Publications by authors named "Karl Jepsen"

Hip areal BMD (aBMD) is widely used to identify individuals with increased fracture risk. Low aBMD indicates low strength, but this association differs by sex with men showing greater strength for a given aBMD than women. To better understand the structural basis giving rise to this sex-specific discrepancy, cadaveric proximal femurs from White female and male donors were imaged using nano-CT and loaded in a sideways fall configuration to assess strength.

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Bone development is a highly orchestrated process that establishes the structural basis of bone strength during growth and functionality across the lifespan. This developmental process is generally robust in establishing mechanical function, being adaptable to many genetic and environmental factors. However, not all factors can be fully accommodated, leading to abnormal bone development and lower bone strength.

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Bone mineral density (BMD) is heavily relied upon to reflect structural changes affecting hip strength and fracture risk. Strong correlations between BMD and strength are needed to provide confidence that structural changes are reflected in BMD and, in turn, strength. This study investigated how variation in bone structure gives rise to variation in BMD and strength and tested whether these associations differ with external bone size.

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Morphological parameters measured for the second metacarpal from hand radiographs are used clinically for assessing bone health during growth and aging. Understanding how these morphological parameters relate to metacarpal strength and strength at other anatomical sites is critical for providing informed decision-making regarding treatment strategies and effectiveness. The goals of this study were to evaluate the extent to which 11 morphological parameters, nine of which were measured from hand radiographs, relate to experimentally measured whole-bone strength assessed at multiple anatomical sites and to test whether these associations differed between men and women.

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Article Synopsis
  • Bone strength tends to decrease with age, but not all older men experience fractures, suggesting some maintain better bone strength despite aging.
  • A study used latent profile analysis to identify subgroups among older men based on mechanical properties of bones, finding a significant difference in strength between a subgroup with higher strength (OHM) and one with lower strength (OLM).
  • The OLM group showed significantly weaker whole bone and tissue-level strengths compared to younger individuals, indicating that understanding different subgroups is crucial for assessing fracture risk in older populations.
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  • The study investigates how aging affects bone strength and composition differently in various regions of the femur.
  • Age-related changes in bone porosity and mechanical properties were found to vary significantly, with the strongest decline in mechanical strength seen in the anterior region.
  • Multivariate analyses indicate that certain factors, like porosity and mineral content, explained a significant portion of strength and strain differences, emphasizing the need to consider region-specific data rather than pooled analyses for more accurate insights.
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Background: Fractures represent a triple threat to adults with cerebral palsy (CP): common, accumulate early in adulthood, and are consequential to health. An economic evaluation of fractures in CP is needed to highlight priorities for allocating resources to clinical and public health programs aimed at preventing fractures and their disease sequela.

Objective: To identify short-term healthcare costs associated with fractures among adults with CP.

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  • The study explores how the surface texture of titanium implants impacts cell behavior after they are placed in the body.
  • Nanoscale textured implants led to better bone integration and higher expression of the Osterix gene, which is vital for bone formation, compared to smooth-surfaced implants.
  • Advanced imaging and analysis techniques confirmed that implants with nanoscale features promoted greater cell adhesion and bone growth, highlighting the importance of implant surface design for enhancing healing outcomes.
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Aim: To understand associations among bone mineral density (BMD), bone mineral content (BMC), and bone area, and their association with fractures in adults with cerebral palsy (CP).

Method: This retrospective cohort study included 78 adults with CP with a hip dual energy X-ray absorptiometry (DXA) from 1st December 2012 to 3rd May 2021 performed at the University of Michigan. Data-driven logistic regression techniques identified which, if any, DXA-derived bone traits (e.

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Applications of vibrational spectroscopy to assess bone disease and therapeutic interventions are continually advancing, with tissue mineral and protein composition frequently investigated. Here, we used two spectroscopic approaches for determining bone composition in a mouse model () of the brittle bone disease osteogenesis imperfecta (OI) with and without antiresorptive agent treatment (alendronate, or ALN, and RANK-Fc). Near-infrared (NIR) spectral analysis using a fiber optic probe and attenuated total reflection Fourier transform infrared spectroscopy (ATR FTIR) mode were applied to investigate bone composition, including water, mineral, and protein content.

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Image-based measurements of bone integrity are used to estimate failure properties and clinical fracture risk. This paper (1) reviews recent imaging studies that have enhanced our understanding of the mechanical pathways to bone fracture and (2) discusses the influence that inter-individual differences in image-based measurements may have on the clinical assessment of fracture risk RECENT FINDINGS: Increased tissue mineralization is associated with improved bone strength but reduced fracture toughness. Trabecular architecture that is important for fatigue resistance is less important for bone strength.

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Despite poor graft integration among some patients that undergo an anterior cruciate ligament (ACL) reconstruction, there has been little consideration of the bone quality into which the ACL femoral tunnel is drilled and the graft is placed. Bone mineral density of the knee decreases following ACL injury. However, trabecular and cortical architecture differences between injured and non-injured femoral ACL entheses have not been reported.

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Background: Anti-seizure medication (ASM) is necessary to manage epilepsy and often prescribed to children and adolescents, but can lead to iatrogenic effects, including bone fragility by altering bone metabolism. Disrupting bone metabolism during crucial developmental stages could have a lasting adverse effect on bone health. Therefore, the objective of this propensity score-matched, observational cohort study was to determine if age when initiating ASM therapy across developmental stages (from pre- to post-puberty) for individuals with epilepsy was associated with an increased risk of fragility fracture.

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Background: Recent surgical techniques have focused on anatomic repair of lesser toe metatarsophalangeal (MTP) plantar plate tears, yet it remains unknown whether the plantar plate has the biological capacity to heal these repairs. Therefore, a better understanding of the plantar plate vasculature in response to injury may provide further insight into the potential for healing after anatomic plantar plate repair. Recently, a study demonstrated that the microvasculature of the normal plantar plate is densest at the proximal and distal attachments.

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Background: Individuals with cerebral palsy (CP) are vulnerable to non-trauma fracture (NTFx) and premature mortality due to respiratory disease (RD); however, very little is known about the contribution of NTFx to RD risk among adults with CP. The purpose of this study was to determine if NTFx is a risk factor for incident RD and if NTFx exacerbates RD risk in the adult CP population.

Methods: Data from 2011 to 2016 Optum Clinformatics® Data Mart and a random 20% sample Medicare fee-for-service were used for this retrospective cohort study.

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Understanding skeletal aging and predicting fracture risk is increasingly important with a growing elderly population. We hypothesized that when categorized by external bone size, the male femoral diaphysis would show different strength-age trajectories which can be explained by changes in morphology, composition and collagen cross-linking. Cadaveric male femora were sorted into narrow (n = 15, 26-89 years) and wide (n = 15, 29-82 years) groups based upon total cross-sectional area of the mid-shaft normalized to bone length (Tt.

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Background: Individuals with cerebral palsy (CP) manifest skeletal fragility problems early in life, are vulnerable to non-trauma fracture (NTFx), and have a high burden of premature mortality. No studies have examined the contribution of NTFx to mortality among adults with CP. The purpose of this study was to determine if NTFx is a risk factor for mortality among adults with CP and if NTFx exacerbates mortality risk compared to adults without CP.

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Bone morphogenetic protein (BMP) signaling in osteoblasts plays critical roles in skeletal development and bone homeostasis. Our previous studies showed loss of function of BMPR1A, one of the type 1 receptors for BMPs, in osteoblasts results in increased trabecular bone mass in long bones due to an imbalance between bone formation and bone resorption. Decreased bone resorption was associated with an increased mature-to-immature collagen cross-link ratio and mineral-matrix ratios in the trabecular compartments, and increased tissue-level biomechanical properties.

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Individuals with cerebral palsy (CP) have poor skeletal and cardiovascular health. However, no studies have examined if skeletal fragility enhances cardiovascular disease (CVD) risk for this population. The purpose of this study was to determine whether adults with CP have higher 12-month CVD incidence following a low-trauma fracture compared with adults without CP.

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Background: Fracture is a high-burden condition that accelerates unhealthful aging and represents a considerable economic burden. Adults with neurodevelopmental disabilities (NDDs) may be susceptible for fracture at younger ages compared to adults without NDDs; and yet, very little is known about the burden of fracture for these underserved populations. The purpose of this study was to determine the sex-stratified prevalence of all-cause fracture among adults with NDDs, as compared to adults without NDDs, and if comorbidity of NDDs is associated with greater risk of fracture.

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Background: Individuals with neurodevelopmental disabilities (NDDs) have poor development and preservation of skeletal health throughout the lifespan, and are especially vulnerable to low-trauma fracture and post-fracture health complications. However, no studies have examined if adults with NDDs have greater post-fracture mortality risk compared to adults without NDDs. The purpose of this study was to determine whether adults with NDDs have greater 12-month mortality rates following a low-trauma fracture compared to adults without NDDs.

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Administration of sclerostin-neutralizing antibody (Scl-Ab) treatment has been shown to elicit an anabolic bone response in growing and adult mice. Prior work characterized the response of individual mouse strains but did not establish whether the impact of Scl-Ab on whole bone strength would vary across different inbred mouse strains. Herein, we tested the hypothesis that two inbred mouse strains (A/J and C57BL/6J (B6)) will show different whole bone strength outcomes following sclerostin-neutralizing antibody (Scl-Ab) treatment during growth (4.

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Objective: Glucocorticoids (GCs) are commonly prescribed as treatment for chronic inflammatory diseases. Prolonged use of GCs is a common cause of atraumatic osteonecrosis (ON) and secondary osteoporosis. Currently, there is no effective treatment for this disease; therefore, a reliable animal model would be useful to study both the pathology and novel treatment strategies for patients with the disease.

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