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Forest structure and dynamics vary across the Amazon Basin in an east-west gradient coincident with variations in soil fertility and geology. This has resulted in the hypothesis that soil fertility may play an important role in explaining Basin-wide variations in forest biomass, growth and stem turnover rates. Soil samples were collected in a total of 59 different forest plots across the Amazon Basin and analysed for exchangeable cations, carbon, nitrogen and pH, with several phosphorus fractions of likely different plant availability also quantified. Physical properties were additionally examined and an index of soil physical quality developed. Bivariate relationships of soil and climatic properties with above-ground wood productivity, stand-level tree turnover rates, above-ground wood biomass and wood density were first examined with multivariate regression models then applied. Both forms of analysis were undertaken with and without considerations regarding the underlying spatial structure of the dataset. Despite the presence of autocorrelated spatial structures complicating many analyses, forest structure and dynamics were found to be strongly and quantitatively related to edaphic as well as climatic conditions. Basin-wide differences in stand-level turnover rates are mostly influenced by soil physical properties with variations in rates of coarse wood production mostly related to soil phosphorus status. Total soil P was a better predictor of wood production rates than any of the fractionated organic- or inorganic-P pools. This suggests that it is not only the immediately available P forms, but probably the entire soil phosphorus pool that is interacting with forest growth on longer timescales. A role for soil potassium in modulating Amazon forest dynamics through its effects on stand-level wood density was also detected. Taking this into account, otherwise enigmatic variations in stand-level biomass across the Basin were then accounted for through the interacting effects of soil physical and chemical properties with climate. A hypothesis of self-maintaining forest dynamic feedback mechanisms initiated by edaphic conditions is proposed. It is further suggested that this is a major factor determining endogenous disturbance levels, species composition, and forest productivity across the Amazon Basin.

Soil samples were collected in six South American countries in a total of 71 different 1 ha forest plots across the Amazon Basin as part of the RAINFOR project. They were analysed for total and exchangeable cations, C, N, pH with various P fractions also determined. Physical properties were also examined and an index of soil physical quality proposed. A diverse range of soils was found. For the western areas near the Andean cordillera and the southern and northern fringes, soils tend to be distributed among the lower pedogenetic levels, while the central and eastern areas of Amazonia have more intensely weathered soils. This gives rise to a large variation of soil chemical and physical properties across the Basin, with soil properties varying predictably along a gradient of pedogenic development. Nutrient pools generally increased slightly in concentration from the youngest to the intermediate aged soils after which a gradual decline was observed with the lowest values found in the most weathered soils. Soil physical properties were strongly correlated with soil fertility, with favourable physical properties occurring in highly weathered and nutrient depleted soils and with the least weathered, more fertile soils having higher incidence of limiting physical properties. Soil phosphorus concentrations varied markedly in accordance with weathering extent and appear to exert an important influence on the nitrogen cycle of Amazon forest soils.

Xylem density is a physical property of wood that varies between individuals, species and environments. It reflects the physiological strategies of trees that lead to growth, survival and reproduction. Measurements of branch xylem density, ρx, were made for 1653 trees representing 598 species, sampled from 87 sites across the Amazon basin. Measured values ranged from 218 kg m−3for a Cordia sagotii (Boraginaceae) from Mountagne de Tortue, French Guiana to 1130 kg m−3 for an Aiouea sp. (Lauraceae) from Caxiuana, Central Pará, Brazil. Analysis of variance showed significant differences in average ρx across regions and sampled plots as well as significant differences between families, genera and species. A partitioning of the total variance in the dataset showed that species identity (family, genera and species) accounted for 33% with environment (geographic location and plot) accounting for an additional 26%; the remaining "residual" variance accounted for 41% of the total variance. Variations in plot means, were, however, not only accountable by differences in species composition because xylem density of the most widely distributed species in our dataset varied systematically from plot to plot. Thus, as well as having a genetic component, branch xylem density is a plastic trait that, for any given species, varies according to where the tree is growing in a predictable manner. Within the analysed taxa, exceptions to this general rule seem to be pioneer species belonging for example to the Urticaceae whose branch xylem density is more constrained than most species sampled in this study. These patterns of variation of branch xylem density across Amazonia suggest a large functional diversity amongst Amazonian trees which is not well understood.

Forest structure and dynamics have been noted to vary across the Amazon Basin in an east-west gradient in a pattern which coincides with variations in soil fertility and geology. This has resulted in the hypothesis that soil fertility may play an important role in explaining Basin-wide variations in forest biomass, growth and stem turnover rates. To test this hypothesis and assess the importance of edaphic properties in affect forest structure and dynamics, soil and plant samples were collected in a total of 59 different forest plots across the Amazon Basin. Samples were analysed for exchangeable cations, C, N, pH with various P fractions also determined. Physical properties were also examined and an index of soil physical quality developed. Overall, forest structure and dynamics were found to be strongly and quantitatively related to edaphic conditions. Tree turnover rates emerged to be mostly influenced by soil physical properties whereas forest growth rates were mainly related to a measure of available soil phosphorus, although also dependent on rainfall amount and distribution. On the other hand, large scale variations in forest biomass could not be explained by any of the edaphic properties measured, nor by variation in climate. A new hypothesis of self-maintaining forest dynamic feedback mechanisms initiated by edaphic conditions is proposed. It is further suggested that this is a major factor determining forest disturbance levels, species composition and forest productivity on a Basin wide scale. [ABSTRACT FROM AUTHOR]

Soil samples were collected in six South American countries in a total of 71 different 1 ha forest plots across the Amazon Basin as part of the RAINFOR project. They were analysed for total and exchangeable cations, C, N, pH with various P fractions also determined. Physical properties were also examined and an index of soil physical quality proposed. A diverse range of soils was found. For the western areas near the Andean cordillera and the southern and northern fringes, soils tend to be distributed among the lower pedogenetic levels, while the central and eastern areas of Amazonia have more intensely weathered soils. This gives rise to a large variation of soil chemical and physical properties across the Basin, with soil properties varying predictably along a gradient of pedogenic development. Nutrient pools generally increased slightly in concentration from the youngest to the intermediate aged soils after which a gradual decline was observed with the lowest values found in the most weathered soils. Soil physical properties were strongly correlated with soil fertility, with favourable physical properties occurring in highly weathered and nutrient depleted soils and with the least weathered, more fertile soils having higher incidence of limiting physical properties. Soil phosphorus concentrations varied markedly in accordance with weathering extent and appear to exert an important influence on the nitrogen cycle of Amazon forest soils. [ABSTRACT FROM AUTHOR]

Background: Unicompartmental knee arthroplasty (UKA) is a surgical treatment for knee osteoarthritis associated with lower morbidity compared with total knee arthroplasty (TKA) in patients with isolated unicompartmental knee arthritis. As disparities have been noted broadly in arthroplasty care, it follows that such disparities might be present in the utilization of UKA relative to TKA. This study therefore examined racial/ethnic, socioeconomic, and payer status differences in utilization of UKA., Methods: Patients who underwent UKA or TKA between 2016 and 2020 in the National Inpatient Sample were identified. Multivariable Poisson regression models adjusted for hospital geographic region and patient characteristics [age, sex, and Elixhauser Comorbidity Index (ECI)] were used to examine the effect of race/ethnicity, socioeconomic status, and payer status on incidence rate ratio of UKA relative to TKA., Results: Of the 8472 UKA patients and 639,937 TKA patients identified between 2016 and 2020, 8027 (94.7%) UKA patients and 606,028 (94.7%) TKA patients met inclusion criteria. Patients who underwent UKA were significantly younger (63.5 ± 10.7 years) than patients who underwent TKA (66.8 ± 9.5 years; p < 0.001) and had significantly lower ECI scores (1.8 ± 1.5) than patients who underwent TKA (2.2 ± 1.6; p < 0.001). Black patients were less likely to undergo UKA relative to TKA compared with white patients [incidence rate ratio (IRR) 0.64, confidence interval (CI) 0.58-0.71, p < 0.001]. Compared with patients in income quartile 4, patients in income quartiles 1 and 2 underwent UKA at a lower relative rate (IRR 0.85, CI 0.79-0.90, p < 0.001 and IRR 0.87, CI 0.82-0.93, p < 0.001, respectively). Compared with patients with private insurance, patients with Medicare underwent UKA at a lower relative rate (IRR 0.83, CI 0.79-0.88, p < 0.001)., Conclusions: Black patients, lower-income patients, and Medicare-insured patients undergo UKA at a lower relative rate than white, higher-income, and privately insured patients, respectively. Further research may help elucidate reasons for these differences and identify targets for intervention., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. As the NIS is a large database containing deidentified patient information, studies using this database do not constitute human subjects research. Consent for publication: Not applicable. Competing interests: The authors declare that they have no competing interests., (© 2024. The Author(s).)

Introduction: Medical school curricula offer limited exposure to orthopaedic surgery, and few national initiatives aim to prepare students for orthopaedic surgery subinternships, which are critical for success in matching into orthopaedic residency. In this study, we evaluated the effectiveness of a single-day virtual "Subinternship Summit" for medical students in 2 key areas: 1) enhancing participants' confidence in their preparedness for orthopaedic subinternship rotations and 2) mitigating any disparities based on student characteristics, such as race/ethnicity, gender, or whether or not the student's school is affiliated with a "home" orthopaedic program., Methods: In March 2024, a single-day national virtual summit was held, featuring panels on topics relevant to performance during orthopaedic subinternships. The panelists included senior medical students, orthopaedic residents, and attending orthopaedic surgeons from across the United States. Surveys were administered to participants through Qualtrics before and after the summit to collect demographic data and to assess confidence in 6 domains of subinternship performance using 5-point Likert-scale items: overall preparedness, on-call responsibilities, "soft skills," role in the operating room, role in the outpatient clinic, and understanding of resources. Our analysis included descriptive statistics, paired t tests, and multivariable linear regression. Significance was set at p < 0.05., Results: Of 787 medical students who registered for summit, 426 attended, of whom 180 (42%) completed both the presummit and postsummit surveys. Before the summit, students reported low confidence in all domains, with 5 of 6 domains averaging less than moderate (3/5 points). Multivariable analysis revealed no differences in presummit confidence across various demographic characteristics. After the summit, all 6 domains showed significant increases in confidence, with the lowest average being 4/5 (all, p < 0.001)., Conclusions: This virtual summit effectively increased medical students' confidence in their preparedness and knowledge about orthopaedic surgery subinternships. Given the weight of subinternship performance in the match process, such an initiative may have the potential to increase medical students' success in residency applications., Level of Evidence: Level V. See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSOA/A714)., (Copyright © 2024 The Authors. Published by The Journal of Bone and Joint Surgery, Incorporated. All rights reserved.)

Introduction: Orthopaedic surgery has the greatest degree of gender disparity among all medical specialties, presenting a little-explored opportunity to recruit women into orthopaedics early in the pipeline, particularly as undergraduate students. This study aimed to characterize the opinions of female premedical students regarding orthopaedic surgery as well as to assess the effectiveness of a virtual intervention in increasing interest in or improving attitudes toward the field., Methods: In this prospective study, recruitment emails were sent to premedical advisors, who then circulated a survey that solicited responses from female-identifying premedical students. The survey consisted of questions about demographics, Likert scale questions about opinions of orthopaedic surgery, and an open-response section. At the end of the survey, respondents were provided the option to register for a Zoom panel, in which 4 female physicians described their experiences as women in orthopaedic surgery. Survey responses were analyzed using unpaired t tests for continuous variables and analysis of variance and Tukey's post hoc analysis for Likert scale responses., Results: A total of 259 female premedical students completed the survey. Respondents most strongly agreed with the statements "orthopaedics is a male-dominated field" and "I wish I learned more about orthopaedics in college." Interest in pursuing orthopaedic surgery was greater among respondents who had undergone orthopaedic surgery, personally knew an orthopaedic surgeon, personally knew a female orthopaedic surgeon, or had shadowed in orthopaedic surgery. After attending the panel, attendees' interest in orthopaedic surgery significantly increased (p < 0.001), and attendees disagreed significantly more strongly with the notion that gender would limit their opportunities in orthopaedics (p = 0.013)., Conclusion: Early exposure to orthopaedic surgery was consistently associated with increased interest among respondents. In addition, exposure to female orthopaedic surgeons was associated with more positive opinions of orthopaedics, and the mentorship intervention proved effective at increasing interest in the field. These results reinforce the need for targeted, early-exposure programs to recruit premedical women into orthopaedic surgery., Level of Evidence: Level IV. See Instructions for Authors for a complete description of levels of evidence., Competing Interests: DML has a leadership or fiduciary role in other board, society, committee, or advocacy group, paid or unpaid, in the Ruth Jackson Orthopaedic Society, the American Society for Surgery of the Hand, the Board of Specialty Societies, and the Council of Orthopaedic Residency Directors, not related to the present study. JS has a leadership or fiduciary role in other board, society, committee, or advocacy group, paid or unpaid, in the Ruth Jackson Orthopaedic Society, not related to the present study. All other authors have no conflicts of interest to declare. Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSOA/A713)., (Copyright © 2024 The Authors. Published by The Journal of Bone and Joint Surgery, Incorporated. All rights reserved.)

Introduction: Delay in surgical management for orthopaedic emergencies and severe fracture types can result in notable morbidity and even mortality for patients. Disparities in various facets of orthopaedic care have been identified based on race/ethnicity, socioeconomic status, and payer status, but disparities in time to surgery have been poorly explored. The purpose of this study was, therefore, to investigate whether disparities exist in time to emergent orthopaedic surgery., Methods: Patients who underwent surgery for hip fracture, femur fracture, pelvic fracture, septic knee, septic hip, or cauda equina syndrome over 2012 to 2020 were identified using national data. Multivariable linear regression models were constructed, controlling for age, sex, race/ethnicity, payer status, socioeconomic status, hospital setting, and comorbidities to examine the effect of payer status and race/ethnicity, on time to surgery., Results: Over 2012 to 2020, 247,370 patients underwent surgery for hip fracture, 64,827 for femur fracture, 14,130 for pelvic fracture, 14,979 for septic knee, 3,205 for septic hip, and 4,730 for cauda equina syndrome. On multivariable analysis, patients with Medicaid experienced significantly longer time to surgery for hip fracture, femur fracture, pelvic fracture, septic knee, and cauda equina syndrome ( P < 0.05 all). Black patients experienced longer time to surgery for hip fracture, femur fracture, septic knee, septic hip, and cauda equina syndrome, and Hispanic patients experienced longer time to surgery for hip fracture, femur fracture, pelvic fracture, and cauda equina syndrome ( P < 0.05 all)., Discussion: The results of this study demonstrate that Medicaid-insured patients, and often minority patients, experience longer delays to surgery than privately insured and White patients. Future work should endeavor to identify causes of these disparities to promote creation of policies aimed at improving timely access to care for Medicaid-insured and minority patients., Level of Evidence: III., (Copyright © 2024 by the American Academy of Orthopaedic Surgeons.)

Background: With advancements in perioperative blood management and the use of tranexamic acid, the rate of transfusions after total knee arthroplasty (TKA) has substantially decreased. As these principles are refined, other modifiable risk factors, such as preoperative anemia, may play an increasingly important role in transfusion risk for patients undergoing TKA., Methods: A multicenter, national database was utilized to identify patients undergoing TKA from 2010 to 2021. Anemia was defined by World Health Organization definitions as < 12 g/dL for women and < 13 g/dL for men. A predictive model was created using backwards elimination logistic regression to predict transfusion risk, controlling for demographic and medical covariates. The coefficient of anemia was then analyzed for each year. The trend over time was fitted with a best-fit linear regression equation., Results: There were 509,117 patients who underwent TKA, and had a mean age of 67 years (range, 18 to 89). There were 57,716 (11%) patients who were anemic preoperatively, and 15,426 (3%) of patients required a transfusion. Rate of transfusion decreased from 10.6% in 2010 to 0.6% in 2021. The odds ratio associated with anemia as a predictor of transfusion increased from 3.1 (95% confidence interval: 2.1 to 4.6) in 2010 to 14.0 (95% confidence interval: 8.9 to 24) in 2021., Conclusions: The results of this study demonstrate that the importance of preoperative anemia as a predictor of transfusion has increased over the past decade as rates of transfusion have decreased. As perioperative blood management protocols improve, preoperative anemia should be considered an important focus of intervention to reduce the risk of transfusion prior to TKA., Level of Evidence: III., (Copyright © 2024 Elsevier Inc. All rights reserved.)

Study Design: Retrospective review., Objective: To determine whether the Activity Measure for Post-Acute Care (AM-PAC) "6-Clicks" score is associated with the development of postoperative ileus., Summary of Background Data: Adult spinal deformity (ASD) surgery has a high complication rate. One common complication is postoperative ileus, and poor postoperative mobility has been implicated as a modifiable risk factor for this condition., Methods: Eighty-five ASD surgeries in which ≥5 levels were fused were identified in a single institution database. A physical therapist/physiatrist collected patients' daily postoperative AM-PAC scores, for which we assessed first, last, and daily changes. We used multivariable linear regression to determine the marginal effect of ileus on continuous AM-PAC scores; threshold linear regression with Bayesian information criterion to identify a threshold AM-PAC score associated with ileus; and multivariable logistic regression to determine the utility of the score thresholds when controlling for confounding variables., Results: Ten of 85 patients (12%) developed ileus. The mean day of developing ileus was postoperative day 3.3±2.35. The mean first and last AM-PAC scores were 16 and 18, respectively. On bivariate analysis, the mean first AM-PAC score was lower in patients with ileus than in those without (13 vs. 16; P< 0.01). Ileus was associated with a first AM-PAC score of 3 points lower (Coef. -2.96; P< 0.01) than that of patients without ileus. Patients with an AM-PAC score<13 had 8 times greater odds of developing ileus ( P= 0.023). Neither the last AM-PAC score nor the daily change in AM-PAC score was associated with ileus., Conclusions: In our institutional cohort, a first AM-PAC score of <13, corresponding to an inability to walk or stand for more than 1 minute, was associated with the development of ileus. Early identification of patients who cannot walk or stand after surgery can help determine which patients would benefit from prophylactic management., Level of Evidence: Level-III., Competing Interests: B.J.N. reports grants/research support from DePuy Synthes and is on the speaker’s bureau for Medtronic. K.M.K. reports personal fees and other from DePuy Synthes, other from Stryker, personal fees from Ethicon, other from SpineCraft, other from Orthofix, outside the submitted work. R.L.S. reports grants/research support from DePuy Synthes and is on the Boards of Directors for the North American Spine Society and the International Society for Quality of Life Research. The remaining authors declare no conflicts of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Study Design: Retrospective review., Objectives: We substratified the mFI-5 frailty index to reflect controlled and uncontrolled conditions and assess their relationship to perioperative complications., Summary of Background Data: Risk assessment before adult spinal deformity (ASD) surgery is critical because the surgery is highly invasive with a high complication rate. Although frailty is associated with risk of surgical complications, current frailty measures do not differentiate between controlled and uncontrolled conditions., Methods: Frailty was calculated using the mFI-5 index for 170 ASD patients with fusion of ≥5 levels. Uncontrolled frailty was defined as blood pressure >140/90 mm Hg, HbA1C >7% or postprandial glucose >180 mg/dL, or recent chronic obstructive pulmonary disease (COPD) exacerbation, while on medication. Patients were divided into nonfrailty, controlled frailty, and uncontrolled frailty cohorts. The primary outcome measure was perioperative major and wound complications. Bivariate analysis was performed. Multivariable analysis assessed the relationship between frailty and perioperative complications., Results: The cohorts included 97 nonfrail, 54 controlled frail, and 19 uncontrolled frail patients. Compared with nonfrail patients, patients with uncontrolled frailty were more likely to have age older than 60 years (84% vs. 24%), hyperlipidemia (42% vs. 20%), and Oswestry Disability Index (ODI) score >42 (84% vs. 52%) ( P <0.05 for all). Controlled frailty was associated with those older than 60 years (41% vs. 24%) and hyperlipidemia (52% vs. 20%) ( P <0.05 for all). On multivariable regression analysis controlling for hyperlipidemia, functional independence, motor weakness, ODI>42, and age older than 60 years, patients with uncontrolled frailty had greater odds of major complications (OR 4.24, P =0.03) and wound complications (OR 9.47, P =0.046) compared with nonfrail patients. Controlled frailty was not associated with increased risk of perioperative complications ( P >0.05 for all)., Conclusions: Although patients with uncontrolled frailty had higher risk of perioperative complications compared with nonfrail patients, patients with controlled frailty did not, suggesting the importance of controlling modifiable risk factors before surgery., Level of Evidence: 3., Competing Interests: Dr. Kebaish reports consultant fees and other support from DePuy Synthes and Stryker, as well as support from Orthofix and SpineCraft. Dr. Neuman reports grants/research support from DePuy Synthes and is on the speaker’s bureau for Medtronic. The remaining authors declare no conflict of interest., (Copyright © 2024 Wolters Kluwer Health, Inc. All rights reserved.)

Purpose: An abundance of literature exists linking eating disorders and fracture risk. However, no studies, to our knowledge, have investigated the impact of eating disorders on lower extremity soft tissue injury or surgery risk. The purpose of this study was to determine if anorexia nervosa and bulimia nervosa are associated with prevalence of lower extremity soft tissue injuries and surgeries., Methods: Patients with anorexia nervosa or bulimia nervosa over 2010-2020 were identified through the International Classification of Diseases (ICD) codes in the PearlDiver Claims Database. Patients were matched by age, gender, comorbidities, record dates, and region to control groups without anorexia or bulimia. Soft tissue injuries were identified through ICD codes, and surgeries were identified through Current Procedural Terminology codes. Differences in relative prevalence were analyzed using chi-square analysis., Results: Patients with anorexia had a significantly increased prevalence of meniscus tears (RR = 1.57, CI 1.22-2.03, p  = 0.001) or deltoid ligament sprains (RR = 1.83, CI 1.10-3.03, p  = 0.025), and patients with bulimia had a significantly increased prevalence of meniscus tears (RR = 1.98, CI 1.56-2.51, p  < 0.001), medial collateral ligament sprains (RR = 3.07, CI 1.72-5.48, p  < 0.001), any cruciate ligament tears (RR = 2.14, CI 1.29-3.53, p  = 0.004), unspecified ankle sprains (RR = 1.56, CI 1.22-1.99, p  < 0.001), or any ankle ligament sprains (RR = 1.27, CI 1.07-1.52, p  = 0.008). Patients with anorexia had a significantly increased prevalence of anterior cruciate ligament reconstructions (RR = 2.83, CI 1.12-7.17, p  = 0.037) or any meniscus surgeries (RR = 1.54, CI 1.03-2.29, p  = 0.042), and patients with bulimia had a significantly increased prevalence of partial meniscectomies (RR = 1.80, CI 1.26-2.58, p  = 0.002) or any meniscus surgeries (RR = 1.83, CI 1.29-2.60, p  < 0.001)., Conclusions: Anorexia and bulimia are associated with increased prevalence of soft tissue injuries and surgeries. Orthopedic surgeons should be aware of this risk, and patients presenting to clinics should be informed of the risks associated with these diagnoses and provided with resources promoting recovery to help prevent further injury or surgery.

Background: Obesity adversely impacts outcomes of total hip arthroplasty (THA), leading surgeons to impose body mass index cutoffs for patient eligibility and encourage preoperative weight loss. This study aimed to determine if preoperative weight loss impacts outcomes of THA in the general patient population and if it mitigates poor outcomes in obese patients., Methods: Patients who underwent THA from 2013-2020 were identified in the National Surgical Quality Improvement Program (NSQIP) database. Patients were stratified by weight loss of >10% of body weight over the preceding 6 months. We used multivariable linear and logistic regression models, adjusted for age, sex, race/ethnicity, and comorbidities, to examine the effect of significant preoperative weight loss on 30-day outcomes after THA in the general and obese patient populations., Results: In the overall population, patients who lost significant weight preoperatively had significantly increased length of stay, were more likely to have a non-home discharge, return to the operating room, or be readmitted, and were more likely to experience numerous medical complications. In the obese population, patients who lost significant weight preoperatively had significantly increased length of stay and were more likely to require a transfusion or experience any medical complication., Discussion: Rapid significant preoperative weight loss is not associated with improved postoperative outcomes after THA in the obese population and is associated with worse outcomes in the general population. Arthroplasty surgeons should balance these risks with the risks of obesity when advising patients about preoperative weight loss prior to THA., Level of Evidence: III., (© 2024. The Author(s).)

Background: Although Coronavirus disease 2019 (COVID-19) infection causes major morbidity and mortality, it is unclear what the impact of postoperative COVID-19 infection is on 30-day outcomes after total joint arthroplasty (TJA)., Methods: There were 2,340 patients who underwent TJA in 2021, identified using the National Surgical Quality Improvement Program database, with 925 total hip arthroplasty (THA) patients (39.5%) and 1,415 total knee arthroplasty (TKA) patients (60.5%), overall. Propensity score matching was implemented using patient demographics and preoperative medical conditions to compare outcomes for postoperative COVID-19-positive and COVID-19-negative patients who underwent TKA or THA., Results: Postoperative COVID-19-positive THA patients were found to have a significantly increased risk of pneumonia (odds ratio [OR] 42.57), sepsis (OR 12.77), readmission (OR 12.06), non-home discharge (OR 3.78), and longer length of stay (hazard ratio 1.62). Postoperative COVID-19-positive TKA patients had an increased risk of 30-day mortality (OR 14.17), superficial infection (OR 3.17), pneumonia (OR 34.68), unplanned intubation (OR 18.31), ventilator use for more than 48 hours (OR 18.31), pulmonary embolism (OR 11.98), urinary tract infection (OR 5.16), myocardial infarction (OR 16.02), deep vein thrombosis (OR 4.69), non-home discharge (OR 1.79), reoperation (OR 3.17), readmission (OR 9.61), and longer length of stay (hazard ratio 1.49)., Conclusions: Patients who contracted COVID-19 within 30 days after TJA were at increased risk of mortalities, medical complications, readmissions, reoperations, and non-home discharges. It is important for orthopedic surgeons to understand these adverse outcomes to better counsel patients and mitigate these risks, particularly in higher risk populations., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Elastic stable intramedullary nailing (ESIN) has been shown to be an effective form of surgical management for lower-extremity diametaphyseal fractures in pediatric patients, but studies are limited because ESIN treatment for these fractures is relatively uncommon. We sought to determine whether ESIN can be used effectively in the most distal or proximal short-segment forms of these fractures. We queried the electronic medical record system at Johns Hopkins Hospital using Current Procedural Terminology codes for femur and tibia fractures treated with ESIN in patients under 18 years old between January 2015 and October 2022. Preoperative and postoperative radiographs were subsequently reviewed to identify patients with a proximal or distal third femoral or tibial shaft fracture treated with ESIN and to define criteria for short-segment diametaphyseal fractures. We used Beaty radiological criteria to evaluate radiographic outcomes and Flynn titanium elastic nails (TENs) outcome scale to assess clinical recovery after radiographic evidence of union. There were 43 children who met the inclusion criteria. Among them, 10 patients had short-segment diametaphyseal fractures. There were 22 (51.2%) who sustained femur fractures and 21 (48.8%) who sustained tibia fractures. Using Beaty radiologic criteria, ESIN was associated with more satisfactory outcomes in patients with distal or proximal third shaft fractures (32/33) than in patients with short-segment diametaphyseal fractures (7/10) (P = .03). Using the TENs outcome scale, 21 (63.4%) patients with distal or proximal third shaft fractures had excellent results, 11 (33.3%) had satisfactory results, and 1 (3%) had a poor result. Among patients with short-segment diametaphyseal fractures, 4 (40%) had excellent results, 5 (50%) had satisfactory results, and 1 (10%) had a poor result. There were no differences in TENs outcomes between the groups (P = .24). Patients with short-segment lower-extremity diametaphyseal fractures treated with ESIN had worse radiographic outcomes but did no worse clinically than patients with distal or proximal third shaft fractures. Consequently, ESIN should be considered a safe and effective surgical management option for pediatric patients with even the most distal or proximal forms of these fractures., Competing Interests: The authors have no funding and conflicts of interest to disclose., (Copyright © 2024 the Author(s). Published by Wolters Kluwer Health, Inc.)

Background: Body mass index (BMI) has been shown to influence risk for revision total hip arthroplasty (rTHA), but few studies have specifically examined which causes of rTHA are most likely in different BMI classes. We hypothesized that patients in different BMI classes would undergo rTHA for disparate reasons., Methods: Ninety-eight thousand six hundred seventy patients undergoing rTHA over 2006-2020 were identified in the National Inpatient Sample. Patients were classified as underweight, normal-weight, overweight/obese, or morbidly obese. Multivariable logistic regression was used to analyze the impact of BMI on rTHA for periprosthetic joint infection (PJI), dislocation, periprosthetic fracture (PPF), aseptic loosening, or mechanical complications. Analyses were adjusted for age, sex, race/ethnicity, socioeconomic status, insurance, geographic region, and comorbidities., Results: Compared to normal-weight patients, underweight patients were 131% more likely to have a revision due to dislocation and 63% more likely due to PPF. Overweight/obese patients were 19% less likely to have a revision due to dislocation and 10% more likely due to PJI. Cause for revision in morbidly obese patients was 4s1% less likely to be due to dislocation, 8% less likely due to mechanical complications, and 90% more likely due to PJI., Conclusions: Overweight/obese and morbidly obese patients were more likely to undergo rTHA for PJI and less likely for mechanical reasons compared to normal weight patients. Underweight patients were more likely to undergo rTHA for dislocation or PPF. Understanding the differences in cause for rTHA among the BMI classes can aid in patient-specific optimization and management to reduce postoperative complications., Level of Evidence: III., (© 2024. The Author(s).)

Background: Lisfranc fracture-dislocation is an uncommon but serious injury that currently lacks universal consensus on optimal operative treatment. Two common fixation methods are open reduction and internal fixation (ORIF) and primary arthrodesis (PA). The objective of this study is to analyze the cost difference between ORIF and PA of Lisfranc injuries, along with the contribution of medical services to overall costs., Methods: This was a retrospective cost analysis of the MarketScan database from 2010 to 2020. MarketScan is an insurance and commercial claims database that integrates deidentified patient information. It captures person-specific clinical utilization, expenditures, and enrollment across inpatient and outpatient services. Patients undergoing primary ORIF ( CPT code 28615) vs PA (28730 and 28740) for Lisfranc fracture-dislocation were identified. The primary independent variable was ORIF vs PA of Lisfranc injury. Total costs due to operative management was the primary objective. The utilization of and costs contributed by medical services was a secondary outcome., Results: From 2010 to 2020, a total of 7268 patients underwent operative management of Lisfranc injuries, with 5689 (78.3%) ORIF and 1579 (21.7%) PA. PA was independently associated with increased net and total payment and coinsurance, clinic visits, and imaging, and patients attended significantly more PT sessions., Conclusion: Using this large database that does not characterize severity or extent of injury, we found that treatment of Lisfranc fracture-dislocation with ORIF was associated with substantially lower initial episode of treatment costs compared with PA. Specific excessive cost drivers for PA were clinic visits, PT sessions, and imaging., Level of Evidence: Level III, retrospective cohort study., Competing Interests: The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article. ICMJE forms for all authors are available online., (© The Author(s) 2024.)

Background: Few studies have investigated whether social determinants of health disparities (SDHD), which include economic, social, education, health care, and environmental factors, identified through International Classification of Diseases (ICD) codes are associated with increased odds for poor health outcomes. We aimed to investigate the association between SDHD, identified through this novel methodology, as well as postoperative complications following total knee arthroplasty (TKA)., Methods: Using a national insurance claims database, a retrospective cohort analysis was performed. Patients were selected using Current Procedural Terminology and ICD codes for primary TKA between 2010 and 2019. Patients were stratified into 2 groups using ICD codes, those who had SDHD and those who did not, and propensity matched 1:1 for age, sex, a comorbidity score, and other comorbidities. After matching, 207,844 patients were included, with 103,922 patients in each cohort. Odds ratios (ORs) for 90-day medical and 2-year surgical complications were obtained using multivariable logistical regressions., Results: In patients who have SDHD, multivariable analysis demonstrated higher odds of readmission (OR): 1.12; P = .013) and major and minor medical complications (OR: 2.09; P < .001) within 90-days as well as higher odds of revision surgery (OR: 1.77; P < .001) and periprosthetic joint infection (OR: 1.30; P < .001) within 2-years., Conclusion: The SDHD are an independent risk factor for revision surgery and periprosthetic joint infection after TKA. In addition, SDHD is also an independent risk factor for all-cause hospital readmissions and both minor and major complications., Level of Evidence: III., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Body mass index (BMI) impacts risk for revision total knee arthroplasty (rTKA), but the relationship between BMI and cause for revision remains unclear. We hypothesized that patients in different BMI classes would have disparate risk for causes of rTKA., Methods: There were 171,856 patients who underwent rTKA from 2006 to 2020 from a national database. Patients were classified as underweight (BMI < 19), normal-weight, overweight/obese (BMI 25 to 39.9), or morbidly obese (BMI > 40). Multivariable logistic regressions adjusted for age, sex, race/ethnicity, socioeconomic status, payer status, hospital geographic setting, and comorbidities were used to examine the effect of BMI on risk for different rTKA causes., Results: Compared to normal-weight controls, underweight patients were 62% less likely to undergo revision due to aseptic loosening, 40% less likely due to mechanical complications, 187% more likely due to periprosthetic fracture, 135% more likely due to periprosthetic joint infection (PJI). Overweight/obese patients were 25% more likely to undergo revision due to aseptic loosening, 9% more likely due to mechanical complications, 17% less likely due to periprosthetic fracture, and 24% less likely due to PJI. Morbidly obese patients were 20% more likely to undergo revision due to aseptic loosening, 5% more likely due to mechanical complications, and 6% less likely due to PJI., Conclusion: Mechanical reasons were more likely to be the cause of rTKA in overweight/obese and morbidly obese patients, compared to underweight patients, for whom revision was more likely to be infection or fracture related. Increased awareness of these differences may promote patient-specific management to reduce complications., Level of Evidence: III., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Total ankle arthroplasty is increasingly being used for the treatment of ankle osteoarthritis when compared to arthrodesis. However, there has been limited investigation into disparities in utilization of these comparable procedures. This study examined racial/ethnic, socioeconomic, and payer status disparities in the likelihood of undergoing total ankle arthroplasty compared with ankle arthrodesis. Patients with a diagnosis of ankle osteoarthritis from 2006 through 2019 were identified in the National Inpatient Sample, then subclassified as undergoing total ankle arthroplasty or arthrodesis. Multivariable logistic regression models, adjusted for hospital location, primary or secondary osteoarthritis diagnosis, and patient characteristics (age, sex, infection, and Elixhauser comorbidities), were used to examine the effect of race/ethnicity, socioeconomic status, and payer status on the likelihood of undergoing total ankle arthroplasty versus arthrodesis. Black and Asian patients were 34% and 41% less likely than White patients to undergo total ankle arthroplasty rather than arthrodesis (p < .001). Patients in income quartiles 3 and 4 were 22% and 32% more likely, respectively, than patients in quartile 1 to undergo total ankle arthroplasty rather than arthrodesis (p = .001 and p = .01, respectively). In patients <65 years of age, privately insured and Medicare patients were 84% and 37% more likely, respectively, than Medicaid patients to undergo total ankle arthroplasty rather than arthrodesis (p < .001). Racial/ethnic, socioeconomic, and payer status disparities exist in the likelihood of undergoing total ankle arthroplasty versus arthrodesis for ankle osteoarthritis. More work is needed to establish drivers of these disparities and identify targets for intervention, including improvements in parity in relative procedure utilization., (Copyright © 2023. Published by Elsevier Inc.)

Background: Preoperative anemia has been shown to be associated with complications after numerous orthopedic procedures. No studies to our knowledge have examined its impact on outcomes after open reduction internal fixation (ORIF) of distal radius fracture (DRF). We hypothesized that patients with preoperative anemia would have increased likelihood of adverse outcomes, and likelihood would increase with severity of anemia., Methods: A total of 14 136 patients underwent ORIF for DRF over 2012-2021, identified in the National Surgical Quality Improvement Program database. Patients were classified by World Health Organization criteria as nonanemic (hematocrit >36% for women, >39% for men), mildly anemic (hematocrit 33%-36% for women, 33%-39% for men), or moderately to severely anemic (hematocrit <33% for women or men). Multivariable regressions adjusted for age, sex, race, and comorbidities statistically different between anemic and nonanemic patients were used to examine the effect of anemia on postoperative outcomes., Results: Mildly anemic patients had significantly longer length of stay and were significantly more likely to experience readmission and sepsis ( P < .05 all). Moderately to severely anemic patients had significantly longer length of stay and were significantly more likely to experience readmission, postoperative transfusion, septic shock, and any adverse event ( P < .05 all)., Conclusions: Preoperative anemia is associated with increased likelihood of adverse outcomes after ORIF for DRF, and likelihood increases with severity of anemia. Surgeons should monitor patients for preoperative anemia and endeavor to identify the source of and, if safe and possible, correct the anemia preoperatively or manage and educate patients postoperatively., Competing Interests: Declaration of Conflicting InterestsThe author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Introduction: Data regarding racial/ethnic and socioeconomic differences in revision total hip arthroplasty (rTHA) and revision total knee arthroplasty (rTKA) have been inconsistent. This study examined racial/ethnic and socioeconomic disparities in comorbidity-adjusted risk and reason for rTHA and rTKA., Methods: Patients who underwent rTHA or rTKA between 2006 and 2014 in the National Inpatient Sample were identified. Multivariable logistic regression models adjusted for payer status, hospital geographic setting, and patient characteristics (age, sex, and Elixhauser Comorbidity Index) were used to examine the effect of race/ethnicity and socioeconomic status on trends in annual risk of rTHA/rTKA and causes of rTHA/rTKA., Results: Black patients were less likely to undergo rTHA and more likely to undergo rTKA while Hispanic patients were more likely to undergo rTHA and less likely to undergo rTKA ( P < 0.001 for all) compared with White patients. Patients residing in areas of lower income quartiles were more likely to undergo rTHA and rTKA compared with those in the highest quartile ( P < 0.001), and these disparities persisted and widened over time. Black, Hispanic, and Asian patients were less likely to undergo rTHA/rTKA because of dislocation compared with White patients ( P < 0.001 for all). Patients from areas of lower income quartiles were more likely to undergo rTHA because of septic complications and less likely to require both rTHA and rTKA because of mechanical complications ( P < 0.001 for all)., Discussion: Racial/ethnic and socioeconomic disparities exist in risk and cause of rTHA and rTKA. Increasing awareness and a focus on minimizing variability in hospital quality may help mitigate these disparities., (Copyright © 2023 by the American Academy of Orthopaedic Surgeons.)

Background: Mental health conditions affect tens of millions of Americans. In recent years, particularly with the advent of the coronavirus disease 2019 pandemic, there has been a burst of interest in mental health and mental illness among orthopaedic surgical patients. The mental health of orthopaedic surgeons themselves has also come into focus, with high reported rates of burnout and depression. The aim of this article was to evaluate trends in publication on mental health and mental illness in orthopaedic surgery., Methods: Web of Science and PubMed were queried to conduct a systematic review. Studies that discussed orthopaedic surgery and mental illnesses or mental health topics over 2001 to 2022 were included. Publications were analyzed by article-, author-, and topic-level characteristics., Results: A total of 416 studies were analyzed after application of inclusion and exclusion criteria. Publication volume increased dramatically, demonstrating quadratic growth over 2001 to 2022 (p < 0.001). Eighty-eight percent of studies focused on patients and 10% on surgeons, with studies about patients more likely to focus on mental illness and those about surgeons more likely to focus on mental health (p < 0.001). Twenty percent of publications had a female senior author, and 5 authors collectively accounted for 10% of all publications. Eight journals published more than 10 publications, accounting for 35% of all publications. The most productive subspecialties were arthroplasty (135, 30%), general orthopaedics (87, 21%), and spine (69, 17%). Mental illnesses that were least represented included schizophrenia, bipolar disorder, eating disorders, attention-deficit/hyperactivity disorder, and personality disorders (1% or less of total publications each)., Conclusion: This analysis showed a dramatically increasing trend in publications on mental health and mental illness in orthopaedic surgery. A high concentration of publications came from a subset of journals and senior authors, and women were overrepresented as senior authors relative to their representation in the field. The results of this analysis identified gaps in the literature, including underrepresented subspecialties, understudied mental illnesses, and study of orthopaedic surgeon mental health, and thus highlighted areas for future investigation., Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSREV/A965)., (Copyright © 2023 by The Journal of Bone and Joint Surgery, Incorporated.)

Background: With lack of regulation and incentivisation on YouTube for high-quality healthcare information, it is important to objectively evaluate the quality of information on trigger finger - a common condition for hand surgeon referral. Methods: YouTube was queried (11/21/2021) for videos on trigger finger release surgery. Videos were excluded if they were about unrelated topics or not in English. The most viewed 59 videos were categorised by source as physician or non-physician. Two independent reviewers quantified the reliability, quality and content of each video, with inter-rater reliability assessed using Kohen's Kappa test. Reliability was assessed using the Journal of the American Medical Association (JAMA) score. Quality was assessed using the DISCERN score with high-quality videos defined as those with scores in the sample upper 25 th percentile. Content was assessed using the informational content score (ICS) with scores in the sample upper 25 th percentile indicating more complete information. Two-sample t -tests and logistic regression were used to assess variations between sources. Results: Videos by physicians had higher DISCERN quality (42.6 ± 7.9, 36.4 ± 10.3; p = 0.02) and informational content (5.8 ± 2.6, 4.0 ± 1.7; p = 0.01) scores compared to those by non-physician sources. Videos by physicians were associated with increased odds of high-quality (Odds Ratio [OR] 5.7, 95% Confidence Interval [95% CI] 1.3-41.3) and provided more complete patient information (OR 6.3, 95% CI 1.4-48.9). The lowest DISCERN sub-scores for all videos were discussion of the uncertainties and risks associated with surgery. The lowest ICS for all videos were in the diagnosis of trigger finger (11.9%) and non-surgical prognosis (15.3%). Conclusions: Physician videos have more complete and higher quality information on trigger finger release. Additionally, discussion of treatment risks, areas of uncertainty, the diagnostic process, non-surgical prognosis and transparency on references used were identified as lacking content. Level of Evidence: Level III (Therapeutic).

Background Context: Low early postoperative mobility (LEPOM) has been shown to be associated with increased length of hospital stay, complication rates, and likelihood of nonhome discharge. However, few studies have examined preoperative characteristics associated with LEPOM in adult spinal deformity (ASD) patients., Purpose: To investigate which preoperative patient characteristics may be associated with LEPOM after ASD surgery., Design: Retrospective review., Patient Sample: Included were 86 ASD patients with fusion of ≥5 levels for whom immediate-postoperative AM-PAC Basic Mobility Inpatient Short Form (6-Clicks) scores had been obtained., Outcome Measures: The primary outcome of this study was the likelihood of LEPOM, defined as an AM-PAC score ≤15, which is associated with inability to stand for more than 1 minute., Methods: Significant cutoffs for preoperative characteristics associated with LEPOM were determined via threshold linear regression. Multivariable logistic regression was used to assess the impact of preoperative characteristics on the likelihood of LEPOM., Results: LEPOM was recorded in 38 patients (44.2%). Threshold regression identified the following cutoffs to be associated with LEPOM: preoperative Patient Reported Outcomes Measurement Information System (PROMIS) scores of ≥68 for Pain, <28.3 for Physical Function, and ≥63.4 for Anxiety; preoperative Oswestry disability index (ODI) score of ≥60; and body mass index (BMI) of ≥35.2. On multivariate analysis, preoperative PROMIS scores of ≥68 for Pain (odds ratio [OR] 5.3, confidence interval [CI] 1.2-22.8, p=.03), <28.3 for Physical Function (OR 10.1, CI 1.8-58.2, p=.01), and ≥63.4 for Anxiety (OR 4.7, CI 1.1-20.8, p=.04); preoperative ODI score ≥60 (OR 38.8, CI 4.0-373.6, p=.002); BMI ≥35.2 (OR 14.2, CI 1.3-160.0, p=.03), and male sex (OR 5.4, CI 1.2-23.7, p=.03) were associated with increased odds of LEPOM., Conclusions: Preoperative PROMIS Pain, Physical Function, and Anxiety scores; ODI score; BMI; and male sex were associated with LEPOM. Several of these characteristics are modifiable risk factors and thus may be candidates for optimization before surgery., Level of Evidence: III., Competing Interests: Declarations of competing interests Dr Kebaish reports consultant fees and royalty from DePuy Synthes, royalty from Stryker, consulting fees from Ethicon, royalty from SpineCraft, and royalty from Orthofix. Dr Neuman reports grants/research support from DePuy Synthes and is on the speaker's bureau for Medtronic. All other authors report no conflicts of interest concerning the materials or methods used in this study or the findings specified in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Background: Despite an established increased fracture risk in eating disorder patients, no studies, to our knowledge, have investigated the association between eating disorders and upper extremity soft tissue injury or surgery incidence. Given the association of eating disorders with nutritional deficiency and musculoskeletal sequelae, we hypothesized that patients with eating disorders would have an increased risk of soft tissue injury and surgery. The aim of this study was to elucidate this link and investigate if these incidences are increased in patients with eating disorders., Methods: Cohorts of patients with anorexia ner-vosa or bulimia nervosa, identified using International Classification of Diseases (ICD) -9 and -10 codes, were identified in a large national claims database over 2010-2021. Control groups without these respective diagnoses were constructed, matched by age, sex, Charlson Comorbidity Index, record date, and geographical region. Upper extremity soft tissue injuries were identified using ICD-9 and -10 codes and surgeries using Current Procedural Terminology codes. Differences in incidence were analyzed using chi-square tests., Results: Patients with anorexia and bulimia were significantly more likely to sustain a shoulder sprain (RR=1.77; RR=2.01, respectively), rotator cuff tear (RR=1.39; RR=1.62), elbow sprain (RR=1.85; RR=1.95), hand/wrist sprain (RR=1.73; RR=16.0), hand/wrist ligament rupture (RR=3.33; RR=1.85), any upper extremity sprain (RR=1.72; RR=1.85), or any upper extremity tendon rupture (RR=1.41; RR=1.65). Patients with bulimia were also more likely to sustain any upper extremity ligament rupture (RR=2.88). Patients with anorexia and bulimia were significantly more likely to undergo SLAP repair (RR=2.37; RR=2.03, respectively), rotator cuff repair (RR=1.77; RR=2.10), biceps tenodesis (RR=2.73; RR=2.58), any shoulder surgery (RR=2.02; RR=2.25), hand tendon repair (RR=2.09; RR=2.12), any hand surgery (RR=2.14; RR=2.22), or any hand/wrist surgery (RR=1.87; RR=2.06)., Conclusion: Eating disorders are associated with an increased incidence of numerous upper extremity soft tissue injuries and orthopaedic surgeries. Further work should be undertaken to elucidate the drivers of this increased risk. Level of Evidence: III ., (Copyright © The Iowa Orthopaedic Journal 2023.)

Background Context: Adult spinal deformity (ASD) surgery requires an extended recovery period and often non-routine discharge. The Activity Measure for Post-Acute Care (AM-PAC) Basic Mobility Inpatient Short Form (6-Clicks) is a prediction tool, validated for other orthopedic procedures, to assess a patient's ability to mobilize after surgery., Purpose: To assess the thresholds of AM-PAC scores that determine non-home discharge disposition in patients who have undergone ASD surgery., Study Design: Retrospective review PATIENT SAMPLE: Ninety consecutive ASD patients with ≥5 levels fused who underwent surgery from 2015 to 2018, with postoperative AM-PAC scores measured before discharge, were included., Outcome Measures: Non-home discharge disposition METHODS: Patients with routine home discharge were compared to those with non-home discharge. Bivariate analysis was first conducted to compare these groups by preoperative demographics, comorbidities, radiographic alignment, surgical characteristics, HRQOLs, and AM-PAC measurements. Threshold linear regression with Bayesian information criteria was utilized to identify the optimal cutoffs for AM-PAC scores associated with increased likelihood of non-home discharge. Finally, multivariable analysis controlling for age, sex, comorbidities, levels fused, perioperative complication, and home support was conducted to assess each threshold., Results: Thirty-six (40%) of 90 patients analyzed had non-home discharge. On bivariate analysis, first AM-PAC score (13.5 vs. 17), last AM-PAC score (17 vs. 20), and AM-PAC change per day (+.387 vs. +1) were all significantly associated with non-home discharge. Threshold regression identified that cutoffs of ≤15 for first AM-PAC score, <17 for last AM-PAC score, and <+0.625 for daily AM-PAC change were associated with non-home discharge. On multivariable analysis, first AM-PAC score ≤15 (odds ratio [OR] 11.28; confidence interval [CI] 2.96-42.99; p<.001), last AM-PAC score <17 (OR 33.57; CI 5.85-192.82; p<.001), and AM-PAC change per day <+0.625 (OR 6.24; CI 2.01-19.43; p<.001) were all associated with increased odds of non-home discharge., Conclusions: First AM-PAC score of 15 or less can help predict non-home discharge. A goal of daily AM-PAC increases of 0.625 points toward a final AM-PAC score of 17 can aid in achieving home discharge. The early AM-PAC mobility threshold of ≤15 may help prepare for non-home discharge, while AM-PAC daily changes per day <0.625 and final AM-PAC <17 may provide goals for mobility improvement during the early postoperative period in order to prevent non-home discharge., Competing Interests: Conflicts of interest Dr. Kebaish reports consultant fees and royalty from DePuy Synthes, royalty from Sryker, consulting fees from Ethicon, royalty from SpineCraft, and royalty from Orthofix. Dr. Neuman reports grants/research support from DePuy Synthes and is on the speaker's bureau for Medtronic. All other authors report no conflicts of interest concerning the materials or methods used in this study or the findings specified in this paper., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Case: We present the case of an 81-year-old woman who developed profound hypercalcemia requiring admission to the intensive care unit after calcium sulfate bead use during revision hip arthroplasty. The patient's serum calcium level peaked at 21.0 mg/dL and was associated with acute encephalopathy. After treatment with calcitonin and bisphosphonates, her serum calcium level normalized and her mentation improved., Conclusion: The risk of clinically significant hypercalcemia should be considered when using calcium sulfate during orthopaedic surgery., Competing Interests: Disclosure: The Disclosure of Potential Conflicts of Interest forms are provided with the online version of the article (http://links.lww.com/JBJSCC/B823)., (Copyright © 2022 by The Journal of Bone and Joint Surgery, Incorporated.)

The present research is an investigation of how changes in the rate of motion are percieved. Five separate experiments were performed with the use of filmed stimulus material and a variety of response measures, including both categorical judgments and reporduction techniques. It was found that (a) the smaller the ratio of terminal to initial velocity, the less frequent the judgments of acceleration or deceleration, (b) deceleration was significantly easier to perceive than acceleration, (c) the perception of acceleration was facilitated when the velocity of a lead-in segment was the same as the velocity at onset of motion, (d) a short tunnel centered in the motion path facilitated the perception of acceleration and deceleration, and (e) instantaneous changes in velocity were much more easily perceived than gradual changes. A one-event model for the perception of motion change in which there is a continuous interplay between earlier, later, and interpolated motion segments is favored over a two-event model in which earlier and later segments of velocity are compared.