An Epidemiologic Comparison of Injuries to Skiers and Snowboarders Treated at United States Emergency Departments, 2000-2019.

Skiing and snowboarding are popular competitive and recreational sports that can be associated with significant injury. Previous studies of skiing and snowboarding injuries have been conducted, but studies evaluating injury types and patterns over long periods of time are needed to drive effective injury prevention efforts. We hypothesized that injury patterns would differ among snowboarders and skiers and that the number of injuries remained constant over time. This is a retrospective study of patients presenting with skiing or snowboarding injuries to the United States emergency departments from 2000 to 2019. A total of 34,720 injured skiers (48.0%) and snowboarders (52.0%) presented to US emergency departments over a 20-year period, representing an estimated 1,620,576 injuries nationwide. There is a decreasing trend of the number of injuries over the study period (p=0.012). Males represented the majority (65.7%) of injuries. Skiers were older than snowboarders (mean 30.1 vs. 20.0 years; p<0.001) and patients aged<18 represented more snowboarding (57.0%) than skiing (43.0%) injuries (p<0.001). Common diagnoses included fractures (33.0%) and sprains/strains (26.9%). Snowboarders primarily presented with upper extremity injuries, meanwhile, skiers primarily presented with lower extremity injuries. Most patients (93.2%), were treated and discharged from the emergency departments. Understanding the epidemiology of injuries presenting to emergency departments can help guide prehospital care and medical coverage allocation for resorts and event organizers, as well as identifying areas for targeted injury prevention efforts.

The Role of Level of Play in Concussions in High School Athletes.

OBJECTIVES: To examine level of play (LOP) as a risk factor for concussion severity and recovery-related outcomes among high school athletes, stratified by sex, and among boys, by sport (football, non-football male sports). DESIGN/SETTING: Secondary analysis of data collected through the High School Reporting Information Online surveillance system for academic years 2007-2008 through 2018-2019. PARTICIPANTS: A total of 9916 concussions were reported between the academic years 2007-2008 and 2018-2019 from 9 sports (5189 from football; 2096 from non-football male sports; 2631 from female sports). MAIN OUTCOME MEASURE: Examined the association between LOP (Freshman, Junior Varsity [JV], and Varsity teams) and concussion outcomes (number of concussion symptoms, symptom resolution time [SRT], and time to return to play [RTP]). RESULTS: Compared with Varsity football athletes, concussed JV football athletes had on average 0.19 fewer concussion symptoms, longer SRT (>1 week vs <1 week: odds ratio [OR] = 1.3; 95% confidence interval [CI], 1.1-1.5), and longer RTP (1-3 weeks vs <1 week: OR = 1.5; 95% CI, 1.2-1.9; >3 weeks vs <1 week: OR = 1.6; 95% CI, 1.1-2.3). Compared with Varsity football athletes, Freshman football athletes had on average 0.48 fewer concussion symptoms, longer SRT (OR = 1.3; 95% CI, 1.1-1.5), and longer RTP (1-3 weeks vs <1 week: OR = 1.5; 95% CI, 1.1-2.0; >3 weeks vs <1 week: OR = 2.0; 95% CI, 1.3-3.0). Similarly, compared with female athletes on Varsity teams, concussed JV female athletes had longer RTP (1-3 weeks vs <1 week: OR = 1.8; 95% CI, 1.2-2.7). Trend analyses revealed an increase in the number of concussion symptoms between 2015-2016 and 2018-2019, a decrease between 2009-2010 and 2018-2019 for SRT of less than 1 week, and an increase between 2014-2015 and 2018-2019 for RTP of less than 1 week among Varsity football athletes. Among Varsity female athletes, there was a linear decrease during the study period for RTP of less than 1 week. CONCLUSIONS: Despite a higher number of symptoms overall and in recent years, Varsity football players had shorter RTP than Freshman and JV athletes.

Are Different Aged Youth Skiers and Snowboarders Experiencing Different Injury Characteristics?

INTRODUCTION: Skiing and snowboarding are popular winter sports with significant youth participation and inherent potential for injury. We investigated the relationship between age and injury characteristics exhibited by youth skiers and snowboarders. METHODS: In this cross-sectional study, we investigated injury characteristics among youth skiers and snowboarders at a ski resort, examining the association between age and injury type. We compared injury characteristics among young children (aged 3-6 y), school-aged children (aged 7-14 y), and older adolescents (aged 15-17 y) using χ2, and examined predictive variables for injuries at different anatomical locations using logistic regression. RESULTS: Compared with snowboarding, skiing was associated with greater odds of lower extremity (adjusted odds ratio [aOR]=6.8, 95% confidence interval [CI]: 4.89, 9.47, P<0.001) and head/face/neck (aOR=1.63, 95% CI: 1.20, 2.21, P=0.002) injuries. Compared with skiing, snowboarding was associated with greater odds of upper extremity injury (aOR=5.9, 95% CI: 4.6, 7.6, P<0.001). Age group significantly affected injury mechanism (χ2 [df=12, n=1129]=42.882, P<0.0001) and diagnosis (χ2 [df=12, n=1129]=43.093, P<0.0001). Young child skiers had the highest proportion of injuries to the head/neck/face and lower extremities and a significantly higher proportion of collision injuries and fractures than older skiers. Young child skiers most frequently injured the lower leg/ankle, while older skiers most frequently injured the knee. CONCLUSIONS: Youth skiers exhibited predominately lower extremity injuries, while snowboarders exhibited predominately upper extremity injuries. Age significantly affected injury mechanism and injury diagnosis in youth skiers. Specifically, younger skiers tended to suffer more fractures and collision injuries than older youth skiers.

SalterHarris fractures in paediatric skiers and snowboarders.

The incidence of paediatric fractures among winter sport athletes is not adequately studied. Our objective was to categorize fractures that occurred in paediatric skiers and snowboarders at a single ski resort. X-rays of 756 skiers/snowboarders aged 3-17 diagnosed with a fracture were categorized using the Salter-Harris (SH) classification. SH fractures were seen in 158 (21%) patients, with 123 (77%) being Type II. There were no significant differences between patients with a SH fracture and patients with a non-SH fracture for age, sex, snowboarding or skiing, mechanism of injury, terrain or the resort conditions on the day of injury. The most common mechanism of injury was falling onto snow while collisions resulted in more severe injuries. Compared to fractures without growth plate involvement, a higher proportion of SH fractures were seen in the humerus, radius, fibula and thumb; a lower proportion of SH fractures were observed at the tibia and clavicle.

Facilitators and barriers for parental consent to pediatric emergency research.

BACKGROUND: Obtaining informed consent for clinical research in the pediatric emergency department (ED) is challenging. Our objective was to understand the factors that influence parental consent for ED studies. METHODS: This was a cross-sectional survey assessing parents' willingness to enroll their children into an ED research study. Parents reporting a willingness to enroll in ED studies were presented with two hypothetical scenarios, a low-risk and a high-risk study, and then asked about decision influencers affecting consent. Parents expressing a lack of willingness to enroll were asked which decision influencers impacted their consent decision. RESULTS: Among 118 parents, 90 (76%) stated they would be willing to enroll their child into an ED study; of these, 86 (96%) would consent for a low-risk study and 54 (60%) would consent for a high-risk study. Caucasian parents, and those with previous research exposure, were more likely to report willingness to participate. Those who would consent to the high-risk study cited "benefits that research would provide to future children" most strongly influenced their decision to agree. CONCLUSIONS: ED investigators should highlight the benefits for future children and inquire about parents' previous exposure to research to enhance ED research enrollment. Barriers to consent in non-Caucasian families should be further investigated. IMPACT: Obtaining consent for pediatric emergency research is challenging and this study identified factors influencing parental consent for research in EDs. Benefits for future children and parents' previous research experience were two of the most influential factors in parents' willingness to consent to ED research studies. These findings will help to improve enrollment in ED research studies and better our understanding of how to promote the health and well-being of pediatric patients.

Lower Center Edge Angle and Bioipolar Cartilage Lesions Are Associated With Conversion to Hip Arthroplasty Within 2 Years Following Hip Arthroscopy: A Matched Cohort Analysis.

PURPOSE: The purpose of this study was to determine whether radiographic parameters, intraoperative findings, patient-reported outcome measures, or intraoperative interventions that were performed differentiate those patients with >2 mm of joint space who convert under two years to total hip arthroplasty (THA) after undergoing hip arthroscopy for femoroacetabular impingement (FAI) when compared to those converting after 2 years. METHODS: Included in this study were patients who underwent conversion to THA within 2 years of primary hip arthroscopy from a prospectively collected patient registry from 2007 to 2017. Patients who underwent early conversions to arthroplasty were matched 1:1 with patients who converted after 2 years, based upon age and gender. Preoperative outcome scores were collected, including Short Form-12, modified Harris Hip Score, and Hip Outcome Score. Additionally, variables from the preoperative radiographic evaluation, surgical findings, and procedures performed were also compared. RESULTS: Forty-nine patients were included in the early conversion group and were matched with 49 patients in the later conversion group. Patients with lateral center edge angles of less than 25° were more likely to be in the early failure group [OR: 3.9; 95% CI: 1.01 to 15]. Patients with unipolar chondral defects on either the femoral (P = .128) or acetabular side (P = .656) were not at increased odds for early conversion compared to later conversion; however, those with bipolar chondral lesions at the time of surgery had increased odds of early conversions [OR: 3.3; 95% CI: 1.4 to 8] (P = .01). Neither surgical treatment nor preoperative patient-reported outcome measures were associated with early conversion. CONCLUSIONS: In patient with >2 mm of joint space, lateral center edge angles of less than 25° and those with bipolar articular cartilage lesions seen at the time of hip arthroscopy are at increased risk for conversion to total hip arthroplasty within two years. LEVEL OF EVIDENCE: Level III, retrospective comparison study.

Epidemiology of Concussions in High School Boys' Ice Hockey, 2008/09 to 2016/17 School Years.

OBJECTIVE: This study examined the epidemiology of concussions in high school boys' ice hockey during the 2008/09 to 2016/17 school years. DESIGN: Prospective cohort study. Athletic trainers from an average 33 high schools annually reported boys' ice hockey concussion and athlete-exposure (AE) data for the High School Reporting Information Online system. SETTING: Convenience sample of high school boys' ice hockey programs during the 2008/09 to 2016/17 school years. PATIENTS OR OTHER PARTICIPANTS: High school boys' ice hockey players (aged ∼14-18 years). INDEPENDENT VARIABLES: Concussion data on event type, injury mechanism, symptom resolution time, and time loss were obtained. MAIN OUTCOME MEASURES: Concussion rates with 95% confidence intervals (CIs) and distributions were calculated. RESULTS: Overall, 348 concussions were reported in boys' ice hockey during the 2008/09 to 2016/17 academic years, leading to a concussion rate of 0.68/1000 AEs (95% CI, 0.61-0.75). Most occurred in competitions (85.6%), particularly after the first period (72.1% of all competition concussions). Among practice concussions, most occurred after the first hour of practice (60.0%). Most concussions were due to player contact (47.7%) and boards/glass contact (31.9%). Although 69.0% of concussed athletes had symptoms resolve in less than 7 days, only 14.1% returned to activity within a week. CONCLUSIONS: Most concussions occurred within the second and third periods. Preventive strategies that counter an increased risk of concussion due to a greater intensity of gameplay coupled with increased fatigue may be warranted. Moreover, athletes may further benefit from prevention efforts that focus on anticipating impacts during gameplay.

Effect of environmental conditions on injury rates at a Colorado ski resort.

OBJECTIVE: To determine the effect of daily environmental conditions on skiing and snowboarding-related injury rates. METHODS: Injury information was collected from a mountainside clinic at a large Colorado ski resort for the 2012/2013 through 2016/2017 seasons. Daily environmental conditions including snowfall, snow base depth, temperature, open terrain and participant visits were obtained from historical resort records. Snowpack and visibility information were obtained for the 2013/2014 through 2014/2015 seasons and included in a subanalysis. Negative binomial regression was used to estimate injury rate ratios (IRRs) and 95% CIs. RESULTS: The overall injury rate among skiers and snowboarders was 1.37 per 1000 participant visits during 2012/2013 through 2016/2017. After adjustment for other environmental covariates, injury rates were 22% higher (IRR=1.22, 95% CI 1.14 to 1.29) on days with <2.5 compared with ≥2.5 cm of snowfall, and 14% higher on days with average temperature in the highest quartile (≥-3.1°C) compared with the lowest (<-10.6°C; IRR=1.14, 95% CI 1.03 to 1.26). Rates decreased by 8% for every 25 cm increase in snow base depth (IRR=0.92, 95% CI 0.88 to 0.95). In a subanalysis of the 2013/2014 and 2014/2015 seasons including the same covariates plus snowpack and visibility, only snowpack remained significantly associated with injury rates. Rates were 71% higher on hardpack compared with powder days (IRR=1.71, 95% CI 1.18 to 2.49) and 36% higher on packed powder compared with powder days (IRR 1.36, 95% CI 1.12 to 1.64). CONCLUSIONS: Environmental conditions, particularly snowfall and snowpack, have a significant impact on injury rates. Injury prevention efforts should consider environmental factors to decrease injury rates in skiers and snowboarders.

The Epidemiology and Management of Exertional Heat Illnesses in High School Sports During the 2012/2013­2016/2017 Academic Years.

Context: Recent data on exertional heat illness (EHI) in high school sports are limited yet warranted to identify specific settings with the highest risk of EHI. Objective: To describe the epidemiology of EHI in high school sports during the 2012/2013-2016/2017 academic years. Design: Descriptive epidemiology study. Setting: Aggregate injury and exposure data collected from athletic trainers working in high school sports in the United States. Patients or Other Participants: High school athletes during the 2012/2013-2016/2017 academic years. Intervention: High School Reporting Information Online surveillance system data from the 2012/2013-2016/2017 academic years were analyzed. Main Outcome Measures: EHI counts, rates per 10,000 athlete exposures (AEs), and distributions were examined by sport, event type, and US census region. EHI management strategies provided by athletic trainers were analyzed. Injury rate ratios with 95% confidence intervals (CIs) compared EHI rates. Results: Overall, 300 EHIs were reported for an overall rate of 0.13/10,000 AE (95% CI, 0.11 to 0.14). Of these, 44.3% occurred in American football preseason practices; 20.7% occurred in American football preseason practices with a registered air temperature ≥90°F and ≥1 hour into practice. The EHI rate was higher in American football than all other sports (0.52 vs 0.04/10,000 AE; injury rate ratio = 11.87; 95% CI, 9.22 to 15.27). However, girls' cross-country had the highest competition EHI rate (1.18/10,000 AE). The EHI rate was higher in the South US census region than all other US census regions (0.23 vs 0.08/10,000 AE; injury rate ratio = 2.96; 95% CI, 2.35 to 3.74). Common EHI management strategies included having medical staff on-site at the onset of EHI (92.7%), removing athlete from play (85.0%), and giving athlete fluids via the mouth (77.7%). Conclusions: American football continues to have the highest overall EHI rate although the high competition EHI rate in girls' cross-country merits additional examination. Regional differences in EHI incidence, coupled with sport-specific variations in management, may highlight the need for region- and sport-specific EHI prevention guidelines.

Epidemiology of lacrosse injuries treated at the United States emergency departments between 1997 and 2015.

Lacrosse has gained substantial popularity across age groups in the past few decades, but epidemiologic sex differences of lacrosse injuries in emergency settings have not been well described. We characterized and described lacrosse-related injuries presenting to United States Emergency Departments (US EDs) using data from the National Electronic Injury Surveillance System (NEISS). From 1997 to 2015, 7,587 lacrosse-related injuries were treated at US EDs (national estimate of 256,358 injuries). Males accounted for 75.5% of injuries. Average age was 16.0 ± 5.0 (range 5-71) years. Sprains/strains (25.4%), contusions/abrasions (23.9%), and fractures (18.7%) were the most common diagnoses. Females sustained a higher proportion of sprains/strains (36.0%) than males (21.9%) (p< 0.01), while males sustained a higher proportion of fractures (injury proportion ratios [IPR]; 21.3% vs. 10.8%, p< 0.01). Similar proportions of concussions were observed (IPR; 6.1% in males, 6.2% among females). Differences in injury patterns may be secondary to differences in rules and equipment between the two sports.

A comparison of recreational skiing- and snowboarding-related injuries at a Colorado ski resort, 2012/13-2016/17.

The purpose of this study was to compare injury patterns between recreational skiers and snowboarders. Injured skiers (n = 3,961) and snowboarders (n = 2,428) presented to a mountainside medical clinic, 2012/13-2016/17. Variables investigated for analysis included demographics/characteristics, injury event information, and injury information. Skiers were older than snowboarders (34.3 ± 19.3 vs. 23.2 ± 10.5 years, p < 0.001); a greater proportion of skiers were female (46.3% vs. 27.8%, p < 0.001). Most skiers (84.4%) and snowboarders (84.5%) were helmeted at the time of injury (p = 0.93). Snowboarders were most frequently beginners (38.9%), skiers were intermediates (37.8%). Falls to snow (skiers = 72.3%, snowboarders = 84.8%) and collisions with natural objects (skiers = 9.7%, snowboarders = 7.4%) were common injury mechanisms. Common skiing injuries were knee sprains (20.5%) and head trauma (8.9%); common snowboarding injuries were wrist fractures (25.7%), shoulder separations (9.1%), and head trauma (9.0%). Given that injury patterns significantly differ between sports, it is important for clinicians, ski patrollers, and resorts to develop and deliver sport-specific injury prevention interventions to most effectively decrease injury burden.

Postconcussion Academic Support in Children Who Attend a Primary Care Provider Follow-up Visit after Presenting to the Emergency Department.

OBJECTIVE: To examine whether a primary care provider (PCP) follow-up visit after emergency department evaluation of concussion improved the children's likelihood of receiving academic support. STUDY DESIGN: This was a prospective cohort study. Concussed children, aged 8-18 years, presenting to a regional pediatric trauma center emergency department (n = 160) were contacted 7 and 30 days after injury to gather data on PCP follow-up, symptoms, quality of life, and receipt of academic support instituted after and because of the concussion. Bivariate comparisons of demographics, concussion characteristics, quality of life, and symptoms were made between children who did and did not receive support using independent samples t tests, Wilcoxon rank sum tests, or χ2 tests. ORs and 95% CIs were calculated using multivariable logistic regression with backwards elimination to test the association between attending an outpatient follow-up visit and the receipt of academic support for variables where P < .2 in bivariate comparisons. RESULTS: Overall, 51.3% (n = 82) received academic support; of these, 84.2% attended a follow-up visit compared with 71.8% of 78 children who attended a follow-up visit but did not receive support (P = .06). Children who received support were more likely to have commercial insurance; experience a sports-related injury mechanism; have parents whose primary language was English; suffer from learning disabilities and migraines; and be non-Hispanic (P < .05). There was no association between attending a follow-up visit and receipt of academic support (adjusted OR 1.83; 95% CI 0.75-4.45). CONCLUSIONS: Although the majority of children received academic support postconcussion, accommodations were associated with several demographic, medical history, and injury characteristics, but not attending a PCP follow-up visit.

Gun retailers as storage partners for suicide prevention: what barriers need to be overcome?

INTRODUCTION: Safe storage of guns outside the household while someone is at risk for suicide is important for suicide prevention. Some gun retailers offer temporary firearm storage as a community resource. Others may be willing if perceived barriers can be addressed. METHODS: We invited all gun retailers in eight Mountain West states to respond to a questionnaire about the barriers they perceive in offering temporary, voluntary gun storage for community members. RESULTS: Ninety-five retailers responded (25% response rate). Fifty-eight percent believed federal laws make it harder to store guns and 25% perceived state laws to be obstacles. Over 60% cited legal liability in storing and returning guns as barriers. Other important barriers included cost, space and logistical issues of drop off and pick up. CONCLUSIONS: Strategies to reduce legal and other barriers will need to be addressed to better engage gun retailers as a community resource for safe gun storage.

Factors Influencing Primary Care Follow-Up After Pediatric Mild Traumatic Brain Injury.

OBJECTIVE: To identify socioeconomic, demographic, and caregiver factors associated with children attending primary care provider (PCP) follow-up after emergency department (ED) evaluation for mild traumatic brain injury (mTBI). SETTING: Pediatric trauma center ED. PARTICIPANTS: Children 8 to 18 years of age sustaining mTBI less than 48 hours prior to an ED visit. Mean age of the 183 participants was 12 years with no significant differences between those who attended follow-up and those who did not in race, ethnicity, insurance provider, or PCP office setting. DESIGN: Thirty-day longitudinal cohort study. MAIN MEASURES: Insurance type, PCP practice setting, and a caregiver attitudes survey regarding mTBI recovery and management (5 questions each scored on a 5-point Likert scale). The primary outcome was attending a PCP follow-up visit within 1 month of injury. RESULTS: Females were more likely than males to attend PCP follow-up (adjusted odds ratio: 2.27 [95% confidence interval: 1.00-5.18]). Increasing scores on the caregiver attitudes survey indicating greater concerns about recovery were significantly associated with attending PCP follow-up (adjusted odds ratio: 1.12 per unit increase in composite score [95% confidence interval: 1.02-1.23]). No other socioeconomic, demographic, or injury characteristics were associated with attending PCP follow-up. CONCLUSIONS: The ED counseling regarding PCP follow-up of mTBI should stress the importance of follow-up care to monitor recovery and identify presence of lingering symptoms.

Epidemiology of knee internal derangement injuries in United States high school girls' lacrosse, 2008/09-2016/17 academic years.

Research on knee internal derangement (KID) injuries in high school girls' lacrosse is limited, yet needed to identify sport-specific risk factors. This study describes the epidemiology of KID injuries in United States high school girls' lacrosse during the 2008/09-2016/17 academic years. Athletic trainers (ATs) reported injury and athlete-exposure (AE) data to the High School Reporting Information Online (RIO) surveillance system. KID injuries involved the anterior cruciate ligament (ACL), posterior cruciate ligament (PCL), medial collateral ligament (MCL), lateral collateral ligament (LCL), and menisci. Injury rates per 10,000AE and injury rate ratios (IRR) with 95% confidence intervals (CI) were reported. Linear regression assessed injury rate time trends. ATs reported 148 KID injuries (rate = 1.92/10,000AE). The injury rate was higher in competition than practice (IRR = 8.40; 95%CI: 5.66-12.49). ACLs comprised a large proportion of KID injuries (46.6%). The ACL injury rate increased over time (P = 0.002), highlighting the need to develop/refine lacrosse-specific KID injury prevention programs.

Development of nap neurophysiology: preliminary insights into sleep regulation in early childhood.

Although all young children nap, the neurophysiological features and associated developmental trajectories of daytime sleep remain largely unknown. Longitudinal studies of napping physiology are fundamental to understanding sleep regulation during early childhood, a sensitive period in brain and behaviour development and a time when children transition from a biphasic to a monophasic sleep-wakefulness pattern. We investigated daytime sleep in eight healthy children with sleep electroencephalography (EEG) assessments at three longitudinal points: 2 years (2.5-3.0 years), 3 years (3.5-4.0 years) and 5 years (5.5-6.0 years). At each age, we measured nap EEG during three randomized conditions: after 4 h (morning nap), 7 h (afternoon nap) and 10 h (evening nap) duration of prior wakefulness. Developmental changes in sleep were most prevalent in the afternoon nap (e.g. decrease in sleep duration by 30 min from 2 to 3 years and by 20 min from 3 to 5 years). In contrast, nap sleep architecture (% of sleep stages) remained unchanged across age. Maturational changes in non-rapid eye movement sleep EEG power were pronounced in the slow wave activity (SWA, 0.75-4.5 Hz), theta (4.75-7.75 Hz) and sigma (10-15 Hz) frequency ranges. These findings indicate that the primary marker of sleep depth, SWA, is less apparent in daytime naps as children mature. Moreover, our fundamental data provide insight into associations between sleep regulation and functional modifications in the central nervous system during early childhood.

Motor function is associated with 1,25(OH)(2)D and indices of insulin-glucose dynamics in non-diabetic older adults.

BACKGROUND: Advancing age is accompanied by changes in metabolic characteristics, such as reduced insulin sensitivity and low levels of vitamin D, which may exacerbate age-related declines in physical function. AIMS: The aim of the present study was to determine the associations between insulin-glucose dynamics, vitamin D metabolites, and performance on a battery of motor tasks in healthy, non-diabetic older adults. METHODS: Sixty-nine community-dwelling men and women (65-90 years) were recruited. Insulin-glucose dynamics were determined by an intravenous glucose tolerance test, and vitamin D metabolites were measured. Motor function was characterized by the time to walk 500 m, chair-rise time, lower body strength, dorsiflexor steadiness and endurance time, and muscle coactivation. RESULTS: Significant unadjusted correlations were found between insulin-glucose dynamics and 1,25-dihydroxyvitamin D [1,25(OH)2D] with walk time, strength, steadiness, endurance time, and muscle activation (p < 0.05). A significant amount of the variance in walking endurance was explained by the sex of the individual, 1,25(OH)2D, and fasting blood insulin (R (2) = 0.36, p < 0.001). Strength could be partially explained by age, body fatness, and fasting glucose (R (2) = 0.55, p < 0.001). DISCUSSION: Poor motor function in non-diabetic older men and women was associated with indices of insulin-glucose dynamics and the bio-active vitamin D metabolite 1,25(OH)2D. Walking endurance and strength were explained by 1,25(OH)2D and fasting blood glucose and insulin, even after adjusting for age, sex, and body fat. CONCLUSION: Motor function in a relatively small sample of non-diabetic older men and women was associated with metabolic factors that increase in prevalence with aging.

Normative Values of Isometric Shoulder Strength Among Healthy Adults.

Background: Normative data is useful for comparing measured values of strength with population norms and can avoid the issues associated with limb symmetry index. The available normative shoulder strength values are limited by constraints on research designs and variability in subject groups which prevents this data being successfully extrapolated to the greater population. Purpose: The purpose of this study was to establish normative isometric strength values for various movements of the shoulder that are specific to function and rotator cuff strength. A secondary goal of this study was to analyze the effect of age, gender, weight, height, activity level and arm dominance on shoulder strength. Design: Observational cohort study. Methods: Subjects in four age groups (20-29, 30-39, 40-49, 50-59) were included in this study-200 males (40.0 ± 11.6 years, 179.1 ± 6.5 cm, 81 ± 13.0 kg) and 200 females (40.1 ± 11.5 years, 165.3 ± 7.4sm, 64.4 ± 11.6 kg). Bilateral isometric strength measurements were taken with a handheld dynamometer testing seven shoulder movements. Tables of normative strength data were constructed. Multivariate analyses were performed to analyze the effects of age, gender, weight, height and activity level on isometric shoulder strength. Results: Men were stronger than women (p<0.001). Age was not associated with most strength measures with the exception of dominant arm abduction (p<0.004), non-dominant arm abduction (p<0.028) and non-dominant arm scapular plane abduction (p<0.004) which had a negative association with strength. Weight was positively associated with strength (p<0.001). Activity level was positively associated with all strength measures (p<0.05) except dominant sided abduction (p=0.056). There were no statistically significant differences between dominant and non-dominant sides. Conclusion: This normative data may be useful to the clinician, as it permits a standard against which to compare shoulder strength for various age groups. Clinicians can have confidence that the uninvolved limb, if symptom free, can be used as an adequate benchmark for strength measures. Levels of Evidence: Level 3©The Author(s).

Acromioclavicular joint injuries at a Colorado ski resort.

BACKGROUND: Acromioclavicular joint (ACJ) injuries are among the most common injuries in contact and non-contact sports. As winter sports become more popular, there has been an increase in shoulder injuries among recreational skiers and snowboarders. METHODS: This was a retrospective analysis of all patients who presented to the Denver Health Winter Park Medical Center with ACJ injury from 2012 to 2017. We examined the incidence of ACJ injuries, the injury mechanism, demographics, and type of ACJ injuries among skiers and snowboarders treated at the clinic. RESULTS: A total of 341 ACJ injuries (6.7% of total visits) were encountered during the study period. The majority of ACJ injures were type I (41.3%) and mainly occurred in men (86.5%). Most (96.8%) of the cases were primary ACJ injuries on the right shoulder (56.9%). The average age of patients with ACJ injuries was 30.0 years (range 10-72). More than half (62.2%) of ACJ injuries occurred while snowboarding. The most common mechanism of injury (93.5%) was fall to the snow while skiing/snowboarding. Women were more likely to have a type I ACJ injury than men (80.4% vs 35.4%; P < 0.001). Women with ACJ injuries were more likely to suffer the injury while skiing than snowboarding (71.7% vs 28.3%; P < 0.001), compared to men who were more likely to suffer the injury while snowboarding than skiing (67.5% vs 32.5%; P < 0.001). CONCLUSIONS: Most of the ACJ injuries were type I and occurred mostly in men. Snowboarders were more likely to have an ACJ injury than skiers. LEVEL OF EVIDENCE: Level IV, Epidemeiology Study.

The Relationship Between the Joint Space and Outcomes After Hip Arthroscopic Surgery for Femoroacetabular Impingement: Reevaluating the 2-mm Rule.

BACKGROUND: A limited joint space (<2 mm) is associated with poorer outcomes and conversion to total hip arthroplasty (THA) after hip arthroscopic surgery. As indications for hip arthroscopic surgery expand, it is important to reevaluate established risk factors among large patient populations. PURPOSE: To reevaluate the relationship between the radiographic joint space and outcomes after hip arthroscopic surgery and to assess the validity of a joint space of 2 mm as the accepted cutoff for successful hip arthroscopic surgery. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: Patients aged 18 to 50 years who underwent hip arthroscopic surgery for femoroacetabular impingement between January 2008 and December 2016 and had a minimum 2-year follow-up were included. Patients with previous ipsilateral hip surgery, a history of hip fractures, dysplasia (lateral center-edge angle <20°), or osteoarthritis (Tonnis grade >2) were excluded. The joint space was categorized as diminished (≤2 mm), borderline (>2 to ≤3 mm), or preserved (>3 mm). Minimum 2-year patient-reported outcomes (modified Harris Hip Score [mHHS], Hip Outcome Score-Activities of Daily Living [HOS-ADL], Hip Outcome Score-Sports-Specific Subscale [HOS-SSS]), revision rates, and rates of conversion to THA were compared between groups. RESULTS: A total of 699 patients (782 hips) with a mean age of 33.8 ± 10.1 years met 2-year inclusion criteria. The mean follow-up time was 4.2 ± 2.1 years. Overall, 51 hips (6.5%) had a diminished joint space, 297 (38.0%) had a borderline joint space, and 434 (55.5%) had a preserved joint space. Patients with a diminished joint space had larger femoral and acetabular defects compared with those with larger joint spaces. All groups had improved patient-reported outcome scores compared with baseline (P < .001 for all), and there were no differences between the groups in the percentage of patients who reached the minimal clinically important difference or patient acceptable symptom state. There were also no differences between the groups in revision rates (P = .95). A greater number of hips with a diminished joint space converted to THA (n = 8 [15.7%]) compared with those with a borderline (n = 9 [3.0%]) or preserved (n = 9 [2.1%]) joint space (P < .001). Considering joint space as a continuous variable, adjusted logistic regression showed that for every millimeter decrease in the joint space, the odds of conversion to THA increased by a factor of 2.5 (odds ratio, 2.5 [95% CI, 1.6-3.8]). CONCLUSION: This study demonstrated that patients with a diminished joint space were at a higher risk of conversion to THA. Although 2 mm should not serve as a strict cutoff, patients should be counseled based on their preoperative radiographic findings accordingly.