Assessing the safety of physical rehabilitation in critically ill patients: a Delphi study.

BACKGROUND: Physical rehabilitation of critically ill patients is implemented to improve physical outcomes from an intensive care stay. However, before rehabilitation is implemented, a risk assessment is essential, based on robust safety data. To develop this information, a uniform definition of relevant adverse events is required. The assessment of cardiovascular stability is particularly relevant before physical activity as there is uncertainty over when it is safe to start rehabilitation with patients receiving vasoactive drugs. METHODS: A three-stage Delphi study was carried out to (a) define adverse events for a general ICU cohort, and (b) to define which risks should be assessed before physical rehabilitation of patients receiving vasoactive drugs. An international group of intensive care clinicians and clinician researchers took part. Former ICU patients and their family members/carers were involved in generating consensus for the definition of adverse events. Round one was an open round where participants gave their suggestions of what to include. In round two, participants rated their agreements with these suggestions using a five-point Likert scale; a 70% consensus agreement threshold was used. Round three was used to re-rate suggestions that had not reached consensus, whilst viewing anonymous feedback of participant ratings from round two. RESULTS: Twenty-four multi-professional ICU clinicians and clinician researchers from 10 countries across five continents were recruited. Average duration of ICU experience was 18 years (standard deviation 8) and 61% had publications related to ICU rehabilitation. For the adverse event definition, five former ICU patients and one patient relative were recruited. The Delphi process had a 97% response rate. Firstly, 54 adverse events reached consensus; an adverse event tool was created and informed by these events. Secondly, 50 risk factors requiring assessment before physical rehabilitation of patients receiving vasoactive drugs reached consensus. A second tool was created, informed by these suggestions. CONCLUSIONS: The adverse event tool can be used in studies of physical rehabilitation to ensure uniform measurement of safety. The risk assessment tool can be used to inform clinical practise when risk assessing when to start rehabilitation with patients receiving vasoactive drugs. Trial registration This study protocol was retrospectively registered on https://www.researchregistry.com/ (researchregistry2991).

Outbreak Associated with SARS-CoV-2 B.1.617.2 (Delta) Variant in an Elementary School - Marin County, California, May-June 2021.

On May 25, 2021, the Marin County Department of Public Health (MCPH) was notified by an elementary school that on May 23, an unvaccinated teacher had reported receiving a positive test result for SARS-CoV-2, the virus that causes COVID-19. The teacher reported becoming symptomatic on May 19, but continued to work for 2 days before receiving a test on May 21. On occasion during this time, the teacher read aloud unmasked to the class despite school requirements to mask while indoors. Beginning May 23, additional cases of COVID-19 were reported among other staff members, students, parents, and siblings connected to the school. To characterize the outbreak, on May 26, MCPH initiated case investigation and contact tracing that included whole genome sequencing (WGS) of available specimens. A total of 27 cases were identified, including that of the teacher. During May 23-26, among the teacher's 24 students, 22 students, all ineligible for vaccination because of age, received testing for SARS-CoV-2; 12 received positive test results. The attack rate in the two rows seated closest to the teacher's desk was 80% (eight of 10) and was 28% (four of 14) in the three back rows (Fisher's exact test; p = 0.036). During May 24-June 1, six of 18 students in a separate grade at the school, all also too young for vaccination, received positive SARS-CoV-2 test results. Eight additional cases were also identified, all in parents and siblings of students in these two grades. Among these additional cases, three were in persons fully vaccinated in accordance with CDC recommendations (1). Among the 27 total cases, 22 (81%) persons reported symptoms; the most frequently reported symptoms were fever (41%), cough (33%), headache (26%), and sore throat (26%). WGS of all 18 available specimens identified the B.1.617.2 (Delta) variant. Vaccines are effective against the Delta variant (2), but risk of transmission remains elevated among unvaccinated persons in schools without strict adherence to prevention strategies. In addition to vaccination for eligible persons, strict adherence to nonpharmaceutical prevention strategies, including masking, routine testing, facility ventilation, and staying home when symptomatic, are important to ensure safe in-person learning in schools (3).

Crisis Decision-Making at the Speed of COVID-19: Field Report on Issuing the First Regional Shelter-in-Place Orders in the United States.

CONTEXT: In March, 2020, the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), the causal agent of coronavirus disease 2019 (COVID-19), was spreading in the Bay Area, especially in Santa Clara County, causing increases in cases, hospitalizations, and deaths. PROGRAM: The Association of Bay Area Health Officials (ABAHO) represents 13 Bay Area health jurisdictions. IMPLEMENTATION: On March 15, 2020, the local health officers of 7 ABAHO members (counties of Alameda, Contra Costa, Marin, San Francisco, San Mateo, and Santa Clara and the city of Berkeley) decided to issue legal orders on March 16 for 6.7 million residents to shelter in place to prevent the spread of SARS-CoV-2, the causal agent of COVID-19. The Bay Area was the first region in the United States to shelter in place, and within days, other regions in the United States followed. EVALUATION: Subsequent comparative analyses have confirmed that acting early in issuing shelter-in-place orders prevented a large number of cases, hospitalizations, and deaths in the Bay Area throughout the United States. The quality of a decision-in this case, for crisis decision making-cannot be judged by the outcome. A good decision can have a bad outcome, and a bad decision can have a good outcome. The quality of a decision depends only on the quality of the decision-making process at the time the decision was made. DISCUSSION: In this Field Report, we review how we made this collective decision. With the benefit of hindsight and reflection, we recount our story through the lens of public health legal authority, meta-leadership, and decision intelligence. Our purpose is to improve the crisis decision-making skills of public health officials by improving how we make high-stakes decisions each day in our continuing fight to contain the SARS-CoV-2 pandemic, to save lives, and to eliminate COVID-19 racial/ethnic inequities.

Mesenchymal stem cells for sensorineural hearing loss: a systematic review of preclinical studies.

Sensorineural hearing loss (SNHL) is the most common form of hearing loss that is routinely treated with hearing aids or cochlear implants. Advances in regenerative medicine have now led to animal studies examining the possibility of restoring injured hair cells with mesenchymal stem/stromal cell (MSC) administration. We conducted a systematic review and meta-analysis to collate the existing preclinical literature evaluating MSCs as a treatment for SNHL and quantify the effect of MSCs on functional hearing. Our protocol was published online on CAMARADES. Searches were conducted in four medical databases by two independent investigators. Twelve studies met inclusion and were evaluated for risk of bias using SYRCLE. Rodent models were commonly used (n = 8, 66%), while auditory brainstem response (ABR) and distortion product otoacoustic emissions (DPOAE) were the most frequent measures assessing hearing loss. MSCs were derived from multiple tissue sources, including bone marrow, adipose tissue, and umbilical cord blood and the dose ranged from 4 × 103 to 1 × 107 cells. Treatment with MSCs resulted in an improvement in ABR and DPOAE (mean difference-15.22, + 9.10, respectively). Despite high heterogeneity and multiple "unclear" domains in the risk of bias, this review provides evidence that MSCs may have a beneficial effect in hearing function.

Sibling-Controlled Study of Parental Bonding, Coping, and Urgent Health-Care Use in Families With Children With Nonepileptic Seizures.

Objectives: Pediatric psychogenic nonepileptic seizures (PNES) is a functional somatic symptom condition with significant health-care service burden. While both family and individual factors play an important role in the development and maintenance of PNES, little is known about what predicts urgent health-care use in families with children who have PNES. The aim of the current study was to explore whether child coping and parental bonding styles influence the decision to seek urgent medical care in these families. Methods: Data were analyzed from youth of age 8-18 years, 47 with PNES, and their 25 sibling controls. Parents provided the number of youth emergency room visits and hospitalizations in the preceding year. Youth completed a questionnaire about their coping styles and a measure about their mothers' and fathers' bonding styles. Using a mixed model with family as a random effect, we regressed urgent health-care use on participant type (youth with PNES or sibling), parental bonding style, and youth coping style, controlling for number of child prescription medications. Results: Higher urgent health-care use was associated with having PNES, coping via monitoring, and perceiving one's father to be rejecting and overprotective. Lower urgent health-care use was associated with coping via venting and with perceiving one's mother to be caring and overprotective. Conclusions: This study provides preliminary empirical support for family-based clinical efforts to reduce child urgent health-care use by enhancing effective child coping skills and improving parental response to child impairment and distress in families with youth with PNES.

Risk factors for learning problems in youth with psychogenic non-epileptic seizures.

OBJECTIVES: This study examined the risk factors for learning problems (LP) in pediatric psychogenic non-epileptic seizures (PNES) and their specificity by comparing psychopathology, medical, cognitive/linguistic/achievement, bullying history, and parent education variables between subjects with PNES with and without LP and between subjects with PNES and siblings with LP. METHODS: 55 subjects with PNES and 35 siblings, aged 8-18years, underwent cognitive, linguistic, and achievement testing, and completed somatization and anxiety sensitivity questionnaires. A semi-structured psychiatric interview about the child was administered to each subject and parent. Child self-report and/or parent report provided information on the presence/absence of LP. Parents also provided each subject's medical, psychiatric, family, and bullying history information. RESULTS: Sixty percent (33/55) of the PNES and 49% (17/35) of the sibling subjects had LP. A multivariable logistic regression demonstrated that bullying and impaired formulation of a sentence using a stimulus picture and stimulus word were significantly associated with increased likelihood of LP in the PNES youth. In terms of the specificity of the LP risk factors, a similar analysis comparing LP in the youth with PNES and sibling groups identified anxiety disorder diagnoses and bullying as the significant risk factors associated with LP in the PNES youth. CONCLUSIONS: These findings emphasize the need to assess youth with PNES for LP, particularly if they have experienced bullying, have linguistic deficits, and meet criteria for anxiety disorder diagnoses.

Metallothionein-I/II Promotes Axonal Regeneration in the Central Nervous System.

The adult CNS does not spontaneously regenerate after injury, due in large part to myelin-associated inhibitors such as myelin-associated glycoprotein (MAG), Nogo-A, and oligodendrocyte-myelin glycoprotein. All three inhibitors can interact with either the Nogo receptor complex or paired immunoglobulin-like receptor B. A conditioning lesion of the sciatic nerve allows the central processes of dorsal root ganglion (DRG) neurons to spontaneously regenerate in vivo after a dorsal column lesion. After a conditioning lesion, DRG neurons are no longer inhibited by myelin, and this effect is cyclic AMP (cAMP)- and transcription-dependent. Using a microarray analysis, we identified several genes that are up-regulated both in adult DRGs after a conditioning lesion and in DRG neurons treated with cAMP analogues. One gene that was up-regulated under both conditions is metallothionein (MT)-I. We show here that treatment with two closely related isoforms of MT (MT-I/II) can overcome the inhibitory effects of both myelin and MAG for cortical, hippocampal, and DRG neurons. Intrathecal delivery of MT-I/II to adult DRGs also promotes neurite outgrowth in the presence of MAG. Adult DRGs from MT-I/II-deficient mice extend significantly shorter processes on MAG compared with wild-type DRG neurons, and regeneration of dorsal column axons does not occur after a conditioning lesion in MT-I/II-deficient mice. Furthermore, a single intravitreal injection of MT-I/II after optic nerve crush promotes axonal regeneration. Mechanistically, MT-I/II ability to overcome MAG-mediated inhibition is transcription-dependent, and MT-I/II can block the proteolytic activity of α-secretase and the activation of PKC and Rho in response to soluble MAG.

A multisite controlled study of risk factors in pediatric psychogenic nonepileptic seizures.

OBJECTIVE: Psychogenic nonepileptic seizures (PNES) in youth are symptoms of a difficult to diagnose and treat conversion disorder. PNES is associated with high medical and psychiatric morbidity, but specific PNES risk factors in the pediatric population are not known. We examined if youth with PNES have a distinct biopsychosocial risk factor profile compared to their siblings and if the interrelationships between these risk factors differentiate the PNES probands from the sibling group. METHODS: This multisite study included 55 youth with a confirmed diagnosis of PNES (age range 8.6-18.4 years) and their 35 sibling controls (age range 8.6-18.1 years). A video EEG and psychiatric assessment confirmed the PNES diagnosis. Parents reported on each child's past and present medical/epilepsy, psychiatric, family, and educational history. Each child underwent a structured psychiatric interview, standardized cognitive and academic achievement testing, and completed self-report coping, daily stress, adversities, and parental bonding questionnaires. RESULTS: Compared to their siblings, the PNES probands had significantly more lifetime comorbid medical, neurological (including epilepsy), and psychiatric problems; used more medications and intensive medical services; had more higher anxiety sensitivity, practiced solitary emotional coping, and experienced more lifetime adversities. A principal components analysis of these variables identified a somatopsychiatric, adversity, epilepsy, and cognitive component. The somatopsychiatric and adversity components differentiated the probands from the siblings, and were highly significant predictors of PNES with odds ratios of 15.1 (95% CI [3.4, 67.3], and 9.5 (95% CI [2.0, 45.7]), respectively. The epilepsy and cognitive components did not differentiate between the PNES and sibling groups. SIGNIFICANCE: These findings highlight the complex biopsychosocial and distinct vulnerability profile of pediatric PNES. They also underscore the need for screening the interrelated risk factors included in the somatopsychiatric and adversity components and subsequent mental health referral for confirmation of the diagnosis and treatment of youth with PNES.

Assessment of salivary cadmium levels and breast density in the Marin Women's Study.

BACKGROUND: We aimed to determine if salivary cadmium (Cd) levels had any association with breast density, hoping to establish a less invasive cost-effective method of stratifying Cd burden as an environmental breast cancer risk factor. METHODS: Salivary Cd levels were quantified from the Marin Women's Study, a Marin County, California population composite. Volumetric compositional breast density (BDsxa ) data were measured by single x-ray absorptiometry techniques. Digital screening mammography was performed by the San Francisco Mammography Registry. Radiologists reviewed mammograms and assigned a Breast Imaging-Reporting and Data System score. Early morning salivary Cd samples were assayed. Association analyses were then performed. RESULTS: Cd was quantifiable in over 90% of saliva samples (mean = 55.7 pg/L, SD = 29). Women with higher saliva Cd levels had a non-significant odds ratio of 1.34 with BI-RAD scores (3 or 4) (95% CI 0.75-2.39, p = 0.329). Cd levels were higher in current smokers (mean = 61.4 pg/L, SD = 34.8) than former smokers or non-smokers. These results were non-significant. Pilot data revealed that higher age and higher BMI were associated with higher BI-RAD scores (p < 0.001). CONCLUSION: Salivary Cd is a viable quantification source in large epidemiologic studies. Association analyses between Cd levels and breast density may provide additional information for breast cancer risk assessment, risk reduction plans, and future research directions. Further work is needed to demonstrate a more robust testing protocol before the extent of its usefulness can be established.

Social Acceptability of Health Behavior Posts on Social Media: An Experiment.

INTRODUCTION: Social media sites like Twitter (now X) are increasingly used to create health behavior metrics for public health surveillance. Yet little is known about social norms that may bias the content of posts about health behaviors. Social norms for posts about four health behaviors (smoking tobacco, drinking alcohol, physical activity, eating food) on Twitter/X were evaluated. METHODS: This was a randomized experiment delivered via web-based survey to adult, English-speaking Twitter/X users in three Michigan, USA, counties from 2020 to 2022 (n=559). Each participant viewed 24 posts presenting experimental manipulations regarding four health behaviors and answered questions about each post's social acceptability. Principal component analysis was used to combine survey responses into one perceived social acceptability measure. Linear mixed models with the Benjamini-Hochberg correction were implemented to test seven study hypotheses in 2023. RESULTS: Supporting six hypotheses, posts presenting healthier (CI: 0.028, 0.454), less stigmatized behaviors (CI: 0.552, 0.157) were more socially acceptable than posts regarding unhealthier, stigmatized behaviors. Unhealthy (CI: -0.268, -0.109) and stigmatized behavior (CI: -0.261, -0.103) posts were less acceptable for more educated participants. Posts about collocated activities (CI: 0.410, 0.573) and accompanied by expressions of liking (CI: 0.906, 1.11) were more acceptable than activities undertaken alone or disliked. Contrary to one hypothesis, posts reporting unusual activities were less acceptable than usual ones (CI: -0.472, 0.312). CONCLUSIONS: Perceived social acceptability may be associated with the frequency and content of health behavior posts. Users of Twitter/X and other social media platform posts to estimate health behavior prevalence should account for potential estimation biases from perceived social acceptability of posts.

COVID-19 Vaccine Perceptions Survey for Real-Time Vaccine Outreach in Marin County, California.

BACKGROUND: Understanding and addressing coronavirus disease 2019 (COVID-19) vaccine hesitancy is crucial to informing vaccination outreach strategies and achieving high vaccination coverage. Marin County, California, United States, has a history of vaccine hesitancy regarding childhood vaccinations required for school entry. OBJECTIVES: We aimed to describe and address COVID-19 vaccine hesitancy in Marin County to inform outreach and messaging. Our objectives were to identify subgroups with high COVID-19 vaccine hesitancy early in distribution, better understand local concerns and feedback about the COVID-19 vaccine distribution process, and inform tailored vaccine messaging to increase vaccination confidence and coverage. METHODS: The survey, which was administered from January 3 to May 10, 2021, queried demographics, vaccine acceptance, reasons for hesitancy, and reasons for acceptance. Open-ended questions were used for respondents to report additional reasons for hesitancy and for general feedback about the vaccine distribution process. We conducted quantitative and qualitative analyses stratified by COVID-19 vaccine acceptance to identify subgroups with high hesitancy. Results were shared weekly in real-time with leadership and key community partners working on vaccine outreach. RESULTS: Among the 5,618 survey responses, there were differences in vaccine hesitancy by sociodemographic characteristics with the highest hesitancy reported among subgroups identifying as Black/African American and young adult, and within the lowest family income grouping. The most common reason for vaccine hesitancy was "uncertain about the side effects of the vaccine" (67.3% endorsement) and responses varied by race and ethnicity. Qualitative data revealed equity-related, vaccine distribution, and vaccine access themes that were not present in structured responses. Vaccine hesitancy survey results were paired with vaccination coverage and COVID-19 case data to inform tailored outreach strategies and priorities week-to-week. CONCLUSIONS: Marin County had some of the highest COVID-19 vaccination rates in the United States during the pandemic and met equity goals aimed at ensuring vulnerable populations received vaccinations. Presenting real-time survey findings with leadership and key community partners informed a timely and tailored COVID-19 vaccine outreach and delivery strategy.

Life Expectancy and Causes of Premature Death by Subgroup for Community-Based Action in Marin County, California, 2017-2021.

INTRODUCTION: Marin is a medium-sized county in California's San Francisco Bay Area. Despite its historically higher-than-average life expectancy and socioeconomic level, known economic and health disparities by race, ethnicity, and geography became more visible during the COVID-19 pandemic.  Methods: We calculated life expectancy, measured years of potential life lost (YPLLs), and described premature mortality for the five years of 2017-2021 by race, ethnicity, census tract, and resource level (as measured by Healthy Places Index [HPI]) to provide data on inequities to guide community-centered action to reduce premature mortality.  Results: Life expectancy for the county was 85.2 years. The non-Hispanic African American/Black population experienced the lowest life expectancy of 77.1 years, 11.6 years lower than the non-Hispanic Asian population which had the highest life expectancy (88.7 years). There was a 14.9-year difference in life expectancy between the census tracts with the lowest (77.1 years) and highest (92.0 years) estimates. We found a moderate, positive association between census tract resource level (HPI) and life expectancy (r=0.58, p<0.01). The leading causes of premature death were cancer, diseases of the circulatory system, and accidental overdoses, with variation by subgroup.  Conclusion: These data highlight health disparities that persist in Marin County and can inform data-driven public health strategies to narrow gaps in longevity between communities.

Seasonality of tuberculosis in the United States, 1993-2008.

BACKGROUND: Although seasonal variation in tuberculosis incidence has been described in several recent studies, the mechanism underlying this seasonality remains unknown. Seasonality of tuberculosis disease may indicate the presence of season-specific risk factors that could potentially be controlled if they were better understood. We conducted this study to determine whether tuberculosis is seasonal in the United States and to describe patterns of seasonality in specific populations. METHODS: We performed a time series decomposition analysis of tuberculosis cases reported to the Centers for Disease Control and Prevention from 1993 through 2008. Seasonal amplitude of tuberculosis disease (the difference between the months with the highest and lowest mean case counts), was calculated for the population as a whole and for populations with select demographic, clinical, and epidemiologic characteristics. RESULTS: A total of 243 432 laboratory-confirmed tuberculosis cases were reported over a period of 16 years. A mean of 21.4% more cases were diagnosed in March, the peak month, compared with November, the trough month. The magnitude of seasonality did not vary with latitude. The greatest seasonal amplitude was found among children aged <5 years and in cases associated with disease clusters. CONCLUSIONS: Tuberculosis is a seasonal disease in the United States, with a peak in spring and trough in late fall. The latitude independence of seasonality suggests that reduced winter sunlight exposure may not be a strong contributor to tuberculosis risk. Increased seasonality among young children and clustered cases suggests that disease that is the result of recent transmission is more influenced by season than disease resulting from activation of latent infection.

The use of the reverse shoulder arthroplasty for treatment of failed total shoulder arthroplasty.

BACKGROUND: This study evaluated the outcomes of patients with failed total shoulder arthroplasty (TSA) who were treated with conversion to reverse shoulder arthroplasty (RSA). MATERIALS AND METHODS: We performed a retrospective case series of 24 consecutive patients with failed TSA who were treated with conversion to RSA. Twenty-two patients (16 women, 6 men) had a minimum 2-year clinical and radiographic follow-up. The average age at the time of revision was 68 years (range, 51-84 years). Indications for conversion to RSA included failure of TSA from glenohumeral instability in 19, mechanical failure of the humeral or glenoid component in 10, and infection in 2. RESULTS: The median total American Shoulder and Elbow Surgeons score improved from 38.5 preoperatively to 67.5 (P < .001). Visual analog scale pain scores decreased from 5 to 1.5 (P < .001), and function improved from 2 to 6.5 (P < .001). The median Simple Shoulder Test improved from 1 to 5 (P = .006). Forward flexion improved from 50° to 130° (P < .001), abduction from 45° to 100° (P < .001), and external rotation from 12.5° to 49.5° (P = .056). Internal rotation improved from a spinal level of S2 to L3 (P = .064). Fourteen patients rated their outcome as excellent, 3 as good, 3 as satisfactory, and 2 as unsatisfactory. The overall complication rate was 22.7% (5 of 22). CONCLUSION: RSA can be an effective treatment for failed TSA by decreasing pain and improving shoulder function. However, RSA in the revision setting is associated with a higher complication rate.

Proximal humeral malunion treated with reverse shoulder arthroplasty.

BACKGROUND: The purpose of this study was to determine the outcomes of patients with proximal humeral malunions treated with reverse shoulder arthroplasty (RSA). MATERIALS AND METHODS: Sixteen patients were treated with RSA for sequelae of a proximal humeral fracture with a malunion. Clinical outcomes (American Shoulder and Elbow Surgeons [ASES] score, Simple Shoulder Test, visual analog scale [VAS] score for pain and function, range of motion, and patient satisfaction) and radiographs were evaluated at a minimum follow-up of 2 years. Wilcoxon signed-rank tests were used to analyze preoperative and postoperative data. RESULTS: All patients required alteration of humeral preparation with increased retroversion of greater than 30°. The total ASES score improved from 28 to 63 (P = .001), ASES pain score from 15 to 35 (P = .003), ASES functional score from 15 to 27 (P = .015), VAS pain score from 7 to 3 (P = .003), VAS function score from 0 to 5 (P = .001), and Simple Shoulder Test score from 1 to 4 (P = .0015). Forward flexion improved from 53° to 105° (P = .002), abduction from 48° to 105° (P = .002), external rotation from 5° to 30° (P = .015), and internal rotation from S1 to L3 (P = .005). There were no major complications reported. Postoperative radiographic evaluation showed 2 patients with evidence of notching and 1 patient with proximal humeral bone resorption. CONCLUSION: RSA is indicated for treating the most severe types of proximal humeral fracture sequelae. The results of RSA for proximal humeral malunions with altered surgical technique yield satisfactory outcomes in this difficult patient population.

Complications in reverse total shoulder arthroplasty.

Reverse total shoulder arthroplasty was initially used to manage complex shoulder problems. Indications have been expanded to include rotator cuff arthropathy, massive rotator cuff tear, failed shoulder arthroplasty, and fracture sequelae. Increased use of primary reverse total shoulder arthroplasty has led to reports of associated problems unique to the procedure. The most common complications include neurologic injury, periprosthetic fracture, hematoma, infection, scapular notching, dislocation, mechanical baseplate failure, and acromial fracture. Little information has been published regarding best practices for managing these complications.

How reverse shoulder arthroplasty works.

BACKGROUND: The reverse total shoulder arthroplasty was introduced to treat the rotator cuff-deficient shoulder. Since its introduction, an improved understanding of the biomechanics of rotator cuff deficiency and reverse shoulder arthroplasty has facilitated the development of modern reverse arthroplasty designs. QUESTIONS/PURPOSES: We review (1) the basic biomechanical challenges associated with the rotator cuff-deficient shoulder; (2) the biomechanical rationale for newer reverse shoulder arthroplasty designs; (3) the current scientific evidence related to the function and performance of reverse shoulder arthroplasty; and (4) specific technical aspects of reverse shoulder arthroplasty. METHODS: A PubMed search of the English language literature was conducted using the key words reverse shoulder arthroplasty, rotator cuff arthropathy, and biomechanics of reverse shoulder arthroplasty. Articles were excluded if the content fell outside of the biomechanics of these topics, leaving the 66 articles included in this review. RESULTS: Various implant design factors as well as various surgical implantation techniques affect stability of reverse shoulder arthroplasty and patient function. To understand the implications of individual design factors, one must understand the function of the normal and the cuff-deficient shoulder and coalesce this understanding with the pathology presented by each patient to choose the proper surgical technique for reconstruction. CONCLUSIONS: Several basic science and clinical studies improve our understanding of various design factors in reverse shoulder arthroplasty. However, much work remains to further elucidate the performance of newer designs and to evaluate patient outcomes using validated instruments such as the American Society for Elbow Surgery, simple shoulder test, and the Constant-Murley scores.

Effects of tilt and glenosphere eccentricity on baseplate/bone interface forces in a computational model, validated by a mechanical model, of reverse shoulder arthroplasty.

HYPOTHESIS/BACKGROUND: Reverse shoulder arthroplasty is being used with greater frequency for patients with severe rotator cuff deficiency. There are several commercially available reverse shoulder devices, each with different glenosphere options. The purpose of this study was to determine: (1) forces at the baseplate-bone interface in glenospheres with centers of rotation located concentrically and eccentrically to the center of the baseplate; and (2) if baseplate-bone forces can be optimized by altering tilt of the baseplate. METHODS: A validated computer model was used to compare concentric glenospheres with neutral offset to eccentrically offset glenospheres (6 mm inferior or 6 mm lateral) in 3 baseplate tilts: 15° inferior, neutral, or 15° superior. A baseplate, simulated bone, screws, and humeral component were modeled, and forces underneath the baseplate were calculated as the arm was abducted through 90° of glenohumeral motion. RESULTS: For lateral and concentric glenospheres, inferior tilt provides the most even distribution of forces (mean difference in force between superior and inferior portions of baseplate: 11.3 N and 24.7 N, respectively) and superior tilt provides the most uneven distribution of forces (109.3 N and 78.7 N, respectively). For inferior eccentric glenospheres, inferior tilt provides the most uneven distribution of forces (58.7 N) and neutral tilt provides the most even distribution of forces (27.7 N). CONCLUSION: This is the first study to investigate force distribution under the baseplate in inferior eccentric glenospheres. Although inferior tilting of the baseplate is recommended for concentric and laterally offset glenospheres, this same recommendation may be detrimental to inferiorly offset glenospheres and warrants further investigation.

Phased Return of Students to 77 Transitional Kindergarten-8th Grade Schools With Cohesive Mitigation Strategies Serving as Protective Factors Against the Increase of COVID-19 Cases in Marin County: September 2020-January 2021.

Background and objective Earlier uncertain implications of the coronavirus disease 2019 (COVID-19) pandemic on the pediatric population prompted the authorities to close schools worldwide under the premise that school settings would serve as drivers of an increase in the cases of COVID-19. Safe and equitable full-in-person school instruction is a critical factor in the continued educational gains of children and for their general well-being. The objective of this study was to report epidemiological trends related to the increasing percentage of students returning to in-person instruction, the suspected in-school transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, and countywide COVID-19 case rates during the first 21 weeks of school reopening in Marin County, CA, in the fall of 2020. Materials and methods The institutional review board (IRB) approval was waived for this study as it did not involve any identifiable human subjects data. Retrospective electronic reviews of countywide COVID-19 daily case count and COVID-19-related reports associated with in-person school participants from 77 schools in Marin County, CA, from September 8, 2020, to January 29, 2021, were conducted. The data were made available in collaboration with the Marin County Office of Education (MCOE) and Marin County Department of Health and Human Services (Marin HHS). Descriptive trends analyses were performed to determine whether the phased increase of students attending in-person learning was a significant contributor to countywide COVID-19 incidence rate, crude rate, and in-school COVID-19 viral transmission. This is the first long retrospective study of COVID-19 data among the reopened school population during the second half of the first pandemic year. It was conducted in a 21-week surveillance period involving an immense collaboration between Marin County's public health officials and school administrators. Results Over the 21-week observational period involving 17,639 students, 4,938 school staff, and 899,175 student days, the countywide COVID-19 crude rate decreased (from 89.9 to 35.89 per 10,000) as more students returned to in-person learning. The schools' strict adherence to public health guidance and site-specific safety plans against COVID-19 yielded a significantly reduced incidence rate of 0.84% among in-person learning participants; only nine cases were traced to suspected in-school SARS-CoV-2 transmission by way of rigorous contact tracing. The countywide COVID-19 incidence rate was 2.09%. Conclusions It is possible to minimize COVID-19 transmissions in in-person learning settings with cohesive mitigation strategies, specifically strict adherence to proper masking by students and staff while on school grounds. There is no clear correlation that the increasing phased return of students to in-person school drove an increase in countywide COVID-19 cases in Marin County, CA. Our findings revealed that schools were capable of safely resuming operations by following public health orders and recommendations. The increasing percentage of students returning to in-person school did not drive an increased COVID-19 case rate in the community. On the contrary, this analysis revealed that there was a drop in countywide COVID-19 cases as the phased student return percentage increased.

Use of SMS-linked electronic surveys for COVID-19 case investigation and contact tracing - Marin County, CA, USA.

OBJECTIVES: We sought to quantify the proportion of contacts reported by persons with COVID-19 through a short message service (SMS)-linked survey in comparison to the proportion of contacts reported during a follow-up phone-interview. We also sought to assess improvement in contact tracing timeliness associated with sending SMS-linked surveys. STUDY DESIGN: During December 4-15, 2020, persons identified as COVID-19 cases whose data was entered into Marin County's contact tracing database on even days received a SMS-linked survey and persons whose data was entered on odd days did not; all were called for case investigation and contact tracing. Chi-square test and Fisher's exact test were used to compare demographic data. Chi-square test was used to contrast categorical outcomes, and Wilcoxon's rank-sum test was used for continuous outcomes. RESULTS: Among 350 SMS-linked survey recipients, 85 (24%) responded and 4 (1%) reported contacts using the survey; an additional 303 contacts were reported during phone interviews. Without phone interviews, 99% of reported contacts would have been missed. There was no meaningful difference between study arms in the proportion of contacts notified within 48 h. CONCLUSIONS: This SMS-linked survey had low participation and was not useful for identifying contacts. Phone interviews remained crucial for COVID-19 contact tracing.