that photoradiation would be efficient in improving bone mass in osteopenic rats. Sixty female animals, divided into six groups, were used: sham-operated control (SC), osteopenic control (OC), sham-operated irradiated with the dose of 120 J/cm(2) (I120), osteopenic irradiated with the dose of 120 J/cm(2) (O120), sham-operated irradiated with the dose of 60 J/cm(2) (I60), and osteopenic irradiated with the dose of 60 J/cm(2) (O60) Animals were 90 days old when operated. Laser irradiation was initiated 8 weeks after operation, and it was performed 3 times a week for 2 months. Femora were submitted to a biomechanical test and to a physical properties evaluation. Maximal load of O120 did not show any difference when compared with SC and I120, but it was higher than the O60 group. Wet weight, dry weight, and bone volume of O60 and O120 did not show any difference when compared with SC. The results of the present study indicate that photoradiation had stimulatory effects on femora of osteopenic rats, mainly at the dose of 120 J/cm.(2) However, further studies are needed to investigate the effects of different parameters, wavelengths, and sessions of applications on ovariectomized rats.

The aim of this study was to investigate the effects of photoradiation--infrared at 830 nm--used in two doses, on femora of osteopenic rats. Osteoporosis has recently been recognized as a major public health problem. Based on stimulatory effects of photoradiation on the proliferation of bone cells, we hypothesized that photoradiation would be efficient in improving bone mass in osteopenic rats. Sixty female animals, divided into six groups, were used: sham-operated control (SC), osteopenic control (OC), sham-operated irradiated with the dose of 120 J/cm(2) (I120), osteopenic irradiated with the dose of 120 J/cm(2) (O120), sham-operated irradiated with the dose of 60 J/cm(2) (I60), and osteopenic irradiated with the dose of 60 J/cm(2) (O60) Animals were 90 days old when operated. Laser irradiation was initiated 8 weeks after operation, and it was performed 3 times a week for 2 months. Femora were submitted to a biomechanical test and to a physical properties evaluation. Maximal load of O120 did not show any difference when compared with SC and I120, but it was higher than the O60 group. Wet weight, dry weight, and bone volume of O60 and O120 did not show any difference when compared with SC. The results of the present study indicate that photoradiation had stimulatory effects on femora of osteopenic rats, mainly at the dose of 120 J/cm.(2) However, further studies are needed to investigate the effects of different parameters, wavelengths, and sessions of applications on ovariectomized rats.

The aim of this study was to investigate the effects of low-level laser therapy (LLLT; infrared, 830 nm) on the bone properties and bone strength of rat femora after ovariectomy (OVX). Osteoporosis affects 30% of postmenopausal women, and it has been recognized as a major public health problem. Based on the stimulatory effects of LLLT on proliferation of bone cells, we hypothesized that LLLT would be efficient in preventing bone mass loss in OVX rats. Forty female rats were divided into four groups: sham-operated control (SC), OVX control (OC), sham-operated irradiated at a dose of 120 J/cm(2) (I120), and OVX irradiated at a dose of 120 J/cm(2) (O120). Animals were operated at the age of 90 days. Laser irradiation was initiated 1 day after the operation and was performed three times a week, for 2 months. Femora were submitted to a biomechanical test and a physical properties evaluation. Maximal load of O120 was higher than in control groups. Wet weight, dry weight, and bone volume of O120 did not show any difference when compared with SC. The results of the present study indicate that LLLT was able to prevent bone loss after OVX in rats. However, further studies are needed to investigate the effects of different parameters, wavelengths, and sessions of applications on OVX rats.

The aim of this study was to investigate the effects of low-level laser therapy (LLLT), 830 nm, on femora of exercised osteopenic rats. Sixty female rats were used, which were divided into six groups: sham-operated control, osteopenic control, sham-operated trained, osteopenic trained, sham-operated trained and irradiated, and osteopenic trained and irradiated. The exercise program and the laser irradiation were performed 48 h over an 8-week period. The exercise program was made in a container, filled with warm water, and consisted of jumps (four series, with ten jumps). The laser irradiation was performed with a Ga-Al-As laser, 830 nm, 100 W/cm2, 120 J/cm2. Femora were submitted to a physical and geometrical properties evaluation, a biomechanical test, and calcium and phosphorus evaluation. Exercised animals showed higher bone strength and physical properties values. However, the LLLT did not improve the stimulatory effects of the exercise on the osteopenic rats. The exercise program was able to increase femora strength and physical properties of osteopenic rats. However, concurrent treatments did not produce a more pronounced effect on femora.

Experimental studies as well as studies in free-ranging animals have shown that endocrine-disrupting chemicals (EDCs) impair bone tissue composition and strength. The aim of the present study was to expand our studies on bone tissue in a new group of animals by investigating whether bone tissue in frogs is an additional potential target of EDCs. Adult male European common frogs (Rana temporaria) were divided into 5 groups (n = 20) and injected (sc, single injection) with p,p'-DDE, a total dose of 0.01, 0.1, 1, or 10 mg of p,p'-DDE/kg body weight, respectively. A control group was treated with the vehicle (corn oil). Two weeks after injection the frogs were euthanized and samples taken. The diaphysis of the excised left femur was scanned using peripheral quantitative computed tomography (pQCT) and cortical variables, such as cortical bone mineral density (BMD), cortical cross-sectional area (CSA), and periosteal circumference, were determined. In addition, biomechanical three-point bending of the bones was conducted, with the load being applied to the same point as where the pQCT measurement was performed. The results from the pQCT measurements show that bone tissue in male frogs exposed to p,p'-DDE is negatively affected. A significant decrease in cortical BMD at the diaphysis was observed in frogs exposed to 1 mg p,p'-DDE. However, the biomechanical testing of the bones showed no significant differences between exposed and control group. Although this is the only study performed to date examining the possible relationships between EDCs and negative effects on frog bones, it supports both previous experimental findings in rodents and findings in free-ranging animals.