Comparison of patients undergoing revision total hip arthroplasty and patients undergoing re-revision.

OBJECTIVE: The aim of this study is to compare the demographic, clinical, and surgical characteristics of patients who underwent revision hip replacement surgery and those who underwent re-revision surgery. The secondary outcome is the investigation of the factors that play a role in estimating the time between primary arthroplasty surgery and revision surgery. PATIENTS AND METHODS: The patients who underwent revision hip arthroplasty in our clinic between 2010- 2020, patients with at least 2 years of follow-up, and who underwent re-revision surgery if needed were included. Demographic and clinical data were investigated. RESULTS: Of the 153 patients who met the study criteria, 120 (78.5%) underwent revision (Group 1) and 33 (21.5%) underwent re-revision (Group 2). The mean age of Group 1 was 53.5 (32-85), and of Group 2 was 67 (38-81) (p=0.003). In both groups, patients who underwent hip replacement due to fracture had more revisions and re-revisions (p=0.794). While 53.3 of the patients in Group 1 did not need additional implants, 72.7% of the patients in Group 2 needed additional implants (p=0.010). Fracture-dislocation, fistula, and the need for debridement after the revision were statistically significantly higher in patients who underwent re-revision. Harris hip scores (HHS) were statistically lower in patients who went for re-revision. CONCLUSIONS: The need for reoperation in patients who have undergone revision total hip arthroplasty (THA) surgery is due to the fact that the patient's age is advanced and the indication for surgery is a fracture. While the rate of fistula, fracture, dislocation, and debridement increases after re-revision surgeries, the HHS values that indicate clinical success also decrease. We believe that studies with larger participation and longer follow-up periods are needed to explain this issue better.

Irisin immunohistochemistry in gastrointestinal system cancers.

Cancer is the leading cause of morbidity and mortality worldwide. Some studies have shown that high heat kills cancer cells. Irisin is a protein involved in heat production by converting white into brown adipose tissue, but there is no information about how its expression changes in cancerous tissues. We used irisin antibody immunohistochemistry to investigate changes in irisin expression in gastrointestinal cancers compared to normal tissues. Irisin was found in human brain neuroglial cells, esophageal epithelial cells, esophageal epidermoid carcinoma, esophageal adenocarcinoma and neuroendocrine esophageal carcinoma, gastric glands, gastric adenosquamous carcinoma, gastric neuroendocrine carcinoma, gastric signet ring cell carcinoma, neutrophils in vascular tissues, intestinal glands of colon, colon adenocarcinoma, mucinous colon adenocarcinoma, hepatocytes, hepatocellular carcinoma, islets of Langerhans, exocrine pancreas, acinar cells and interlobular and interlobular ducts of normal pancreas, pancreatic ductal adenocarcinoma, and intra- and interlobular ducts of cancerous pancreatic tissue. Histoscores (area × intensity) indicated that irisin was increased significantly in gastrointestinal cancer tissues, except liver cancers. Our findings suggest that the relation of irisin to cancer warrants further investigation.

Pharmacokinetics of meloxicam in adult goats: a comparative study of subcutaneous, oral and intravenous administration.

AIMS: To determine the plasma disposition of meloxicam in goats following S/C, oral or I/V administration at a single dose of 0.5 mg/kg bodyweight. METHODS: Five healthy Saanen goats, aged 12-14 months and weighing 35-40 kg, were used for a three phase cross-over design with a 10-day washout period, with meloxicam administered I/V, then orally and S/C. Heparinised blood samples (5 mL) were collected from all animals prior to drug administration (0 hours) and subsequently up to 96 hours. Concentrations of meloxicam in plasma were measured using high performance liquid chromatography. Concentration-time curves were fitted and pharmacokinetic parameters were estimated for each administration group. RESULTS: Subcutaneous administration of meloxicam exhibited unique plasma distribution characteristics that differed from oral and I/V administration. Mean peak plasma concentrations were greater (1.91 (SD 0.39) vs. 0.71 (SD 0.17) µg/mL) and the time to reach them shorter (3.20 (SD 1.64) vs. 14.33 (SD 2.19) hours) following S/C compared with oral administration (p<0.05). The terminal half-life was longer (15.16 (SD 4.74) vs. 10.69 (SD 1.49) hours) and the MRT was shorter (15.67 (SD 2.37) vs. 24.33 (SD 3.12) hours) following S/C than oral administration (p<0.05), but bioavailability was similar (98.24 (SD 9.62) vs. 96.49 (SD 10.71)%). CONCLUSION AND CLINICAL RELEVANCE: Subcutaneous administration of meloxicam resulted in long-term presence of drug at high concentration in goat plasma. This unique plasma disposition characteristic may offer an advantage in some clinical cases towards potentially improving the treatment efficacy in goats.

Chiari type I malformation with high foramen magnum anomaly.

A 14-year-old male with a neck pain and hypoesthesia in the upper extremities was diagnosed with Chiari type I malformation (CMI) and syringomyelia. The posterior part of the occipital bone was removed via cranio-cervical decompression. The accuracy of measuring the posterior cranial fossa (PCF) and foramen magnum (FM) dimensions were evaluated and compared with the literature. The linear PCF and FM dimensions as well as volumes were measured using computed tomography (CT) images with different techniques. The volume data were compared with similar data from literature. Use of the posterior fossa approach remains controversial when treating patients with minor little brain stem dislocation, small PCF, and or incomplete C1, but the approach can easily be applied if FM and PCF sizes are known. Linear measurements that were assessed for concordance with CT measurements had the best agreement. Quantification of PCF volume and high FM should be taken into consideration for differential diagnosis of tonsillar herniation and prediction of surgical outcome in CMI.

The role of exercise in migraine treatment.

This review aims to provide a comprehensive overview of the literature on the use of exercise for migraine treatment with regard to its efficacy, mechanism of action and role in practice. Many randomized studies have reported the efficacy of prophylactic treatment of migrane with medications such as beta blockers or antiepileptic drugs. Studies on alternative approaches, like aerobic exercise and biofeedback, are however limited but also considered to be effective. Scientific databases were searched with keywords "exercise" and "migraine". The resulting publications were gathered, examined and discussed throughly. Past studies had limitations and were few in number, but more recent randomized controlled studies have concretely provided level of evidence about the effectiveness of exercise in prophylactic treatment of migraine. Core properties of exercise like intensity, duration, frequency, type and warming up period are required to be monitored while treating migraine to increase the beneficial effects and, also to prevent injuries and side effects which may include exertional headache. Isometric neck exercise is helpful when the migraine is accompanied by neck pain. Patient population with low beta endorphin level in blood, high physical fitness and high motivation receives significant benefits from the exercise treatment. The action of exercise on migraine is in general related to neurochemical factors, psychological states and increase in cardivascular and cerebrovascular fitness. Considering its effectiveness and minimal side effects, migraine patients should often be encouraged to practice physical exercise with intensity, frequency and duration that should be carefully instituted to achieve the most beneficial outcome while preventing potential injuries and side effects.

Human brains found in a fire-affected 4000-years old Bronze Age tumulus layer rich in soil alkalines and boron in Kutahya, Western Anatolia.

Undecomposed human bodies and organs always attracted interest in terms of understanding biological tissue stability and immortality. Amongst these, cases of natural mummification found in glaciers, bog sediments and deserts caused even more attention. In 2010, an archeological excavation of a Bronze Age layer in a tumulus near the Western Anatolia city Kütahya revealed fire affected regions with burnt human skeletons and charred wooden objects. Inside of the cracked skulls, undecomposed brains were discernible. To analyze the burial taphonomy of the rare phenomenon of brain preservation, we analyzed brains, bone, teeth and surrounding soils elements using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). Adipocere formation or saponification of postmortem tissue fat requires high levels of alkalinity and especially potassium. Indeed, ICP-MS analysis of the brain, teeth and bone and also of the surrounding soil revealed high levels of potassium, magnesium, aluminum and boron, which are compatible with the famous role of Kütahya in tile production with its soil containing high level of alkalines and tile-glazing boron. Fatty acid chromatography revealed simultaneous saturation of fats and protection of fragile unsaturated fatty acids consistent with soil-presence of both pro-oxidant and anti-oxidant trace metals. Computerized tomography revealed protection of diencephalic, metencephalic and occipital tissue in one of the best-preserved specimens. Boron was previously found as an intentional preservative of Tutankhamen and Deir el Bahari mummies. Here, in natural soil with its insect-repellant, anti-bacterial and fire-resistance qualities it may be a factor to preserve heat-affected brains as almost bioporcellain specimens.

Plexiform fibrohistiocytic tumor of bone.

Plexiform fibrohistiocytic tumor is an extremely rare soft tissue tumor with a low malignancy potential. The patient is usually a child or a young adolescent and the tumor is usually localized in the upper extremities. We report on a case of a 21-year old male with a plexiform fibrohistiocytic tumor in the left fibula admitted to our hospital due to a swelling and pain in the left lower extremity. Radiologically a lytic lesion in the distal end of left fibula consistent with a non-aggressive lesion with low biological activity was found. Treated with curettage, the specimen revealed plexiform proliferation of mononuclear histiocyte-like cells, multinucleated osteoclast-like cells, and spindle fibroblast-like cells in variable proportions histopathologically. Immunohistochemical stains were positive for CD68 in scattered fashion in histiocytes and giant cells, and spindle like cells showed positivity for smooth muscle actin. Under electron microscopy, rough endoplasmic reticulum and collagen bundles in the spindle cells suggested fibroblastic differentiation. Also multiple large electron-dense lysosomal granules in histiocytoid cells were found. Multinucleated giant cells exhibited osteoclast-like appearance. All these findings suggested plexiform fibrohistiocytic tumor. Interestingly, the tumor was localized in bone. During the follow up for 27 months after the resection, there was no recurrence or metastasis.

Cardiac rupture due to fall: a case study.

Studies have shown that cardiac ruptures due to blunt trauma are seen more often than expected. However, epicardial injuries and atrial ruptures are common findings in deaths due to falls. Our aim is to present a unique, isolated cardiac rupture in a 2 year-old child resulting from a fall from a bed, to evaluate autopsy findings among the literature from a medico-legal point of view.

High-resolution magnetic resonance imaging and diffusion tensor imaging of the porcine temporomandibular joint disc.

OBJECTIVES: Diffusion tensor imaging (DTI) is an MRI modality for characterizing the property, microstructural organization and function in tissues such as the brain and spinal cord. Prior to this investigation, DTI had not been adapted for studies of the temporomandibular joint (TMJ) disc. Objectives were to test the feasibility of DTI to evaluate the porcine TMJ disc and to use DTI to observe differences in magnitude of anisotropy of water diffusion between TMJ disc regions. METHODS: Five adult pig TMJs were scanned on a 9.4 Tesla horizontal bore MRI scanner using an inductively coupled surface coil. High-resolution gradient-echo and diffusion-weighted spin-echo based images were obtained. The mean diffusivity and fractional anisotropy (FA) were computed in different regions of the disc. Two observers were calibrated to review the two-dimensional and three-dimensional images. Polarized light microscopy was used as the gold standard for collagen fibre orientation. RESULTS: In the sagittal plane, the mean diffusivity was higher in the posterior (1.28+/-0.10 x 10(-3) mm(-2) s(-1)) and anterior (1.27+/-0.08 x 10(-3) mm(-2) s(-1)) bands compared with the intermediate zone (0.96+/-0.01 x 10(-3) mm(-2) s(-1)), and the FA index was also lowest in the intermediate zone. In the coronal plane, the mean diffusivity was higher in the medial (1.42+/-0.01 x 10(-3) mm(-2) s(-1)) and lateral (1.21+/-0.12 x 10(-3) mm(-2) s(-1)) aspects than in the centre (1.09+/-0.08 x 10(-3) mm(-2) s(-1)), and the FA index was also lowest in the centre. CONCLUSIONS: DTI is a useful method for non-invasively characterizing the structure/property relationships of the porcine TMJ disc.

Tracking kidney volume in mice with polycystic kidney disease by magnetic resonance imaging.

Polycystic kidney disease is characterized by the progressive enlargement of kidneys due to expanding fluid-filled cysts with the rate of renal volume increase held to be a marker of disease progression. Magnetic resonance imaging (MRI) is used to monitor changes in renal volume in patients with polycystic kidney disease; however, it has not been effectively used in mice to monitor changes in kidney volume during drug treatment studies. We used a powerful 9.4-T horizontal bore magnetic resonance scanner to track changes in kidney volume in pcy/pcy mice, an ortholog of nephronophthisis type 3. Mice were sequentially scanned from 4 to 30 weeks of age and kidney volumes determined from high-resolution images. Kidney volume and maximal cross-sectional surface area correlated positively with kidney weight and the histologic determination of surface area. The increase in kidney volume was exponential up to 20 weeks of age, after which there was a plateau consistent with the replacement of normal parenchyma by fibrotic tissue. Our study demonstrates that MRI accurately determines the rate of kidney volume increase in mice with polycystic kidney disease and hence may be useful in assessing the effectiveness of therapeutic agents to slow disease progression.

High tibial osteotomy for medial compartment osteoarthritis: a comparison of clinical and radiological results from closed wedge and focal dome osteotomies.

This study aimed to evaluate the clinical and radiological results of closed wedge osteotomy (11 knees) and focal dome osteotomy (14 knees) in cases of high tibial osteotomy undertaken for varus knee with medial compartment osteoarthritis. Clinical evaluation was performed using the Knee Society Score and no significant difference was seen between the two groups at final follow-up. Radiological evaluation was made on the basis of the pre- and postoperative mechanical axis, postoperative movement of the tibial axis, loss of correction at final follow-up and patellar height measured using the Insall-Salvati index. Statistically significant differences were seen with focal dome osteotomy compared with closed wedge osteotomy in the InsallSalvati index at final follow-up, the amount of correction loss and the change in tibial axis location. It is concluded that, in the treatment of medial compartment osteoarthritis by high tibial osteotomy, focal dome osteotomy is more beneficial than closed wedge osteotomy in not creating any additional deformity.

A pharmacokinetic model for quantitative evaluation of spinal cord injury with dynamic contrast-enhanced magnetic resonance imaging.

A multicompartment pharmacokinetic model was proposed to quantitatively describe the distribution of the contrast agent gadopentetate-dimeglumine (Gd) in an experimental spinal cord injury (SCI). Concentration of Gd was measured in different compartments with in vivo dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in the acute phase of injury. The concentration data for each rat was fitted to the model to estimate transfer rates between different compartments. The results indicate: 1) lack of uptake of Gd in normal cord tissue, 2) rapid exchange of Gd between plasma and cerebrospinal fluid in both normal and injured cord tissues, and 3) slower uptake of Gd in injured cord. With this approach, it is possible to quantify the integrity of the blood-spinal cord barrier (BSCB) in vivo, evaluate the pathobiology of injured cord, assess the efficacy of interventions, and monitor the progression of injury with postinjury time.

In vivo magnetic resonance microscopy of rat spinal cord at 7 T using implantable RF coils.

An inductively coupled implanted coil was designed for high-resolution magnetic resonance (MR) studies of rat spinal cord (SC) in vivo at 7 T. The practical issues involved in implementation of the coil at high fields are discussed, and the adjustment of various parameters for optimizing coil performance are described. The utility of the coil was demonstrated with anatomical, magnetization transfer, diffusion tensor imaging, and proton MR spectroscopy (MRS).

Phase aberration effects in elastography.

In sonography, phase aberration plays a role in the corruption of sonograms. Phase aberration does not have a significant impact on elastography, if statistically similar phase errors are present in both the pre- and postcompression signals. However, if the phase errors are present in only one of the pre- or postcompression signal pairs, the precision of the strain estimation process will be reduced. In some cases, increased phase errors may occur only in the postcompression signal due to changes in the tissue structure with the applied compression. Phase-aberration effects increase with applied strain and may be viewed as an image quality derating factor, much like frequency-dependent attenuation or undesired lateral tissue motion. In this paper, we present a theoretical and simulation study of the effects of phase aberration on the elastographic strain-estimation process, using the strain filter approach.

Dynamic contrast-enhanced MRI of experimental spinal cord injury: in vivo serial studies.

The progression of experimental spinal cord injury (SCI) was followed with in vivo dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and neurobehavioral studies on postinjury days 0, 2, 4, 7, 10, 14, 17, 21, 28, 35, and 42. Gadopentate dimeglumine (Gd) was administered IV and postcontrast, T(1)-weighted, axial images were acquired repetitively for up to 60 min. Images were analyzed to determine the spatial and temporal evolution of the intensity enhancement. A statistical decision mechanism was developed to objectively detect the enhancement. Strong and rapid enhancement was observed at the epicenter of injury, indicating a significant compromise in blood spinal cord barrier. The enhanced regions in each slice were combined to estimate the area and volume of the lesion. On the day of injury, around 85% of the total cord area at the epicenter showed enhancement within the first 15 min of Gd administration. At the same time, the enhanced volumes attained nearly 40% of the total cord volume and extended axially over 8 mm along the cord. These quantities decreased steadily with time, with a concomitant improvement in the motor functions. The volume of enhancement correlated highly with the neurobehavioral tests (r = -0.87). DCE-MRIs revealed small hyperintense regions distributed inside white matter about two weeks postinjury. Based on histology, these enhancements appear to represent new vessels with "leaky endothelium." Magn Reson Med 45:614-622, 2001.

C-reactive protein values and erythrocyte sedimentation rates after total hip and total knee arthroplasty.

We studied the changes in serum C-reactive protein levels (CRP) and erythrocyte sedimentation rates (ESR) in patients with primary osteoarthritis, who underwent uncomplicated arthroplasty. Of the 28 patients studied, 12 had cementless total hip replacement (THR), and 16 underwent cemented total knee replacement (TKR) with a tourniquet. In both groups serum CRP levels increased rapidly after surgery, peaking on day 2 (THR 23.17 mg/dl, TKR 26.02 mg/dl), and dropping gradually to pre-operative values on day 21 in THR patients and at the end of the second month in TKR patients. ESR peaked on day 5 after operation (THR 100.5 mm/h, TKR 101.3 mm/h), dropping close to pre-operative values at the end of the third month in THR patients and at the end of the ninth month in TKR patients, although, even after a year, ESRs were slightly above their pre-operative values. Serum CRP levels changed more rapidly than ESRs and returned to normal more rapidly. CRP and ESR values tended to be higher in TKR than in THR patients.

Dynamics of errors in 3D motion estimation and implications for strain-tensor imaging in acoustic elastography.

For the purpose of quantifying the noise in acoustic elastography, a displacement covariance matrix is derived analytically for the cross-correlation based 3D motion estimator. Static deformation induced in tissue from an external mechanical source is represented by a second-order strain tensor. A generalized 3D model is introduced for the ultrasonic echo signals. The components of the covariance matrix are related to the variances of the displacement errors and the errors made in estimating the elements of the strain tensor. The results are combined to investigate the dependences of these errors on the experimental and signal-processing parameters as well as to determine the effects of one strain component on the estimation of the other. The expressions are evaluated for special cases of axial strain estimation in the presence of axial, axial-shear and lateral-shear type deformations in 2D. The signals are shown to decorrelate with any of these deformations, with strengths depending on the reorganization and interaction of tissue scatterers with the ultrasonic point spread function following the deformation. Conditions that favour the improvements in motion estimation performance are discussed, and advantages gained by signal companding and pulse compression are illustrated.

Spatial and temporal evolution of hemorrhage in the hyperacute phase of experimental spinal cord injury: in vivo magnetic resonance imaging.

To follow the spatial and temporal evolution of hemorrhage, in vivo MRI studies of experimental spinal cord injury (SCI) were performed on 17 rats in the very acute phase (hyperacute), starting as early as 9 min and continued up to 400 min posttrauma. Axial MR images were processed slice by slice over a 21 mm length around the epicenter of the injury. The data were analyzed statistically and fitted to an empirically derived function to characterize the spatial and temporal evolution of hemorrhage. The results indicated that 1) the initial hemorrhage in the very early phase of the injury area covered 12.5% of the total cord area and subsequently increased with a time constant of 700 min, 2) a major portion of the hemorrhage was concentrated spatially within the 4 mm distance from the epicenter, 3) the volume of hemorrhage normalized to its initial value increased linearly at a rate of approximately 0.0015 min(-1), and 4) edema was observed at the gray- and white-matter junction as early as 12 min postinjury. In general, edema appeared to be focal and scattered in this phase of the injury, which made its quantification unreliable on MRI.

Maximum-likelihood approach to strain imaging using ultrasound

A maximum-likelihood (ML) strategy for strain estimation is presented as a framework for designing and evaluating bioelasticity imaging systems. Concepts from continuum mechanics, signal analysis, and acoustic scattering are combined to develop a mathematical model of the ultrasonic waveforms used to form strain images. The model includes three-dimensional (3-D) object motion described by affine transformations, Rayleigh scattering from random media, and 3-D system response functions. The likelihood function for these waveforms is derived to express the Fisher information matrix and variance bounds for displacement and strain estimation. The ML estimator is a generalized cross correlator for pre- and post-compression echo waveforms that is realized by waveform warping and filtering prior to cross correlation and peak detection. Experiments involving soft tissuelike media show the ML estimator approaches the Cramer-Rao error bound for small scaling deformations: at 5 MHz and 1.2% compression, the predicted lower bound for displacement errors is 4.4 microns and the measured standard deviation is 5.7 microns.

Direct strain estimation in elastography using spectral cross-correlation.

Spectral estimation of tissue strain has been performed previously by using the centroid shift of the power spectrum or by estimating the variation in the mean scatterer spacing in the spectral domain. The centroid shift method illustrates the robustness of the direct, incoherent strain estimator. In this paper, we present a strain estimator that uses spectral cross-correlation of the pre- and postcompression power spectrum. The centroid shift estimator estimates strain from the mean center frequency shift, while the spectral cross-correlation estimates the shift over the entire spectrum. Spectral cross-correlation is shown to be more sensitive to small shifts in the power spectrum and, thus, provides better estimation for smaller strains when compared to the spectral centroid shift. Spectral cross-correlation shares all the advantages gained using the spectral centroid shift, in addition to providing accurate and precise strain estimation for small strains. The variance and noise properties of the spectral strain estimators quantified by their respective strain filters are also presented.