From bimodal to unimodal: The transformed incidence of osteosarcoma in the United States.

Background: Osteosarcoma is the most common primary bone malignancy. It has classically been described as having a bimodal incidence by age. We sought to identify whether the bimodal incidence distribution still exists for osteosarcoma using the SEER and NIS databases. Methods: Incidence rates of primary osteosarcoma between 2000-2021 were analyzed by age at diagnosis, year of occurrence, sex, and tumor site from the SEER Research Data, 17 Registries, Nov 2023 Sub (2000-2021). The incidence of cases in 35-64 year-olds and 65 and above was compared statistically to determine if there is an increased incidence in the later ages. Incidence of tumors of the long bones of the lower limbs from the NIS discharge database 2012-2019 was also analyzed for comparison. Results: Overall, 5,129 cases of osteosarcoma were reported in the SEER database. Across the 22 calendar year span, a consistent first peak appeared in the second decade of life. There was no consistent second peak in the 35+ age group. There were 86,100 discharges with long bone tumors analyzed in the NIS data which exhibited nearly identical patterns. Conclusions: Our analysis shows that the incidence of osteosarcoma is no longer bimodally distributed but rather unimodally distributed.

Adverse Childhood Experiences and Depression among Homeless Young Adults: A Social Determinants of Health Perspective.

Homelessness is a pervasive issue in the United States that presents significant challenges to public health. Homeless young adults (HYAs) are at particular risk for increased incidence and severity of depression. Using primary survey data (n = 205) collected in the Phoenix Metropolitan Area, Arizona, from June to August 2022, this study aims to examine the relationship between adverse childhood experiences (ACEs) and depression among HYAs. We adopted the ACEs 10-item scale to measure childhood traumatic experiences, whereas depression was measured by using a PHQ-4 depression scale and diagnosed depression. Regression models were conducted to test the relationships between ACEs and depression outcomes while controlling for the covariates at the individual, interpersonal, and socioeconomic/living environment levels. The average PHQ-4 score was 5.01 (SD = 3.59), and 59.69% of HYAs reported being diagnosed previously with depression. The mean ACEs score was 5.22 out of 10. Other things being equal, for every one unit increase in ACEs scores, the odds of being diagnosed with depression increased by 11.5%, yet it was not statistically significant, while the PHQ-4 score increased by 0.445 (p < 0.001). Overall, HYAs were disproportionately affected by depression. This study elucidates the complex relationship between ACEs and depression among HYAs.

Race and Sex Disparities in Lower Extremity Total Joint Arthroplasty: A Retrospective Database Study.

INTRODUCTION: Total joint arthroplasty (TJA) is successful in improving health-related quality of life. However, outcomes vary in the literature due to modifiable and non-modifiable factors. Modifiable factors consist of body mass index (BMI), nutrition, and tobacco use. Non-modifiable risk factors include age, race, sex, and socioeconomic status. Prior literature has focused on racial disparities in terms of the utilization of lower extremity arthroplasty. The purpose of this study is to determine the effect of race and sex on the in-hospital complication rate, length of stay, and charges associated with primary TJA. METHODS: This retrospective cohort utilized complex survey data from the National Inpatient Sample (NIS) between 2016 and 2019. The use of the International Classification of Disease-10 Procedure Codes (ICD-10 PCS) for right hip, left hip, right knee, and left knee TJA yielded a preliminary total of 2,660,280 patients. The exclusion criteria were bilateral arthroplasty and concomitant unilateral hip and knee arthritis. Major complications were defined as acute myocardial infarction, cardiac arrest, pulmonary embolism, adult respiratory distress syndrome, stroke, shock, and septicemia. Odds ratio (OR) and beta coefficients were adjusted for age, sex, primary payer, hospital region, hospital teaching status, and year. Total charges were adjusted for inflation using the Consumer Price Index data reported by the US Bureau of Labor Statistics. RESULTS: A total of 2,589,510 patients met our inclusion criteria; 87.6%, 5.9%, 4.8%, 1.4%, and 0.3% of people were 'White', 'Black', 'Hispanic', 'Asian, or Pacific Islander', and 'Native American', as defined by the National (Nationwide) Inpatient Sample (NIS) Variable 'RACE'. Black individuals experienced a significantly greater major complication rate compared to White individuals (0.87% vs. 0.74%, OR 1.25, p-value = 0.0004). Black and Hispanic individuals experienced a significantly greater minor complication rate compared to White individuals (6.39% vs. 4.12%, odds ratio (OR) 1.61, p-value < 0.0001; 4.68% vs. 4.12%, OR 1.17, p-value < 0.0001). Black, Hispanic, Asian or Pacific Islander, and Native American individuals stayed, on average, 0.33, 0.19, 0.19, and 0.25 days longer than White individuals (2.78, 2.54, 2.55, 2.56 vs. 2.37 days, p<0.0001). None of these statistically significant differences exceeded the established minimal clinically important difference of two days. Black, Hispanic, and Asian or Pacific Islander patients were charged $5,751, $18,656, and $12,119 more than White patients ($72,122, $85,027, $78,490, and $59,297 vs. $66,371, p ≤ 0.0165). Native American patients were charged $7,074 less than White patients ($59,297 vs. $66,371, p < 0.0001). CONCLUSIONS: Black and Hispanic TJA patients may have higher complication rates than White TJA patients. The differences in length of stay between race groups may not affect outcomes. Hispanic patients received significantly more charges than White patients, and Native American patients received significantly fewer charges than White patients after controlling for non-modifiable risk factors. Addressing the charge disparities may reduce the total national cost burden associated with TJA. The present study highlights the need for further studies on healthcare outcomes related to race and sex.

Infiltration of intramuscular adipose tissue impairs skeletal muscle contraction.

KEY POINTS: Muscle infiltration with adipose tissue (IMAT) is common and associated with loss of skeletal muscle strength and physical function across a diverse set of pathologies. Whether the association between IMAT and muscle weakness is causative or simply correlative remains an open question that needs to be addressed to effectively guide muscle strengthening interventions in people with increased IMAT. In the present studies, we demonstrate that IMAT deposition causes decreased muscle strength using mouse models. These findings indicate IMAT is a novel therapeutic target for muscle dysfunction. ABSTRACT: Intramuscular adipose tissue (IMAT) is associated with deficits in strength and physical function across a wide array of conditions, from injury to ageing to metabolic disease. Due to the diverse aetiologies of the primary disorders involving IMAT and the strength of the associations, it has long been proposed that IMAT directly contributes to this muscle dysfunction. However, infiltration of IMAT and reduced strength could both be driven by muscle disuse, injury and systemic disease, making IMAT simply an 'innocent bystander.' Here, we utilize novel mouse models to evaluate the direct effect of IMAT on muscle contraction. First, we utilize intramuscular glycerol injection in wild-type mice to evaluate IMAT in the absence of systemic disease. In this model we find that, in isolation from the neuromuscular and circulatory systems, there remains a muscle-intrinsic association between increased IMAT volume and decreased contractile tension (r2  > 0.5, P < 0.01) that cannot be explained by reduction in contractile material. Second, we utilize a lipodystrophic mouse model which cannot generate adipocytes to 'rescue' the deficits. We demonstrate that without IMAT infiltration, glycerol treatment does not reduce contractile force (P > 0.8). Taken together, this indicates that IMAT is not an inert feature of muscle pathology but rather has a direct impact on muscle contraction. This finding suggests that novel strategies targeting IMAT may improve muscle strength and function in a number of populations.