Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

Postoperative racial disparities following spine surgery are less pronounced in the outpatient setting

BACKGROUND CONTEXT

Racial disparities in spine surgery have been thoroughly documented in the inpatient (IP) setting. However, despite an increasing proportion of procedures being performed as same-day surgeries, whether similar differences have developed in the outpatient (OP) setting remains to be elucidated.

PURPOSE

This study aimed to investigate racial differences in postoperative outcomes between Black and White patients following OP and IP lumbar and cervical spine surgery.

STUDY DESIGN/SETTING

Retrospective cohort study.

PATIENT SAMPLE

Patients who underwent IP or OP microdiscectomy, laminectomy, anterior cervical discectomy and fusion (ACDF), or cervical disc replacement (CDR) between 2017 and 2021.

OUTCOME MEASURES

Thirty-day rates of serious and minor adverse events, readmission, reoperation, non-home discharge, and mortality.

METHODS

A retrospective review of patients who underwent IP or OP microdiscectomy, laminectomy, anterior cervical discectomy and fusion (ACDF), or cervical disc replacement (CDR) between 2017 and 2021 was conducted using the National Surgical Quality Improvement Program (NSQIP) database. Disparities between Black and White patients in (1) adverse event rates, (2) readmission rates, (3) reoperation rates, (4) non-home discharge rates, (5) mortality rates, (6) operative times, and (7) hospital LOS between Black and White patients were measured and compared between IP and OP surgical settings. Multivariable logistic regression analyses were used to adjust for potential effects of baseline demographic and clinical differences.

RESULTS

Of 81,696 total surgeries, 49,351 (60.4%) were performed as IP and 32,345 (39.6%) were performed as OP procedures. White patients accounted for a greater proportion of IP (88.2% vs. 11.8%) and OP (92.7% vs. 7.3%) procedures than Black patients. Following IP surgery, Black patients experienced greater odds of serious (OR 1.214, 95% CI 1.077-1.370, p=.002) and minor adverse events (OR 1.377, 95% CI 1.113-1.705, p=.003), readmission (OR 1.284, 95% CI 1.130-1.459, p<.001), reoperation (OR 1.194, 95% CI 1.013-1.407, p=.035), and non-home discharge (OR 2.304, 95% CI 2.101-2.528, p<.001) after baseline adjustment. Disparities were less prominent in the OP setting, as Black patients exhibited greater odds of readmission (OR 1.341, 95% CI 1.036-1.735, p=0.026) but were no more likely than White patients to experience adverse events, reoperation, individual complications, non-home discharge, or death (p>.050 for all).

CONCLUSIONS

Racial inequality in postoperative complications following spine surgery is evident, however disparities in complication rates are relatively less following OP compared to IP procedures. Further work may be beneficial in elucidating the causes of these differences to better understand and mitigate overall racial disparities within the inpatient setting. These decreased differences may also provide promising indication that progress towards reducing inequality is possible as spine care transitions to the OP setting.

Publication Rates Vary Across Orthopaedic Subspecialties: A Longitudinal Analysis of AAOS Abstracts

Background

Presentation of research at national orthopaedic meetings and subsequent publication are important for both information exchange among surgeons and individual academic advancement. However, the academic landscape and pressures that researchers face may differ greatly across different subspecialties. This study attempts to explore and quantify differences in research presented at national conferences and its implication on ultimate likelihood of publication in peer-reviewed journals.

Methods

All abstracts from the Annual Meetings of the American Academy of Orthopaedic Surgeons (AAOS) from 2016 and 2017 were reviewed and categorized based on subspecialty focus. Resulting publications were identified using a systematic search of PubMed and Google Scholar databases. Multivariate binary logistic regression modelling was used to assess the predictive value of abstract characteristics on eventual publication.

Results

A total of 1805 abstracts from the 2016 and 2017 AAOS conferences were reviewed. The overall publication rate of abstracts following the AAOS meetings was 71.6%, with an average time to publication from abstract submission deadline and impact factor of 19.8 months and 2.878, respectively. Statistical differences were observed across subspecialties with respect to publication rate (p<0.001), time to publication (p<0.001), and impact factor (p<0.001). The subspecialty with the highest publication rate, largest impact factor, and shortest average time to publication was Sports Medicine with 83.2%, 3.98, and 17.6 months, respectively; despite lower average sample size (p<0.001) and frequency of multicenter design (p<0.001) compared with other subspecialties. The subspecialty with the lowest publication rate and impact factor was Hand and Wrist with 53.3% and 1.41, respectively. Multivariate logistic regression analysis demonstrates a lower likelihood for internationally authored abstracts (OR: 0.75, p=0.021) and higher likelihood for basic science abstracts (OR: 1.52, p-value=0.023) to reach publication.

Conclusion

Differences in publication rate across orthopaedic subspecialties were observed with articles in sports medicine more likely to be published, published quickly, and featured in a higher impact factor journals. Understanding these differences, and how they relate to the publication and promotion of novel research, is important for orthopaedic researchers. Level of Evidence: IV.

Effects of 24-week prebiotic intervention on self-reported upper respiratory symptoms, gastrointestinal symptoms, and markers of immunity in elite rugby union players

OBJECTIVES

Elite rugby union players face numerous physiological and psychological stressors which can increase upper respiratory and gastrointestinal illness risk, and in turn can compromise training and competitive performance. This study aimed to investigate the effect of daily prebiotic supplementation on upper respiratory symptoms, gastrointestinal symptoms, and markers of immune function in elite rugby union players.

METHODS

Thirty-three elite rugby union players were randomly assigned to consume a prebiotic (2.8 g/day galactooligosaccharide) or placebo (2.8 g/day maltodextrin), daily for 168 days under double-blind conditions. Participants completed daily and weekly questionnaires for self-reported upper respiratory and gastrointestinal symptoms respectively. Blood and saliva samples were collected at 0, 84, and 168 days for assessment of plasma TNF-α and CRP, and saliva IgA respectively.

RESULTS

The prebiotic group experienced a 2-day reduction in upper respiratory symptom duration (P = 0.045). Gastrointestinal symptom severity and incidence were lower in the prebiotic group compared to the placebo group (P < 0.001, P = 0.041) respectively. Salivary immunoglobulin A secretion rate was 42% greater in the prebiotic group compared to the placebo group at day 168 (P = 0.004), no differences in CRP and TNF-α were found (P > 0.05).

CONCLUSION

A 168-day dietary prebiotic intervention reduced the duration of upper respiratory symptoms and reduced the incidence and severity of gastrointestinal symptoms in elite rugby union players. These findings suggest that seasonal prebiotic interventions may be beneficial for reducing illness in elite rugby union players, improving their availability to train and compete.Key pointsElite athletes are susceptible to upper respiratory symptoms and gastrointestinal symptoms which may impact upon training availability and competition performance.For the first time, this study shows that a dietary prebiotic intervention can reduce the duration of upper respiratory symptoms by 2 days in elite rugby union players.Dietary prebiotic supplementation can improve the incidence and severity of gastrointestinal symptoms experienced by elite rugby union players.Prebiotic supplementation was able to increase salivary IgA secretion after 168 days.These findings can inform practice suggesting that seasonal prebiotic use has the potential to modulate immune function and reduce illness in elite rugby union, which may improve a player's availability to train and compete.The mechanisms by which prebiotics reduce URS and GIS require further research exploration.

Validation of the ACL-RSI Scale in Pediatric and Adolescent Patients

BACKGROUND

The Anterior Cruciate Ligament-Return to Sport after Injury (ACL-RSI) scale is a 12-item questionnaire assessing psychological readiness to return to sport after anterior cruciate ligament reconstruction. It has been validated for use in adults in multiple languages and in an abbreviated 6-question short form. Additionally, literature has been published using this scale in pediatric and adolescent populations, however it has not yet been validated for use with them.

PURPOSE

To validate the ACL-RSI scale for use with pediatric and adolescent patients.

STUDY DESIGN

Cohort study (Diagnosis); Level of evidence, 2.

METHODS

Scores of 6- and 12-item ACL-RSI scales for patients undergoing return-to-sport readiness testing 6 to 8 months after anterior cruciate ligament reconstruction were analyzed. Convergent validity testing was performed against the International Knee Documentation Committee (IKDC)/Pediatric IKDC score, Single Assessment Numeric Evaluation (SANE) score, and peak torque asymmetry of knee flexion and extension using Spearman correlations. Discriminant validity testing was performed against age (Spearman correlation), body mass index (Spearman correlation), and sex (Mann-Whitney U test). Reliability testing was performed by calculating Cronbach's alpha. Floor and ceiling effects were assessed by calculating the number of minimum and maximum scores in the cohort.

RESULTS

A total of 51 patients were included in the final analysis. The mean age at surgery was 15.2 ± 2.2 years, and 51.0% were female. The 6- and 12-item ACL-RSI scales demonstrated a strong significant positive correlation with IKDC/Pediatric IKDC scores (R = 0.723 and 0.717, respectively; P < .001) and moderate significant positive correlation with Single Assessment Numeric Evaluation scores (R = 0.516 and 0.502, respectively; P < .001) Age at surgery, body mass index, and sex were not correlated with either ACL-RSI scale. Cronbach's alpha values of the 12- and 6-item ACL-RSI scales in this population were 0.959 and 0.897, respectively. For both the 12- and the 6-item ACL-RSI scales, no floor or ceiling effects were found as the minimum score (0) was not observed in either version, and the maximum score (100) was only observed twice (3.9%) in both versions.

CONCLUSION

The ACL-RSI scale is valid to use with pediatric and adolescent patients. The 6-item scale may be a better choice because it has fewer redundancies and minimizes the risk of questionnaire fatigue.

Observation of the effect of gravity on the motion of antimatter

Einstein's general theory of relativity from 19151 remains the most successful description of gravitation. From the 1919 solar eclipse2 to the observation of gravitational waves3, the theory has passed many crucial experimental tests. However, the evolving concepts of dark matter and dark energy illustrate that there is much to be learned about the gravitating content of the universe. Singularities in the general theory of relativity and the lack of a quantum theory of gravity suggest that our picture is incomplete. It is thus prudent to explore gravity in exotic physical systems. Antimatter was unknown to Einstein in 1915. Dirac's theory4 appeared in 1928; the positron was observed5 in 1932. There has since been much speculation about gravity and antimatter. The theoretical consensus is that any laboratory mass must be attracted6 by the Earth, although some authors have considered the cosmological consequences if antimatter should be repelled by matter7-10. In the general theory of relativity, the weak equivalence principle (WEP) requires that all masses react identically to gravity, independent of their internal structure. Here we show that antihydrogen atoms, released from magnetic confinement in the ALPHA-g apparatus, behave in a way consistent with gravitational attraction to the Earth. Repulsive 'antigravity' is ruled out in this case. This experiment paves the way for precision studies of the magnitude of the gravitational acceleration between anti-atoms and the Earth to test the WEP.

Changes in height, weight, and body mass index after posterior spinal fusion in juvenile and adolescent idiopathic scoliosis

Purpose

Posterior spinal fusion for idiopathic scoliosis is known to increase spinal height, but the impacts on weight and resulting body mass index are unknown. This study assesses body mass index, weight, and height percentile changes over time after posterior spinal fusion for idiopathic scoliosis.

Methods

Body mass index, weight, and height age- and sex-adjusted percentiles for patients with idiopathic scoliosis undergoing posterior spinal fusion between January 2016 and August 2022 were calculated based on growth charts from the Centers for Disease Control for Disease Control and compared to preoperative values at 2 weeks, 3 months, 6 months, 1 year, and 2 years. The data were analyzed for normality with a Shapiro-Wilk test, and percentiles were compared with the Wilcoxon signed-rank tests.

Results

On average, 12.1 ± 2.3 levels were fused in 269 patients 14.4 ± 1.9 years, and percentiles for body mass index, weight, and height preoperatively were 55.5 ± 29.4%, 57.5 ± 28.9%, and 54.6 ± 30.4%, respectively. Body mass index and weight percentiles decreased at 2 weeks (-10.7%, p < 0.001; -4.6%, p < 0.001, respectively) and 3 months (-6.9%, p < 0.001; -3.2%, p < 0.001, respectively) postoperatively. Postoperative weight loss at 2 weeks averaged 2.25 ± 3.09% of body weight (0.98 ± 4.5 kg), normalizing by 3 months. Body mass index percentile normalized at 1 year, but height percentile was increased at 2 weeks (2.42 ± 1.72 cm, p < 0.001) and through 2 years.

Conclusion

Despite initial height increase due to deformity correction, acute postoperative weight and body mass index percentile decreases postoperatively normalize by 1-year body mass index percentile. Physicians may benefit from utilizing this information when discussing the postoperative course of posterior spinal fusion with idiopathic scoliosis.

Level of evidence

4, Retrospective Case Series.

Removing or Only Moving a Barrier? Screening Applications with US Medical Licensing Examination Step 2CK Instead of Step 1 May Benefit Women but Not Underrepresented Minorities in Orthopaedics

Most orthopaedic surgery program directors report using a minimum score cutoff for the US Medical Licensing Examination Step 1 examination when evaluating residency applicants. The transition to a Pass/Fail grading system beginning in the 2022-2023 application cycle will alter applicant evaluation in the interview selection process. The impact of this change, particularly on women and underrepresented minority (URM) applicants, remains unclear. This study was designed to evaluate how a shift to screening applications using Step 2 Clinical Knowledge (CK) instead of Step 1 scores could impact selection for residency interviews.

Methods

We reviewed all 855 Electronic Residency Application Service applications submitted to the University of Pennsylvania's orthopaedic surgery residency program in the 2020-2021 cycle. Applicant age, sex, medical school of graduation, self-identified race, and permanent zip code were evaluated for association with Step 1 and Step 2CK scores using a 2-sample t test. A multivariable linear regression analysis was conducted to understand the predictive value of demographic features and medical school features on Step 1 and 2CK scores.

Results

Multivariable linear regression revealed both Step 1 and 2CK scores were lower for applicants of URM status (Step 1: p < 0.001; Step 2CK: p < 0.001) and from international medical schools (p = 0.043; p = 0.006). Step 1 scores but not Step 2CK scores were lower for applicants who were women (p < 0.001; p = 0.730), ≥30 years of age (p < 0.001; p = 0.079), and from medical schools outside the top 25 in National Institutes of Health (NIH) funding or US News and World Report (USNWR) ranking (p = 0.001; p = 0.193).

Conclusions

Conversion of Step 1 grading to Pass/Fail may reduce barriers for groups with lower average Step 1 scores (URM, female, ≥30 years of age, and from institutions with lower NIH funding or USNWR rankings). However, if Step 2CK scores replace Step 1 as a screening tool, groups with lower Step 2CK scores, notably URM applicants, may not experience this benefit.

Level of Evidence

Level IV. See Instructions for Authors for a complete description of levels of evidence.

Elamipretide mitigates ischemia-reperfusion injury in a swine model of hemorrhagic shock

ischemia-reperfusion injury (IRI) after hemorrhage is potentiated by aortic occlusion or resuscitative endovascular balloon occlusion of the aorta (REBOA). Given the central role of mitochondrial injury in shock, we hypothesized that Elamipretide, a peptide that protects mitochondria, would mitigate IRI after hemorrhagic shock and REBOA. Twelve pigs were subjected to hemorrhagic shock and 45 min of REBOA. After 25 min of REBOA, animals received either saline or Elamipretide. Animals were transfused with autologous blood during balloon deflation, and pigs were resuscitated with isotonic crystalloids and norepinephrine for 4.25 h. Elamipretide-treated animals required less crystalloids than the controls (62.5 [50-90] and 25 [5-30] mL/kg, respectively), but similar amounts of norepinephrine (24.7 [8.6-39.3] and 9.7 [2.1-12.5] mcg/kg, respectively). Treatment animals had a significant reduction in serum creatinine (control: 2.7 [2.6-2.8]; Elamipretide: 2.4 [2.4-2.5] mg/dL; p = 0.04), troponin (control: 3.20 [2.14-5.47] ng/mL, Elamipretide: 0.22 [0.1-1.91] ng/mL; p = 0.03), and interleukin-6 concentrations at the end of the study. There were no differences in final plasma lactate concentration. Elamipretide reduced fluid requirements and protected the kidney and heart after profound IRI. Further understanding the subcellular consequences of REBOA and mitochondrial rescue will open new therapeutic avenues for patients suffering from IRI after hemorrhage.

Percentage of intrathoracic stomach predicts operative and post-operative morbidity, persistent reflux and PPI requirement following laparoscopic hiatus hernia repair and fundoplication

PURPOSE

Large hiatus hernias are relatively common and can be associated with adverse symptoms and serious complications. Operative repair is indicated in this patient group for symptom management and the prevention of morbidity. This study aimed to identify predictors of poor outcomes following laparoscopic hiatus hernia repair and fundoplication (LHHRaF) to aid in counselling potential surgical candidates.

METHODOLOGY

A retrospective analysis was performed from a prospectively maintained, multicentre database of patients who underwent LHHRaF between 2014 and 2020. Revision procedures were excluded. Hernia size was defined as the intraoperative percentage of intrathoracic stomach, estimated by the surgeon to the nearest 10%. Predictors of outcomes were determined using a prespecified multivariate logistic regression model.

RESULTS

625 patients underwent LHHRaF between 2014 and 2020 with 443 patients included. Median age was 65 years, 62.9% were female and 42.7% of patients had ≥ 50% intrathoracic stomach. In a multivariate regression model, intrathoracic stomach percentage was predictive of operative complications (P = 0.014, OR 1.05), post-operative complications (P = 0.026, OR 1.01) and higher comprehensive complication index score (P = 0.023, OR 1.04). At 12 months it was predictive of failure to improve symptomatic reflux (P = 0.008, OR 1.02) and persistent PPI requirement (P = 0.047, OR 1.02). Operative duration and blood loss were predicted by BMI (P = 0.004 and < 0.001), Type III/IV hernias (P = 0.045 and P = 0.005) and intrathoracic stomach percentage (P = 0.009 and P < 0.001). Post-operative length of stay was predicted by age (P < 0.001) and emergency presentation (P = 0.003).

CONCLUSION

In a multivariate regression model, intrathoracic stomach percentage was predictive of operative and post-operative morbidity, PPI use, and failure to improve reflux symptoms at 12 months.

A Glass Ceiling in Orthopedic Surgery: Publication Trends by Gender

Women are underrepresented across the field of orthopedic surgery and may face barriers to academic advancement. Research presentation at national meetings and publication record are important drivers of advancement in academic orthopedic surgery. However, little is known regarding potential gender differences in publication after orthopedic conference research presentation. This investigation analyzed research presentations at the Annual Meeting of the American Academy of Orthopaedic Surgeons in 2016 and 2017. Author gender was determined through a search of institutional and professional networking websites for gender-specific pronouns. Resulting publications were identified using a systematic search of PubMed and Google Scholar databases. A total of 1696 of 1803 (94.1%) abstracts from 2016 to 2017 had identifiable gender for both the first and last authors, with 1213 (71.5%) abstracts ultimately being published. There were no differences in average sample size or level of evidence between genders. Abstracts authored by women were significantly less likely to lead to publication compared with those by men (67.1% vs 72.1%, P=.023), with articles authored by women having a longer median time to publication (median, 20 months [interquartile range, 19] vs 17 months [interquartile range, 15]; P=.003). This discrepancy was most apparent in adult reconstruction, with women having a 15.5% lower rate of publication (55.1% [27/49] vs 70.6% [307/435]; P=.026) and lower publication journal impact factor (2.7±1.4 vs 3.4±3.4, P=.040) than men. Potential reasons for these discrepancies, including disproportionate domestic obligations, inadequate mentorship, and bias against female researchers, should be addressed. [Orthopedics. 2023;46(2):e118-e124.].

Risk of ventriculoperitoneal shunt malfunction in operatively treated early onset spinal deformity

PURPOSE

Ventriculoperitoneal (VP) shunt placement is a common neurosurgical procedure performed in patients with early onset scoliosis (EOS). To provide insight into the risks of spine lengthening operations, we investigate the rate of VP shunt complications in patients with EOS undergoing spinal deformity correction interventions.

METHODS

A retrospective review was performed of all patients with EOS at a single institution undergoing spinal deformity correction procedures from 2007 to 2018. Patients having undergone VP shunt implantation prior to deformity correction were included. A minimum of 2-year follow-up was required for inclusion. Clinical records and imaging studies were reviewed.

RESULTS

Nineteen patients with VP shunts underwent Vertical Expandable Prosthetic Titanium Rib (VEPTR) implantation for treatment of early onset spinal deformity. The mean age at shunt placement and spine instrumentation surgery was 13.7 months (1 day to 13 years) and 6.1 years (0.5-15.1) respectively. The diagnoses associated with shunt implantation were: 12 spina bifida, 3 structural defects or obstructions, 2 intraventricular hemorrhage, 1 cerebral palsy, and 1 campomelic dwarfism. During the first 2 years following rib-based insertion, there was a mean of 2.5 expansion/revision procedures (0-5) with no shunt-related complications. The mean length of follow-up in this series was 7.0 years (2.6-13.2). A total of three (16%) patients required shunt revision following their rib-based device insertion, two patients with proximal shunt malfunctions and one with a mid-catheter breakage, at 2.4, 2.6, and 5.6 years, respectively, after rod implantation (Fig. 2). Each of these shunt revisions occurred more than 50 days following an expansion procedure (1.9, 2.9, and 5.7 months, respectively).

CONCLUSION

Growing instrumentation procedures in EOS are associated with low risk for post-operative shunt complications in patients with ventriculoperitoneal shunts. There were no shunt revision procedures performed in the first 2 years following rib-based device insertion. Sixteen percent of patients went on to require a shunt revision at some point during their follow-up, which is comparable to the baseline rate of shunt revision in non-EOS patients.

LEVEL OF EVIDENCE

IV, Case series.

The effect of trait self-control on dyspnoea and tolerance to a CO2 rebreathing challenge in healthy males and females

BACKGROUND

High trait self-control is associated with greater tolerance of unpleasant sensations including effort and pain. Dyspnoea and pain have several commonalities and this study aimed to investigate for the first time whether trait self-control influences responses to a hypercapnic rebreathing challenge designed to induce dyspnoea. As sex also influences tolerance to dyspnoea, we also sought to investigate whether this moderated the role of trait self-control.

METHODS

Participants (n = 65, 32 females) scoring high or low for trait self-control, performed a standardised rebreathing challenge, in which inspired carbon dioxide (CO₂) gradually increased over a period of 6 min or until an intolerable level of dyspnoea. Air hunger (AH) intensity - a distinctive quality of dyspnoea, was measured every 30 s. The multidimensional dyspnoea profile (MDP) was completed after the rebreathing challenge for a more complete overview of breathing discomfort.

RESULTS

Males high in trait self-control (SCHIGH) (302 ± 42 s), tolerated the rebreathing challenge for longer than males low in self-control (SCLOW) (252 ± 66 s, P = 0.021), experienced slower increases in AH intensity during the rebreathing challenge (0.03 ± 0.01 cm^.s ^- 1 vs. 0.04 ± 0.01 cm^.s ^- 1,P = 0.045) and reported lower perceived mental effort on the MDP (4.94 ± 2.46 vs. 7.06 ± 1.60, P = 0.007). There was no difference between SCHIGH and SCLOW females for challenge duration. However, SCHIGH females (9.29 ± 0.66 cm) reported greater air hunger at the end of the challenge than SCLOW females (7.75 ± 1.75 cm, P = 0.003). It is possible that SCLOW females were unwilling to tolerate the same perceptual intensity of AH as the SCHIGH females.

CONCLUSIONS

These results indicate that individuals high in trait self-control are more tolerant of dyspnoea during a CO₂ rebreathing challenge than low self-control individuals. Tolerance of the stimulus was moderated by the sex of the participant, presenting an interesting opportunity for future research.

Weight gain and gastrostomy tube safety during serial body casting for early onset scoliosis

PURPOSE

Serial casting has been shown to improve curve deformity for patients with early-onset scoliosis (EOS). However, despite prior literature demonstrating the importance of weight and nutrition in EOS patients, there is limited information regarding complications and weight gain ability for children undergoing serial casting. Additionally, parents of patients undergoing serial casting often have concerns regarding weight gain and patient comfort, which tend to be amplified in patients with gastrostomy tubes (g-tubes). We aim to understand changes in weight, g-tube complications, and cast-related complications in patients being treated with serial casting.

METHODS

A single center retrospective review of all EOS patients less than 6 years old treated with serial casting was performed. Patient weight out of cast throughout their treatment was converted to a percentile based on CDC growth charts. Patients with documented calls regarding cast concerns, complications requiring cast removal, or g-tube procedures were recorded.

RESULTS

A total of 32 patients treated with serial casting were included with four having g tubes. Overall, the average weight percentile increased from pre-casting to post-casting (27-38%, p < 0.001) with 21 patients showing an increase. Of the 22 patients with a starting weight below the 25th percentile, 14 (64%) demonstrated an increase. Patients with g tubes increased an average of 4.2 kg during casting compared to 3.0 kg in patients without g tubes (p = 0.588). 18 parents registered a cast concern during the treatment and 5 patients required at least one early cast removal. No difference in cast concerns (p = 0.597) or cast removals (p = 0.488) was observed when comparing patients with g tubes to those without. There were no instances of g-tube dysfunction during casting.

CONCLUSION

While the average weight percentile for patients initiating serial casting is below average, the majority increased their weight percentile during treatment. Patients with and patients without g tubes were able to maintain or gain weight during casting treatment. While it was common for parents to contact providers with cast concerns, patients with g tubes did not appear to have a greater risk of cast or g tube-related complications.

LEVEL OF EVIDENCE

Level IV.

Lawson Criterion for Ignition Exceeded in an Inertial Fusion Experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion.

Pediatric Orthopedic Trauma Care During the COVID-19 Pandemic: A Survey of the Pediatric Orthopedic Society of North America

Background: The COVID-19 pandemic has dramatically altered the practice of pediatric orthopedic trauma surgery in both outpatient and inpatient settings. While significant declines in patient volume have been noted, the impact on surgeon decision-making is unclear. Purpose: We sought to investigate changes in pediatric orthopedic trauma care delivery as a result of COVID-19 and determine their implications for future orthopedic practice. Methods: An electronic survey was distributed to all members (N = 1515) of the Pediatric Orthopedic Society of North America (POSNA) in March to April 2021; only members who provided care for pediatric orthopedic trauma patients were asked to complete it. The survey included questions on hospital trauma call, inpatient care, outpatient clinic practice, and 3 unique fracture case scenarios. Results: A total of 147 pediatric orthopedic surgeons completed the survey, for a 9.7% response rate, with 134 (91%) taking trauma call at a hospital as part of their practice. Respondents reported significant differences across institutions regarding COVID-19 testing, hospital rounding, and employee COVID-19 screening. Changes in outpatient fracture management were observed, including a decreased number of follow-up visits for nondisplaced clavicle fractures, distal radius buckle fractures, and toddler's fractures. Of respondents who changed their fracture follow-up schedules due to COVID-19, over 75% indicated that they would continue these outpatient treatment schedules after the pandemic. Conclusions: This survey found changes in pediatric orthopedic trauma care as a result of the COVID-19 pandemic. The use of telemedicine and abbreviated follow-up practices for common fracture types are likely to persist following the resolution of the COVID-19 pandemic.

"Will I Need a Brace?": likelihood of curve progression to bracing range in adolescent idiopathic scoliosis

PURPOSE

Bracing treatment for adolescent idiopathic scoliosis (AIS) is typically initiated in skeletally immature patients with primary curves greater than 25°. The goal of this study was to develop a model predicting a patient's likelihood of progressing to bracing treatment.

METHODS

All patients with AIS presenting to a large pediatric spine center with a primary curve below 25° and skeletally immature (Sanders stage 1-6) were included. A patient was considered to have progressed into the bracing range if their primary curve reached a 25° threshold prior to skeletal maturity. Binary logistic regression analysis was performed to predict the likelihood of curve progression into bracing range.

RESULTS

A total of 180 patients (71% female) were included in this study with an average presenting age of 13.2 ± 1.4 years. At presentation, 31 (17%) were pre-peak height velocity, 62 (34%) were at their peak height velocity, and 87 (48%) were in the late adolescent growth stage. The high-risk patient group was defined as Sanders 1-2 and curve size > 10 and < 25° or Sanders 3-6 and curve size > 20 but < 25°. Those in the high-risk group demonstrated an over 5 times higher risk of progression to bracing range when accounting for age, sex, and curve location (OR: 5.168, 95% CI: 2.212-12.071, p < 0.001).

CONCLUSION

Patient's curve magnitude and skeletal maturity can be used to predict their likelihood of curve progression to greater than 25° and thus require bracing treatment. Orthopaedic providers can consider earlier treatment interventions or stricter follow-up adherence for patients at high risk for progression.

LEVEL OF EVIDENCE

3-retrospective cohort study.

MRI Predictors of Residual Dysplasia in Developmental Dysplasia of the Hip Following Open and Closed Reduction

BACKGROUND

Following open or closed reduction for children with developmental dysplasia of the hip, there remains a significant risk of residual acetabular dysplasia which can compromise the long-term health of the hip joint. The purpose of this study was to use postoperative in-spica magnetic resonance imaging (MRI) data to determine factors predictive of residual acetabular dysplasia at short-term follow-up.

METHODS

We retrospectively reviewed 63 hips in 48 patients which underwent closed or open reduction and spica casting for developmental dysplasia of the hip. MRI performed in-spica at ∼3-week follow-up were used to assess 11 validated metrics and 2 subjective factors. Acetabular index (AI) was measured on anteroposterior pelvic radiographs at 2-year postoperative follow-up. Binary logistic regression was then used to identify variables predictive of residual dysplasia, defined as an AI greater than the 90th percentile for age based on historic normative data.

RESULTS

Average age at surgical reduction was 9.3±3.2 months. 58.7% (37/63) of reductions were open. A total of 43 (68.3%) hips demonstrated residual acetabular dysplasia at 2 years postoperatively based on normative values. In those with persistent dysplasia, patients were on average older at the time of reduction (10.0 mo±3.2 vs. 8.0 mo±2.8, P=0.010) and more likely female (88.4% vs. 60.0%, P=0.010). Patients with residual dysplasia were more likely to have mild subluxation on postoperative MRI (40.0% vs. 10.5%, P=0.022). Hips with a cartilaginous acetabular index (CAI) of >23 degrees were 7.6 times more likely to develop residual dysplasia. Type of reduction (ie, closed vs. open) did not appear to influence the rate of residual dysplasia (P=0.682).

CONCLUSION

In this series, the rate of residual dysplasia after surgical reduction was higher than most previous reports, with no appreciable difference between closed and open reductions. Older age, female sex, and a higher CAI were associated with a greater risk of persistent radiographic dysplasia. In particular, hips with a CAI >23 degrees were 7.6 times more likely to be dysplastic at 2-year follow-up.

LEVEL OF EVIDENCE

Level III.

Practice Variation in Use of Neuroimaging Among Infants With Concern for Abuse Treated in Children's Hospitals

IMPORTANCE

Infants who appear neurologically well and have fractures concerning for abuse are at increased risk for clinically occult head injuries. Evidence of excess variation in neuroimaging practices when abuse is suspected may indicate opportunity for quality and safety improvement.

OBJECTIVE

To quantify neuroimaging practice variation across children's hospitals among infants with fractures evaluated for abuse, with the hypothesis that hospitals would vary substantially in neuroimaging practices. As a secondary objective, factors associated with neuroimaging use were identified, with the hypothesis that age and factors associated with potential biases (ie, payer type and race or ethnicity) would be associated with neuroimaging use.

DESIGN, SETTING, AND PARTICIPANTS

This cross-sectional study included infants with a femur or humerus fracture or both undergoing abuse evaluation at 44 select US children's hospitals in the Pediatric Health Information System (PHIS) from January 1, 2016, through March 30, 2020, including emergency department, observational, and inpatient encounters. Included infants were aged younger than 12 months with a femur or humerus fracture or both without overt signs or symptoms of head injury for whom a skeletal survey was performed. To focus on infants at increased risk for clinically occult head injuries, infants with billing codes suggestive of overt neurologic signs or symptoms were excluded. Multivariable logistic regression was used to investigate demographic, clinical, and temporal factors associated with use of neuroimaging. Marginal standardization was used to report adjusted percentages of infants undergoing neuroimaging by hospital and payer type. Data were analyzed from March 2021 through January 2022.

EXPOSURES

Covariates included age, sex, race and ethnicity, payer type, fracture type, presentation year, and hospital.

MAIN OUTCOMES AND MEASURES

Use of neuroimaging by CT or MRI.

RESULTS

Of 2585 infants with humerus or femur fracture or both undergoing evaluations for possible child abuse, there were 1408 (54.5%) male infants, 1726 infants (66.8%) who were publicly insured, and 1549 infants (59.9%) who underwent neuroimaging. The median (IQR) age was 6.1 (3.2-8.3) months. There were 748 (28.9%) Black non-Hispanic infants, 426 (16.5%) Hispanic infants, 1148 (44.4%) White non-Hispanic infants. In multivariable analyses, younger age (eg, odds ratio [OR] for ages <3 months vs ages 9 to <12 months, 13.2; 95% CI, 9.54-18.2; P < .001), male sex (OR, 1.47; 95% CI, 1.22-1.78; P < .001), payer type (OR for public vs private insurance, 1.48; 95% CI, 1.18-1.85; P = .003), fracture type (OR for femur and humerus fracture vs isolated femur fracture, 5.36; 95% CI, 2.11-13.6; P = .002), and hospital (adjusted range in use of neuroimaging, 37.4% [95% CI 21.4%-53.5%] to 83.6% [95% CI 69.6%-97.5%]; P < .001) were associated with increased use of neuroimaging, but race and ethnicity were not. Publicly insured infants were more likely to undergo neuroimaging (62.0%; 95% CI, 60.0%-64.1%) than privately insured infants (55.1%; 95% CI, 51.8%-58.4%) (P = .001).

CONCLUSIONS AND RELEVANCE

This study found that hospitals varied in neuroimaging practices among infants with concern for abuse. Apparent disparities in practice associated with insurance type suggest opportunities for quality, safety, and equity improvement.

Study Groups and POSNA: A Review of Podium Presentations From 2006 to 2020

BACKGROUND

Study groups are multicenter collaborations aimed at improving orthopaedic decision-making through higher-powered, more generalizable studies. New research is disseminated through peer-reviewed literature and academic meetings, including the Pediatric Orthopaedic Society of North America (POSNA) annual meeting, which brings together academic and medical professionals in pediatric orthopaedics. The goal of this study was to identify patterns in podium presentations (PP) at the POSNA annual meeting resulting from multicenter study groups during a 15-year period.

METHODS

A total of 2065 PP from the 2006 to 2020 POSNA annual meetings were identified. The abstracts of each PP were reviewed to determine if they resulted from a multicenter study group and for characteristics including subspecialty focus. PP from 2006 to 2018 were further reviewed for publication in academic journals. Pearson correlation was used to assess change in the number of PP resulting from study groups overtime. Univariate analysis was used to compare characteristics of PP based on study group involvement (significance P<0.05).

RESULTS

The proportion of PP resulting from study groups increased from 2.2% (n=2) in 2006 to 9.4% in 2020 (n=16) (R2=0.519, P=0.002). Of the PP resulting from study groups, 52.9% focused on spine, 26.5% on hip, 2.9% on sports, and 2.0% on trauma. This is compared with a distribution of 16.7% (P<0.001) spine, 15.9% (P=0.005) hip, 9.5% (P=0.026) sports, and 14.6% (P<0.001) trauma focus of PP not from study groups. There was no difference in publication rate of PP resulting from study groups compared with those that were not (69.1% vs. 66.2%, P=0.621).

CONCLUSIONS

In the 15-year period from 2006 to 2020, there was a nearly 5-fold increase in the proportion of POSNA PP resulting from study groups. Spine surgery is disproportionately supported by study groups, suggesting that there is an opportunity to establish new study groups across the breadth of pediatric orthopaedics.

LEVEL OF EVIDENCE

Level V.

Predicting Outcomes of Talar Osteochondritis Dissecans Lesions in Children

Background

Reports detailing the rates of radiographic healing after treatment of talar osteochondritis dissecans (TOCD) remain scarce. There is also a paucity of data characterizing treatment outcomes and the risk factors associated with poor outcomes in children with TOCD.

Purpose

To identify factors associated with healing, assess treatment outcomes, and develop a clinically useful nomogram for predicting healing of TOCD in children.

Study Design

Case-control study; Level of evidence, 3.

Methods

This was a retrospective review of all patients ≤18 years of age with TOCD from a single pediatric institution over a 12-year period. Surgical treatment was left to the discretion of the treating surgeon based on standard treatment techniques. Medical records and radiographs were reviewed for patient and clinical data, lesion characteristics, and skeletal maturity. Radiographic healing was evaluated at the 1-year follow-up, and patients with complete versus incomplete healing were compared using multivariable logistic regression models to examine the predictive value of the variables.

Results

The authors analyzed 92 lesions in 74 patients (mean age, 13.1 ± 2.7 years [range, 7.1-18.0 years]; 61% female). Of these, 58 (63%) lesions were treated surgically (drilling, debridement, microfracture, bone grafting, or loose body removal), and the rest were treated nonoperatively. Complete radiographic healing was seen in 43 (47%) lesions. In bivariate analysis, patients with complete healing were younger (P = .006), were skeletally immature (P = .013), and had a lower body mass index (BMI; P < .001) versus those with incomplete healing. In a multivariate regression model, the factors that correlated significantly with the rate of complete healing were age at diagnosis, BMI, and initial surgical treatment. The lesion dimensions were not significantly associated with the likelihood of healing. A nomogram was developed using the independent variables that correlated significantly with the likelihood of complete radiographic healing.

Conclusion

Complete radiographic healing of TOCD lesions was more likely in younger patients with a lower BMI. The effect of initial surgical treatment on potential healing rate was greater in older patients with a higher BMI.

What's New in Pain Management for Pediatric Orthopaedic Surgery

BACKGROUND

Improving pain control and decreasing opioid prescription and usage continue to be emphasized across both pediatric and adult populations. The purpose of this review is to provide a comprehensive assessment of recent literature and highlight new advancements pertaining to pain control in pediatric orthopaedic surgery.

METHODS

An electronic search of the PubMed database was performed for keywords relating to perioperative pain management of pediatric orthopaedic surgery. Search results were filtered by publication date for articles published between January 1, 2015 and December 1, 2020 and yielded 404 papers.

RESULTS

A total of 32 papers were selected for review based upon new findings and significant contributions in the following categories: risk factors for increased opioid usage, opioid overprescribing and disposal, nonpharmacologic interventions, nonsteroidal anti-inflammatory drugs, peripheral nerve blocks, spine surgery specific considerations, surgical pathway modifications, and future directions.

CONCLUSIONS

There have been many advances in pain management for pediatric patients following orthopaedic surgery. Rapid recovery surgical care pathways are associated with shorter length of stay and improved pain control in pediatric spine surgery. Opioid overprescribing continues to be common and information regarding safe opioid disposal practices should be routinely provided for pediatric patients undergoing surgery.

LEVEL OF EVIDENCE

Level IV-literature review.

Entire-spine Magnetic Resonance Imaging Findings and Costs in Children With Presumed Adolescent Idiopathic Scoliosis

BACKGROUND

Patients with adolescent idiopathic scoliosis (AIS) are commonly monitored for curve progression with spinal radiographs; however, the utility of magnetic resonance imaging (MRI) screening is unclear. The purpose of this study was to assess the findings of screening MRI for patients with a nonsurgical curve size ordered during routine clinical care and compare them with MRI ordered for patients with large curves as part of preoperative screening.

METHODS

All consecutive patients with presumed AIS who underwent entire-spine MRI with a presumed diagnosis of idiopathic scoliosis at a single institution between 2017 and 2019 were retrospectively reviewed. Patients were stratified based on MRI indication into the following groups: preoperative evaluation, pain, neurological symptoms, abnormal radiographic curve appearance, rapidly progressive curve, and other. Neural axis abnormalities recorded included concern for tethered spinal cord, syringomyelia, and Chiari malformation. The MRI findings of preoperative patients with large curves were compared with all other patients. The number needed to diagnose (NND) a neurological finding was calculated in patients whose MRIs were ordered during routine clinical care. The amount charged for each patient undergoing entire-spine MRI was determined by review of our institution's Financial Decision Support system.

RESULTS

There were 344 patients included in this study with 214 (62%) MRIs performed for preoperative evaluation. Although MRI abnormalities were found in 49% of patients, only 7.0% (24/344) demonstrated neural axis abnormalities with no difference between preoperative and other indications (P=0.37). For patients with nonsurgical curves undergoing MRI due to a complaint of back pain (n=28), there were no neural axis abnormalities, and a lower rate of disk herniation/degenerative changes detected compared with preoperative MRI (3.6% vs. 18%, P=0.06). Among the 15 patients undergoing MRI for a neurological concern, 1 had a neural axis abnormality that required surgical detethering. The NND for MRI to detect a neural axis abnormality that potentially required neurosurgical intervention in nonpreoperative patients with a neurological concern was 34.4. The average cost for MRI was $17,816 (range: $2601 to $22,411) with a total cost of $2,368,439 for nonsurgical curves.

CONCLUSIONS

Entire-spine MRI for nonpreoperative indications including pain, abnormal radiographic curve appearance, and rapid curve progression has minimal utility for patients with AIS. For patients with neurological complaints, the NND a potentially treatment-altering finding with MRI is 34.4.

LEVEL OF EVIDENCE

Level II-diagnostic.

Sympathetic cooling of positrons to cryogenic temperatures for antihydrogen production

The positron, the antiparticle of the electron, predicted by Dirac in 1931 and discovered by Anderson in 1933, plays a key role in many scientific and everyday endeavours. Notably, the positron is a constituent of antihydrogen, the only long-lived neutral antimatter bound state that can currently be synthesized at low energy, presenting a prominent system for testing fundamental symmetries with high precision. Here, we report on the use of laser cooled Be+ ions to sympathetically cool a large and dense plasma of positrons to directly measured temperatures below 7 K in a Penning trap for antihydrogen synthesis. This will likely herald a significant increase in the amount of antihydrogen available for experimentation, thus facilitating further improvements in studies of fundamental symmetries.

Risk of Scoliosis Progression in Nonoperatively Treated Adolescent Idiopathic Scoliosis Based on Skeletal Maturity

BACKGROUND

Hand radiographs for skeletal maturity staging are now frequently used to evaluate remaining growth potential for patients with adolescent idiopathic scoliosis (AIS). Our objective was to create a model predicting a patient's risk of curve progression based on modern treatment standards.

METHODS

We retrospectively reviewed all AIS patients presenting with a major curve <50 degrees, available hand radiographs, and complete follow up through skeletal maturity at our institution over a 3-year period. Patients with growth remaining underwent rigid bracing of curves >25 degrees, whereas patients between 10 and 25 degrees were observed. Treatment success was defined as reaching skeletal maturity with a major curve <50 degrees. Four risk categories were identified based on likelihood of curve progression.

RESULTS

Of 609 AIS patients (75.4% female) presenting with curves over 10 degrees and reaching skeletal maturity at most recent follow up, 503 (82.6%) had major thoracic curves. 16.3% (82/503) of thoracic curves progressed into surgical treatment range. The highest risk group (Sanders 1 to 6 and curve 40 to 49 degrees, Sanders 1 to 2 and curve 30 to 39) demonstrate a 30% success rate with nonoperative treatment. This constitutes an 111.1 times (95% confidence interval: 47.6 to 250.0, P<0.001) higher risk of progression to surgical range than patients in the lowest risk categories (Sanders 1 to 8 and curve 10 to 19 degrees, Sanders 3 to 8 and curve 20 to 29 degrees, Sanders 5 to 8 and curve 30 to 39 degrees).

CONCLUSIONS

Skeletal maturity and curve magnitude have strong predictive value for future curve progression. The results presented here represent a valuable resource for orthopaedic providers regarding a patient's risk of progression and ultimate surgical risk.

LEVEL OF EVIDENCE

Level III-retrospective cohort study.

Association between timing of kyphoplasty and opioid prescribing risk after vertebral fracture

OBJECTIVE

Approximately 550,000 Americans experience vertebral fracture annually, and most receive opioids to treat the resulting pain. Kyphoplasty of the fractured vertebra is a procedural alternative that may mitigate risks of even short-term opioid use. While reports of kyphoplasty's impact on pain scores are mixed, no large-scale data exist regarding opioid prescribing before and after the procedure. This study was conducted to determine whether timing of kyphoplasty following vertebral fracture is associated with duration or intensity of opioid prescribing.

METHODS

This retrospective cohort study used 2001-2014 insurance claims data from a single, large private insurer in the US across multiple care settings. Patients were adults with vertebral fractures who were prescribed opioids and underwent balloon-assisted kyphoplasty within 4 months of fracture. Opioid overdose risk was stratified by prescribed average daily morphine milligram equivalents using CDC guidelines. Filled prescriptions and risk categories were evaluated at baseline and 90 days following kyphoplasty.

RESULTS

Inclusion criteria were met by 7119 patients (median age 77 years, 71.7% female). Among included patients, 3505 (49.2%) were opioid naïve before fracture. Of these patients, 31.1% had new persistent opioid prescribing beyond 90 days after kyphoplasty, and multivariable logistic regression identified kyphoplasty after 8 weeks as a predictor (OR 1.34, 95% CI 1.02-1.76). For patients previously receiving opioids, kyphoplasty > 4 weeks after fracture was associated with persistently elevated prescribing risk (OR 1.84, 95% CI 1.23-2.74).

CONCLUSIONS

New persistent opioid prescribing occurred in nearly one-third of patients undergoing kyphoplasty after vertebral fracture, although early treatment was associated with a reduction in this risk. For patients not naïve to opioids before fracture diagnosis, early kyphoplasty was associated with less persistent elevation of opioid overdose risk. Subsequent trials must compare opioid use by vertebral fracture patients treated via operative (kyphoplasty) and nonoperative (ongoing opioid) strategies before concluding that kyphoplasty lacks value, and early referral for kyphoplasty may be appropriate to avoid missing a window of efficacy.

Correlation of Pulmonary Function to Novel Radiographic Parameters of Collapsing Parasol Deformity in Spinal Muscular Atrophy

Spinal muscular atrophy (SMA) is a neuromuscular disease with manifestations of scoliosis, pulmonary function decline, and, uniquely, collapse of the ribs. Methods to quantify rib deformity and its impact on pulmonary function are sparse. The authors propose new radiographic measurements to quantify the aspect of SMA known as collapsing parasol deformity and correlate these measurements with pulmonary function. Twenty-eight full-spine radiographs of pediatric SMA patients were measured twice by 3 independent investigators, with 2 weeks separating each measurement. Radiographic measurements, demographics, spirometry results, and assisted ventilation rating were obtained. Twenty-one patients with spirometry metrics were assessed to correlate pulmonary function and spinal measurements. The intrarater intraclass correlation coefficient (ICC) for the measurements ranged from 0.706 to 0.99, and the interrater ICC ranged from 0.64 to 0.97. Eighteen of 19 variables had ICC values greater than 0.75 for inter- and intrarater reliability. Twenty-one patients with forced expiratory volume in 1 second and forced vital capacity were assessed in terms of these measurements. Ratio of the concave hemithoracic width at T6/convex hemithoracic width at T6 (P=.004) and ratio of convex vertical rib displacement at the apical rib/concave vertical rib displacement (P=.021) were both significantly correlated with decreased pulmonary function. No significant correlation was found examining the average vertical rib displacement at the apical rib. High inter-and intrarater reliability can be obtained in a variety of spinal measurements of SMA patients. Various measurements are correlated to diminished pulmonary function, specifically variables showing asymmetric changes in the chest cavity. [Orthopedics. 2021;44(2):e287-e293.].

Rib-based Distraction Device Implantation Before Age 3 Associated With Higher Unplanned Rate of Return to the Operating Room

BACKGROUND

Surgical treatment of early-onset scoliosis (EOS) with rib-based implants such as the vertical expandable prosthetic titanium rib (VEPTR) is associated with a high rate of complications including surgical site infection, skin breakdown, and implant migration. Many of these complications warrant the need for unplanned reoperations, increasing the burden on an already vulnerable patient population, and introducing the further risk of infection. To provide insight into the risks of early intervention, we investigate the relationship between initial device implantation before the age of 3 and the rate of unplanned reoperation.

METHODS

A retrospective review was performed of all patients at a single institution who had undergone VEPTR insertion for EOS with at least a 2-year follow-up from 2007 to 2016. Patients were stratified into the case-cohort (0 to 2 y of age) or the comparison cohort (3 to 10 y of age) based on age at the time of device implantation. Multivariate regression accounting for age and scoliosis etiology was performed to identify factors predictive of unplanned reoperation.

RESULTS

A total of 137 of 185 patients treated with VEPTR were identified with 76 (56%) undergoing at least 1 unplanned reoperation during the study time period. There were 68 and 69 patients in the age 0- to 2-year and 3- to 10-year cohorts, respectively. Patients aged 0 to 2 years underwent a higher number of total procedures compared with those aged 3 to 10 (13.1±6.5 vs. 10.6±4.8, P=0.032). A significant difference was found in the rate of unplanned reoperation between the 2 cohorts with 44 (65%) patients aged 0 to 2 and 32 (46%) patients aged 3 to 10 undergoing at least 1 unplanned reoperation (P=0.031). Binary logistic multivariate regression accounting for age and scoliosis etiology demonstrated that patients aged 0 to 2 had a significantly greater odds of undergoing an unplanned reoperation (odds ratio=3.050; 95% confidence interval: 1.285-7.241; P=0.011) compared with patients aged 3 to 10 years.

CONCLUSION

Overall, EOS patients aged 0 to 2 at initial VEPTR implantation are up to 3 times higher risk of undergoing an unplanned reoperation compared with those aged 3 to 10.

LEVEL OF EVIDENCE

Level III.

Preoperative risk stratification minimizes 90-day complications in morbidly obese patients undergoing primary total knee arthroplasty

AIMS

It has been shown that the preoperative modification of risk factors associated with obesity may reduce complications after total knee arthroplasty (TKA). However, the optimal method of doing so remains unclear. The aim of this study was to investigate whether a preoperative Risk Stratification Tool (RST) devised in our institution could reduce unexpected intensive care unit (ICU) transfers and 90-day emergency department (ED) visits, readmissions, and reoperations after TKA in obese patients.

METHODS

We retrospectively reviewed 1,614 consecutive patients undergoing primary unilateral TKA. Their mean age was 65.1 years (17.9 to 87.7) and the mean BMI was 34.2 kg/m² (SD 7.7). All patients underwent perioperative optimization and monitoring using the RST, which is a validated calculation tool that provides a recommendation for postoperative ICU care or increased nursing support. Patients were divided into three groups: non-obese (BMI < 30 kg/m², n = 512); obese (BMI 30 kg/m² to 39.9 kg/m², n = 748); and morbidly obese (BMI > 40 kg/m², n = 354). Logistic regression analysis was used to evaluate the outcomes among the groups adjusted for age, sex, smoking, and diabetes.

RESULTS

Obese patients had a significantly increased rate of discharge to a rehabilitation facility compared with non-obese patients (38.7% (426/1,102) vs 26.0% (133/512), respectively; p < 0.001). When stratified by BMI, discharge to a rehabilitation facility remained significantly higher compared with non-obese (26.0% (133)) in both obese (34.2% (256), odds ratio (OR) 1.6) and morbidly obese (48.0% (170), OR 3.1) patients (p < 0.001). However, there was no significant difference in unexpected ICU transfer (0.4% (two) non-obese vs 0.9% (seven) obese (OR 2.5) vs 1.7% (six) morbidly obese (OR 5.4); p = 0.054), visits to the ED (8.6% (44) vs 10.3% (77) (OR 1.3) vs 10.5% (37) (OR 1.2); p = 0.379), readmissions (4.5% (23) vs 4.0% (30) (OR 1.0) vs 5.1% (18) (OR 1.4); p = 0.322), or reoperations (2.5% (13) vs 3.3% (25) (OR 1.2) vs 3.1% (11) (OR 0.9); p = 0.939).

CONCLUSION

With the use of a preoperative RST, morbidly obese patients had similar rates of short-term postoperative adverse outcomes after primary TKA as non-obese patients. This supports the assertion that morbidly obese patients can safely undergo TKA with appropriate perioperative optimization and monitoring. Cite this article: Bone Joint J 2021;103-B(6 Supple A):45-50.

Changes in Pediatric Sports Injury Presentation During the COVID-19 Pandemic: A Multicenter Analysis

Background:

The current coronavirus 2019 (COVID-19) pandemic has prompted a multitude of public health response measures including social distancing, school cancellations, and cessation of organized sports.

Purpose:

To examine the impact of COVID-19 and corresponding public health measures on the characteristics of common pediatric musculoskeletal injuries associated with sports.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

This was a multicenter retrospective cohort study comparing patients with sports injuries presenting to 3 geographically diverse level I pediatric trauma hospitals and outpatient orthopaedic surgery clinics in the United States during the COVID-19 pandemic and a prepandemic period at the same institutions. Patients were included if they presented for care between February 15 and July 15 in 2020 (pandemic cohort) or between March 15 and April 15 in 2018 and 2019 (prepandemic cohort).

Results:

Included were 1455 patients with an average age of 12.1 ± 4.5 years. When comparing patients presenting in 2018 and 2019 with those presenting in 2020, we observed a decrease in mean age during the pandemic (12.6 ± 4.0 vs 11.0 ± 5.2 years; P = .048). Additionally, a decrease in the proportion of injuries attributed to sports (48.8% vs 33.3%; P < .001) and those occurring at school (11.9% vs 4.0%; P = .001) was observed. The proportion of injuries attributable to clavicle fractures increased during the early stages of the pandemic (13.2% vs 34.7%; P < .001). There was no statistically significant delay to care in injuries presenting during the pandemic (41.5 ± 141.2 vs 19.23 ± 79.1 days; P = .175).

Conclusion:

Across 3 tertiary care institutions, patients were seen without significant delay during the pandemic. We observed a significant decline in pediatric musculoskeletal injuries associated with sports during the COVID-19 pandemic. This decrease has been accompanied by a shift in both injury type and mechanism.

Laser cooling of antihydrogen atoms

The photon-the quantum excitation of the electromagnetic field-is massless but carries momentum. A photon can therefore exert a force on an object upon collision1. Slowing the translational motion of atoms and ions by application of such a force2,3, known as laser cooling, was first demonstrated 40 years ago4,5. It revolutionized atomic physics over the following decades6-8, and it is now a workhorse in many fields, including studies on quantum degenerate gases, quantum information, atomic clocks and tests of fundamental physics. However, this technique has not yet been applied to antimatter. Here we demonstrate laser cooling of antihydrogen9, the antimatter atom consisting of an antiproton and a positron. By exciting the 1S-2P transition in antihydrogen with pulsed, narrow-linewidth, Lyman-α laser radiation10,11, we Doppler-cool a sample of magnetically trapped antihydrogen. Although we apply laser cooling in only one dimension, the trap couples the longitudinal and transverse motions of the anti-atoms, leading to cooling in all three dimensions. We observe a reduction in the median transverse energy by more than an order of magnitude-with a substantial fraction of the anti-atoms attaining submicroelectronvolt transverse kinetic energies. We also report the observation of the laser-driven 1S-2S transition in samples of laser-cooled antihydrogen atoms. The observed spectral line is approximately four times narrower than that obtained without laser cooling. The demonstration of laser cooling and its immediate application has far-reaching implications for antimatter studies. A more localized, denser and colder sample of antihydrogen will drastically improve spectroscopic11-13 and gravitational14 studies of antihydrogen in ongoing experiments. Furthermore, the demonstrated ability to manipulate the motion of antimatter atoms by laser light will potentially provide ground-breaking opportunities for future experiments, such as anti-atomic fountains, anti-atom interferometry and the creation of antimatter molecules.

Dissociation of a Femoral Intramedullary Magnetic Lengthening Nail During Routine Hardware Removal: A Case Report

CASE

A 15-year-old boy with a right femur length discrepancy secondary to infection underwent hardware removal 1-year status-post right femur osteotomy with placement of an antegrade intramedullary magnetic lengthening nail after successful lengthening of 4.2 cm. During hardware removal, dissociation between the proximal (outer) and distal (inner) components of the device was observed. The distal component was removed using an endoscopic pituitary rongeur after considering multiple possible techniques.

CONCLUSIONS

In the event of nail disconnection during removal of an intramedullary implant, we recommend use of a long pituitary rongeur to retrieve the distal nail component.

Brain Α-Tocopherol Concentration is Inversely Associated with Neurofibrillary Tangle Counts in Brain Regions Affected in Earlier Braak Stages: A Cross-Sectional Finding in the Oldest Old

Objectives

Higher vitamin E status has been associated with lower risk of Alzheimer's disease (AD). However, evidence of the association of vitamin E concentration in neural tissue with AD pathologies is limited.

Design

The cross-sectional relationship between the human brain concentrations of α- and γ-tocopherol and the severity of AD pathologies - neurofibrillary tangle (NFT) and neuritic plaque (NP) - was investigated.

Setting & Participants

Brains from 43 centenarians (≥ 98 years at death) enrolled in the Phase III of the Georgia Centenarian Study were collected at autopsy.

Measurements

Brain α- and γ-tocopherol concentrations (previously reported) were averaged from frontal, temporal, and occipital cortices. NP and NFT counts (previously reported) were assessed in frontal, temporal, parietal, entorhinal cortices, amygdala, hippocampus, and subiculum. NFT topological progression was assessed using Braak staging. Multiple linear regression was performed to assess the relationship between tocopherol concentrations and NP or NFT counts, with and without adjustment for covariates.

Results

Brain α-tocopherol concentrations were inversely associated with NFT but not NP counts in amygdala (β = -2.67, 95% CI [-4.57, -0.79]), entorhinal cortex (β = -2.01, 95% CI [-3.72, -0.30]), hippocampus (β = -2.23, 95% CI [-3.82, -0.64]), and subiculum (β = -2.52, 95% CI [-4.42, -0.62]) where NFT present earlier in its topological progression, but not in neocortices. Subjects with Braak III-IV had lower α-tocopherol (median = 69,622 pmol/g, IQR = 54,389-72,155 pmol/g) than those with Braak I-II (median = 72,108 pmol/g, IQR = 64,056-82,430 pmol/g), but the difference was of borderline significance (p = 0.063). γ-Tocopherol concentrations were not associated with either NFT or NP counts in any brain regions assessed.

Conclusions

Higher brain α-tocopherol level is specifically associated with lower NFT counts in brain structures affected in earlier Braak stages. Our findings emphasize the possible importance of α-tocopherol intervention timing in tauopathy progression and warrant future clinical trials.

Racial disparities in peri-operative complications following primary total hip arthroplasty

BACKGROUND

This study assesses if post-operative outcomes following THA vary by racial groups.

METHODS

A review of the ACS-NSQIP database was performed to compare THA patient outcomes from 2008 to 2016 according to race.

RESULTS

During the study period, 117,389 THA patients were identified. Blacks were at significantly increased risk of peri-operative complications in comparison to non-Hispanic Whites, including serious medical morbidity (+27%), and prolonged length of stay (+53%).

CONCLUSIONS

Despite multivariate control and propensity-matched analysis of important risk factors, race independently predicts longer operative times and higher rates of discharge to non-home facilities.

Week 48 Resistance Analyses of the Once-Daily, Single-Tablet Regimen Darunavir/Cobicistat/Emtricitabine/Tenofovir Alafenamide (D/C/F/TAF) in Adults Living with HIV-1 from the Phase III Randomized AMBER and EMERALD Trials

Darunavir/cobicistat/emtricitabine/tenofovir alafenamide (D/C/F/TAF) 800/150/200/10 mg is being investigated in two Phase III trials, AMBER (NCT02431247; treatment-naive adults) and EMERALD (NCT02269917; treatment-experienced, virologically suppressed adults). Week 48 AMBER and EMERALD resistance analyses are presented. Postbaseline samples for genotyping/phenotyping were analyzed from protocol-defined virologic failures (PDVFs) with viral load (VL) ≥400 copies/mL at failure/later time points. Post hoc analyses were deep sequencing in AMBER, and HIV-1 proviral DNA from baseline samples (VL <50 copies/mL) in EMERALD. Through week 48 across both studies, no darunavir, primary PI, or tenofovir resistance-associated mutations (RAMs) were observed in HIV-1 viruses of 1,125 participants receiving D/C/F/TAF or 629 receiving boosted darunavir plus emtricitabine/tenofovir-disoproxil-fumarate. In AMBER, the nucleos(t)ide analog reverse transcriptase inhibitor (N(t)RTI) RAM M184I/V was identified in HIV-1 of one participant during D/C/F/TAF treatment. M184V was detected pretreatment as a minority variant (9%). In EMERALD, in participants with prior VF and genoarchive data (N = 140; 98 D/C/F/TAF and 42 control), 4% had viruses with darunavir RAMs, 38% with emtricitabine RAMs, mainly at position 184 (41% not fully susceptible to emtricitabine), 4% with tenofovir RAMs, and 21% ≥ 3 thymidine analog-associated mutations (24% not fully susceptible to tenofovir) detected at screening. All achieved VL <50 copies/mL at week 48 or prior discontinuation. D/C/F/TAF has a high genetic barrier to resistance; no darunavir, primary PI, or tenofovir RAMs were observed through 48 weeks in AMBER and EMERALD. Only one postbaseline M184I/V RAM was observed in HIV-1 of an AMBER participant. In EMERALD, baseline archived RAMs to darunavir, emtricitabine, and tenofovir in participants with prior VF did not preclude virologic response.

Synthetic Polyampholytes as Macromolecular Cryoprotective Agents

A series of polyampholytes based on different molar ratios on N, N-dimethylaminopropyl methacrylamide (DMAPMA), acrylic acid (AA), and optionally, N- tert-butylacrylamide ( t-BuAAm), were prepared by free radical copolymerization, and tested as DMSO-free cryoprotective agents for 3T3 fibroblast cells by using a standard freeze-rethaw protocol. Polybetaines prepared by reaction of DMAPMA homo and copolymers with 1,3-propane sultone were used as additional controls. Results showed strong effects of copolymer composition, molecular weight, polymer and NaCl concentrations, on post-thaw cell viability. Binary (DMAPMA/AA) copolymers showed best post-thaw cell viability of 70% at a 30/70 mol % ratio of DMAPMA/AA, which increased to 90% upon introduction of 9 mol % t-BuAAm while maintaining the 30/70 mol % cation/anion ratio. The use of acrylamide linkages in DMAPMA ensures absence of hydrolytic loss of cationic side chains. These polyampholytes were found to decrease ice crystal size and to form a polymer-rich, ice-free layer around cells, reducing damage from intercellular ice crystals during both freezing and thawing steps. These polyampholytes also dehydrate cells during freezing, which helps protect cells from intracellular ice damage. While cell viability immediately after thawing was high, subsequent culturing revealed poor attachment and long-term viability, which is attributed to residual cell damage from intracellular ice formation. Addition of 2 wt % DMSO or 1% BSA to the polymer-based freeze medium was found to mitigate this damage and result in post-thaw viabilities matching those achieved with 10 wt % DMSO.

Observation of the 1S-2P Lyman-α transition in antihydrogen

In 1906, Theodore Lyman discovered his eponymous series of transitions in the extreme-ultraviolet region of the atomic hydrogen spectrum1,2. The patterns in the hydrogen spectrum helped to establish the emerging theory of quantum mechanics, which we now know governs the world at the atomic scale. Since then, studies involving the Lyman-α line-the 1S-2P transition at a wavelength of 121.6 nanometres-have played an important part in physics and astronomy, as one of the most fundamental atomic transitions in the Universe. For example, this transition has long been used by astronomers studying the intergalactic medium and testing cosmological models via the so-called 'Lyman-α forest'3 of absorption lines at different redshifts. Here we report the observation of the Lyman-α transition in the antihydrogen atom, the antimatter counterpart of hydrogen. Using narrow-line-width, nanosecond-pulsed laser radiation, the 1S-2P transition was excited in magnetically trapped antihydrogen. The transition frequency at a field of 1.033 tesla was determined to be 2,466,051.7 ± 0.12 gigahertz (1σ uncertainty) and agrees with the prediction for hydrogen to a precision of 5 × 10-8. Comparisons of the properties of antihydrogen with those of its well-studied matter equivalent allow precision tests of fundamental symmetries between matter and antimatter. Alongside the ground-state hyperfine4,5 and 1S-2S transitions6,7 recently observed in antihydrogen, the Lyman-α transition will permit laser cooling of antihydrogen8,9, thus providing a cold and dense sample of anti-atoms for precision spectroscopy and gravity measurements10. In addition to the observation of this fundamental transition, this work represents both a decisive technological step towards laser cooling of antihydrogen, and the extension of antimatter spectroscopy to quantum states possessing orbital angular momentum.

Healthy ageing: the natural consequences of good nutrition-a conference report

Many countries are witnessing a marked increase in longevity and with this increased lifespan and the desire for healthy ageing, many, however, suffer from the opposite including mental and physical deterioration, lost productivity and quality of life, and increased medical costs. While adequate nutrition is fundamental for good health, it remains unclear what impact various dietary interventions may have on prolonging good quality of life. Studies which span age, geography and income all suggest that access to quality foods, host immunity and response to inflammation/infections, impaired senses (i.e., sight, taste, smell) or mobility are all factors which can limit intake or increase the body's need for specific micronutrients. New clinical studies of healthy ageing are needed and quantitative biomarkers are an essential component, particularly tools which can measure improvements in physiological integrity throughout life, thought to be a primary contributor to a long and productive life (a healthy "lifespan"). A framework for progress has recently been proposed in a WHO report which takes a broad, person-centered focus on healthy ageing, emphasizing the need to better understand an individual's intrinsic capacity, their functional abilities at various life stages, and the impact by mental, and physical health, and the environments they inhabit.

Characterization of the 1S-2S transition in antihydrogen

In 1928, Dirac published an equation 1 that combined quantum mechanics and special relativity. Negative-energy solutions to this equation, rather than being unphysical as initially thought, represented a class of hitherto unobserved and unimagined particles-antimatter. The existence of particles of antimatter was confirmed with the discovery of the positron 2 (or anti-electron) by Anderson in 1932, but it is still unknown why matter, rather than antimatter, survived after the Big Bang. As a result, experimental studies of antimatter3-7, including tests of fundamental symmetries such as charge-parity and charge-parity-time, and searches for evidence of primordial antimatter, such as antihelium nuclei, have high priority in contemporary physics research. The fundamental role of the hydrogen atom in the evolution of the Universe and in the historical development of our understanding of quantum physics makes its antimatter counterpart-the antihydrogen atom-of particular interest. Current standard-model physics requires that hydrogen and antihydrogen have the same energy levels and spectral lines. The laser-driven 1S-2S transition was recently observed 8 in antihydrogen. Here we characterize one of the hyperfine components of this transition using magnetically trapped atoms of antihydrogen and compare it to model calculations for hydrogen in our apparatus. We find that the shape of the spectral line agrees very well with that expected for hydrogen and that the resonance frequency agrees with that in hydrogen to about 5 kilohertz out of 2.5 × 1015 hertz. This is consistent with charge-parity-time invariance at a relative precision of 2 × 10-12-two orders of magnitude more precise than the previous determination 8 -corresponding to an absolute energy sensitivity of 2 × 10-20 GeV.

Erratum: Observation of the hyperfine spectrum of antihydrogen

This corrects the article DOI: 10.1038/nature23446.

Enhanced Control and Reproducibility of Non-Neutral Plasmas

The simultaneous control of the density and particle number of non-neutral plasmas confined in Penning-Malmberg traps is demonstrated. Control is achieved by setting the plasma's density by applying a rotating electric field while simultaneously fixing its axial potential via evaporative cooling. This novel method is particularly useful for stabilizing positron plasmas, as the procedures used to collect positrons from radioactive sources typically yield plasmas with variable densities and particle numbers; it also simplifies optimization studies that require plasma parameter scans. The reproducibility achieved by applying this technique to the positron and electron plasmas used by the ALPHA antihydrogen experiment at CERN, combined with other developments, contributed to a 10-fold increase in the antiatom trapping rate.

Observation of the hyperfine spectrum of antihydrogen

The observation of hyperfine structure in atomic hydrogen by Rabi and co-workers and the measurement of the zero-field ground-state splitting at the level of seven parts in 10¹³ are important achievements of mid-twentieth-century physics. The work that led to these achievements also provided the first evidence for the anomalous magnetic moment of the electron, inspired Schwinger's relativistic theory of quantum electrodynamics and gave rise to the hydrogen maser, which is a critical component of modern navigation, geo-positioning and very-long-baseline interferometry systems. Research at the Antiproton Decelerator at CERN by the ALPHA collaboration extends these enquiries into the antimatter sector. Recently, tools have been developed that enable studies of the hyperfine structure of antihydrogen-the antimatter counterpart of hydrogen. The goal of such studies is to search for any differences that might exist between this archetypal pair of atoms, and thereby to test the fundamental principles on which quantum field theory is constructed. Magnetic trapping of antihydrogen atoms provides a means of studying them by combining electromagnetic interaction with detection techniques that are unique to antimatter. Here we report the results of a microwave spectroscopy experiment in which we probe the response of antihydrogen over a controlled range of frequencies. The data reveal clear and distinct signatures of two allowed transitions, from which we obtain a direct, magnetic-field-independent measurement of the hyperfine splitting. From a set of trials involving 194 detected atoms, we determine a splitting of 1,420.4 ± 0.5 megahertz, consistent with expectations for atomic hydrogen at the level of four parts in 10⁴. This observation of the detailed behaviour of a quantum transition in an atom of antihydrogen exemplifies tests of fundamental symmetries such as charge-parity-time in antimatter, and the techniques developed here will enable more-precise such tests.

Antihydrogen accumulation for fundamental symmetry tests

Antihydrogen, a positron bound to an antiproton, is the simplest anti-atom. Its structure and properties are expected to mirror those of the hydrogen atom. Prospects for precision comparisons of the two, as tests of fundamental symmetries, are driving a vibrant programme of research. In this regard, a limiting factor in most experiments is the availability of large numbers of cold ground state antihydrogen atoms. Here, we describe how an improved synthesis process results in a maximum rate of 10.5 ± 0.6 atoms trapped and detected per cycle, corresponding to more than an order of magnitude improvement over previous work. Additionally, we demonstrate how detailed control of electron, positron and antiproton plasmas enables repeated formation and trapping of antihydrogen atoms, with the simultaneous retention of atoms produced in previous cycles. We report a record of 54 detected annihilation events from a single release of the trapped anti-atoms accumulated from five consecutive cycles.

Antihydrogen studies are important in testing the fundamental principles of physics but producing antihydrogen in large amounts is challenging. Here the authors demonstrate an efficient and high-precision method for trapping and stacking antihydrogen by using controlled plasma.

The precuneus may encode irrationality in human gambling

Humans often make irrational decisions, especially psychiatric patients who have dysfunctional cognitive and emotional circuitry. Understanding the neural basis of decision-making is therefore essential towards patient management, yet current studies suffer from several limitations. Functional magnetic resonance imaging (fMRI) studies in humans have dominated decision-making neuroscience, but have poor temporal resolution and the blood oxygenation level-dependent signal is only a proxy for neural activity. On the other hand, lesion studies in humans used to infer functionality in decision-making lack characterization of neural activity altogether. Using a combination of local field potential recordings in human subjects performing a financial decision-making task, spectral analyses, and non-parametric cluster statistics, we analyzed the activity in the precuneus. In nine subjects, the neural activity modulated significantly between rational and irrational trials in the precuneus (p <; 0.001). In particular, high-frequency activity (70-100 Hz) increased when irrational decisions were made. Although preliminary, these results suggest suppression of gamma rhythms via electrical stimulation in the precuneus as a therapeutic intervention for pathological decision-making.

Age, time living with diagnosed HIV infection, and self-rated health

OBJECTIVES

An increasing proportion of people living with HIV are older adults, who may require specialized care. Adverse physical and psychological effects of HIV infection may be greatest among older people or those who have lived longer with HIV.

METHODS

The ASTRA study is a cross-sectional questionnaire study of 3258 HIV-diagnosed adults (2248 men who have sex with men, 373 heterosexual men and 637 women) recruited from UK clinics in 2011-2012. Associations of age group with physical symptom distress (significant distress for at least one of 26 symptoms), depression and anxiety symptoms (scores ≥ 10 on PHQ-9 and GAD-7, respectively), and health-related functional problems (problems on at least one of three domains of the Euroqol 5D-3L)) were assessed, adjusting for time with diagnosed HIV infection, gender/sexual orientation and ethnicity.

RESULTS

The age distribution of participants was: < 30 years, 5%; 30-39 years, 23%; 40-49 years, 43%; 50-59 years, 22%; and ≥ 60 years, 7%. Overall prevalences were: physical symptom distress, 56%; depression symptoms, 27%; anxiety symptoms, 22%; functional problems, 38%. No trend was found in the prevalence of physical symptom distress with age [adjusted odds ratio (OR) for trend across age groups, 0.96; 95% confidence interval (CI) 0.89, 1.04; P = 0.36]. The prevalence of depression and anxiety symptoms decreased with age [adjusted OR 0.86 (95% CI 0.79, 0.94; P = 0.001) and adjusted OR 0.85 (95% CI 0.77, 0.94; P = 0.001), respectively], while that of functional problems increased (adjusted OR 1.28; 95% CI 1.17, 1.39; P < 0.001). In contrast, a longer time with diagnosed HIV infection was strongly and independently associated with a higher prevalence of symptom distress, depression symptoms, anxiety symptoms, and functional problems (P < 0.001 for trends, adjusted analysis).

CONCLUSIONS

Among people living with HIV, although health-related functional problems were more common with older age, physical symptom distress was not, and mental health was more favourable. These results suggest that a longer time with diagnosed HIV infection, rather than age, is the dominating factor contributing to psychological morbidity and lower quality of life.