Effect of simulated body fluid formulation on orthopedic device apatite-forming ability assessment.

Integration of native bone into orthopedic devices is a key factor in long-term implant success. The material-tissue interface is generally accepted to consist of a hydroxyapatite layer so bioactive materials that can spontaneously generate this hydroxyapatite layer after implantation may improve patient outcomes. Per the ISO 22317:2014 standard, "Implants for surgery - In vitro evaluation for apatite-forming ability of implant materials," bioactivity performance statements can be assessed by soaking the material in simulated body fluid (SBF) and evaluating the surface for the formation of a hydroxyapatite layer; however, variations in test methods may alter hydroxyapatite formation and result in false-positive assessments. The goal of this study was to identify the effect of SBF formulation on bioactivity assessment. Bioglass® (45S5 and S53P4) and non-bioactive Ti-6Al-4V were exposed to SBF formulations varying in calcium ion and phosphate concentrations as well as supporting ion concentrations. Scanning electron microscopy and X-ray powder diffraction evaluation of the resulting hydroxyapatite layers revealed that SBF enriched with double or quadruple the calcium and phosphate ion concentrations increased hydroxyapatite crystal size and quantity compared to the standard formulation and can induce hydroxyapatite crystallization on surfaces traditionally considered non-bioactive. Altering concentrations of other ions, for example, bicarbonate, changed hydroxyapatite induction time, quantity, and morphology. For studies evaluating the apatite-forming ability of a material to support bioactivity performance statements, test method parameters must be adequately described and controlled. It is unclear if apatite formation after exposure to any of the SBF formulations is representative of an in vivo biological response. The ISO 23317 standard test method should be further developed to provide additional guidance on apatite characterization and interpretation of the results.

Impacting Underserved Communities as a GI Trainee.

Gastroenterology fellowship programs commonly include VA and county hospitals whose patient populations consist of some of the most vulnerable and underserved populations in the country who have a multitude of socioeconomic hurdles that limit their ability to address ongoing medical issues, all while having a restricted political voice and receiving care in under-resourced clinical settings. Since trainees are integral to the care of these patients, they have available two approaches that can affect community and hospital-based change, namely quality improvement (QI) and healthcare advocacy. QI projects focused on optimizing colorectal cancer screening, and Helicobacter pylori testing/eradication can provide value at an institutional level. Healthcare advocacy can be approached through involvement in national gastroenterological associations or locally through means such as establishing a fellowship-based advocacy group similar to a journal club. Both routes enable trainees to positively impact underserved communities.

Impact of Insurance Status on Time to Evaluation and Treatment of Meniscal Tears in Children, Adolescents, and College-Aged Patients in the United States.

BACKGROUND: The meniscus is vital for load bearing, knee stabilization, and shock absorption, making a meniscal tear a well-recognized sport-related injury in children and young adults. An inverse relationship between the quality and value of orthopaedic care provided and the overall treatment cycle exists in which delayed meniscal tear treatment increases the likelihood of unfavorable outcomes. Although a majority of children and young adults have health insurance, many athletes within this demographic still face significant barriers in accessing orthopaedic services because of insurance type and household income. PURPOSE: To determine the impact of insurance status and socioeconomic markers on the time to orthopaedic evaluation and treatment as well as the rate of surgical interventions for meniscal tears in children and young adult athletes in the United States. STUDY DESIGN: Cohort study; Level of evidence, 3. METHODS: We conducted a retrospective review of all patients ≤22 years of age who presented to our institution between 2008 and 2016 and who were diagnosed with meniscal tears. Patients were categorized based on insurance and socioeconomic status. Dates of injury, referral, evaluation by an orthopaedic surgeon, and surgery were also recorded. Chi-square and regression analyses were utilized to determine the significance and correlation between the influencing factors and time to referral, evaluation, and surgery. RESULTS: Publicly insured, commercially insured, and uninsured patients comprised 49.4%, 26.6%, and 24.1%, respectively, of the 237 patients included in this study. Insurance status was predictive of time to orthopaedic referral, initial evaluation, and surgery (P < .01). Uninsured and publicly insured patients experienced significant delays during their orthopaedic care compared with commercially insured patients. However, no correlation was found between insurance status or household income and the rate of surgical interventions. CONCLUSION: Publicly insured and uninsured pediatric and college-aged patients faced significant barriers in accessing orthopaedic services, as demonstrated by substantially longer times between the initial injury and referral to an orthopaedic evaluation and surgery; however, these socioeconomic factors did not affect the rate of surgical management. Clinical competency regarding the effects of socioeconomic factors on the time to orthopaedic care and efforts to expedite care among underinsured and underserved children are vital for improving patient outcomes.

Toxicity and photosensitizing assessment of gelatin methacryloyl-based hydrogels photoinitiated with lithium phenyl-2,4,6-trimethylbenzoylphosphinate in human primary renal proximal tubule epithelial cells.

Gelatin methacryloyl (GelMA) and lithium phenyl-2,4,6-trimethylbenzoylphosphinate (LAP) photoinitiator are commonly used in combination to produce a photosensitive polymer but there are concerns that must be addressed: the presence of unreacted monomer is well known to be cytotoxic, and lithium salts are known to cause acute kidney injury. In this study, acellular 10% GelMA hydrogels cross-linked with different LAP concentrations and cross-linking illumination times were evaluated for their cytotoxicity, photosensitizing potential, and elastic moduli. Alamar Blue and CyQuant Direct Cell viability assays were performed on human primary renal proximal tubule epithelial cells (hRPTECs) exposed to extracts of each formulation. UV exposure during cross-linking was not found to affect extract cytotoxicity in either assay. LAP concentration did not affect extract cytotoxicity as determined by the Alamar Blue assay but reduced hRPTEC viability in the CyQuant Direct cell assay. Photocatalytic activity of formulation extracts toward NADH oxidation was used as a screening method for photosensitizing potential; longer UV exposure durations yielded extracts with less photocatalytic activity. Finally, elastic moduli determined using nanoindentation was found to plateau to approximately 20-25 kPa after exposure to 342 mJ/cm2 at 2.87 mW of UV-A exposure regardless of LAP concentration. LAP at concentrations commonly used in bioprinting (<0.5% w/w) was not found to be cytotoxic although the differences in cytotoxicity evaluation determined from the two viability assays imply cell membrane damage and should be investigated further. Complete cross-linking of all formulations decreased photocatalytic activity while maintaining predictable final elastic moduli.

Rising Inpatient Encounters and Economic Burden for Patients with Nonalcoholic Fatty Liver Disease in the USA.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is the fastest-growing chronic liver disease. However, little is known about NAFLD inpatient resource utilization and clinical outcomes. AIMS: The aim of this study was to quantify inpatient NAFLD encounters using patient-level data over time. METHODS: This was a retrospective analysis of de-identified data for NAFLD patients from the California Patient Discharge Database from 2006 to 2013. NAFLD patients were identified by ICD9 codes 571.40, 571.41, 571.49, 571.8, and 571.9. RESULTS: NAFLD patients (n = 91,558) were predominantly female (60%), 45-65 years old (44%), and white (53%). Inpatient encounters increased from 8153 in 2006 to 16,457 in 2013 and were associated with a 207% increase in charges ($686 million in 2006 to $1.42 billion in 2013) and average increase in charges of 9.8% per year adjusting for inflation. Comorbidities (obesity, diabetes, hyperlipidemia, cardiovascular disease, other cancer, and renal disease) increased significantly over time (all P < 0.05). From 2006 to 2011, there were 11,463 deaths (1849 for liver-related hospitalizations) (mean follow-up 4.00 ± 2.13 years). The most significant predictors of death were age > 75 (aHR 3.9, P < 0.0001), male gender (aHR 1.10, P < 0.0001), white race (aHR 1.2, P < 0.0001), decompensated cirrhosis (aHR 2.1, P < 0.0001), and cancer other than HCC (aHR 3.2, P < 0.0001). Within the liver-related hospitalization cohort, mortality predictors were similar, except for Hispanic race (aHR 0.92, P < 0.0096) and renal disease (aHR 1.50, P < 0.0001). CONCLUSIONS: The number of NAFLD inpatient encounters increased significantly from 2006 to 2013, as did the inflation-adjusted inpatient charges. The most significant predictors of death were non-liver cancers (HR 3.11, P < 0.0001, CI 3.06-3.16) and age > 75 years (HR 3.94, P < 0.0001, HR 3.86-4.03).

Detecting Glaucoma Progression Using Guided Progression Analysis with OCT and Visual Field Assessment in Eyes Classified by International Classification of Disease Severity Codes.

PURPOSE: To compare the detection and rates of progressive retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL) loss with spectral-domain (SD) OCT and visual field (VF) loss using Guided Progression Analysis (GPA; Carl Zeiss Meditec, Dublin, CA) in glaucomatous eyes classified using International Classification of Diseases (ICD) diagnosis codes. DESIGN: Retrospective cohort study. PARTICIPANTS: Glaucoma patients with at least 3 years of follow-up and a minimum of 4 SD OCT and 5 reliable VF examinations. METHODS: Glaucoma severity was classified using ICD, 10th Edition, Clinical Modification, diagnosis codes. Rates of RNFL, macular GCIPL, and VF loss were calculated, and progression estimates were compared using generalized estimating equations and McNemar's tests. MAIN OUTCOME MEASURES: Progressive RNFL, GCIPL, and VF loss assessed by GPA criteria. RESULTS: A total of 147 eyes of 116 patients (mean age, 69.9±8.5 years) were included with mean follow-up of 69.67±18.64 months. Overall, 38 of 147 eyes (25.9%) showed RNFL progression, 35 eyes (23.8%) showed GCIPL progression, and 20 eyes (13.6%) showed VF progression. Progression by all 3 methods was noted in 10 eyes (7.0%). Eyes with mild (n = 62) and severe (n = 46) glaucoma showed significantly more progression on SD OCT compared with VF (P < 0.001 and P = 0.004). Retinal nerve fiber layer, GCIPL, and VF progressors showed faster rates of loss in average RNFL, GCIPL, and VF mean deviation compared with nonprogressors (mean ± standard error: -1.47±0.30 µm/year vs. -0.03±0.12 µm/year [P = 0.0001], -1.68±0.34 µm/year vs. -0.29±0.07 µm/year [P = 0.0001], and -1.07±0.20 dB/year vs. -0.19±0.04 dB/year [P = 0.0001], respectively). CONCLUSIONS: Spectral-domain OCT progression was significantly more common than VF progression in glaucomatous eyes classified with mild and severe disease. Structure and function should be monitored closely across the entire spectrum of glaucoma severity.