Tomer Erlich

Variation in tibial functionality and fracture susceptibility among healthy, young adults arises from the acquisition of biologically distinct sets of traits.

Physiological systems like bone respond to many genetic and environmental factors by adjusting traits in a highly coordinated, compensatory manner to establish organ‐level function. To be mechanically functional, a bone should be sufficiently stiff and strong to support physiological loads. Factors impairing this process are expected to compromise strength and increase fracture risk. We tested the hypotheses that individuals with reduced stiffness relative to body size will show an increased risk of fracturing and that reduced strength arises from the acquisition of biologically distinct sets of traits (ie, different combinations of morphological and tissue‐level mechanical properties). We assessed tibial functionality retrospectively for 336 young adult women and men engaged in military training, and calculated robustness (total area/bone length), cortical area (Ct.Ar), and tissue‐mineral density (TMD). These three traits explained 69% to 72% of the variation in tibial stiffness (p < 0.0001). Having reduced stiffness relative to body size (body weight × bone length) was associated with odds ratios of 1.5 (95% confidence interval [CI], 0.5–4.3) and 7.0 (95% CI, 2.0–25.1) for women and men, respectively, for developing a stress fracture based on radiography and scintigraphy. K‐means cluster analysis was used to segregate men and women into subgroups based on robustness, Ct.Ar, and TMD adjusted for body size. Stiffness varied 37% to 42% among the clusters (p < 0.0001, ANOVA). For men, 78% of stress fracture cases segregated to three clusters (p < 0.03, chi‐square). Clusters showing reduced function exhibited either slender tibias with the expected Ct.Ar and TMD relative to body size and robustness (ie, well‐adapted bones) or robust tibias with reduced residuals for Ct.Ar or TMD relative to body size and robustness (ie, poorly adapted bones). Thus, we show there are multiple biomechanical and thus biological pathways leading to reduced function and increased fracture risk. Our results have important implications for developing personalized preventative diagnostics and treatments.

Anemia, Iron Deficiency, and Stress Fractures in Female Combatants During 16 Months

Yanovich, R, Merkel, D, Israeli, E, Evans, RK, Erlich, T, and Moran, DS. Anemia, iron deficiency, and stress fractures in female combatants during 16 months. J Strength Cond Res 25(12): 3412–3421, 2011—The purpose of this study is to evaluate the hematological profile of military recruits in different settings and training programs and to investigate the link between anemia and iron deficiency with stress fracture (SF) occurrence. We surveyed 3 groups of recruits for 16 months: 221 women (F) and 78 men (M) from 3 different platoons of a gender-integrated combat battalion and a control group (CF) of 121 female soldiers from a noncombat unit. Data were fully collected upon induction and at 4 and 16 months from 48F, 21M, and 31CF. Blood tests, anthropometry, physical aerobic fitness, and SF occurrence were evaluated. On induction day, 18.0 and 19.0% of F and CF were found to be anemic, and 61.4 and 50.9%, respectively, were found to have iron deficiency, whereas 7.7% of M were found to be anemic and 10.2% iron deficient. During the 4 months of army basic training (ABT), anemia and iron deficiency prevalence did not change significantly in any group. After 16-months, anemia prevalence decreased by 8% among F and CF and abated in M. Iron deficiency was prevalent in 50.0, 59.4, and 18.8% of F, CF, and M, respectively. Stress fractures were diagnosed in 14 F during ABT, and they had a significantly higher prevalence (p < 0.05) of anemia and iron deficiency anemia compared to F without SFs. The observed link between anemia and iron deficiency on recruitment day and SFs suggests the importance of screening female combat recruits for these deficiencies. To minimize the health impact of army service on female soldiers, preventative measures related to anemia and iron deficiency should be administered. Further research is needed for evaluating the influence of low iron in kosher meat as a possible explanation for the high prevalence of iron deficiency among young Israeli recruits.

The relative contribution of urine extravasation to elevate plasma creatinine levels in acute unilateral ureteral obstruction.

INTRODUCTION Rising levels of plasma creatinine in the setting of acute unilateral ureteral obstruction (AUUO) often reflects acute renal failure, mandating kidney drainage. We hypothesize that re-absorption of peri-renal urine extravasation (PUE), a common result of UUO, contributes significantly to the elevation in plasma creatinine, rendering the latter an inaccurate benchmark for renal function. We explored this hypothesis in a rat model of AUUO and PUE. METHODS In total, 20 rats were equally divided into 4 groups. Groups 1 and 2 underwent unilateral ligation of the ureter with infiltration of rats urine (index group) or saline (control) into the peri-renal space. Two additional control groups underwent peri-renal injection of either urine or saline without AUUO. Plasma creatinine levels were determined immediately prior to the procedure (T0), and hourly for 3 hours (T1, T2 and T3). Renal histology was investigated after 3 hours. RESULTS Rats in the index group had a significantly greater increase in plasma creatinine levels over 3 hours compared to all other groups (p < 0.05). At T3, average plasma creatinine levels for the index group increased by 96% (0.49 ± 0.18 mg/dL) compared to 46% (0.23 ± 0.06 mg/dL increase) in the AUUO and saline group, and less than 15% rise in both the non-obstructed control groups. Our study limitations includes lack of spontaneous PUE and intraperitoneal surgical approach. CONCLUSIONS Absorption of peri-renal urine in the presence of AUUO is a significant contributor to rising plasma creatinine levels, beyond those attributable to the obstruction alone, and may overestimate the extent of the true renal functional impairment.

Renal trauma: the current best practice

The kidneys are the most vulnerable genitourinary organ in trauma, as they are involved in up to 3.25% of trauma patients. The most common mechanism for renal injury is blunt trauma (predominantly by motor vehicle accidents and falls), while penetrating trauma (mainly caused by firearms and stab wound) comprise the rest. High-velocity weapons impose specifically problematic damage because of the high energy and collateral effect. The mainstay of renal trauma diagnosis is based on contrast-enhanced computed tomography (CT), which is indicated in all stable patients with gross hematuria and in patients presenting with microscopic hematuria and hypotension. Additionally, CT should be performed when the mechanism of injury or physical examination findings are suggestive of renal injury (e.g. rapid deceleration, rib fractures, flank ecchymosis, and every penetrating injury of the abdomen, flank or lower chest). Renal trauma management has evolved during the last decades, with a distinct evolution toward a nonoperative approach. The lion’s share of renal trauma patients are managed nonoperatively with careful monitoring, reimaging when there is any deterioration, and the use of minimally invasive procedures. These procedures include angioembolization in cases of active bleeding and endourological stenting in cases of urine extravasation.

MP55-04 REVISITING THE ROLE OF GENDER ON EARLY DIAGNOSED PRIMARY VESICOURETERAL REFLUX IN INFANTS WITH PRENATAL HYDRONEPHROSIS

characterize the inter-rater reliability of VUR grade and UDR in children with VUR. METHODS: Voiding cystourethrograms (VCUG) of 20 pediatric patients (31 VUR-affected kidneys) were independently reviewed by four pediatric urologists in a blinded fashion. For each renal unit, grade was assigned according to the standardized international scale. UDR was calculated by dividing the largest ureteral diameter within the false pelvis by the distance between the L1-L3 vertebral bodies. The mean grade and mean UDR was calculated for each affected kidney. Correlation within each rater was determined using a Pearson’s correlation coefficient. Reliability of VUR grade and UDR was calculated using intraclass correlation coefficients (ICC) using a two-way ANOVA model interrater agreement. RESULTS: VUR grade (ICC 1⁄4 0.87, 95% CI 1⁄4 0.78-0.93) and UDR (ICC 1⁄4 0.95, 95% CI 1⁄4 0.92-0.97) were reliably measured by four independent raters. While UDR and grade were equally reliable measures, UDR had a tighter confidence interval. For each rater, grade and UDR were well-correlated (r 1⁄4 0.73-0.84; p <0.0001). In the upper ranges of measurements, grade was more variable than UDR [Figure]. Using an empirical threshold, the increased variability with grade may lead to significantly more differences in clinical decision-making among physicians (p 1⁄4 0.022). CONCLUSIONS: UDR has good inter-rater reliability among pediatric urologists. There was significantly more clinically relevant variability with grade than with UDR. Our study demonstrates that UDR is a more objective and reliable measure than grade, and may be a useful adjunct in clinical decision making and categorizing VUR.

MP30-09 URETERIC STENT VERSUS PERCUTANEOUS NEPHROSTOMY FOR ACUTE URETERAL OBSTRUCTION - CLINICAL OUTCOME AND QUALITY OF LIFE: A BI-CENTER PROSPECTIVE STUDY

Background To compare quality of life (QoL) indices between ureteral stent (DJS) and nephrostomy tube (PCN) inserted in the setting of acute ureteral obstruction.

Physiological and cognitive military related performances after 10-kilometer march

BackgroundPrior operational activities such as marching in diverse environments, with heavy backloads may cause early fatigue and reduce the unit’s readiness. The purpose of this preliminary study was to evaluate the effect of 10-kilometer (km) march on selected, military oriented, physiological and cognitive performances.Eight healthy young males (age 25 ± 3 years) performed a series of cognitive and physiological tests, first without any prior physiological strain and then after a 10 km march in comfort laboratory conditions (24°C, 50%RH) consisting a 5 km/h speed and 2-6% incline with backload weighing 30% of their body weight.ResultsWe found that the subjects’ time to exhaustion (TTE) after the march decreased by 27% with no changes in anaerobic performance. Cognitive performance showed a significant (20%) reduction in accuracy and a tendency to reduce reaction time after the march.ConclusionsWe conclude that a moderate-intensity march under relatively comfort environmental conditions may differently decrease selected military related physical and cognitive abilities. This phenomenon is probably associated with the type and intensity of the pre-mission physical activity and the magnitude of the associated mental fatigue. We suggest that quantifying these effects, as was presented in this preliminary study, by adopting this practical scientific approach would assist in preserving the soldiers’ performance and health during training and military operations.