Insulin Prevents Hypercholesterolemia by Suppressing 12α-Hydroxylated Bile Acids.

BACKGROUND: The risk of cardiovascular disease in type 1 diabetes remains extremely high, despite marked advances in blood glucose control and even the widespread use of cholesterol synthesis inhibitors. Thus, a deeper understanding of insulin regulation of cholesterol metabolism, and its disruption in type 1 diabetes, could reveal better treatment strategies. METHODS: To define the mechanisms by which insulin controls plasma cholesterol levels, we knocked down the insulin receptor, FoxO1, and the key bile acid synthesis enzyme, CYP8B1. We measured bile acid composition, cholesterol absorption, and plasma cholesterol. In parallel, we measured markers of cholesterol absorption and synthesis in humans with type 1 diabetes treated with ezetimibe and simvastatin in a double-blind crossover study. RESULTS: Mice with hepatic deletion of the insulin receptor showed marked increases in 12α-hydroxylated bile acids, cholesterol absorption, and plasma cholesterol. This phenotype was entirely reversed by hepatic deletion of FoxO1. FoxO1 is inhibited by insulin and required for the production of 12α-hydroxylated bile acids, which promote intestinal cholesterol absorption and suppress hepatic cholesterol synthesis. Knockdown of Cyp8b1 normalized 12α-hydroxylated bile acid levels and completely prevented hypercholesterolemia in mice with hepatic deletion of the insulin receptor (n=5-30), as well as mouse models of type 1 diabetes (n=5-22). In parallel, the cholesterol absorption inhibitor, ezetimibe, normalized cholesterol absorption and low-density lipoprotein cholesterol in patients with type 1 diabetes as well as, or better than, the cholesterol synthesis inhibitor, simvastatin (n=20). CONCLUSIONS: Insulin, by inhibiting FoxO1 in the liver, reduces 12α-hydroxylated bile acids, cholesterol absorption, and plasma cholesterol levels. Thus, type 1 diabetes leads to a unique set of derangements in cholesterol metabolism, with increased absorption rather than synthesis. These derangements are reversed by ezetimibe, but not statins, which are currently the first line of lipid-lowering treatment in type 1 diabetes. Taken together, these data suggest that a personalized approach to lipid lowering in type 1 diabetes may be more effective and highlight the need for further studies specifically in this group of patients.

Offshore wind energy development: Research priorities for sound and vibration effects on fishes and aquatic invertebrates.

There are substantial knowledge gaps regarding both the bioacoustics and the responses of animals to sounds associated with pre-construction, construction, and operations of offshore wind (OSW) energy development. A workgroup of the 2020 State of the Science Workshop on Wildlife and Offshore Wind Energy identified studies for the next five years to help stakeholders better understand potential cumulative biological impacts of sound and vibration to fishes and aquatic invertebrates as the OSW industry develops. The workgroup identified seven short-term priorities that include a mix of primary research and coordination efforts. Key research needs include the examination of animal displacement and other behavioral responses to sound, as well as hearing sensitivity studies related to particle motion, substrate vibration, and sound pressure. Other needs include: identification of priority taxa on which to focus research; standardization of methods; development of a long-term highly instrumented field site; and examination of sound mitigation options for fishes and aquatic invertebrates. Effective assessment of potential cumulative impacts of sound and vibration on fishes and aquatic invertebrates is currently precluded by these and other knowledge gaps. However, filling critical gaps in knowledge will improve our understanding of possible sound-related impacts of OSW energy development to populations and ecosystems.

Utility of Stability and Tear Location in a Classification System for Discoid Meniscus Surgical Planning.

BACKGROUND: Despite the presence of multiple classification systems for discoid meniscus, no system has yet to demonstrate utility in predicting the need for meniscal repair. The purpose of this study was to correlate characteristics associated with meniscal repair and propose a model that can inform preoperative planning and initial counseling of surgical plans and expectations. METHODS: Medical and operative records of 434 knees with lateral discoid meniscus in children and adolescents treated between 1991 and 2016 were reviewed retrospectively to determine the surgical procedure performed (saucerization with or without meniscal repair), discoid meniscal morphology and stability, and location and type of any associated tear. Univariate associations between discoid meniscal characteristics and surgery type were calculated and a logistic regression model of surgery type was generated. RESULTS: In univariate models, unstable menisci (93%, or 179/204, P<0.001) and menisci with tears extending peripherally (75%, or 85/204, P<0.001) were more likely to receive surgery with repair. In isolation, instability demonstrated 89% sensitivity and 94% specificity in predicting surgery with repair. A logistic regression model including stability, tear, and their interaction (stability×tear) showed that that the odds of unstable lateral discoid menisci receiving surgery with repair was 114 times higher than stable menisci (P<0.001) while lateral discoid menisci with peripherally extending tears had 6.4 times higher odds of receiving repair than those that had an isolated central tear (P<0.001). CONCLUSION: Stability and tear location of lateral discoid menisci were associated with surgical treatment in univariate and logistic regression models. The proposed classification system, in which menisci are classified by stability [Stable (S0), Unstable (S1), morphology (Incomplete (M0), Complete (M1))], and tear [No tear (T0), Central tear, isolated (T1), or Central tear, peripheral extension (T2)], is easily remembered and predicts surgical repair for discoid menisci. This scheme can serve to inform preoperative planning and initial counseling of primary surgical management and postoperative expectations. Subsequent research should develop a system that predicts meniscal survival and patient outcomes following the index operation. LEVEL OF EVIDENCE: Level III.

Sprengel's deformity: an analysis of surgically and nonsurgically treated patients.

BACKGROUND: Sprengel's deformity is a congenital anomaly of the scapula and can be associated with reduced shoulder mobility and esthetic concerns. Controversies remain regarding its natural history, radiographic findings, and optimal treatment strategy. METHODS: A total of 74 Sprengel's shoulders in 71 patients presenting to a pediatric referral hospital were retrospectively reviewed including 24 surgically treated shoulders. Median age at initial presentation was 3.8 years. Median age at the final follow-up was 9.6 years. RESULTS: Twenty shoulders were analyzed for range of motion across time. The median composite abduction range was initially 105° and at the last time-point 98°, with a median loss of 15° over 5 years (P = .007). A total of 26% of the nonsurgical shoulders reported pain at the latest follow-up, compared with 1 surgical patient (4%) (P = .028). Older age was independently associated with pain (P < .001); this effect was only seen in nonsurgical patients. Radiographically, the glenoid inclination angle (GIA) independently correlated with the abduction range (P = .001). Surgically treated shoulders underwent a modified Woodward procedure at a median 4.8 years of age. At a median follow-up of 41 months, the abduction range improved in the surgical group from 90° preoperatively to 110° postoperatively, with a median gain of 40° (P < .001). The median GIA changed from -2° to 4° with a median gain of 9° (P = .004). CONCLUSIONS: The natural history of untreated Sprengel's deformity may be one of gradual decline in the abduction range, with a proportion of patients developing pain in adolescence. The GIA correlates with the shoulder abduction range. Surgery with a modified Woodward procedure may alter the natural history of the condition by improving motion and reducing risk of pain later in life.

Nationwide Ethnic/Racial Differences in Surgical Treatment of Discoid Meniscus in Children: A PHIS Database Study.

BACKGROUND: Discoid meniscus, a congenital meniscus variant, may have greater incidence in Asian populations. No US population-based studies have examined the discoid meniscus ethnic/racial distribution. In pediatric patients undergoing meniscus surgery, it is hypothesized that ethnic/racial variability exists in patients with discoid meniscus and this variability is different than in patients with medial meniscus tears. METHODS: The Pediatric Health Information System was queried from 48 hospitals to examine patients 18 years of age and younger between 2015 and 2019, using International Classification of Diseases, 10th Revision, Clinical Modification codes. A cohort of patients treated surgically for discoid meniscus was compared with a cohort of patients treated surgically for medial meniscal tear. These 2 populations were compared based on age, sex, ethnicity/race, Current Procedural Terminology code, insurance, urban versus rural, and region of country. Univariate testing and multivariable logistic modeling were used to test for associations. RESULTS: A discoid meniscus cohort of 399 children (median age, 13.0 y) was compared with a medial meniscus tear cohort of 3157 children (median age, 16.0 y) (P<0.001). Hispanic/Latino children accounted for 36.8% of the discoid lateral meniscus and 22.7% of the medial meniscus populations (P<0.001). Among pediatric patients that had surgery for discoid lateral meniscus or medial meniscus, Hispanic/Latino children had 2.36 times the odds of surgery for discoid meniscus compared with White patients after adjusting for age and insurance (P<0.001). Asian children also had 2.41 times the odds of surgery for discoid meniscus compared with White patients (P=0.017). CONCLUSIONS: This study shows a significant association of ethnicity/race with discoid versus medial meniscus surgical treatment in children. Among pediatric patients undergoing surgery for discoid meniscus, Hispanic/Latino and Asian patients were a significantly larger percentage of the population than White patients. Hispanic/Latino children made up a greater percentage of the population having surgery for a torn discoid meniscus versus a torn medial mensicus. When evaluating pediatric patients, younger age and Asian or Hispanic/Latino ethnicity should increase attention to the possibility of a discoid meniscus. LEVEL OF EVIDENCE: Level IV.

Surgical Management of Medial Discoid Meniscus in Pediatric and Adolescent Patients.

BACKGROUND: Medial discoid meniscus (MDM) is an exceedingly rare anatomic abnormality that presents similarly to other meniscal pathologies. Symptomatic MDM is typically managed arthroscopically with mixed short-term and long-term outcomes, although the existing knowledge about MDM is limited. The purpose of this study was to describe the presentation and surgical treatment of MDM in pediatric and adolescent patients. METHODS: Medical records of 12 knees with MDM in 8 pediatric and adolescent patients treated between 1991 and 2016 were reviewed retrospectively for patient characteristics, clinical manifestations, radiographic findings, operative techniques, and surgical outcomes. RESULTS: Of the 446 knees diagnosed arthroscopically with discoid menisci, lateral discoid meniscus was noted in 434 knees (97.3%) and MDM was present in 12 knees (2.7%). The MDM series included 8 patients of mean age 13.8 years (range: 7.8 to 19.8), of which 5 were males (63%), and 4 (50%) had bilateral involvement. Of the 11 knees with available clinical records, all cases presented symptomatically (pain, mechanical symptoms); 10 (91%) had concurrent physical exam findings. On intraoperative examination, discoid morphologies were described as complete in 4/8 knees (50%) or incomplete in 4/8 (50%), with associated instability in 6/12 (50%). Meniscal tears were reported in 9 cases (75%)-primarily, horizontal cleavage tears. Saucerization was performed in 11 knees (92%), with medial meniscal repair in 7 (58%), when indicated. Retear of the medial meniscus occurred in 4/11 knees (36%) at a mean of 25.8 months postoperation; 2 knees required revisions. One knee developed arthrofibrosis and underwent arthroscopic lysis of adhesions. CONCLUSIONS: MDM is a rare diagnosis, representing 3% of all discoid menisci, with a nonspecific clinical manifestation. Operative management of symptomatic MDM typically involves saucerization and meniscal repair, when indicated, for concurrent tears. Symptom resolution is common short-term, but long-term outcomes include recurrent meniscal tears. Subsequent observational studies are important to evaluate long-term outcomes, such as arthritic changes, with the advancement of arthroscopic techniques for meniscal preservation. LEVEL OF EVIDENCE: Level IV-retrospective case series.

Long-term Minimum 15-Year Follow-up After Lateral Discoid Meniscus Rim Preservation Surgery in Children and Adolescents.

BACKGROUND: Discoid meniscus is a congenital variant typically affecting the lateral meniscus of the knee. Historically, surgical intervention when symptomatic consisted of total meniscectomy; however, after degenerative changes were observed, current treatments now focus on rim preservation with arthroscopic saucerization and meniscal repair for instability, when indicated. The purpose of our study was to examine long-term patient-reported outcomes of lateral discoid meniscus (LDM) treated with meniscal-preserving techniques. METHODS: Ninety-eight patients treated arthroscopically for LDM at a single institution at a minimum of 15 years ago were retrospectively identified and contacted by mailers and telephone to participate. Subjective functional outcomes and patient satisfaction data were collected using a questionnaire that included the validated International Knee Documentation Committee Subjective Knee Evaluation Form, Lysholm Score, Marx Activity Rating Scale, Tegner Activity Score, and Western Ontario and McMaster University Osteoarthritis Index Osteoarthritis Index. Patient and surgical characteristics and patient-reported outcomes were summarized by mean and SD, median and interquartile range (interquartile range), or frequency and percent, as appropriate. RESULTS: Of the 46 patients contacted (response rate of 46/98 eligible), 25 (54%) completed the questionnaires. The mean (±SD) age at initial surgery was 10.8 (±3.4) and 30.3 (±3.7) years at final follow-up. The mean (±SD) follow-up time from initial surgery was 19.5 (±2.8) years (range, 16 to 27). Patient-reported outcomes included: International Knee Documentation Committee 77.4±17.2, Lysholm 78.6±21, Western Ontario and McMaster University Osteoarthritis Index 7.6±11.3, Tegner Activity 7 (of 10), and Marx Activity Rating Scale 8 (of 10). Eleven (44%) cases underwent subsequent LDM-related surgery on the ipsilateral knee(s). There were no cases of total knee replacement. CONCLUSIONS: Overall, patient-reported outcomes were favorable at a minimum of 15-year follow-up after rim-preserving saucerization of LDM. While two thirds of patients were satisfied with their surgical outcomes, nearly half of patients underwent revision saucerization with or without meniscal repair. Subsequent long-term follow-up studies with objective outcome measures are important to further elucidate the natural history of LDM and understand how rim-preserving procedures may prevent the development of degenerative processes. LEVEL OF EVIDENCE: Level IV-case series, prognostic study.

Markers of cholesterol synthesis are elevated in adolescents and young adults with type 2 diabetes.

BACKGROUND: Changes in cholesterol absorption and cholesterol synthesis may promote dyslipidemia and cardiovascular disease in individuals with type 2 diabetes mellitus (T2DM). OBJECTIVE: To assess cholesterol synthesis and absorption in lean individuals, obese individuals, and individuals with T2DM. METHODS: We measured lathosterol and lanosterol (markers of cholesterol synthesis) as well as campesterol and ß-sitosterol (markers of cholesterol absorption) in the serum of 15 to 26 years old individuals with T2DM (n = 95), as well as their lean (n = 98) and obese (n = 92) controls. RESULTS: Individuals with T2DM showed a 51% increase in lathosterol and a 65% increase in lanosterol compared to lean controls. Similarly, obese individuals showed a 31% increase in lathosterol compared to lean controls. Lathosterol and lanosterol were positively correlated with body mass index, fasting insulin and glucose, serum triglycerides, and C-reactive protein, and negatively correlated with HDL-cholesterol. In contrast, campesterol and ß-sitosterol were not altered in individuals with T2DM. Moreover, campesterol and ß-sitosterol were negatively correlated with body mass index, fasting insulin, and C-reactive protein and were positively correlated with HDL-cholesterol. CONCLUSIONS: Adolescents and young adults with T2DM show evidence of increased cholesterol synthesis compared to non-diabetic lean controls. These findings suggest that T2DM may promote cardiovascular disease by increasing cholesterol synthesis, and provide additional rationale for the use of cholesterol synthesis inhibitors in this group.

What Proportion of Patients Undergoing Bernese Periacetabular Osteotomy Experience Nonunion, and What Factors are Associated with Nonunion?

BACKGROUND: The Bernese periacetabular osteotomy (PAO) is one of the most-used surgical techniques to treat symptomatic acetabular dysplasia. Although good functional and radiographic short-term and long-term outcomes have been reported, several complications after PAO have been described. One complication that may compromise clinical results is nonunion of an osteotomy. However, the exact prevalence and risk factors associated with nonunion are poorly elucidated. QUESTIONS/PURPOSES: (1) What proportion of patients have complete bony healing versus nonunion during the first year after PAO? (2) What is the clinical and functional impact of nonunion at a minimum of 1 year after PAO, as assessed by the modified Harris hip score (mHHS) and the Hip Disability and Osteoarthritis Outcome Score (HOOS)? (3) What patient-specific or surgery-specific factors are associated with nonunion at 6 months and at a minimum of 1 year postoperatively? METHODS: Between January 2012 and December 2015, we retrospectively identified 314 patients who underwent PAO at our institution. During this period, 28 patients with a diagnosis different from symptomatic acetabular dysplasia (reverse PAO for acetabular over-coverage: n = 25; PAO for skeletal chondrodysplasia: n = 3) underwent PAO but were ineligible to participate. Hence, 286 patients underwent PAO to treat symptomatic acetabular dysplasia during the study period and were considered eligible. Inclusion criteria were patients with a complete set of postoperative radiographs (AP, Dunn lateral, and false-profile) at 12 months or more postoperatively. Eighteen percent (51 of 286) of the patients underwent staged, bilateral PAOs, but we only included the first PAO. Finally, 14% (41 of 286) of the patients were excluded because they had an incomplete set of postoperative radiographs at 12 months or more. The study comprised 245 patients. Eighty-five percent (209 of 245) of the patients were female and the mean age at surgery was 24 years ± 9 years. The healing status (complete healing vs. nonunion) was recorded for ischial, superior pubic, supraacetabular, and posterior column osteotomies at each subsequent visit. Nonunion was defined as noncontiguous osseous union with a persistent radiolucent line across any osteotomy site and was recorded at 3 months, approximately 6 months, and approximately 12 months postoperatively. Calculation of Cohen's kappa statistic coefficients showed the classification had perfect interobserver agreement (0.53; 95% confidence interval, 0.12-0.93), but there was moderate intraobserver agreement between those who healed and those with nonunion. The HOOS and mHHS were collected preoperatively and at a minimum of 1 year after PAO. The HOOS contains five separate subscales for pain, symptoms, activity of daily living, sport and recreational function, and hip-related quality of life. The HOOS responses are normalized on a scale of 0 (worst) to 100 (best). The mHHS includes pain and function scales and is overall interpreted on a scale from 0 (worst) to 100 (best). Eighty-six percent (211 of 245) of the patients with a complete set of images at their 12-month visit completed the mHHS and 89% (217 of 245) completed the HOOS. We collected information from the patients' medical records about their symptomatic status and additional treatment for nonunion. A logistic regression analysis was used to investigate factors associated with nonunion at 6 and 12 months postoperatively. RESULTS: Only 45% (96 of 215) of the patients had complete radiographic healing of all osteotomy sites at the 6-month visit and 55% (119 of 215) had not healed completely. However, 92% (225 of 245) demonstrated complete radiographic healing of all osteotomy sites at approximately 1 year postoperatively. The proportion of nonunion at a minimum of 12 months after PAO was 8% (20 of 245 patients). There was no difference in the mHHS after 1 year or more of follow-up between patients with nonunion and patients with complete healing after PAO (nonunion mean mHHS: 73; 95% CI, 62-85 versus healed: 82; 95% CI, 80-85; p = 0.13) and HOOS pain (nonunion mean HOOS pain: 80; 95% CI, 71-90 versus healed: 86; 95% CI, 83-88; p = 0.16). Similarly, no difference was identified for HOOS symptoms (nonunion mean: 72; 95% CI, 63-80 versus healed: 78; 95% CI, 75-81; p = 0.11), HOOS activities of daily living (nonunion mean: 86; 95% CI, 78-94 versus healed: 91; 95% CI, 89-93; p = 0.09), HOOS sports and recreation (nonunion mean: 70; 95% CI, 57-83 versus healed: 78; 95% CI, 75-82; p = 0.18); and HOOS quality of life (nonunion mean: 60; 95% CI, 46-75 versus healed: 69; 95% CI, 65-72; p = 0.28). After controlling for potentially confounding variables such as gender, age, chisel type, and preoperative anterior center-edge angle, we found that higher BMI (per 1 k/m; odds ratio 1.14; 95% CI, 1.06-1.22; p < 0.01), older age (per 1 year; OR 1.05; 95% CI, 1.01-1.08; p < 0.01) and more-severe acetabular dysplasia as assessed by a decreased preoperative lateral center-edge angle (per 1°; OR 1.06; 95% CI, 1.02-1.11; p < 0.01) were independently associated with nonunion of one or more osteotomy sites at 6 months postoperatively. Only age was an independent predictor of nonunion at 12 months postoperatively (per 1 year; OR 1.06; 95% CI, 1.01-1.11; p = 0.02). CONCLUSIONS: Our study helps us to understand radiographic healing during the first year after PAO to treat symptomatic acetabular dysplasia. Fewer than half of the patients had complete healing of their osteotomies at 6 months postoperatively. More than 90% of patients can expect to have completely healed osteotomy sites at 12 months postoperatively. Surgeons should avoid unnecessary interventions if nonunion is observed radiographically at 6 months postoperatively. Although there was no difference in the HOOS and mHHS between patients with nonunion and those with complete healing, further research with a larger cohort is needed to clarify the impact of nonunion on clinical and functional outcomes after PAO. Surgeons should consider using strategies to enhance osteotomy healing in those who undergo PAO, such as optimizing vitamin D levels and using local bone grafts in older patients, those with a high BMI, and patients with severe acetabular dysplasia. LEVEL OF EVIDENCE: Level III, therapeutic study.

Mercury exposure in migrating songbirds: correlations with physical condition.

Many migratory songbirds are at high risk of methylmercury (MeHg) exposure due to their trophic position and foraging in and around wetland habitats. Methylmercury has the potential to alter migratory behaviors and physiology via neurological impairment or reduced flight performance and can be remobilized from songbird muscle tissue during migration, increasing the risk of acute MeHg exposure. To document MeHg exposure and its relationship with physical condition in migratory songbirds, we sampled passerine blood and feathers at a migration stopover site on Key Biscayne, FL during fall and spring from 2009 to 2012. We found evidence that spring blood total mercury (THg) concentrations decreased throughout the day and that fall feather THg concentrations changed over the migratory season. Total mercury exposure was marginally correlated with migratory fat stores and related to changes in pectoral muscle thickness by time of day. These patterns suggest that environmentally relevant levels of THg are related to, and may be influencing, the physical condition of free-living migrating songbirds. Further research and monitoring during the migratory period will be important to elucidate exposure risk across multiple species and assess the potential for effects during this complex period of the annual cycle.

Acetabular Retroversion and Decreased Posterior Coverage Are Associated With Sports-related Posterior Hip Dislocation in Adolescents.

BACKGROUND: Leverage of the femoral head against the acetabular rim may lead to posterior hip dislocation during sports activities in hips with femoroacetabular impingement (FAI) deformity. Abnormal concavity of the femoral head and neck junction has been well described in association with posterior hip dislocation. However, acetabular morphology variations are not fully understood. QUESTIONS/PURPOSES: The purpose of this study was to compare the acetabular morphology in terms of acetabular version and coverage of the femoral head in adolescents who sustained a posterior hip dislocation during sports and recreational activities with a control group of patients without a history of hip disease matched by age and sex. METHODS: In this case-control study, we identified 27 adolescents with posterior hip dislocation sustained during sports or recreational activities who underwent a CT scan of the hips (study group) and matched them to patients without a history of hip disease being evaluated with CT for possible appendicitis (control group). Between 2001 and 2017, we treated 71 adolescents (aged 10-19 years old) for posterior hip dislocations. During the period in question, we obtained CT scans or MR images after closed reduction of a posterior hip dislocation. One patient was excluded because of a diagnosis of Down syndrome. Twenty-one patients who were in motor vehicle-related accidents were also excluded. Twelve patients were excluded because MRI was obtained instead of CT. Finally, three patients with no imaging after reduction and seven patients with inadequate CT reformatting were excluded. Twenty-seven patients (38%) had CT scans of suitable quality for analysis, and these 27 patients constituted the study group. We compared those hips with 27 age- and sex-matched adolescents who had CT scans for appendicitis and who had no history of hip pain or symptoms (control group). One orthopaedic surgeon and one pediatric musculoskeletal radiologist, not invoved in the care of the patients included in the study, measured the lateral center-edge angle, acetabular index, acetabular depth/width ratio, acetabular anteversion angle (10 mm from the dome and at the level of the center of the femoral heads), and the anterior and posterior sector angles in the dislocated hip; the contralateral uninvolved hip of the patients with hip dislocations; and both hips in the matched control patients. Both the study and control groups had 25 (93%) males with a mean age of 13 (± 1.7) years. Inter- and intrarater reliability of measurements was assessed with intraclass correlation coefficient (ICC). There was excellent reliability (ICC > 0.90) for the acetabular anteversion angle measured at the center of the femoral head, the acetabular version 10 mm from the dome, and the posterior acetabular sector angle. RESULTS: The mean acetabular anteversion angle (± SD) was lower in the study group at 10 mm from the acetabular dome (-0.4° ± 9° versus 4° ± 4°; mean difference -5°; 95% confidence interval [CI], -9 to -0.3; p = 0.015) and at the center of the femoral heads (10° ± 5° versus 14° ± 4°; mean difference -3°; 95% CI, -6 to -0.9; p = 0.003). A higher proportion of acetabula was severely retroverted in the study group (14 of 27 [52%]; 95% CI, 33%-71% versus four of 27 [15%]; 95% CI, 1%-28%; p = 0.006). The mean posterior acetabular sector angle was lower in the study group (82° ± 8° versus 90° ± 6°; mean difference -8°; 95% CI, -11 to -4; p < 0.001), whereas no difference was found for the anterior acetabular sector angle (65° ± 6° versus 65° ± 7°; mean difference 0.3°; 95% CI, -3 to 4; p = 0.944). There was no difference for the lateral center-edge angle (27° ± 6° versus 26° ± 5°; p = 0.299), acetabular index (5° ± 3° versus 6 ± 4°; p = 0.761), or acetabular depth/width ration (305 ± 30 versus 304 ± 31; p = 0.944) between groups. Acetabular anteversion angle at the center of the femoral heads (11° ± 4° versus 14° ± 4°; p = 0.006) and the posterior acetabular sector angle (86° ± 7 ° versus 91° ± 6°; p = 0.007) were lower in the contralateral uninvolved hips compared with control hips. CONCLUSIONS: Decreased acetabular anteversion angle and posterior acetabular coverage of the femoral head were associated with posterior dislocation of the hip in adolescents with sports-related injury even in the absence of a high-energy mechanism. Further studies are necessary to clarify whether a causative effect exists between acetabular and femoral morphology and the dislocation of the hip in patients with sports-related injuries. LEVEL OF EVIDENCE: Level III, prognostic study.

Predicting the offshore distribution and abundance of marine birds with a hierarchical community distance sampling model.

Proposed offshore wind energy development on the Atlantic Outer Continental Shelf has brought attention to the need for baseline studies of the distribution and abundance of marine birds. We compiled line transect data from 15 shipboard surveys (June 2012-April 2014), along with associated remotely sensed habitat data, in the lower Mid-Atlantic Bight off the coast of Delaware, Maryland, and Virginia, USA. We implemented a recently developed hierarchical community distance sampling model to estimate the seasonal abundance of 40 observed marine bird species. Treating each season separately, we included six oceanographic parameters to estimate seabird abundance: three static (distance to shore, slope, sediment grain size) and three dynamic covariates (sea surface temperature [SST], salinity, primary productivity). We expected that avian bottom-feeders would respond primarily to static covariates that characterize seafloor variability, and that surface-feeders would respond more to dynamic covariates that quantify surface productivity. We compared the variation in species-specific and community-level responses to these habitat features, including for rare species, and we predicted species abundance across the study area. While several protected species used the study area in summer during their breeding season, estimated abundance and observed diversity were highest for nonbreeding species in winter. Distance to shore was the most common significant predictor of abundance, and thus useful in estimating the potential exposure of marine birds to offshore development. In many cases, our expectations based on feeding ecology were confirmed, such as in the first winter season, when bottom-feeders associated significantly with the three static covariates (distance to shore, slope, and sediment grain size), and surface-feeders associated significantly with two dynamic covariates (SST, primary productivity). However, other cases revealed significant relationships between static covariates and surface-feeders (e.g., distance to shore) and between dynamic covariates and bottom-feeders (e.g., primary productivity during that same winter). More generally, we found wide interannual, seasonal, and interspecies variation in habitat relationships with abundance. These results show the importance of quantifying detection and determining the ecological drivers of a community's distribution and abundance, within and among species, for evaluating the potential exposure of marine birds to offshore development.

Impact of anesthesia and surgery for congenital heart disease on the vitamin d status of infants and children: a prospective longitudinal study.

BACKGROUND: Vitamin D is recognized as a pleiotropic hormone important for the functioning of organ systems, including those central to critical illness pathophysiology. Recent studies have reported associations between vitamin D status and outcome among critically ill adults and children. Preoperative vitamin D status, impact of operative techniques, and relationship between immediate postoperative vitamin D levels and clinical course have not been described in the pediatric congenital heart disease (CHD) population. The objective of this study was to describe the impact of CHD surgery on vitamin D status and relationship between postoperative levels and clinical course. METHODS: A prospective cohort study was conducted from 2009 to 2011 at a single tertiary care pediatric hospital. A total of 58 children with CHD were enrolled and blood collected preoperatively, intraoperatively, and postoperatively. Serum 25-hydroxyvitamin D (25OHD) was measured using liquid chromatography-mass spectrometry. RESULTS: The mean preoperative 25OHD was 58.0 nM (SD, 22.4), with 42% being deficient (<50 nM). Postoperatively, we identified a 40% decline in 25OHD to 34.2 nM (SD, 14.5) with 86% being deficient. Intraoperative measurements determined that initiation of cardiopulmonary bypass coincided with abrupt decline. CHD patients requiring catecholamines had lower postoperative 25OHD (38.2 vs. 26.5 nM, P=0.007), findings confirmed through multivariate logistic regression. Lower postoperative 25OHD was associated with increased fluid requirements and intubation duration. CONCLUSIONS: Most CHD patients are vitamin-D deficient postoperatively due to low preoperative levels and a significant intraoperative decline. Interventional studies will be required to determine whether prevention of postoperative vitamin D deficiency improves outcome.

Low-Intensity Pulsed Ultrasonography Plus Arthroscopic Drilling Does Not Improve Bone Healing More Than Arthroscopic Drilling Alone in Pediatric Patients With Stable Osteochondritis Dissecans of the Knee.

Purpose: To determine whether adjuvant use of bone stimulation would improve the rate of healing in the operative management of stable osteochondritis dissecans (OCD) of the knee in pediatric patients. Methods: This retrospective matched case-control study was performed at a single tertiary care pediatric hospital between January 2015 and September 2018. Patients who underwent antegrade drilling for stable femoral condyle OCD with greater than 2 years' follow-up were included. Preference was for all to receive postoperative bone stimulation; however, some were denied because of insurance coverage. This enabled us to create 2 matched groups of those who received postoperative bone stimulation and those who did not. Patients were matched on skeletal maturity, lesion location, sex, and age at surgery. The primary outcome measure was the rate of healing of the lesions determined by postoperative magnetic resonance imaging measurements at 3 months. Results: Fifty-five patients were identified who met the inclusion and exclusion criteria. Twenty patients from the bone stimulator group (BSTIM) were matched to 20 patients from the no bone stimulator group (NBSTIM). Mean age for BSTIM at surgery was 13.2 years ± 2.0 (range, 10.9-16.7) and for NBSTIM at surgery 12.9 years ± 2.0 (range, 9.3-17.3). At 2 years, 36 patients (90%) in both groups went on to clinical healing without further interventions. In BSTIM, there was a mean decrease of 0.9 (±1.8) mm in lesion on coronal width and 12 patients (63%) had overall improved healing; in NBSTIM there was a mean decrease of 0.8 (±3.6) mm in coronal width and 14 patients (78%) had improved healing. No statistical differences in the rate of healing were found between the 2 groups (P = .706). Conclusion: In antegrade drilling of stable knee OCD lesions in pediatric and adolescent patients, adjuvant bone stimulator use did not appear to improve radiographic or clinical healing. Level of evidence: Level III, retrospective case-control study.

Early Adherence to Prescribed Brace Wear for Adolescent Idiopathic Scoliosis Is Associated With Future Brace Wear.

STUDY DESIGN: Retrospective cohort study. OBJECTIVE: To assess if initial adherence to prescribed brace wear for adolescent idiopathic scoliosis (AIS) predicts future adherence and curve improvement. SUMMARY OF BACKGROUND DATA: AIS bracing can be effective if patients adhere to prescribed brace wear. Previous research has associated age, sex, and brace prescription length with future adherence. We hypothesize that a patient's initial adherence to brace wear may be associated with future adherence and outcomes. MATERIALS AND METHODS: Consecutive AIS patients who met the Scoliosis Research Society (SRS) criteria for bracing from 2015 to 2019 at a single center were reviewed. Patients were stratified into groups based on their adherence during the initial one-month brace wean-in period-adherent patients were defined as wearing the brace >80% of the daily prescribed amount. Brace wear was recorded by a thermosensor and assessed during the wean-in period, six-, 12-, and 24-month postbracing appointments. Statistical testing was conducted to analyze if initial adherence was associated with future adherence, curve change, and bracing success -defined as reaching Risser stage 4 with a Cobb angle <40°. RESULTS: Sixty patients (mean age=12.5 yr) were included, of which the majority were females (83%) with thoracic curves (70%). Thirty-two patients were considered adherent, and this cohort demonstrated improved adherence relative to the nonadherent group at the six-, 12-, and 24-month appointments ( P <0.001). Adherent patients also showed a significant reduction in their scoliosis at the 12-month appointment, unlike nonadherent patients ( P <0.001). Ninety-seven percent of adherent patients achieved bracing success compared with 71% of nonadherent ( P =0.016). Females were more likely to be adherent than males. CONCLUSIONS: Initial adherence to prescribed AIS brace wear was associated with future adherence, bracing success, and curve improvement. Early recognition of nonadherence may offer an opportunity for supportive intervention to improve brace wear behavior.

Surface and subsurface oceanographic features drive forage fish distributions and aggregations: Implications for prey availability to top predators in the US Northeast Shelf ecosystem.

Forage fishes are a critical food web link in marine ecosystems, aggregating in a hierarchical patch structure over multiple spatial and temporal scales. Surface-level forage fish aggregations (FFAs) represent a concentrated source of prey available to surface- and shallow-foraging marine predators. Existing survey and analysis methods are often imperfect for studying forage fishes at scales appropriate to foraging predators, making it difficult to quantify predator-prey interactions. In many cases, general distributions of forage fish species are known; however, these may not represent surface-level prey availability to predators. Likewise, we lack an understanding of the oceanographic drivers of spatial patterns of prey aggregation and availability or forage fish community patterns. Specifically, we applied Bayesian joint species distribution models to bottom trawl survey data to assess species- and community-level forage fish distribution patterns across the US Northeast Continental Shelf (NES) ecosystem. Aerial digital surveys gathered data on surface FFAs at two project sites within the NES, which we used in a spatially explicit hierarchical Bayesian model to estimate the abundance and size of surface FFAs. We used these models to examine the oceanographic drivers of forage fish distributions and aggregations. Our results suggest that, in the NES, regions of high community species richness are spatially consistent with regions of high surface FFA abundance. Bathymetric depth drove both patterns, while subsurface features, such as mixed layer depth, primarily influenced aggregation behavior and surface features, such as sea surface temperature, sub-mesoscale eddies, and fronts influenced forage fish diversity. In combination, these models help quantify the availability of forage fishes to marine predators and represent a novel application of spatial models to aerial digital survey data.

Closed Reduction and Immobilization of Pediatric Fifth Metacarpal Neck Fractures.

BACKGROUND: There is no clear consensus for the criteria for closed treatment of metacarpal neck fractures. Our objective was to determine whether closed reduction of pediatric fifth metacarpal neck fractures results in a clinically meaningful improvement in radiographic angulation. METHODS: We performed a retrospective cohort study of pediatric patients with fifth metacarpal neck fractures treated with closed reduction. Radiographs were examined for sagittal fracture angulation measured post-reduction, 2 to 14 days post-reduction, and 21 to 35 days post-reduction. We compared the angulation for open versus closed physes, initial fracture angulation greater than or less than 50°, and immobilization in extension versus intrinsic-plus position. RESULTS: Fifty-four subjects were included with an average age of 14.8 years at the time of injury and a mean initial fracture angulation of 42.7°. The improvement in fracture angulation was 8.3° (90% confidence interval [CI], 5.9-10.7) on post-reduction radiographs, 8.5° (90% CI, 6.1-10.9) at 2 to 14 days post-reduction, and 4.3° (90% CI, 1.4-7.2) at 21 to 35 days post-reduction. Subgroup analysis showed that patients with injury angle greater than or equal to 50° had significantly higher mean reductions than those with injury angle less than 50°. In this group, angulation improved 15.6° (90% CI, 8.5-22.7) post-reduction, 15.1° (90% CI, 10.1-20.1) at 2 to 14 days post-reduction, and 16.5° (90% CI, 10.4-22.6) at 21 to 35 days post-reduction. CONCLUSIONS: Closed reduction of pediatric fifth metacarpal neck fractures with initial fracture angulation less than 50° may not meaningfully improve sagittal alignment. For fractures with initial angulation greater than or equal to 50°, closed reduction resulted in clinically important, statistically significant, and lasting improvements of 16.5°.

Pediatric Tracheostomy Care Simulation: Real-Life Scenarios in a Safe Learning Environment.

BACKGROUND: Pediatric patients require tracheostomy tube placement as a last resort for critical airway management. Around-the-clock care is needed at discharge because of the high risk of morbidity and mortality associated with a tracheostomy. The potential for catastrophic sequalae can create a high stress home environment. A simulation program that used a high-fidelity manikin was implemented to reduce complications, morbidity and mortality, and improve skills for real-life medical scenarios. METHODS: A tracheostomy care simulation program was implemented at a large tertiary care children's hospital from October 2019 to October 2020. Caregivers participated in a pre-post program survey and rated 9 statements on a 5-point scale with regard to knowledge, confidence, and comfort level of taking care of their child at home. Emergency scenarios included accidental tracheostomy tube dislodgement, tracheostomy tube plugging, cardiac arrest, and ventilator failure. Classes were recorded for objective start-to-finish scenario time stamps and prompt rates. A medical chart review was performed 90 d after discharge. RESULTS: Eighteen caregivers for 10 children participated. For the 10 children, there was a 9.1% increase in the average total score agreement from pre to post survey, with scores going from "agree" to "strongly agree" (P = .001). Each subset of questions had a significant increase in scores after participation: knowledge, P = .002; confidence, P = .006; and comfort, P = .01. The caregivers required an average 20% prompt rate for the next step in the scenario. Children were 70% female, 80% white, and 60% had public insurance and had their tracheostomy tube placed at a median age of 4 months (range, 0 months to 24 years). Three children (n = 3/9 [33.3%]) were readmitted for tracheitis within 90 d after being discharged to home. CONCLUSIONS: Caregiver knowledge, confidence, and comfort levels were increased after participation. Pediatric patients with a tracheostomy are medically fragile, therefore, it is important for caregivers to be aware of and prepared for common tracheostomy emergencies and to "experience" emergency situations firsthand.

The incidence and risk factors for stress fracture following periacetabular osteotomy.

AIMS: The aims of this study were to characterize the incidence and risk factors associated with stress fractures following periacetabular osteotomy, and to determine their effect on osteotomy union. METHODS: We retrospectively reviewed all periacetabular osteotomies (PAOs) performed for developmental dysplasia of the hip (DDH) at one institution over a six-year period between 2012 and 2017. Perioperative factors were recorded, and included demographic and surgical data. Postoperatively, patients were followed for a minimum of one year with anteroposterior and false profile radiographs of the pelvis to monitor for evidence of stress fracture and union of osteotomies. We characterized the incidence and locations of stress fractures, and used univariate and multivariable analysis to identify factors predictive of stress fracture and the association of stress fracture on osteotomy union. RESULTS: A total of 331 patients underwent PAO during the study period with 56 (15.4%) stress fractures: 46 fractures of the retroacetabular posterior column, five cases of ischiopubic stress fracture, and five cases of concurrent ischiopubic and retroacetabular stress fractures. Overall, 86% (48/56) healed without intervention. Univariate analysis revealed that stress fractures occurred more frequently in females (p = 0.040), older patients (mean age 27.6 years (SD 8.4) vs 23.8 (SD 9.0); p = 0.003), and most often with the use of the broad Mast chisel (28.5%; p < 0.001). Multivariable analysis revealed that increasing age (odds ratio (OR) 1.04; 95% CI 1.01 to 1.07; p = 0.028) and use of the broad Mast chisel (OR 5.1 (95% CI 1.3 to 19.0) compared to narrow Ganz chisel; p = 0.038) and surgeon (p = 0.043) were associated with increased risk of stress fracture. Patients with stress fractures were less likely to have healed osteotomies after one-year follow-up (76% vs 96%; p < 0.001). CONCLUSION: Stress fracture of the posterior column may be an under-recognized complication following PAO, and the rate may be influenced by surgical technique. Consideration should be given to using a narrow chisel during the ischial cut to reduce the risk of stress propagation through the posterior column.Cite this article: Bone Joint J 2022;104-B(9):1017-1024.

Use of the superpopulation approach to estimate breeding population size: an example in asynchronously breeding birds.

Many populations of animals are fluid in both space and time, making estimation of numbers difficult. Much attention has been devoted to estimation of bias in detection of animals that are present at the time of survey. However, an equally important problem is estimation of population size when all animals are not present on all survey occasions. Here, we showcase use of the superpopulation approach to capture-recapture modeling for estimating populations where group membership is asynchronous, and where considerable overlap in group membership among sampling occasions may occur. We estimate total population size of long-legged wading bird (Great Egret and White Ibis) breeding colonies from aerial observations of individually identifiable nests at various times in the nesting season. Initiation and termination of nests were analogous to entry and departure from a population. Estimates using the superpopulation approach were 47-382% larger than peak aerial counts of the same colonies. Our results indicate that the use of the superpopulation approach to model nesting asynchrony provides a considerably less biased and more efficient estimate of nesting activity than traditional methods. We suggest that this approach may also be used to derive population estimates in a variety of situations where group membership is fluid.