Browsing by Subject "fracture"

Now showing 1 - 10 of 12
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    Application of Salubrinal for Bone Fracture Healing
    (Office of the Vice Chancellor for Research, 2014-04-11) Yokota, Hiroki; Lin, Chien-Chi
    The long-term objective of this project is to commercialize a novel synthetic chemical agent, salubrinal, for treatment of bone growth and fracture healing. Bone morphogenetic proteins (BMPs) are clinically administered as growth stimulators for bone fracture healing. However, BMPs are not only expensive, but also stimulate ectopic bone formation and potentially induce cancer. A synthetic chemical agent that permits facile storage and administration could reduce costs, and provide longer shelf-life, and better bone healing outcomes. Currently, no synthetic chemical agents as a stimulator of fracture healing are clinically available. The research team recently identified “salubrinal,” a synthetic chemical agent, as a potential therapeutic stimulator of bone growth and fracture healing. An invention disclosure and a U.S. patent were filed. In this FORCES project, we are examining efficacy of salubrinal using a mouse model of closed tibia fracture. The results strongly indicate that salubrinal can accelerate bone fracture healing.
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    Can Deterministic Mechanical Size Effects Contribute to Fracture and Microdamage Accumulation in Trabecular Bone?
    (2010-07) Siegmund, Thomas; Allen, Matthew R.; Burr, David B.
    Failure of bone under monotonic and cyclic loading is related to the bone mineral density, the quality of the bone matrix, and the evolution of microcracks. The theory of linear elastic fracture mechanics has commonly been applied to describe fracture in bone. Evidence is presented that bone failure can be described through a non-linear theory of fracture. Thereby, deterministic size effects are introduced. Concepts of a non-linear theory are applied to discern how the interaction among bone matrix constituents (collagen and mineral), microcrack characteristics, and trabecular architecture can create distinctively differences in the fracture resistance at the bone tissue level. The non-linear model is applied to interpret pre-clinical data concerning the effects of anti-osteoporotic agents on bone properties. The results show that bisphosphonate (BP) treatments that suppress bone remodeling will change trabecular bone in ways such that the size of the failure process zone relative to the trabecular thickness is reduced. Selective estrogen receptor modulators (SERMs) that suppress bone remodeling will change trabecular bone in ways such that the size of the failure process zone relative to the trabecular thickness is increased. The consequences of these changes are reflected in bone mechanical response and predictions are consistent with experimental observations in the animal model which show that BP treatment is associated with more brittle fracture and microcracks without altering the average length of the cracks, whereas SERM treatments lead to a more ductile fracture and mainly increase crack length with a smaller increase in microcrack density. The model suggests that BPs may be more effective in cases in which bone mass is very low, whereas SERMS may be more effective when milder osteoporotic symptoms are present.
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    The Demographics of Fractures and Dislocations Across the Entire United States due to Common Sports and Recreational Activities
    (Sage, 2020-03) Meixner, Cory; Loder, Randall T.; Orthopaedic Surgery, School of Medicine
    Background: There exists little nationwide data regarding fracture and dislocation patterns across a wide variety of sporting activities for all ages and sexes. Hypothesis: Participant demographics (age and sex) will vary with regard to fracture and joint dislocation sustained during sport-related activities. Study Design: Descriptive epidemiology study. Level of Evidence: Level 3. Methods: The National Electronic Injury Surveillance System All Injury Program data 2005 through 2013 were accessed; 18 common sports and recreational activities in the United States were selected. Statistical software was used to calculate the numbers of fractures and dislocations, and incidence was calculated using US Census Bureau data. Multivariate logistic regression analysis determined the odds ratios (ORs) for the occurrence of a fracture or dislocation. Results: A fracture occurred in 20.6% and a joint dislocation in 3.6% of the emergency department visits for sports-related injuries; annual emergency department visit incidence was 1.51 for fractures and 0.27 for dislocations (per 1000 people). Most of the fractures occurred in football (22.5%). The OR for fracture was highest for inline skating (OR, 6.03), males (OR, 1.21), Asians, whites, and Amerindians compared with blacks (OR, 1.46, 1.25, and 1.18, respectively), and those older than 84 years (OR, 4.77). Most of the dislocations occurred in basketball (25.7%). The OR for dislocation was highest in gymnastics (OR, 4.08), males (OR, 1.50), Asians (OR, 1.75), and in those aged 20 to 24 years (OR, 9.04). The most common fracture involved the finger, and the most common dislocation involved the shoulder. Conclusion: Inline skating had the greatest risk for fracture, and gymnastics had the greatest risk for joint dislocation. Clinical Relevance: This comprehensive study of the risks of sustaining a fracture or dislocation from common sports activities across all age groups can aid sports health providers in a better understanding of those sports at high risk and be proactive in prevention mechanisms (protective gear, body training).
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    The effects of occlusion on single miniplate osteosyntheses of the mandible
    (2017-11) Katona, Thomas R.
    Aim: Miniplate osteosyntheses of a fractured mandible is a complex structural engineering problem that has been modeled experimentally, analytically and numerically. In general, the more realistic the model, the more difficult it is to appreciate its nuances. Thus, a purpose of this paper is to present a basic analytical model that illustrates the most fundamental principles of static equilibrium as it applies to the mechanics of single miniplate osteosynthesis designs. The second purpose is to use the model to demonstrate the effects of changes in occlusion on the loads experienced by the structures. Materials and methods: The 3 equations of static equilibrium were derived from the free-body-diagram of the distal segment of a vertically fractured reduced mandible. The equations were solved parametrically with variations in plate screw locations, anterior-posterior locations of occlusal contact, and occlusal contact force direction, including the simulation of sticky foods. Results: The results indicate a profound effect of occlusal contact force location and direction on the magnitudes and/or directions of the forces acting on the screw and the miniplate, and on the location and magnitude of the interfragmental bone-bone compression force. Conclusions: In some respects, this model is as barebones as is possible. Atypically however, it includes occlusal contact force direction. The results strongly suggest that all analyses of plating systems should account not only for occlusal contact force location and magnitude, but also its direction.
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    Fractures in Patients with CKD: Time for Action
    (American Society of Nephrology, 2016-11-07) Moe, Sharon M.; Nickolas, Thomas L.; Medicine, School of Medicine
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    Iatrogenic Peroneal Nerve Palsy Rates Secondary to Open Reduction Internal Fixation for Tibial Plateau Fractures Using an Intraoperative Distractor
    (Wolters Kluwer, 2020-01) Pattyn, Ryan; Loder, Randall; Mullis, Brian H.; Orthopaedic Surgery, School of Medicine
    Objective: To report the rate of peroneal nerve palsy after routine use of intraoperative distraction during open reduction internal fixation (ORIF) for lateral unicondylar and bicondylar tibial plateau fracture (TPF) repairs. Design: Retrospective chart review Setting: Level I trauma center Patients: Patients with traumatic TPF treated with ORIF between 2007 and 2017 Intervention: ORIF for lateral unicondylar and bicondylar TPF. Main Outcome Measurement: Presence and resolution of neurovascular injury Results: There were a total of 21 lateral unicondylar and 40 bicondylar TPFs repaired via ORIF in 60 patients identified during the study period with one year follow up and complete records for review. Thirty-six patients had staged external fixation prior to ORIF while 24 were treated with ORIF initially. Of the staged patients, 9 of 36 (25%) developed nerve palsy while those undergoing initial ORIF (not staged) developed palsy in only one case (1 of 24, or 4%). Of the patients who developed nerve palsy 9 of 10 (90%) were staged with an initial external fixator prior to ORIF. The incidence of iatrogenic peroneal nerve palsy secondary to intraoperative distraction was 16.4% (10 of 61). Only 60% (6 of 10) of peroneal nerve palsies recovered clinically with a mean recovery time of approximately 14 weeks. Comparison of demographics in patients with peroneal nerve palsy versus those without yielded no significant difference by sex (p = 0.08), age (p =0.27), fracture type (p = 0.29), tobacco use (p = 0.44) or alcohol use (p = 0.78). Conclusions: Peroneal nerve palsy is a common sequela of ORIF for TPFs involving the lateral compartment utilizing an intraoperative distractor. Staged external fixation followed by definitive ORIF using intra-operative distraction, was associated with significant risk for developing nerve palsy (9/10). Many patients (40%) who develop peroneal nerve palsies do not recover, leading to permanent loss of motor and/or sensory function for 7% of patients studied. None of the epidemiologic variables evaluated yielded predictive value for development of peroneal nerve palsy or subsequent resolution. Caution should be exercised in avoiding over distraction when using intraoperative distraction, especially in those cases that had staged fixation, most notably bicondylar injuries.
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    Lack of Evidence for a Harmful Effect of Sodium–Glucose Cotransporter 2 (SGLT2) Inhibitors on Fracture Risk among Type 2 Diabetes Patients: A Network and Cumulative Meta-Analysis of Randomized Controlled Trials
    (Wiley, 2016) Tang, Huilin L.; Li, D. D.; Zhang, J. J.; Hsu, Y. H.; Zhai, S. D.; Song, Yiqing; Department of Epidemiology, School of Public Health
    Aim To evaluate the comparative effects of sodium-glucose co-transporter 2 (SGLT2) inhibitors on risk of bone fracture in patients with type 2 diabetes mellitus (T2DM). Methods PubMed, EMBASE, CENTRAL and ClinicalTrials.gov were systematically searched from inception to 27 January 2016 to identify randomized controlled trials (RCTs) reporting the outcome of fracture in patients with T2DM treated with SGLT2 inhibitors. Pairwise and network meta-analyses, as well as a cumulative meta-analysis, were performed to calculate odds ratios (ORs) and 95% confidence intervals (CIs). Results A total of 38 eligible RCTs (10 canagliflozin, 15 dapagliflozin and 13 empagliflozin) involving 30 384 patients, with follow-ups ranging from 24 to 160 weeks, were included. The fracture event rates were 1.59% in the SGLT2 inhibitor groups and 1.56% in the control groups. The incidence of fracture events was similar among these three SGLT2 inhibitor groups. Compared with placebo, canagliflozin (OR 1.15; 95% CI 0.71-1.88), dapagliflozin (OR 0.68; 95% CI 0.37-1.25) and empagliflozin (OR 0.93; 95% CI 0.74-1.18) were not significantly associated with an increased risk of fracture. Our cumulative meta-analysis indicated the robustness of the null findings with regard to SGLT2 inhibitors. Conclusions Our meta-analysis based on available RCT data does not support the harmful effect of SGLT2 inhibitors on fractures, although future safety monitoring from RCTs and real-world data with detailed information on bone health is warranted.
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    Multi-scale analysis of cathode microstructural effects on electrochemical and stress responses of lithium-ion batteries
    (Elsevier, 2022-11-15) Lee, Yoon Koo; Park , Juhyun; Shin, Hosop; Mechanical and Energy Engineering, School of Engineering and Technology
    The electrochemical and stress responses of lithium-ion batteries (LIBs) are highly dependent on the three-dimensional (3D) microstructure of electrodes, and substantial fundamental research is required to optimize the electrode design for high-energy, high-power LIBs with fast charging capabilities. Herein, we report a multi-scale LIB model that enables the examination of full-cell battery performance while investigating the detailed electrochemical and stress responses of the cathode using the variational multi-scale enrichment method. With the high computational efficiency of the developed model, the cathode microstructural effects were studied systematically by varying the particle size, volume fraction, and particle arrangement of 3D cathode microstructures at different C-rates. The results show that the arrangement of active material particles and their interconnectivity, rather than the particle size itself, are the determining factors for the spatial lithium-ion concentration and stress distribution of the cathode, affecting the overall electrochemical performance of LIBs. Our study provides valuable insights into the design and optimization of the cathode architecture to maximize the electrochemical performance under different operating conditions.
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    Objective metric of energy absorbed in tibial plateau fractures corresponds well to clinician assessment of fracture severity
    (Wolters Kluwer, 2016-10) Kempton, Laurence B.; Dibbern, Kevin; Anderson, Donald D.; Morshed, Saam; Higgins, Thomas F.; Marsh, J. Lawrence; McKinley, Todd O.; Orthopaedic Surgery, School of Medicine
    Objectives Determine the agreement between subjective assessments of fracture severity and an objective CT-based metric of fracture energy in tibial plateau fractures. Methods Six fellowship-trained orthopaedic trauma surgeons independently rank-ordered 20 tibial plateau fractures in terms of severity based upon AP and lateral knee radiographs. A CT-based image analysis methodology was used to quantify the fracture energy, and agreement between the surgeons’ severity rankings and the fracture energy metric was tested by computing their concordance, a statistical measure that estimates the probability that any two cases would be ranked with the same ordering by two different raters or methods. Results Concordance between the six orthopaedic surgeons ranged from 82% to 93%, and concordance between surgeon severity rankings and the computed fracture energy ranged from 73% to 78%. Conclusions There is a high level of agreement between experienced surgeons in their assessments of tibial plateau fracture severity, and a slightly lower agreement between the surgeon assessments and an objective CT-based metric of fracture energy. Taken together, these results suggest that experienced surgeons share a similar understanding of what makes a tibial plateau fracture more or less severe, and an objective CT-based metric of fracture energy captures much but not all of that information. Further research is ongoing to characterize the relationship between surgeon assessments of severity, fracture energy, and the eventual clinical outcomes for patients with fractures of the tibial plateau.