Workplace Violence in the Pediatric Emergency Department: A National Survey of Physicians in the United States.

OBJECTIVES: Previous work shows that health care workers, and particularly emergency department (ED) staff, are at an above average risk of workplace violence (WPV), defined as verbal threats or physical violence in the workplace. Previous data suggest that staff of a single pediatric ED frequently feel unsafe. The objective of this study was to conduct the first national survey study to assess the prevalence and incidence of WPV in the pediatric ED. METHODS: In this cross-sectional survey study, a representative sample of US pediatric emergency medicine physicians were invited to participate in a national survey adapted from the previously validated Workplace Violence in the Health Sector questionnaire from the World Health Organization. The primary outcome measure was the proportion of physicians who have been exposed to WPV. Rates of exposure to violence, reporting habits, and physician perception of various violence prevention strategies were studied secondarily. RESULTS: Surveys were completed by 207 (45%) invited participants, representing 31 US children's hospitals. The prevalence of WPV exposure was 96%. Physical violence with a weapon was witnessed by 20% of participants. Injuries requiring medical attention or time off work were experienced by 10% of participants. Half of participants never reported violent events. Security guards were welcome by 99%, armed law enforcement officers by 70%, and metal detectors by 81% of physicians. Self-arming was opposed by 85% of respondents. CONCLUSIONS: Exposure to WPV is frequent among pediatric emergency medicine physicians with a prevalence similar to that of general emergency departments. Workplace violence remains underreported. This national survey contributes to the objective evaluation of individual- and systems-level violence prevention interventions.

Determining the performance of lignin-based flocculants in improving biosludge dewaterability.

In the wastewater treatment plant of pulp and paper mills, biosludge dewatering is needed to reduce the sludge handling and disposal costs. It is usually facilitated by means of the addition of synthetic polymers. There is increasing interest in replacing synthetic polymers with biopolymers derived from low value by-products or industrial residuals to improve the environmental footprint of dewatering. In this study, lignin-based flocculants (LBF) were tested for their ability to improve the biosludge dewaterability based on Capillary Suction Time (CST) and dry cake solids achieved with a Crown Press. The results demonstrate that LBFs alone can significantly enhance dewatering with a decrease in CSTs from 72.7 ± 5.1 s (unconditioned biosludge) to 23.3 ± 0.4 s and an increase in dry cake solids after pressing from 7.1 ± 0.5% to 13.9 ± 1.3% with a relatively high dosage of 7.5% w/w. However, with dual conditioning a LBF and 0.1% w/w anionic polyacrylamide (APAM), the required dosage of LBF was reduced to 3% w/w to achieve a dry cake solids content of 13.8 ± 0.4%, the same as that achieved with Zetag8165, a commercial synthetic polymer. LBF addition lowered the particle surface charge, allowing the particles to agglomerate and enhancing for the biosludge dewaterability. The application of LBFs for sludge dewatering offers novel considerable promise for providing more sustainable approaches by optimizing the use of lignin from different extraction processes, applying various types of lignin modifications in combination with anionic polymers, and exploring different methods of disposal or utilization of the dewatered sludge.

Retiring From Pediatric Emergency Medicine Too Soon?: A Survey to Discover the Reasons and Start a Conversation About Solutions.

OBJECTIVE: Pediatric emergency medicine is a subspecialty known for high acuity, high stress, and variable scheduling that may be difficult to maintain as one gets older. This survey sought to gain information on the reasons or plans for early retirement in pediatric emergency medicine and offer ways to address these concerns to improve longevity in the field. METHODS: A cross-sectional survey was sent via email to board-certified pediatric emergency medicine physicians who were older than 50 years to assess preretirement and postretirement considerations. Results were collected from October 3, 2019, through March 15, 2020. RESULTS: Pediatric emergency medicine physicians who find it more difficult to perform simple procedures are 3.02 (1.23-7.36) times more likely to retire before the age of 66 years. In addition, women were significantly more likely to report an intention to retire before the age of 66 years versus men (50% vs 31%, P = 0.022). DISCUSSION: The topic of retirement in a field that requires a wide range of procedural skills as well as constantly evolving technology is important. Understanding when and why physicians choose to retire may identify strategies to make it possible for pediatric emergency medicine physicians to prolong their careers. This may involve changes in work hours, a shift in responsibilities to a greater educational or mentor role, and/or providing opportunities to maintain skills. CONCLUSIONS: Perceived basic procedure skills deterioration significantly increased the risk for early retirement. In addition, women were significantly more likely to express intention to retire before the age of 66 years. Further research should be directed toward obtaining more detailed information to develop strategies to retain pediatric emergency medicine physicians in a capacity that benefits the physician, their institution, and their patients.

Maintenance of Certification Pediatrics: Pediatric Emergency Medicine (PEM): The New Part 3 Maintenance of Certification Assessment Option.

ABSTRACT: Starting in 2022, the American Board of Pediatrics will launch the Maintenance of Certification Assessment for Pediatrics: Pediatric Emergency Medicine (MOCA-Peds: PEM) longitudinal assessment, which will provide an at-home alternative to the point-in-time examination. This longitudinal assessment will help engage PEM physicians participating in continuing certification in a more flexible and continuous lifelong, self-directed learning process while still providing a summative assessment of their knowledge. This commentary provides background information on MOCA-Peds and an introduction to MOCA-Peds: PEM and how it gives the PEM physician another option to participate in continuing certification.

Assessing the Utility of Urine Testing in Febrile Infants 2 to 12 Months of Age With Bronchiolitis.

BACKGROUND: The utility of testing for urinary tract infection (UTI) in febrile infants with bronchiolitis is indeterminate. OBJECTIVE: The objective of this study was to investigate if the incidence of UTIs in febrile infants 2 to 12 months of age with bronchiolitis is higher than the presumed incidence of asymptomatic bacteriuria and determine risk factors associated with UTIs in this population. METHODS: This prospective multicenter cross-sectional study was conducted in the emergency departments of 6 children's hospitals between November 2011 and June 2015. We obtained a convenience sample of febrile infants with bronchiolitis 2 to 12 months of age who were tested for UTI. Patient characteristics analyzed included age, maximum temperature, duration of fever, ethnicity, sex, and circumcision status. RESULTS: A total of 442 patients (including 86 from a previously published pilot study) were enrolled. Mean age was 5.5 months, 65.2% were Latino, 50.9% were male, and 27.6% of male infants were circumcised. Urinary tract infections were found in 33 patients (7.69%, binomial; 95% confidence interval [CI], 5.19%-10.33%). Urinary tract infections were not related to age, height of temperature, duration of fever, or ethnicity. Uncircumcised males were significantly more likely to have UTIs than circumcised males (7.64% vs 0%, P = 0.03). Odds ratios (ORs) were lower for circumcised males but not uncircumcised males when compared with females (OR, 0.12; CI, 0.0-0.71; P = 0.01 vs OR, 0.77; CI, 0.33-1.74; P = 0.64). CONCLUSIONS: Febrile infants 2 to 12 months of age with bronchiolitis have a clinically significant incidence of UTI, suggesting that UTI evaluation should be considered in these patients.

Asthma specialist care preferences among parents of children receiving emergency department care for asthma.

Objective: To learn factors associated with desire for asthma specialist care among parents of children seeking emergency department (ED) care for asthma, and if referral was indicated based on national asthma guidelines. Methods: We surveyed parents of children ages 0-18 years seeking pediatric ED asthma care, then comparisons were made according to parental level of interest in asthma specialist care, with regard to socio-demographics, asthma morbidity and care, by chi-squared and logistic regression. Results: Of 149 children, 20% reported specialist care, but 75% met guideline criteria for referral. About 80% of parents not seeing an asthma specialist expressed a desire to see one. Higher rates of prior urgent care visits (48% vs. 22%, p = 0.03), ED visits (82% vs. 35%, p < 0.001) and oral steroid use (53% vs. 22%, p = 0.009) were reported by parents who desired an asthma specialist compared with parents who did not. 87% of parents not seeing a specialist attributed this to a perceived lack of necessity by their primary care provider. An ED visit within the prior 12 months was the most significant predictor in parental desire for specialist care (odds ratio 9.75; 95% CI 3.42-27.76) in adjusted logistic regression models. Conclusion: High rates of parental preference for asthma specialist care suggest that directly querying parents may be an efficient method to identify children appropriate for specialist care in the ED.

Alkane Oxidation: Methane Monooxygenases, Related Enzymes, and Their Biomimetics.

Methane monooxygenases (MMOs) mediate the facile conversion of methane into methanol in methanotrophic bacteria with high efficiency under ambient conditions. Because the selective oxidation of methane is extremely challenging, there is considerable interest in understanding how these enzymes carry out this difficult chemistry. The impetus of these efforts is to learn from the microbes to develop a biomimetic catalyst to accomplish the same chemical transformation. Here, we review the progress made over the past two to three decades toward delineating the structures and functions of the catalytic sites in two MMOs: soluble methane monooxygenase (sMMO) and particulate methane monooxygenase (pMMO). sMMO is a water-soluble three-component protein complex consisting of a hydroxylase with a nonheme diiron catalytic site; pMMO is a membrane-bound metalloenzyme with a unique tricopper cluster as the site of hydroxylation. The metal cluster in each of these MMOs harnesses O2 to functionalize the C-H bond using different chemistry. We highlight some of the common basic principles that they share. Finally, the development of functional models of the catalytic sites of MMOs is described. These efforts have culminated in the first successful biomimetic catalyst capable of efficient methane oxidation without overoxidation at room temperature.

LA phonospirometry technique compared to pediatric respiratory assessment measure and peak expiratory flow measurement as a novel technique to assess the severity of an asthma exacerbation.

Objective: Asthma is a common chronic disease treated in emergency departments. The measurements of Peak Expiratory Flow (PEF) and Pediatric Respiratory Assessment Measure (PRAM) scores have been recommended as objective techniques in the assessment of acute asthma exacerbations, but have multiple barriers limiting their use. The Los Angeles phonospirometry technique is an easier, trans-cultural technique. The technique assesses dyspnea by measuring how many seconds a child is able to chant "LA LA LA" in a single breath. The objective of this study is to determine the correlation of this technique with PEF measurements and PRAM scores in children with acute asthma exacerbations, both before and after nebulized bronchodilator treatment. Methods: A convenient sample of children aged 5-17 years being treated for asthma in the ED was enrolled. Phonospirometry, PRAM, and PEF measurements were obtained through pre and post inhaled bronchodilator treatments. The highest values from each measurement were correlated using Spearman's correlation coefficient. Results: A total of 91 children were enrolled. The correlations at pre-treatment, after first, second, and third treatments between phonospirometry and PEF were 0.38 (p < 0.001), 0.60 (p < 0.001), 0.54 (p < 0.001), 0.52 (p < 0.01), respectively; between phonospirometry and PRAM were -0.37 (p < 0.001), -0.42 (p < 0.001), -0.26 (p < 0.05), and -0.06 (p > 0.05), respectively; and between PEF and PRAM were -0.6 (p < 0.01), -0.54 (p < 0.001), -0.38 (p < 0.01), and -0.36 (p - 0.05), respectively. Conclusions: This novel technique correlates mild to moderately with PEF, and shows promising aide in the assessment of children with acute asthma exacerbations.

Predictors of prior asthma specialist care among pediatric patients seen in the emergency department for asthma.

Background: Asthma guidelines recommend specialist care for patients experiencing poor asthma outcomes during emergency department (ED) visits. The prevalence and predictors of asthma specialist care among an ED population seeking pediatric asthma care are unknown. Objective: To examine, in an ED population, factors associated with prior asthma specialist use based on parental reports of prior asthma morbidity and asthma care. Methods: Parents of children ages 0 to 17 years seeking ED asthma care were surveyed regarding socio-demographics, asthma morbidity, asthma management and current asthma specialist care status. We compared prior asthma care and morbidity between those currently cared for by an asthma specialist versus not. Multivariable logistic regression models to predict factors associated with asthma specialist use were adjusted for parent education and insurance type. Results: Of 150 children (62% boys, mean age 4.7 years, 69% Hispanic), 22% reported asthma specialist care, 75% did not see a specialist and for 3% specialist status was unknown. Care was worse for those not seeing a specialist, including under-use of controller medications (24% vs. 64%, p < 0.001) and asthma action plans (20% vs. 62%, p < 0.001). Multivariable logistic regression revealed that lack of recommendation by the primary care physician reduced the odds of specialist care (OR 0.01, 95% CI <0.01, 0.05, p < 0.001). Conclusions: Asthma specialist care was infrequent among this pediatric ED population, consistent with the sub-optimal chronic asthma care we observed. Prospective trials should further investigate if systematic referral to asthma specialists during/after an ED encounter would improve asthma outcomes.

TGF-b1 or hypoxia enhance glucose metabolism and lactate production via HIF1A signaling in tendon cells.

Purpose/Aim of the study: Healthy tendons are maintained in homeostasis through controlled usage of glucose for energy and redox equilibrium. Tendon cell stress imposed by overuse injury or vascular insufficiency is accompanied by activation of wound healing pathways which facilitate an adaptive response and the restoration of homeostasis. To understand this response at the gene expression level we have studied the in vivo effects of injected TGF-ß1 in a murine model of tendinopathy, as well as treatment of murine tendon explants with either TGF-ß1 or hypoxia in vitro. METHODS AND RESULTS: We provide evidence (from expression patterns and immunohistochemistry) that both in vivo and in vitro, the stress response in tendon cells may be metabolically controlled in part by glycolytic reprogramming. A major feature of the response to TGF-ß1 or hypoxia is activation of the Warburg pathway which generates lactate from glucose under normoxia and thereby inhibits mitochondrial energy production. CONCLUSIONS: We discuss the likely outcome of this major metabolic shift in terms of the potential benefits and damage to tendon and suggest how incorporation of this metabolic response into our understanding of initiation and progression of tendinopathies may offer new opportunities for diagnosis and the monitoring of therapies.

Utilization of just-in-time training for nursing education using the LA Phonospirometry asthma tool.

OBJECTIVE: Just-in-time training (JITT) has been used to teach and re-teach known medical techniques, but has not been used to teach novel techniques. We aimed to assess the performance retention of JITT on a novel asthma exacerbation severity assessment technique known as Los Angeles (LA) Phonospirometry. METHODS: This was a prospective cohort study using a convenience sample of pediatric emergency department registered nurses (RNs) who were asked to watch a brief instructional digital video on LA Phonospirometry, and then asked to practice the technique on a research assistant (RA). A checklist was used to evaluate proficiency with the primary outcome being the number correct on the checklist. The secondary outcome included whether or not they could identify a common error demonstrated by the RA. RNs were re-tested after 4-6 months to assess skill retention. RESULTS: Forty RNs were enrolled in the study and six were lost to follow-up. The mean time from the first to second testing was 5.4 months ± 0.5 months. The mean score of the first part of the checklist on the initial testing was 4.6 ± 0.7 and on second testing was 3.8 ± 1.5 (p = 0.008). This represented a drop in scores and thus minimal knowledge decay of 18% (from 91% to 73%). The mean values for number of errors picked up for the first test and second test were 1.3 and 1.5, respectively (p = 0.2). CONCLUSIONS: JITT demonstrated feasibility as a rapid instructional tool for RNs, with a limited decay in cognitive knowledge surrounding the LA Phonospirometry technique.

Predictors of safe discharge for pediatric drowning patients in the emergency department.

OBJECTIVES: The purpose of this study is to determine if stable, well-appearing, drowning patients who have normal age-adjusted vital signs and pulse oximetry upon arrival to the emergency department may be safely discharged without a prolonged observation period. METHODS: Medical records were retrospectively reviewed for drowning patients presenting to a single pediatric emergency department from 1995 to 2014. Data were collected on vital signs and pulse oximetry at presentation, chest x-ray results, disposition and complications for each encounter. Patients were identified as having either normal or abnormal initial vital signs and pulse oximetry, and were compared based on disposition and complication rates. RESULTS: Two hundred seventy-six records were initially evaluated and 91 were excluded. Thirty-six percent had normal age-adjusted vital signs upon arrival. Patients with abnormal temperature, respiratory rate or pulse oximetry, as well as those with any abnormal initial cardiopulmonary physical exam findings, abnormal mental status, or chest radiograph findings, were more likely to be admitted to the hospital. Eight patients developed respiratory complications after presentation to the emergency department. Those with abnormal pulse oximetry readings on arrival were more likely to develop complications. Only two patients who developed complications had initially normal vital signs and each had evidence of clinical deterioration within 1h of arrival. CONCLUSIONS: The overall complication rate in initially stable, well-appearing drowning patients is low. An abnormal pulse oximetry reading at presentation may help predict subsequent complications. Those patients with normal age-adjusted vital signs and physical exam at presentation may not require a prolonged observation period.

Clinical Utility of Noninvasive Method to Measure Specific Gravity in the Pediatric Population.

BACKGROUND: Clinicians rely on any combination of signs and symptoms, clinical scores, or invasive procedures to assess the hydration status in children. Noninvasive tests to evaluate for dehydration in the pediatric population are appealing. OBJECTIVE: The objective of our study is to assess the utility of measuring specific gravity of tears compared to specific gravity of urine and the clinical assessment of dehydration. METHODS: We conducted a prospective cohort convenience sample study, in a pediatric emergency department at a tertiary care children's hospital. We approached parents/guardians of children aged 6 months to 4 years undergoing transurethral catheterization for evaluation of urinary tract infection for enrollment. We collected tears and urine for measurement of tear specific gravity (TSG) and urine specific gravity (USG), respectively. Treating physicians completed dehydration assessment forms to assess for hydration status. RESULTS: Among the 60 participants included, the mean TSG was 1.0183 (SD = 0.007); the mean USG was 1.0186 (SD = 0.0083). TSG and USG were positively correlated with each other (Pearson Correlation = 0.423, p = 0.001). Clinical dehydration scores ranged from 0 to 3, with 87% assigned a score of 0, by physician assessment. Mean number of episodes of vomiting and diarrhea in a 24-hour period were 2.2 (SD = 3.9) and 1.5 (SD = 3.2), respectively. Sixty-two percent of parents reported decreased oral intake. CONCLUSION: TSG measurements yielded similar results compared with USG. Further studies are needed to determine if TSG can be used as a noninvasive method of dehydration assessment in children.

One-Pot Tandem Photoredox and Cross-Coupling Catalysis with a Single Palladium Carbodicarbene Complex.

The combination of conventional transition-metal-catalyzed coupling (2 e- process) and photoredox catalysis (1 e- process) has emerged as a powerful approach to catalyze difficult cross-coupling reactions under mild reaction conditions. Reported is a palladium carbodicarbene (CDC) complex that mediates both a Suzuki-Miyaura coupling and photoredox catalysis for C-N bond formation upon visible-light irradiation. These two catalytic pathways can be combined to promote both conventional transition-metal-catalyzed coupling and photoredox catalysis to mediate C-H arylation under ambient conditions with a single catalyst in an efficient one-pot process.

Biomechanical Performance of Medial Row Suture Placement Relative to the Musculotendinous Junction in Transosseous Equivalent Suture Bridge Double-Row Rotator Cuff Repair.

PURPOSE: To compare the biomechanical performance of medial row suture placement relative to the musculotendinous junction (MTJ) in a cadaveric transosseous equivalent suture bridge (TOE-SB) double-row (DR) rotator cuff repair (RCR) model. METHODS: A TOE-SB DR technique was used to reattach experimentally created supraspinatus tendon tears in 9 pairs of human cadaveric shoulders. The medial row sutures were passed either near the MTJ (MTJ group) or 10 mm lateral to the MTJ (rotator cuff tendon [RCT] group). After the supraspinatus repair, the specimens underwent cyclic loading and load to failure tests. The localized displacement of the markers affixed to the tendon surface was measured with an optical tracking system. RESULTS: The MTJ group showed a significantly higher (P = .03) medial row failure (5/9; 3 during cyclic testing and 2 during load to failure testing) compared with the RCT group (0/9). The mean number of cycles completed during cyclic testing was lower in the MTJ group (77) compared with the RCT group (100; P = .07) because 3 specimens failed in the MTJ group during cyclic loading. There were no significant differences between the 2 study groups with respect to biomechanical properties during the load to failure testing. CONCLUSIONS: In a cadaveric TOE-SB DR RCR model, medial row sutures through the MTJ results in a significantly higher rate of medial row failure. CLINICAL RELEVANCE: In rotator cuff tears with tendon tissue loss, passage of medial row sutures through the MTJ should be avoided in a TOE-SB RCR technique because of the risk of medial row failure.

Teaching Splinting Techniques Using a Just-in-Time Training Instructional Video.

OBJECTIVE: Splinting is a multistep procedure that is seldom performed by primary care physicians. Just-in-time training (JITT) is an emerging teaching modality and can be an invaluable asset for infrequently performed procedures or in locations where teaching resources and trained professionals are limited. Our objective was to determine the utility of JITT for teaching medical students the short-arm (SA) volar splinting technique. METHODS: This was a prospective randomized controlled pilot study. An instructional video on SA volar splinting was produced. Students viewed the video or had access to standard medical textbooks (control group) immediately before applying an SA volar splint. The students were assessed for the quality of the splint via a standard 6-point skills checklist. The times required for presplinting preparation and for completion of the splint were also measured. RESULTS: Just-in-time training group students scored higher on the splint checklist (mean [SD], 5.45 [1.06]; 95% confidence interval [CI], 4.99-5.92 vs mean [SD], 1.58 [1.12]; 95% CI, 1.04-2.12; P < 0.0001), had higher pass rates (73%; 95% CI, 53%-93% vs 0%; P < 0.0001), and required less time (minutes) for presplinting preparation (mean [SD], 7.86 [2.45]; 95% CI, 6.78-8.94 vs mean [SD], 9.89 [0.46]; 95% CI, 9.67-10.12; P < 0.0001) compared with the control group. No difference was seen in the time required to complete a splint, successful or not. CONCLUSIONS: In comparison with reading standard textbooks, watching a brief JITT instructional video before splinting yielded faster learning times combined with more successful procedural skills. The use of a JITT instructional video may have potential applications, including globally, as an alternative resource for teaching and disseminating procedural skills, such as SA volar splinting.

Exploring the kinetic and thermodynamic aspects of four-electron electrochemical reactions: electrocatalysis of oxygen evolution by metal oxides and biological systems.

Finding fundamental and general mechanisms for electrochemical reactions, such as the oxygen evolution reaction (OER) from water and reduction of CO2, plays vital roles in developing the desired electrocatalysts for facilitating solar fuel production. Recently, density functional theory (DFT) calculations have shown that there is a universal scaling relation of adsorption energy between key intermediate species, HO(ad) and HOO(ad), on the surface of metal oxides as OER electrocatalysts. In this paper, a kinetic and thermodynamic model for the four-electron electrochemical reaction based on previous OER mechanisms proposed by DFT calculations is developed to further investigate the electrocatalytic properties over a wide range of metal oxides and photosystem II. The OER activity of metal oxides (i.e. electrocatalytic current) calculated from the DFT-calculated equilibrium potentials with kinetic properties, such as the rate constants for interfacial electron transfer and catalytic turnover, can lead to a volcano-shaped trend that agrees with the results observed in experiments. In addition, the kinetic aspects of the impact on the electrocatalysts are evaluated. Finally, comparing the results of metal oxides and photosystem II, and fitting experimental voltammograms give further insights into kinetic and thermodynamic roles. Here, the general guidelines for designing OER electrocatalysts with unified kinetic and thermodynamic properties are presented.

Los Angeles phonospirometry technique: creating a normogram that correlates with peak expiratory flow measurements in children.

OBJECTIVE: Measurement of peak expiratory flow (PEF) is recommended in the assessment of patients with asthma. However, the use of PEF involves multiple barriers, which have limited its use. Phonospirometry, as assessed by a novel Los Angeles phonospirometry technique, has shown good correlation to standard PEF measurements in a pilot study on symptomatic patients with asthma. We sought to develop a normogram for phonospirometry, and to validate the PEF normogram. METHODS: A convenience sample of asymptomatic children ages 3-17 years old was approached for participation in the Emergency Department. Sample size calculations determined that at least 30 children per age group (n = 450) were needed. Children were asked to perform PEF measurements and phonospirometry, measured as the length of time (in s) the child was able to chant "lalala" in a single breath. RESULTS: 510 children were enrolled. Spearman's rho between PEF and phonospirometry was 0.722. Phonospirometry correlated with both age and height, with a Spearman rho of 0.697 and 0.696, respectively. This was slightly lower than the correlation of PEF with age and height with Spearman rhos of 0.877 and 0.902, respectively. A normogram was developed for phonospirometry based on age and height. CONCLUSIONS: This study determined normal value ranges for the Los Angeles phonospirometry technique for age and height, and also showed that the technique has good correlation with PEF. This technique may be used to assess a pediatric patient with an acute asthma exacerbation.

Regional mechanical properties of human patellar tendon allografts.

PURPOSE: Very little is known regarding regional biomechanical properties of patellar tendon allografts. METHODS: Ten human bone-tendon-bone (BTB) patellar grafts were separated into equal thirds and underwent cyclic and failure testing. Grafts were non-irradiated and processed using proprietary sterilization methods. RESULTS: The central third was the thickest region (4.9 ± 0.4 mm) compared to the medial and lateral (p < 0.05). The lateral third was the longest region (58.8 ± 8.8 mm) compared to the medial (47.9 ± 8.5 mm) and central (47.2 ± 8.8 mm) portions (p < 0.05). Cyclic testing demonstrated no regional differences with respect to elongation (n.s.) and creep strain (n.s.). Failure testing demonstrated increased maximum load and stiffness in the central region (1,680 ± 418 N and 278 ± 67 N/mm, respectively) as compared to the medial (1,033 ± 214 N, p < 0.002, 201 ± 37 N/mm, p < 0.03) and lateral thirds (908 ± 412 N, p < 0.03, 173 ± 66 N/mm, p < 0.002). Elongation at maximum load did not vary between regions. Central region maximum stress (41.0 ± 12.5 MPa) was greater than that of the medial third (28.1 ± 3.6 MPa, p < 0.02), with strain at maximum stress larger in the central third (0.21 ± 0.03) compared to lateral (0.16 ± 0.03, p < 0.01). CONCLUSIONS: The central third of a non-irradiated, human bone-patellar tendon-bone construct is thicker and biomechanically superior to the medial and lateral regions in most respects. These findings reinforce the use of the central third of a patellar tendon allograft in anterior cruciate ligament reconstruction. Further investigations are required to determine whether the decreased biomechanical properties of the medial and lateral third of the BTB construct negatively influence the mechanical function of hemi-BTB grafts.