A preliminary safety assessment of vertebral augmentation withP brachytherapy bone cement.

Comprehensive treatment for vertebral metastatic lesions commonly involves vertebral augmentation (vertebroplasty or kyphoplasty) to relieve pain and stabilize the spine followed by multiple sessions of radiotherapy. We propose to combine vertebral augmentation and radiotherapy into a single treatment by addingP, a-emitting radionuclide, to bone cement, thereby enabling spinal brachytherapy to be performed without irradiating the spinal cord. The goal of this study was to address key dosimetry and safety questions prior to performing extensive animal studies.

Comparison of Area Deprivation Index, Socioeconomic Parameters, and Preoperative Demographics With Postoperative Emergency Department Visits After Total Knee Arthroplasty.

Background: This study aims to determine if socioeconomic (SE) parameters, primarily area deprivation index (ADI), relate to postoperative emergency department (ED) visits after total knee arthroplasty (TKA).

Methods: We retrospectively reviewed 2655 patients who underwent TKA in a health system of 4 hospitals. The primary outcome was an ED visit within 90 days, which was divided into those with and without readmission.

Radiographic Predictors of Screw Cutout for Intertrochanteric Fractures Treated With Cephalomedullary Nails.

The objective of this study was to determine the predictive value of tip-apex distance (TAD) and Parker's ratio for screw cutout after treatment of intertrochanteric hip fractures with a long cephalomedullary nail. A total of 97 patients with AO/OTA 31-A1-A3 intertrochanteric fractures and a minimum follow-up of 8 weeks were included. Increased Parker's ratio on the anteroposterior radiograph (OR = 1.

Effect of Acetylsalicylic Acid Dose and Time Discontinued Preoperatively on Outcomes After Total Knee and Hip Arthroplasty.

The purpose of this study was to determine if acetylsalicylic acid (ASA) dose or time discontinued preoperatively affected surgical outcomes in total joint arthroplasty (TJA). The authors hypothesized that ASA worsens surgical outcomes in patients receiving higher doses and in those who discontinue ASA closer to the operative date. A total of 2853 TJAs (1802 primary total knee arthroplasties and 1051 total hip arthroplasties) performed at a tertiary medical center were reviewed.

Short Versus Long Cephalomedullary Nails for Pertrochanteric Hip Fracture.

This study compared patients who underwent treatment with short or long cephalomedullary nails with integrated cephalocervical screws and linear compression. Patients with AO/OTA 31-A2 or A3 pertrochanteric fractures treated with either short (n=72) or long (n=97) InterTAN (Smith & Nephew, Memphis, Tennessee) cephalomedullary nails were reviewed. Information on perioperative measures (estimated blood loss, surgical time, and fluoroscopy time) and postoperative orthopedic complications (infection, implant failure, screw cutout, and periprosthetic femur fracture) was included.

Rivaroxaban Versus Enoxaparin for Venous Thromboembolism Prophylaxis after Hip and Knee Arthroplasty.

The oral Factor Xa inhibitor rivaroxaban (Xarelto) has been the pharmacologic agent used for venous thromboembolism (VTE) prophylaxis after primary hip and knee arthroplasty (THA/TKA) at our institution since February 2012. The purpose of our study was to compare rates of VTE and major bleeding between rivaroxaban and our previous protocol of enoxaparin after THA/TKA. A retrospective cohort study was performed including 2406 consecutive patients at our institution between 1/1/11 and 9/30/13.

Review of Canine Deaths While in Service in US Civilian Law Enforcement (2002-2012).

Background: Working dogs have been proven effective in multiple military and law enforcement applications. Similar to their human counterparts, understanding mortality while still in service can help improve treatment of injuries, and improve equipment and training, to potentially reduce deaths. This is a retrospective study to characterize mortality of working dogs used in civilian law enforcement.

Type I collagen D-spacing in fibril bundles of dermis, tendon, and bone: bridging between nano- and micro-level tissue hierarchy.

Fibrillar collagens in connective tissues are organized into complex and diverse hierarchical networks. In dermis, bone, and tendon, one common phenomenon at the micrometer scale is the organization of fibrils into bundles. Previously, we have reported that collagen fibrils in these tissues exhibit a 10 nm width distribution of D-spacing values.

Nanoscale structure of type I collagen fibrils: quantitative measurement of D-spacing.

This article details a quantitative method to measure the D-periodic spacing of type I collagen fibrils using atomic force microscopy coupled with analysis using a two-dimensional fast fourier transform approach. Instrument calibration, data sampling and data analysis are discussed and comparisons of the data to the complementary methods of electron microscopy and X-ray scattering are made. Examples of the application of this new approach to the analysis of type I collagen morphology in disease models of estrogen depletion and osteogenesis imperfecta (OI) are provided.

Estrogen depletion results in nanoscale morphology changes in dermal collagen.

Tissue cryo-sectioning combined with atomic force microscopy imaging reveals that the nanoscale morphology of dermal collagen fibrils, quantified using the metric of D-periodic spacing, changes under the condition of estrogen depletion. Specifically, a new subpopulation of fibrils with D-spacings in the region between 56 and 59 nm is present 2 years following ovariectomy in ovine dermal samples. In addition, the overall width of the distribution, both values above and below the mean, was found to be increased.

Distribution of type I collagen morphologies in bone: relation to estrogen depletion.

Bone is an amazing material evolved by nature to elegantly balance structural and metabolic needs in the body. Bone health is an integral part of overall health, but our lack of understanding of the ultrastructure of healthy bone precludes us from knowing how disease may impact nanoscale properties in this biological material. Here, we show that quantitative assessments of a distribution of Type I collagen fibril morphologies can be made using atomic force microscopy (AFM).

Comparison of mean bone densities of three preparations of the distal portion of the equine third metacarpal bone measured by use of quantitative computed tomography.

Objective: To evaluate whether cutting equine subchondral bone to demarcate specific regions of interest (ROIs) influences the mean density for that bone as measured via quantitative computed tomography (QCT). Sample population-2 metacarpophalangeal joints from equine cadavers.

Procedures: The distal portion of the third metacarpal bone of each intact metacarpophalangeal joint was scanned via CT to simulate in vivo conditions.

Reporter gene imaging using radiographic contrast from nonradioactive iodide sequestered by the sodium-iodide symporter.

The hypothesis that the human sodium-iodide symporter, NIS, can be used to detect NIS expression using standard radiological techniques was tested using adenoviral transduced NIS expression in human tumor xenografts grown in mice and in a naive dog prostate. Nonradioactive iodide was administered systemically to animals that 1-3 days previously had received a local injection of a replication-competent adenovirus expressing NIS under the control of the CMV promoter. The distribution of radiopacity was assessed in mouse tumors using micro-CT and a clinical X-ray machine and in the prostate of an anesthetized dog using a clinical spiral CT.

Comparison of gross and histopathologic findings with quantitative computed tomographic bone density in the distal third metacarpal bone of racehorses.

Comparison of subchondral bone density determined by quantitative computed tomography (CT) with gross and histopathologic changes have not been made in horses. The goal of this study was to determine if mean quantitative CT density and mean voxel standard deviation are associated with the presence and severity of osteochondral lesions in the palmar aspect of the distal third metacarpal bone in racing horses. Metacarpophalangeal joints from nine racehorses were imaged using CT and scored for gross damage.

Morphological changes in articular cartilage due to static compression: polarized light microscopy study.

We studied the deformation of the extracellular matrices in articular cartilage using a new compression-preservation method in histology. A Hoffman clamp was used to compress the tissue, which remained throughout the paraffin procedure and was removed from the embedded tissue block just before microtoming. Then 14 cartilage-bone blocks from 2 canine humeri were compressed for various strain levels from 5% to 65%.

Complications of anterior cervical discectomy and fusion using recombinant human bone morphogenetic protein-2.

The use of bone morphogenetic protein-2 (rhBMP-2) in spinal fusion has increased dramatically since an FDA approval for its use in anterior lumbar fusion with the LT cage. There are several reports of its use in transforaminal lumbar interbody fusion, posterolateral fusion, and anterior cervical fusion. Reports on adverse effects of rhBMP-2 when used in spinal fusion are scarce in literature.

The effect of yield damage on the viscoelastic properties of cortical bone tissue as measured by dynamic mechanical analysis.

We have previously shown, using Dynamic Mechanical Analysis (DMA), that the presence of a defect in cortical bone tissue affects the apparent viscoelastic properties of that bone. However, mechanically induced damage is more complex than a machined defect making it difficult to predict its effect on bone viscoelasticity. We performed DMA measurements before and after introduction of yield damage into cortical bone beams from sheep radii.

The mechanical phenotype of biglycan-deficient mice is bone- and gender-specific.

Biglycan (bgn) is a small leucine-rich proteoglycan (SLRP) enriched in the extracellular matrix of skeletal tissues. While bgn is known to be involved in the growth and differentiation of osteoblast precursor cells and regulation of collagen fibril formation, it is unclear how these functions impact bone's geometric and mechanical properties, properties which are integral to the structural function of bone. Because the genetic control of bone structure and function is both local- and gender-specific and because there is evidence of gender-specific effects associated with genetic deficiencies, it was hypothesized that the engineered deletion of the gene encoding bgn would result in a cortical bone mechanical phenotype that was bone- and gender-specific.

Do sacrificial bonds affect the viscoelastic and fracture properties of bone?

Sacrificial bonds have been suggested as a toughening mechanism for bone tissue. Ionic bridges formed by divalent calcium ions between collagen molecules have been proposed as candidates for sacrificial bonds. If this mechanism is active at the macroscopic level, we should observe changes in mechanical properties of bone when calcium ions are maintained or removed from the tissue.

The dependence between the strength and stiffness of cancellous and cortical bone tissue for tension and compression: extension of a unifying principle.

A strong positive correlation between the apparent ultimate strength and stiffness of bone tissue that can be expressed by a unified relationship has been observed for cortical bone in tension and low-density cancellous bone in compression. For practical purposes, the existence of a relationship between strength and stiffness is significant in that bone stiffness can be measured in vivo using non-invasive methods. It is generally accepted that bone strength is greater in compression than in tension whereas there is no substantial evidence that bone stiffness in compression is different from that in tension.

Apparent viscoelastic anisotropy as measured from nondestructive oscillatory tests can reflect the presence of a flaw in cortical bone.

There is evidence that damage, viscoelastic stiffness properties, and postyield mechanical properties are related in bone tissue. Our objective was to test whether presence of a flaw would have an influence on the apparent viscoelastic properties of bone. Examining the effect of flaw orientation on apparent viscoelastic properties and utilization of dynamic mechanical analysis (DMA) as a nondestructive means for detection of damage were our secondary objectives.

Effects of end boundary conditions and specimen geometry on the viscoelastic properties of cancellous bone measured by dynamic mechanical analysis.

The viscoelastic properties of cancellous bone can be measured nondestructively in compression testing using a dynamic mechanical analyzer. In this study, we examined the effects of end boundary conditions and specimen geometry on the viscoelastic properties of cancellous bone measured by dynamic mechanical analysis. During dynamic compression testing, the cancellous bone specimens may be mechanically fixed (e.