The Multifactorial Relationship Between Bone Tissue Water and Stiffness at the Proximal Femur.

Bone mechanical function is determined by multiple factors, some of which are still being elucidated. Here, we present a multivariate analysis of the role of bone tissue composition in the proximal femur stiffness of cadaver bones (n = 12, age 44-93). Stiffness was assessed by testing under loading conditions simulating a sideways fall onto the hip.

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.

Learning on a Limb: An outreach module to engage high school students in orthopaedics.

Orthopaedic researchers need new strategies for engaging underrepresented minority (URM) students. Our field has demonstrated noticeable gaps in racial, ethnic, and gender diversity, which inhibit our ability to innovate and combat the severe socioeconomic burden of musculoskeletal disorders. Towards this goal, we designed, implemented, and evaluated Learning on a Limb (LoaL), an orthopaedic research outreach module to teach URM high school students about orthopaedic research.

Elastic properties of 3D printed clavicles are closer to cadaveric bones of elderly donors than commercial synthetic bones.

Synthetic bone models have increasing utility in orthopaedic research due to their low cost and low variability and have been shown to be biomechanically equivalent to human bones in a variety of ways. The rise in additive manufacturing (AM) for orthopaedic applications presents an opportunity to construct synthetic whole-bone models for biomechanical testing applications, but there is a lack of research comparing these AM models to cadaveric or commercially available bone surrogates. This study compares the mechanical properties of 3D printed clavicle models to commercially available (4th generation Sawbones) and human cadaveric clavicles via nondestructive cyclic 4-point bending, axial compression, and torsion, and a final axial compression test to failure.

Learning on a Limb: An outreach module to engage high school students in orthopaedics.

Orthopaedic researchers need new strategies for engaging diverse students. Our field has demonstrated noticeable gaps in racial, ethnic, and gender diversity, which inhibit our ability to innovate and combat the severe socioeconomic burden of musculoskeletal disorders. Towards this goal, we designed, implemented, and evaluated Learning on a Limb, an orthopaedic research outreach module to teach diverse high school students about orthopaedic research.

Real-World Observational Analysis of Clinical Characteristics and Treatment Patterns of Patients with Chronic Sialorrhea.

Chronic sialorrhea is a condition characterized by excessive drooling, often associated with neurological and neuromuscular disorders such as Parkinson's disease, cerebral palsy, and stroke. Despite its prevalence, it remains underdiagnosed and poorly understood, leading to a lack of comprehensive data on patient demographics, clinical characteristics, and treatment patterns. This study aimed to help fill these existing gaps by analyzing real-world data using Optum's de-identified Clinformatics Data Mart Database.

Patient Characteristics and Real-World Use of Botulinum Toxins for the Treatment of Cervical Dystonia, Blepharospasm, and Hemifacial Spasm.

Movement disorders such as cervical dystonia, blepharospasm, and hemifacial spasm negatively impact the quality of life of people living with these conditions. Botulinum toxin (BoNT) injections are commonly used to treat these disorders. We sought to describe patient characteristics, BoNT utilization, and potential adverse events (AEs) among patients with cervical dystonia, blepharospasm, and hemifacial spasm using Optum's de-identified Clinformatics Data Mart Database.

Pediatric and adolescent HIV viral load coverage and suppression rates in the context of the COVID-19 pandemic in 12 PEPFAR-supported sub-Saharan African countries in 2019 and 2020.

The early period of the COVID-19 pandemic limited access to HIV services for children and adolescents living with HIV (C/ALHIV). To determine progress in providing care and treatment services, we describe viral load coverage (VLC) and suppression (VLS) (<1000 copies/ mL) rates during the COVID-19 pandemic in 12 United States President's Emergency Plan for AIDS Relief (PEPFAR)-supported countries. Data for children (0-9 years) and adolescents (10-19 years) on VLC and VLS were analyzed for 12 sub-Saharan African (SSA) countries between 2019 (pre-COVID-19) and 2020 (during COVID-19).

Malaria Transmission at The Zimbabwe-Mozambique Border: An Observational Study of Parasitemia by Travel History and Household Location.

Cross-border human population movement contributes to malaria transmission in border regions, impeding national elimination. However, its impact in low-to-moderate transmission settings is not well characterized. This community-based study in Mutasa District, Zimbabwe, estimated the association of parasite prevalence with self-reported overnight travel to Mozambique and household distance to the border from 2012-2020.

Characterization of TGFβ1-induced tendon-like structure in the scaffold-free three-dimensional tendon cell culture system.

The biological mechanisms regulating tenocyte differentiation and morphological maturation have not been well-established, partly due to the lack of reliable in vitro systems that produce highly aligned collagenous tissues. In this study, we developed a scaffold-free, three-dimensional (3D) tendon culture system using mouse tendon cells in a differentially adherent growth channel. Transforming Growth Factor-β (TGFβ) signaling is involved in various biological processes in the tendon, regulating tendon cell fate, recruitment and maintenance of tenocytes, and matrix organization.

Biomechanics of fracture healing: how best to optimize your construct in the OR.

Orthopaedic surgeons routinely assess the biomechanical environment of a fracture to create a fixation construct that provides the appropriate amount of stability in efforts to optimize fracture healing. Emerging concepts and technologies including reverse dynamization, "smart plates" that measure construct strain, and FractSim software that models fracture strain represent recent developments in optimizing construct biomechanics to accelerate bone healing and minimize construct failure.

Characterization of degradation kinetics of additively manufactured PLGA under variable mechanical loading paradigms.

Controlled degradation of biodegradable poly-lactic-co-glycolic acid (PLGA) trauma implants may increase interfragmentary loading which is known to accelerate fracture healing. Additive manufacturing allows us to tune the mechanical properties of PLGA scaffolds; however, little is known about this novel approach. The purpose of this study was to use in vitro and in vivo models to determine the degradative kinetics of additively manufactured test coupons fabricated with PLGA.

Transition into distance education: A scoping review protocol.

The number of students choosing to complete their studies online rather than in-person is on the rise. The transition to university is crucial for subsequent success, regardless of whether the learning is done face-to-face or remotely. If students can effectively handle the critical requirements associated with the transition to distance learning, their likelihood of success increases.

Evaluation of tendon and ligament microstructure and mechanical properties in a canine model of mucopolysaccharidosis I.

Mucopolysaccharidosis (MPS) I is a lysosomal storage disorder characterized by deficient alpha-l-iduronidase activity, leading to abnormal accumulation of glycosaminoglycans (GAGs) in cells and tissues. Synovial joint disease is prevalent and significantly reduces patient quality of life. There is a strong clinical need for improved treatment approaches that specifically target joint tissues; however, their development is hampered by poor understanding of underlying disease pathophysiology, including how pathological changes to component tissues contribute to overall joint dysfunction.

Functionally graded 3D printed plates for rib fracture fixation.

Background: Design freedom offered by additive manufacturing allows for the implementation of functional gradients - where mechanical stiffness is decreased along the length of the implant. It is unclear if such changes will influence failure mechanisms in the context of rib fracture repair. We hypothesized that our novel functionally graded rib implants would be less stiff than controls and decrease occurrence of secondary fracture at implant ends.

Tension-activated nanofiber patches delivering an anti-inflammatory drug improve repair in a goat intervertebral disc herniation model.

Conventional microdiscectomy treatment for intervertebral disc herniation alleviates pain but does not repair the annulus fibrosus, resulting in a high incidence of recurrent herniation and persistent dysfunction. The lack of repair and the acute inflammation that arise after injury can further compromise the disc and result in disc-wide degeneration in the long term. To address this clinical need, we developed tension-activated repair patches (TARPs) for annulus fibrosus repair and local delivery of the anti-inflammatory factor anakinra (a recombinant interleukin-1 receptor antagonist).

Glisson's capsule matrix structure and function is altered in patients with cirrhosis irrespective of aetiology.

Background & Aims: Glisson's capsule is the interstitial connective tissue that surrounds the liver. As part of its normal physiology, it withstands significant daily changes in liver size. The pathophysiology of the capsule in disease is not well understood.

A Model for Accelerating Access to Care and Treatment for Children and Adolescents Living with HIV in Nigeria, Tanzania, Uganda, and Zambia: The Faith-Based Action for Scaling-Up Testing and Treatment for the Epidemic Response (FASTER) Initiative.

The number of children newly infected with HIV dropped by 50%, from 320 000 in 2010 to 160 000 in 2021. Despite progress, ongoing gaps persist in diagnosis, continuity of care, and treatment optimization. In response, the United States President's Emergency Plan for AIDS Relief created the Faith-based Action for Scaling-Up Testing and Treatment for Epidemic Response (FASTER).

Pooled Safety Analysis of IncobotulinumtoxinA in the Treatment of Neurological Disorders in Adults.

The pooled incidences of treatment-emergent adverse events (TEAEs) were examined by indication using the integrated clinical database of Merz-sponsored, placebo-controlled, or repeat-dose studies of incobotulinumtoxinA in adults with cervical dystonia, blepharospasm, limb spasticity, sialorrhea, or essential tremor of the upper limb. Overall incidences of TEAEs, serious TEAEs, TEAEs leading to discontinuation, fatal TEAEs, TEAEs of special interest (TEAESIs; indicating possible toxin spread), and treatment-related (TR) events were determined for incobotulinumtoxinA and placebo after a single injection and for repeated dose cycles of incobotulinumtoxinA. The most frequent events after a single dose of incobotulinumtoxinA are summarized.

3-D Printed Fracture Models Improve Resident Performance and Clinical Outcomes in Operative Fracture Management.

Objective: To determine if preoperative examination of patient additive manufactured (AM) fracture models can be used to improve resident operative competency and patient outcomes.

Design: Prospective cohort study. Seventeen matched pairs of fracture fixation surgeries (for a total of 34 surgeries) were performed.

Great debates in trauma biomechanics.

At the 2021 annual meeting of the Orthopaedic Trauma Association, the Basic Science Focus Forum hosted its first ever debate-style symposium focused on biomechanics and fracture repair. The 3 subjects of debate were "Mechanics versus Biology-Which is 'More Important' to Consider?" "Locked Plate versus Forward Dynamization versus Reverse Dynamization-Which Way Should I Go?" and "Sawbones versus Cadaver Models-What Should I Believe Most?" These debates were held because fracture healing is a highly organized synergistic response between biological factors and the local mechanical environment. Multiple studies have demonstrated that both factors play roles in governing bone healing responses, and the causal relationships between the 2 remain unclear.

Similar Biomechanics Between the Double-Cortical Button and Docking Techniques for Ulnar Collateral Ligament Reconstruction: A Cadaveric Evaluation.

Background: The docking technique is widely used to perform ulnar collateral ligament (UCL) reconstructions because of its high failure torque and reliable clinical outcomes. A double-cortical button technique was recently described, with advantages including the ability to tension the graft at the ulnar and humeral attachments and the creation of single bone tunnels.

Purpose/hypothesis: To compare the biomechanics between the docking and double-button UCL reconstruction techniques using cadaveric specimens.

Turnover Tendon Lengthening Does Not Alter Biomechanical Strength of Pronator Teres-to-Extensor Carpi Radialis Brevis Tendon Transfer.

Background: The pronator teres (PT) to extensor carpi radialis brevis (ECRB) tendon transfer reestablishes wrist extension. Occasionally, the PT periosteal extension is of suboptimal quality to support a strong transfer. In these instances, turnover lengthening techniques can increase usable tendon length.

The Status of Adolescent Testing and Treatment in PEPFAR-Supported Programs, October 2017 to September 2020.

Background: Adolescents have poorer outcomes across the HIV cascade compared with adults. We aimed to assess progress in HIV case finding, antiretroviral treatment (ART), viral load coverage (VLC), and viral load suppression (VLS) among adolescents enrolled in the US President's Emergency Plan for AIDS Relief (PEPFAR)-supported programs over a 3-year period that included the beginning of the COVID-19 pandemic.

Methods: We analyzed PEPFAR program data in 28 countries/regions for adolescents aged 10-19 years between year 1 (October 2017to September 2018), year 2 (October 2018 to September 2019), and year 3 (October 2019 to September 2020).

Considerations to Improve Pediatric HIV Testing and Close the Treatment Gap in 16 African Countries.

Background: In 2019, South Africa, Nigeria, Tanzania, Democratic Republic of Congo, Uganda, Mozambique, Zambia, Angola, Cameroon, Zimbabwe, Ghana, Ethiopia, Malawi, Kenya, South Sudan and Côte d'Ivoire accounted for 80% of children living with HIV (CLHIV) not receiving HIV treatment. This manuscript describes pediatric HIV testing to inform case-finding strategies.

Methods: We analyzed US President's Emergency Plan for AIDS Relief monitoring, evaluation, and reporting data (October 1, 2018 to September 30, 2019) for these 16 countries.