Advancing HR-pQCT-based homogenised FE models with smooth structured hexahedral meshes.

Nonlinear homogenised finite element (hFE) models can accurately predict stiffness and strength of ultra-distal sections of the radius and tibia using in vivo HR-pQCT images. Recent findings showed good stiffness prediction at these distal sections but a limited ability to reproduce experimental strain localisation. The coarseness of voxel-based meshes reduces the computational effort at the cost of heavily simplifying the underlying geometry of the cortex, the gradient of material properties, and the resulting strain distribution.

The Chondrogenic Potential of the Bovine Tendon Sheath - a Novel Source of Stem Cells for Cartilage Repair.

The human hand is traumatized more frequently than any other bodily part. Trauma and pathological processes (e.g.

Asynchronous calibration of a CT scanner for bone mineral density estimation: sources of error and correction.

The estimation of BMD with CT scans requires a calibration method, usually based on a phantom. In asynchronous calibration, the phantom is scanned separately from the patient. A standardized acquisition protocol must be used to avoid variations between patient and phantom.

Differences in femoral fracture localizations in men and women in Switzerland between 1998 and 2021-reversal of the secular trend?

Unlabelled: Number and age-standardized incidences of femoral fractures by sex and localization were determined annually between 1998 and 2021 in subjects aged 45 years or older living in Switzerland. The number and incidences of femoral neck, pertrochanteric, subtrochanteric, and femoral shaft fractures followed distinct unexpected trend patterns.

Introduction: Long-term incidence trends for femoral fractures by individual localizations are unknown.

A multi-stack registration technique to improve measurement accuracy and precision across longitudinal HR-pQCT scans.

Background: Recent applications of high-resolution peripheral quantitative computed tomography (HR-pQCT) have demonstrated that changes in local bone remodelling can be quantified in vivo using longitudinal three-dimensional image registration. However, certain emerging applications, such as fracture healing and joint analysis, require larger multi-stack scan regions that can result in stack shift image artifacts. These artifacts can be detrimental to the accurate alignment of the bone structure across multiple timepoints.

Previous fracture and subsequent fracture risk: a meta-analysis to update FRAX.

Unlabelled: A large international meta-analysis using primary data from 64 cohorts has quantified the increased risk of fracture associated with a previous history of fracture for future use in FRAX.

Introduction: The aim of this study was to quantify the fracture risk associated with a prior fracture on an international basis and to explore the relationship of this risk with age, sex, time since baseline and bone mineral density (BMD).

Methods: We studied 665,971 men and 1,438,535 women from 64 cohorts in 32 countries followed for a total of 19.

In major joint diseases the human synovium retains its potential to form repair cartilage.

The inner surface layer of human joints, the synovium, is a source of stem cells for the repair of articular cartilage defects. We investigated the potential of the normal human synovium to form novel cartilage and compared its chondrogenic capacity with that of two patient groups suffering from major joint diseases: young adults with femoro-acetabular impingement syndromes of the hip (FAI), and elderly individuals with osteoarthritic degeneration of the knee (OA). Synovial membrane explants of these three patient groups were induced in vitro to undergo chondrogenesis by growth factors: bone morphogenetic protein-2 (BMP-2) alone, transforming growth factor-β1 (TGF-β1) alone, or a combination of these two.

2D-3D reconstruction of the proximal femur from DXA scans: Evaluation of the 3D-Shaper software.

Osteoporosis is currently diagnosed based on areal bone mineral density (aBMD) computed from 2D DXA scans. However, aBMD is a limited surrogate for femoral strength since it does not account for 3D bone geometry and density distribution. QCT scans combined with finite element (FE) analysis can deliver improved femoral strength predictions.

The osteoporosis treatment gap in Switzerland between 1998 and 2018.

Unlabelled: The annual number of patients treated for osteoporosis between 1998 and 2018 in Switzerland increased until 2008 and steadily decreased thereafter. With a continuously growing population at fracture risk exceeding an intervention threshold, the treatment gap has increased and the incidence of hip fractures has stopped declining in the past decade.

Introduction: The existence of an osteoporosis treatment gap, defined as the percentage of patients at risk for osteoporotic fractures exceeding an intervention threshold but remaining untreated, is widely acknowledged.

Clinical observation of diminished bone quality and quantity through longitudinal HR-pQCT-derived remodeling and mechanoregulation.

High resolution peripheral quantitative computed tomography (HR-pQCT) provides methods for quantifying volumetric bone mineral density and microarchitecture necessary for early diagnosis of bone disease. When combined with a longitudinal imaging protocol and finite element analysis, HR-pQCT can be used to assess bone formation and resorption (i.e.

Human Bone Typing Using Quantitative Cone-Beam Computed Tomography.

Introduction: Bone typing is crucial to enable the choice of a suitable implant, the surgical technique, and the evaluation of the clinical outcome. Currently, bone typing is assessed subjectively by the surgeon.

Objective: The aim of this study is to establish an automatic quantification method to determine local bone types by the use of cone-beam computed tomography (CBCT) for an observer-independent approach.

Hospitalizations for major osteoporotic fractures in Switzerland: a long-term trend analysis between 1998 and 2018.

Unlabelled: Between 1998 and 2018, the number of hospitalizations for major osteoporotic fractures increased. After standardization for age, these numerical increases translated into a reduced incidence of hospitalizations for hip fractures and an increased incidence of hospitalizations for spine, proximal humerus, and distal radius fractures in both sexes.

Introduction: The longterm epidemiological trends of hospitalizations for major osteoporotic fractures (MOF) between 1998 and 2018 in Switzerland are unknown.

Update of the fracture risk prediction tool FRAX: a systematic review of potential cohorts and analysis plan.

Unlabelled: We describe the collection of cohorts together with the analysis plan for an update of the fracture risk prediction tool FRAX with respect to current and novel risk factors. The resource comprises 2,138,428 participants with a follow-up of approximately 20 million person-years and 116,117 documented incident major osteoporotic fractures.

Introduction: The availability of the fracture risk assessment tool FRAX® has substantially enhanced the targeting of treatment to those at high risk of fracture with FRAX now incorporated into more than 100 clinical osteoporosis guidelines worldwide.

Unified validation of a refined second-generation HR-pQCT based homogenized finite element method to predict strength of the distal segments in radius and tibia.

Introduction: HR-pQCT based micro finite element (μFE) analyses are considered as "gold standard" for virtual biomechanical analyses of peripheral bone sites such as the distal segment of radius and tibia. An attractive alternative for clinical use is a homogenized finite element method (hFE) based on constitutive models, because of its much shorter evaluation times and modest computational resource requirements. Such hFE models have been experimentally validated for the distal segment of the radius, but neither for the distal segments of the tibia nor for both measurement sites together.

Bone Microarchitecture and Strength in Long-Standing Type 1 Diabetes.

Type 1 diabetes (T1DM) is associated with an increased fracture risk, specifically at nonvertebral sites. The influence of glycemic control and microvascular disease on skeletal health in long-standing T1DM remains largely unknown. We aimed to assess areal (aBMD) and volumetric bone mineral density (vBMD), bone microarchitecture, bone turnover, and estimated bone strength in patients with long-standing T1DM, defined as disease duration ≥25 years.

The Synovium of Human Osteoarthritic Joints Retains Its Chondrogenic Potential Irrespective of Age.

The autologous synovium is a potential tissue source for local induction of chondrogenesis by tissue engineering approaches to repair articular cartilage defects that occur in osteoarthritis. It was the aim of the present study to ascertain whether the aging of human osteoarthritic patients compromises the chondrogenic potential of their knee-joint synovium and the structural and metabolic stability of the transformed tissue. The patients were allocated to one of the following two age categories: 54-65 years and 66-86 years ( = 7-11 donors per time point and experimental group; total number of donors: 64).

A Bibliometric Analysis of Fragility Fractures: Top 50.

: The population is aging and fragility fractures are a research topic of steadily growing importance. Therefore, a systematic bibliometric review was performed to identify the 50 most cited articles in the field of fragility fractures analyzing their qualities and characteristics. : From the Core Collection database in the Thomson Reuters Web of Knowledge, the most influential original articles with reference to fragility fractures were identified in February 2021 using a multistep approach.

Formation Dominates Resorption With Increasing Mineralized Density and Time Postfracture in Cortical but Not Trabecular Bone: A Longitudinal HRpQCT Imaging Study in the Distal Radius.

Clinical evaluation of fracture healing is often limited to an assessment of fracture bridging from radiographic images, without consideration for other aspects of bone quality. However, recent advances in HRpQCT offer methods to accurately monitor microstructural bone remodeling throughout the healing process. In this study, local bone formation and resorption were investigated during the first year post fracture in both the fractured (n = 22) and contralateral (n = 19) radii of 34 conservatively treated patients (24 female, 10 male) who presented with a unilateral radius fracture at the Innsbruck University Hospital, Austria.

The slow release of BMP-7 at a low dose accelerates dental implant healing in an osteopenic environment.

The aim of the present study was to investigate in vivo whether bone morphogenetic protein-7 (BMP-7) was able to promote and accelerate dental implant healing at a low dose in an osteopenic environment by using a delayed drug-release system. Skeletally mature Chinese goats, having physiologically osteopenic (osteoporotic-like) facial bones, served as an animal model. Dental implants were provided with a delayed-release drug-delivery system and BMP-7 was applied at three different dosages.

Induced Experimental Peri-Implantitis and Periodontitis: What Are the Differences in the Inflammatory Response?

This preliminary study investigates the differences between experimental periodontitis and peri-implantitis in a dog model, with a focus on the histopathology, inflammatory responses, and specific immunoregulatory activities driven by Th1/Th2-positive cells. Twelve dental implants were inserted into the edentulated posterior mandibles of 6 beagle dogs and were given 12 weeks for osseointegration. Experimental peri-implantitis and periodontitis (first mandible molar) were then induced using cotton-floss ligatures.

2020 recommendations for osteoporosis treatment according to fracture risk from the Swiss Association against Osteoporosis (SVGO).

Current guidelines from the Swiss Association against Osteoporosis (SVGO) dating from 2015 recommend therapy for men and women at increased fracture risk, specifically those with a vertebral or hip fracture; those with bone mineral density T-score <−2.5 at spine or hip; and those with a high 10-year probability of a major osteoporotic fracture as calculated by using FRAX. However no specific treatment recommendations have been made so far in our country to guide therapy according to the baseline level of risk.

In vivo repeatability of homogenized finite element analysis based on multiple HR-pQCT sections for assessment of distal radius and tibia strength.

Introduction: Micro finite element analysis (μFE) is a widely applied tool in biomedical research for assessing in vivo mechanical properties of bone at measurement sites, including the ultra-distal radius and tibia. A finite element approach (hFE) based on homogenized constitutive models for trabecular bone offers an attractive alternative for clinical use, as it is computationally less expensive than traditional μFE. The respective patient-specific models for in vivo bone strength estimation are usually based on standard clinical high-resolution peripheral quantitative CT (HR-pQCT) measurements.

Anticytokine Activity Enhances Osteogenesis of Bioactive Implants.

In dental clinical practice, systemic steroids are often applied at the end of implant surgeries to reduce postsurgical inflammation (tissue swelling, etc.) and to reduce patient discomfort. However, the use of systemic steroids is associated with generalized catabolic effects and with a temporarily reduced immunological competence.