Pregnancy-Related Spinal Biomechanics: A Review of Low Back Pain and Degenerative Spine Disease.

Pregnancy induces substantial anatomical, hormonal, and biomechanical changes in the spine and pelvis to accommodate fetal growth and maintain postural adaptation. This narrative review synthesizes peer-reviewed evidence regarding pregnancy-related spinal biomechanics, with a particular focus on low back pain, spinopelvic alignment, sacroiliac joint dysfunction, and potential contributions to degenerative spinal conditions. A systematic search of PubMed, Embase, and Google Scholar was conducted using Boolean operators and relevant terms, yielding 1050 unique records, with 53 peer-reviewed articles ultimately cited.

Therapeutic Implants: Mechanobiologic Enhancement of Osteogenic, Angiogenic, and Myogenic Responses in Human Mesenchymal Stem Cells on 3D-Printed Titanium Truss.

This study investigates the effect of mechanotransduction on human mesenchymal stem cells (hMSCs) attached to structural elements of an implant, specifically a titanium truss element. It is found that surface features generated by 3D printing technology promote osteogenic activity, comparable to conventional treatments such as acid etching. Cell morphology and differentiation are evaluated using test coupons with either smooth or rough surface features.

An Appraisal of the Quality of Development and Reporting of Predictive Models in Spine Surgery.

Study DesignLiterature review.ObjectiveThe Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis (TRIPOD) statement was developed to improve the generalizability of predictive models. This study systematically evaluated the quality of predictive models related to spine procedures and assessed their compliance with the TRIPOD guidelines.

ROCK-dependent mechanotransduction of macroscale forces drives fibrosis in degenerative spinal disease.

Chronic repetitive forces on the spinal column promote the development of degenerative spinal disease. Yet the mechanisms linking such macroscale mechanical forces to tissue hypertrophy remain unknown. Here we show that fibrotic regions in human ligamentum flavum naturally exposed to high stress display elevated Rho-associated kinase (ROCK) signalling and an increased density of myofibroblasts expressing smooth muscle actin α.

Restoration of physiologic loading after engineered disc implantation mitigates immobilization-induced facet joint and paraspinal muscle degeneration.

Intervertebral disc degeneration is commonly associated with back and neck pain, and standard surgical treatments do not restore spine function. Replacement of the degenerative disc with a living, tissue-engineered construct has the potential to restore normal structure and function to the spine. Toward this goal, our group developed endplate-modified disc-like angle-ply structures (eDAPS) that recapitulate the native structure and function of the disc.

Pilot study on the in-vitro effect of radiation therapy on bending stiffness of intramedullary photodynamic implants.

Photodynamic implants are an increasingly popular minimally invasive option for the surgical treatment of metastatic bone disease. Following surgery, adjuvant radiation therapy (RT) is frequently administered to achieve better disease control and improve patient quality of life, but the role of RT in implant failures associated with photodynamic implants remains unclear. The aim of this study is to determine if the therapeutic RT range of 10-50 Gy affects the biomechanical properties of photodynamic implants.

Advancing in Silico Clinical Trials for Regulatory Adoption and Innovation.

The evolution of information and communication technologies has affected all fields of science, including health sciences. However, the rate of technological innovation adoption by the healthcare sector has been historically slow, compared to other industrial sectors. Innovation in computer modeling and simulation approaches has changed the landscape in biomedical applications and biomedicine, paving the way for their potential contribution in reducing, refining, and partially replacing animal and human clinical trials.

Nondestructive acoustic modal analysis for assessing bone screw stability: An ex vivo animal study.

Conventional insertion torque and pull-out tests are destructive and unsuitable for clinical bone screw fixation. This study evaluates screw stability using acoustic modal analysis (AMA) and Periotest compared to traditional methods in an ex vivo animal model. Titanium self-tapping screws (STS) and nonself-tapping screws (N-STS) were implanted in the proximal tibia of 12 rabbits.

An Appraisal of the Quality of Development and Reporting of Predictive Models in Neurosurgery: A Systematic Review.

Background And Objectives: Significant evidence has indicated that the reporting quality of novel predictive models is poor because of confounding by small data sets, inappropriate statistical analyses, and a lack of validation and reproducibility. The Transparent Reporting of a multivariable prediction model for Individual Prognosis or Diagnosis (TRIPOD) statement was developed to increase the generalizability of predictive models. This study evaluated the quality of predictive models reported in neurosurgical literature through their compliance with the TRIPOD guidelines.

Pedicled omental flaps for complex wound reconstruction following surgery for primary spine tumors of the mobile spine and sacrum.

Objective: Surgery for primary tumors of the mobile spine and sacrum often requires complex reconstruction techniques to cover soft-tissue defects and to treat wound and CSF-related complications. The anatomical, vascular, and immunoregulatory characteristics of the omentum make it an excellent local substrate for the management of radiation soft-tissue injury, infection, and extensive wound defects. This study describes the authors' experience in complex wound reconstruction using pedicled omental flaps to cover defects in surgery for mobile spine and sacral primary tumors.

The Impact of Preoperative Spinal Injection Timing on Postoperative Complications of Lumbar Decompression Surgery.

Background And Objectives: Epidural steroid injections (ESIs) are commonly used for lower back pain management. The effect of these injections on lumbar decompression surgery outcomes is hitherto underexplored. The study objective was to determine the impact of ESIs on postoperative rates of medical and surgical complications and to define the appropriate interval before lumbar decompression surgery.

A guide to finite element analysis models of the spine for clinicians.

Finite element analysis (FEA) is a computer-based mathematical method commonly used in spine and orthopedic biomechanical research. Advances in computational power and engineering modeling and analysis software have enabled many recent technical applications of FEA. Through the use of FEA, a wide range of scenarios can be simulated, such as physiological processes, mechanisms of disease and injury, and the efficacy of surgical procedures.

Implication of nutritional status for adverse outcomes after surgery for metastatic spine tumors.

Objective: Surgery for metastatic spinal tumors can have a substantial impact on patients' quality of life by alleviating pain, improving function, and correcting spinal instability when indicated. The decision to operate is difficult because many patients with cancer are frail. Studies have highlighted the importance of preoperative nutritional status assessments; however, little is known about which aspects of nutrition accurately inform clinical outcomes.

Resisting subsidence with a truss Implant: Application of the "Snowshoe" principle for interbody fusion devices.

The primary objective was to compare the subsidence resistance properties of a novel 3D-printed spinal interbody titanium implant versus a predicate polymeric annular cage. We evaluated a 3D-printed spinal interbody fusion device that employs truss-based bio-architectural features to apply the snowshoe principle of line length contact to provide efficient load distribution across the implant/endplate interface as means of resisting implant subsidence. Devices were tested mechanically using synthetic bone blocks of differing densities (osteoporotic to normal) to determine the corresponding resistance to subsidence under compressive load.

Evaluation of the efficacy of modal analysis in predicting the pullout strength of fixation bone screws.

Background: Pilot hole preparation has been shown to have an impact on the short and long-term stability of the screw fixation constructs.

Purpose: Investigation and comparison of two nondestructive modal analysis methods with conventional insertion torque (IT) and pullout tests in optimum pilot hole diameter detection.

Methods: Twenty conical core titanium screws were embedded in high-density polyethylene blocks with different pilot hole diameters.

Assessment of Spinal Metastases Surgery Risk Stratification Tools in Breast Cancer by Molecular Subtype.

Background: Breast cancer molecular features and modern therapies are not included in spine metastasis prediction algorithms.

Objective: To examine molecular differences and the impact of postoperative systemic therapy to improve prognosis prediction for spinal metastases surgery and aid surgical decision making.

Methods: This is a retrospective multi-institutional study of patients who underwent spine surgery for symptomatic breast cancer spine metastases from 2008 to 2021 at the Massachusetts General Hospital and Brigham and Women's Hospital.

Effects of rod diameter on kinematics of posterior cervical spine instrumented constructs: an ex vivo study.

Objective: Posterior cervical spine fixation is a robust strategy for stabilizing the spine for a wide range of spinal disorders. With the evolution of spinal implant technology, posterior fixation with lateral mass screws in the subaxial spine is now common. Despite interest in variable rod diameters to meet a wide range of clinical needs such as trauma, revision, and deformity surgery, indications for use of posterior cervical spine fixation are not clear.

Evaluating frailty, mortality, and complications associated with metastatic spine tumor surgery using machine learning-derived body composition analysis.

Objective: Cancer patients with spinal metastases may undergo surgery without clear assessments of prognosis, thereby impacting the optimal palliative strategy. Because the morbidity of surgery may adversely impact recovery and initiation of adjuvant therapies, evaluation of risk factors associated with mortality risk and complications is critical. Evaluation of body composition of cancer patients as a surrogate for frailty is an emerging area of study for improving preoperative risk stratification.

Machine Learning Applications of Surgical Imaging for the Diagnosis and Treatment of Spine Disorders: Current State of the Art.

Recent developments in machine learning (ML) methods demonstrate unparalleled potential for application in the spine. The ability for ML to provide diagnostic faculty, produce novel insights from existing capabilities, and augment or accelerate elements of surgical planning and decision making at levels equivalent or superior to humans will tremendously benefit spine surgeons and patients alike. In this review, we aim to provide a clinically relevant outline of ML-based technology in the contexts of spinal deformity, degeneration, and trauma, as well as an overview of commercial-level and precommercial-level surgical assist systems and decisional support tools.

Biomechanical analysis of stand-alone lumbar interbody cages versus 360° constructs: an in vitro and finite element investigation.

Objective: Low fusion rates and cage subsidence are limitations of lumbar fixation with stand-alone interbody cages. Various approaches to interbody cage placement exist, yet the need for supplemental posterior fixation is not clear from clinical studies. Therefore, as prospective clinical studies are lacking, a comparison of segmental kinematics, cage properties, and load sharing on vertebral endplates is needed.

Bone Mineralization and Spinal Fusion Evaluation of a Truss-based Interbody Fusion Device: Ovine Finite Element Analysis with Confirmatory In Vivo Outcomes.

Study Design: Finite element analysis (FEA) and in vivo ovine spinal interbody fusion study.

Objective: To determine comparative load-induced strain amplitudes, bone mineralization and fusion outcomes associated with different diameter struts in a truss-based interbody fusion device.

Summary Of Background Data: Additive manufacturing technology has been employed to develop implants that actively participate in the fusion process.