The most responsive foot position for non-invasive detection of isolated unstable syndesmotic injuries - a 3D analysis.

Background: The aim of this study was to identify the most responsive foot position for detection of isolated unstable syndesmotic injury.

Methods: Fourteen paired human cadaveric lower legs were positioned in a pressure-controlled radiolucent frame and loaded under 700 N. Computed tomography scans were performed in neutral position, 15° internal / external rotation, and 20° dorsal / plantar flexion of the foot before and after cutting all syndesmotic ligaments.

Accuracy of pelvic bone segmentation for 3d printing: a study of segmentation accuracy based on anatomic landmarks to evaluate the influence of the observer.

Background: 3D printing has a wide range of applications and has brought significant change to many medical fields. However, ensuring quality assurance (QA) is essential for patient safety and requires a QA program that encompasses the entire production process. This process begins with imaging and continues on with segmentation, which is the conversion of Digital Imaging and Communications in Medicine (DICOM) data into virtual 3D-models.

Rheological Analysis and Evaluation of Measurement Techniques for Curing Poly(Methyl Methacrylate) Bone Cement in Vertebroplasty.

Vertebroplasty is a minimally invasive surgical procedure used to treat vertebral fractures, which conventionally involves injecting poly(methyl methacrylate) (PMMA) bone cement into the fractured vertebra. A common risk associated with vertebroplasty is cement leaking out of the vertebra during the injection, which may occur due to a lack of understanding of the complex flow behavior. Therefore, experiments to quantify the cement's flow properties are necessary for understanding and proper handling of the bone cement.

Combining adhesive and nonadhesive injectable hydrogels for intervertebral disc repair in an ovine discectomy model.

Background: Intervertebral disc (IVD) disorders (e.g., herniation) directly contribute to back pain, which is a leading cause of global disability.

First Tarsometatarsal Joint Fusion in Foot-A Biomechanical Human Anatomical Specimen Analysis with Use of Low-Profile Nitinol Staples Acting as Continuous Compression Implants.

: The aim of this study was to investigate under dynamic loading the potential biomechanical benefit of simulated first tarsometatarsal (TMT-1) fusion with low-profile superelastic nitinol staples used as continuous compression implants (CCIs) in two different configurations in comparison to crossed screws and locked plating in a human anatomical model. : Thirty-two paired human anatomical lower legs were randomized to four groups for TMT-1 treatment via: (1) crossed-screws fixation with two 4.0 mm fully threaded lag screws; (2) plate-and-screw fixation with a 4.

A continuum mechanical porous media model for vertebroplasty: Numerical simulations and experimental validation.

The outcome of vertebroplasty is hard to predict due to its dependence on complex factors like bone cement and marrow rheologies. Cement leakage could occur if the procedure is done incorrectly, potentially causing adverse complications. A reliable simulation could predict the patient-specific outcome preoperatively and avoid the risk of cement leakage.

Statistical Morphology and Fragment Mapping of Complex Proximal Humeral Fractures.

: Proximal humerus fractures (PHFs) are common in the elderly, but the treatment results are often poor. A clear understanding of fracture morphology and distribution of cortical bone loss is important for improved surgical decision making, operative considerations, and new implant designs. The aim of this study was to develop a 3D segmentation fracture mapping technique to create a statistical description of the spatial pattern and cortical bone loss of complex PHFs.

Anatomical analysis of different helical plate designs for proximal humeral shaft fracture fixation.

Objectives: Helical plates are preferably used for proximal humeral shaft fracture fixation and potentially avoid radial nerve irritation.

Aims: Safety of applying four different long plate designs (straight, 45°-, 90°-helical and ALPS) with MIPO technique as well as assessment and comparison of their distances to adjacent anatomical structures.

Methods: MIPO was performed in 16 human cadaveric humeri using either a straight (group 1), a 45°-helical (group 2), a 90°-helical (group 3) plate, or an ALPS (group 4).

Venous injection of a triphasic calcium-based implant in a sheep model of pulmonary embolism demonstrates minimal acute systemic effects.

Purpose: Implant leakage is the most common complication of vertebral augmentation. Alternative injectable materials must demonstrate intravascular safety comparable to or better than polymethyl methacrylate (PMMA). This study assessed the systemic effects of a triphasic calcium-based implant or PMMA injected directly into the femoral vein in a large animal model designed to mimic severe intravascular implant leakage.

Continuous Implant Load Monitoring to Assess Bone Healing Status-Evidence from Animal Testing.

: Fracture healing is currently assessed through qualitative evaluation of radiographic images, which is highly subjective in nature. Radiographs can only provide snapshots in time, which are limited due to logistics and radiation exposure. We recently proposed assessing the bone healing status through continuous monitoring of the implant load, utilizing an implanted sensor system, the Fracture Monitor.

Interleukin-1 receptor antagonist enhances the therapeutic efficacy of a low dose of rhBMP-2 in a weight-bearing rat femoral defect model.

In the clinical treatment of fractures, rhBMP-2 administration is associated with a well-established profile of side-effects, including osteolysis and ectopic bone formation, which are driven by pro-inflammatory processes triggered by the use of high doses. Immunomodulatory strategies could minimize the incidence of side-effects by enabling the use of lower, and safer, rhBMP-2 doses. This study investigated whether interleukin-1 receptor antagonist (IL-1Ra) can enhance the therapeutic efficacy of a low dose of rhBMP-2 in a weight-bearing femoral fracture healing model.

Comminuted intraarticular calcaneal fractures: Multiplanar VA locked plating and interlocked nailing incorporate longitudinal strut and provide superior stability - a biomechanical cadaveric study.

Treatment of comminuted intraarticular calcaneal fractures remains controversial and challenging. The aim of this study was to investigate the biomechanical performance of three different methods for fixation of such fractures. Comminuted calcaneal fractures, including Sanders III AB fracture of the posterior facet and Kinner II B fracture of the calcaneocuboid joint (CCJ) articular calcaneal surface, were created in 18 human cadaveric lower legs by osteotomizing.

Comparison and optimization of sheep in vivo intervertebral disc injury model.

Background: The current standard of care for intervertebral disc (IVD) herniation, surgical discectomy, does not repair annulus fibrosus (AF) defects, which is partly due to the lack of effective methods to do so and is why new repair strategies are widely investigated and tested preclinically. There is a need to develop a standardized IVD injury model in large animals to enable comparison and interpretation across preclinical study results. The purpose of this study was to compare IVD injury models in sheep to determine which annulus fibrosus (AF) defect type combined with partial nucleus pulposus (NP) removal would better mimic degenerative human spinal pathologies.

Effect of weightbearing and foot positioning on 3D distal tibiofibular joint parameters.

The aim of this study was to investigate the effect of different loading scenarios and foot positions on the configuration of the distal tibiofibular joint (DTFJ). Fourteen paired human cadaveric lower legs were mounted in a loading frame. Computed tomography scans were obtained in unloaded state (75 N) and single-leg loaded stand (700 N) of each specimen in five foot positions: neutral, 15° external rotation, 15° internal rotation, 20° dorsiflexion, and 20° plantarflexion.

Is there a correlation between pelvic incidence and orientation of the acetabulum? An analysis based on a three-dimensional statistical model of the pelvic ring.

The pelvic ring is a complex anatomical structure building up the connection between the trunk and the legs. Whilst there is a broad discussion in the literature about the dynamic interaction between spine, pelvis and the hip joints, there is still little information about the relation and interaction of the constant pelvic parameters. Based on a three-dimensional (3D) statistical model consisting of 150 uninjured and bony healthy pelves (100 Europeans, 50 Japanese; 81 males, 69 females; average age 74.

Anatomical analysis of different helical plate designs for distal femoral fracture fixation.

Purpose: Helical plates potentially avoid the medial neurovascular structures of the thigh. Two implant designs for additional medial 90° helical plate in double plate constructs for geriatric patients and 180° helical plate for single plating in young patients are potential alternatives to widely used standard straight plates.

Aims: (1) assess the distances to adjacent anatomical structures being at risk when applying medial 90° and 180° helical plates with MIPO technique to the femur, (2) compare these distances with medial straight plates, and (3) correlate measurements performed during surgical dissection with CT angiography.

Influence of screw head diameter on ex vivo fixation of equine lateral condylar fractures with 5.5 mm cortical screws.

Objective: To determine the influence of screw head diameter on equine condylar fracture fixation with 5.5 mm cortical screws.

Study Design: Ex vivo, biomechanical study, blinded, matched-pair design.

Percutaneous fixation of intraarticular joint-depression calcaneal fractures with different screw configurations - a biomechanical human cadaveric analysis.

Purpose: The aim of this study was to assess the biomechanical performance of different screw configurations for fixation of Sanders type II B joint-depression calcaneal fractures.

Methods: Fifteen human cadaveric lower limbs were amputated and Sanders II B fractures were simulated. The specimens were randomized to three groups for fixation with different screw configurations.

Butyrate Inhibits Osteoclast Activity and Regulates Systemic Inflammation and Bone Healing in a Murine Osteotomy Model Compared to Antibiotic-Treated Mice.

Short-chain fatty acids (SCFAs) produced by the gut microbiota have previously been demonstrated to play a role in numerous chronic inflammatory diseases and to be key mediators in the gut-bone signaling axis. However, the role of SCFAs in bone fracture healing and its impact on systemic inflammation during the regeneration process has not been extensively investigated yet. The aim of this study was to first determine the effects of the SCFA butyrate on key cells involved in fracture healing , namely, osteoclasts and mesenchymal stromal cells (MSCs), and second, to assess if butyrate supplementation or antibiotic therapy impacts bone healing, systemic immune status, and inflammation levels in a murine osteotomy model.

Biomechanical analysis of recently released cephalomedullary nails for trochanteric femoral fracture fixation in a human cadaveric model.

Background: Recently, two novel concepts for intramedullary nailing of trochanteric fractures using a helical blade or interlocking dual screws have demonstrated advantages as compared to standard single-screw systems. However, these two concepts have not been subjected to a direct biomechanical comparison so far. The aims of this study were to investigate in a human cadaveric model with low bone quality (1) the biomechanical competence of nailing with the use of a helical blade versus interlocking screws, and (2) the effect of cement augmentation on the fixation strength of the helical blade.

An Enzybiotic Regimen for the Treatment of Methicillin-Resistant Orthopaedic Device-Related Infection.

Orthopaedic device-related infection (ODRI) presents a significant challenge to the field of orthopaedic and trauma surgery. Despite extensive treatment involving surgical debridement and prolonged antibiotic therapy, outcomes remain poor. This is largely due to the unique abilities of , the most common causative agent of ODRI, to establish and protect itself within the host by forming biofilms on implanted devices and staphylococcal abscess communities (SACs).

Modeling of the Human Bone Environment: Mechanical Stimuli Guide Mesenchymal Stem Cell-Extracellular Matrix Interactions.

In bone tissue engineering, the design of in vitro models able to recreate both the chemical composition, the structural architecture, and the overall mechanical environment of the native tissue is still often neglected. In this study, we apply a bioreactor system where human bone-marrow hMSCs are seeded in human femoral head-derived decellularized bone scaffolds and subjected to dynamic culture, i.e.

3D geometry of femoral reaming for bone graft harvesting.

The reamer-irrigator-aspirator (RIA) technique allows to collect large bone graft amounts without the drawbacks of iliac crest harvesting. Nevertheless, clinical cases with occurrence of femur fractures have been reported. Therefore, this study aimed to systematically investigate the three-dimensional geometry of the reamed bone as a function of the reaming diameter and its influence on the associated potential fracture pattern.

Material properties of human vertebral trabecular bone under compression can be predicted based on quantitative computed tomography.

Background: The prediction of the stability of bones is becoming increasingly important. Especially osteoporotic vertebral body fractures are a growing problem and an increasing burden on the health system. Therefore, the aim of this study was to provide the best possible description of the relationship between the material properties of human vertebral trabecular bone measured under the most physiological conditions possible and the bone mineral density (BMD) determined by clinical quantitative computed tomography (QCT).

Anatomical evaluation of the transpubic screw corridor based on a 3D statistical model of the pelvic ring.

Retrograde transpubic screw fixation is a common procedure for the treatment of anterior pelvic ring fractures. With its sparing surgical approach and significant pain relief after screw fixations allowing early mobilisation, it has gained importance especially in the treatment of insufficiency fractures in elderly patients. However, positioning of transpubic screw osteosynthesis is not always possible due to narrowness and curvature of the screw corridor.