Posterior Ligamentum Complex Preservation Alleviate ASD-Related Biomechanical Deterioration in Lumbar Interbody Fusion Models: A Finite Element Analysis.

Background: There are differences in the extent of excision of articular processes, spinal processes and posterior ligamentum complexes (PLC) for posterior approach lumbar interbody fusion. Given that the biomechanical significance of these structures has been verified and that deterioration of the biomechanical environment is the main trigger for complications in both fused and adjacent motion segments, changes in decompression ranges may affect the potential risk of adjacent segmental disease (ASD) biomechanically; however, this topic has yet to be identified.

Methods: Posterior lumbar interbody fusion (PLIF) with different decompression strategies was simulated in a well-validated lumbosacral model.

Anxiety and depression as potential risk factors for limited pain management in patients with elderly knee osteoarthritis: a cross-lagged study.

Background: Pain management for knee osteoarthritis (KOA) patients is challenging. Pain arises from both physiological and psychological interactions, with anxiety and depression potentially contributing as risk factors that hinder effective pain management in KOA patients.

Methods: Before treatment(T1), A total of 206 elderly inpatients with KOA were enrolled based on initial screening criteria.

The ratio between the screw distance and femoral neck width on lateral radiography is a reliable predictor of femoral head necrosis: a clinical review and corresponding numerical simulations.

Background: Fixation instability serves as an initial trigger for femoral head necrosis in patients with femoral neck fractures undergoing internal fixation. The configuration of screw trajectories is critical in determining the stability of the fixation. Our previously published study indicates that abduction of screw trajectories may enhance postoperative angular stability.

The Bony Density of the Pedicle Plays a More Significant Role in the Screw Anchorage Ability Than Other Regions of the Screw Trajectory.

Objective: Osteoporosis is a crucial risk factor for screw loosening. Our studies indicate that the bone mineral density (BMD) in the screw trajectory is a better predictor of screw loosening than the BMD of the lumbar spine or the screw insertion position. Research has shown that anchorage on the screw tip is the most significant factor for screw anchorage ability, while others argue that decreased bony quality in the pedicle poses a significant risk for screw loosening.

Honokiol inhibits human osteosarcoma MG63 cell migration by upregulating FTO and Smad6 to promote autophagy.

Background: Osteosarcoma (OS) is a common primary malignant tumor of bone, most commonly seen in children and adolescents, which has a low survival rate and is a serious threat to patients' lives. Honokiol (HKL) is the main active components of Magnolia officinalis, which have significant anti-tumor properties. The aim of this study was to observe the autophagic and migratory effects of HKL on MG63 cells and to investigate whether the mechanism of action was related to FTO and Smad6.

Contact between leaked cement and adjacent vertebral endplate induces a greater risk of adjacent vertebral fracture with vertebral bone cement augmentation biomechanically.

Background Context: Adjacent vertebral fracture (AVF) is a frequently observed complication after percutaneous vertebroplasty in patients with osteoporotic vertebral compressive fracture (OVCF). Studies have demonstrated that intervertebral cement leakage (ICL) can increase the incidence of AVF, but others have reached opposite conclusions. The stress concentration initially increases the risk of AVF, and dispersive concentrated stress is the main biomechanical function of the intervertebral disc (IVD).

Narrow-bandwidth silicon photonic CROW filter for carrier-extracted self-coherent (CESC) detection.

In this Letter, we report a second-order silicon photonic (SiP) coupled resonator optical waveguide (CROW) filter with an ultra-narrow 10-dB bandwidth of 1.75 GHz and a high extinction ratio (ER) of ∼50 dB. By utilizing this CROW filter, we demonstrated an innovative self-coherent detection, called carrier-extracted self-coherent (CESC) detection.

Impact of screw tip design on screw anchorage: mechanical testing and numerical simulation.

Background: Screw loosening is a commonly reported issue following spinal screw fixation and can lead to various complications. The initial cause of screw loosening is biomechanical deterioration. Previous studies have demonstrated that modifications in screw design can impact the local biomechanical environment, specifically the stress distribution on bone-screw interfaces.

Impact of blade direction on postoperative femoral head varus in PFNA fixed patients: a clinical review and biomechanical research.

Intertrochanteric femur fracture is a common type of osteoporotic fracture in elderly patients, and postoperative femoral head varus following proximal femoral nail anti-rotation (PFNA) fixation is a crucial factor contributing to the deterioration of clinical outcomes. The cross-angle between the implant and bone might influence fixation stability. Although there is a wide range of adjustment in the direction of anti-rotation blades within the femoral neck, the impact of this direct variation on the risk of femoral head varus and its biomechanical mechanisms remain unexplored.

Changes in nail position and antirotation blade angles on the risk of femoral head varus in PFNA fixed patients: a clinical review and comprehensive biomechanical research.

Background: Femoral head varus triggers poor clinical prognosis in intertrochanteric fracture patients with proximal femoral nail antirotation (PFNA) fixation. Studies present that changes in nail position and screw insertion angles will affect fixation stability, but the biomechanical significance of these factors on the risk of femoral head varus has yet to be identified in PFNA fixed patients.

Methods: Clinical data in PFNA fixed intertrochanteric fracture patients have been reviewed, the relative position of intermedullary nail has been judged in the instant postoperative lateral radiography.

Space between bone cement and bony endplate can trigger higher incidence of augmented vertebral collapse: An in-silico study.

Background: The pathogenesis of postoperative complications in patients with osteoporotic vertebral compressive fractures (OVCFs) undergoing percutaneous vertebroplasty (PVP) is multifaceted, with local biomechanical deterioration playing a pivotal role. Specifically, the disparity in stiffness between the bone cement and osteoporotic cancellous bone can precipitate interfacial stress concentrations, potentially leading to cement-augmented vertebral body collapse and clinical symptom recurrence. This study focuses on the biomechanical implications of the space between the bone cement and bony endplate (BEP), hypothesizing that this interface may be a critical locus for stress concentration and subsequent vertebral failure.

The Sanbi Decoction alleviates intervertebral disc degeneration in rats through intestinal flora and serum metabolic homeostasis modulation.

Background: Intervertebral disc degeneration (IVDD) is an essential cause of low back pain (LBP), the incidence of which has risen in recent years and is progressively younger, but treatment options are limited, placing a serious economic burden on society. Sanbi decoction (SBD) is an important classical formula for the treatment of IVDD, which can significantly improve patients' symptoms and is a promising alternative therapy.

Purpose: The aim of this study is to investigate the safety and efficacy of SBD in the treatment of IVDD and to explore the underlying mechanisms by using an integrated analytical approach of microbiomics and serum metabolomics, as well as by using molecular biology.

Increasing the angle between caudal screw and the transverse plane may aggravate the risk of femoral head necrosis by deteriorating the fixation stability in patients with femoral neck fracture.

Necrosis of the femoral head is the main complication in femoral neck fracture patients with triangle cannulated screw fixation. Instant postoperative fixation instability is a main reason for the higher risk of femoral head necrosis. Biomechanical studies have shown that cross screw fixation can effectively optimize fixation stability in patients with proximal humerus fractures and pedicle screw fixation, but whether this method can also effectively optimize the fixation stability of femoral neck fractures and reduce the corresponding risk of femoral head necrosis has yet to be identified.

Modified SiP single-polarization CADD receiver.

In cost-sensitive application scenarios, increasing the data rate per channel under a limited receiver bandwidth is critical, and thus, the transceivers with low costs and high electrical spectral efficiencies (ESEs) are highly desirable. In this Letter, we demonstrate a modified silicon photonic (SiP) carrier-assisted differential detection (CADD) receiver with a record ESE for single polarization. The ESE of the conventional CADD is mainly limited by the transfer function that originated from the optical delay and hybrid.

Intraoperative capsule protection can reduce the potential risk of adjacent segment degeneration acceleration biomechanically: an in silico study.

Background: The capsule of the zygapophyseal joint plays an important role in motion segmental stability maintenance. Iatrogenic capsule injury is a common phenomenon in posterior approach lumbar interbody fusion operations, but whether this procedure will cause a higher risk of adjacent segment degeneration acceleration biomechanically has yet to be identified.

Methods: Posterior lumbar interbody fusion (PLIF) with different grades of iatrogenic capsule injury was simulated in our calibrated and validated numerical model.

IVD fibrosis and disc collapse comprehensively aggravate vertebral body disuse osteoporosis and zygapophyseal joint osteoarthritis by posteriorly shifting the load transmission pattern.

Background: Disuse is a typical phenotype of osteoporosis, but the underlying mechanism has yet to be identified in elderly patients. Disc collapse and intervertebral disc (IVD) fibrosis are two main pathological changes in IVD degeneration (IDD) progression, given that these changes affect load transmission patterns, which may lead to disuse osteoporosis of vertebral bodies and zygapophyseal joint (ZJ) osteoarthritis (ZJOA) biomechanically.

Methods: Clinical data from 59 patients were collected retrospectively.

Incomplete insertion of pedicle screws triggers a higher biomechanical risk of screw loosening: mechanical tests and corresponding numerical simulations.

Screw loosening is a widely reported issue after spinal screw fixation and triggers several complications. Biomechanical deterioration initially causes screw loosening. Studies have shown that incomplete insertion of pedicle screws increases the risk of screw breakage by deteriorating the local mechanical environment.

Stepwise reduction of bony density in patients induces a higher risk of annular tears by deteriorating the local biomechanical environment.

Background Context: The relationship between osteoporosis and intervertebral disc degeneration (IDD) remains unclear. Considering that annular tear is the primary phenotype of IDD in the lumbar spine, the deteriorating local biomechanical environment may be the main trigger for annular tears.

Purpose: To investigate whether poor bone mineral density (BMD) in the vertebral bodies may increase the risk of annular tears via the degradation of the local biomechanical environment.

The cranial vertebral body suffers a higher risk of adjacent vertebral fracture due to the poor biomechanical environment in patients with percutaneous vertebralplasty.

Background Context: Adjacent vertebral fracture (AVF), a frequent complication of PVP, is influenced by factors such as osteoporosis progression, increased intervertebral cement leakage (ICL), and biomechanical deterioration. Notably, the risk of AVF is notably elevated in the cranial vertebral body compared with the caudal counterpart. Despite this knowledge, the underlying pathological mechanism remains elusive.

Nucleus high intensity in the T2-weighted MRI is a potential predictor of annulus tear in cervical injured patients: a case comparative study.

Background: Segmental fusion operations assume paramount significance for individuals afflicted by full layers of annulus tears as they avert the perils of rapid disc degeneration and segmental instability. Structures with high signal intensity in the T2-weighted MRI can predict potential damage to the injured segment. Since local structures are shortly related biomechanically, this may be an effective predictor for annulus tears.

Fixation-induced surgical segment's high stiffness and the damage of posterior structures together trigger a higher risk of adjacent segment disease in patients with lumbar interbody fusion operations.

Background: Adjacent segment disease (ASD) is a commonly reported complication after lumbar interbody fusion (LIF); changes in the mechanical environment play an essential role in the generation of ASD. Traditionally, fixation-induced high stiffness in the surgical segment was the main reason for ASD. However, with more attention paid to the biomechanical significance of posterior bony and soft structures, surgeons hypothesize that this factor may also play an important role in ASD.

SIRT2 regulates extracellular vesicle-mediated liver-bone communication.

The interplay between liver and bone metabolism remains largely uncharacterized. Here, we uncover a mechanism of liver-bone crosstalk regulated by hepatocyte SIRT2. We demonstrate that hepatocyte SIRT2 expression is increased in aged mice and elderly humans.