Higher Annual Total Hip Arthroplasty Volume Decreases the Risk of Intraoperative Periprosthetic Femur Fractures.

BACKGROUND: Periprosthetic femur fracture (PFF) is a complication of total hip arthroplasty (THA). These occur intraoperatively or postoperatively, and documented risk factors of PFFs include women, age greater than 65 years, cementless stems, and inflammatory arthropathies. The aim of this retrospective cohort study was to assess the relationship of years of surgical experience and surgeon annual THA volume on intraoperative and postoperative PFFs. METHODS: Data were collected from a database query, and PFFs were identified as either intraoperative or postoperative. Intraoperative and postoperative PFFs were both compared to a control group of non-PFF patients. Years of surgical experience at the time of surgery and annual THA volume for the primary surgeon were calculated for all cases. Logistic regression analyses were used to calculate odds ratios for each of the surgeon variables when adjusted for patient demographics. RESULTS: Thirty-seven intraoperative and 108 postoperative PFFs were identified and compared to 7,629 controls. From regression analyses, high-volume surgeons (≥50 THA/year) had lower odds of intraoperative PFF (adjusted odds ratio (aOR) = 0.40, P = .020) but not postoperative PFF (aOR = 1.02, P = .921). Surgeon experience (≥15 years since board certification at the time of surgery), was not significantly related to either PFF outcomes. For patient factors, age ≥65 years (aOR = 2.30, P < .001) and women (aOR = 2.69, P < .001) were both significant predictors of postoperative PFFs only. CONCLUSION: Surgeons who performed 50 or more THAs per year had significantly fewer intraoperative PFFs than surgeons who did less than 50 THAs per year. Surgeon experience was not significantly related to PFFs.

Postoperative Chest X-Rays After Open Reduction Internal Fixation of Clavicle Fractures May Not Be Cost-Effective or Necessary.

OBJECTIVES: To assess the use of chest x-rays after open-reduction internal fixation of clavicle fractures. Particularly in detection of acute postoperative pneumothorax and cost-effectiveness of obtaining routine chest x-rays postoperatively. DESIGN: A retrospective cohort study. SETTING: Level I trauma center. PATIENTS: Two hundred thirty-six patients who underwent ORIF from 2013 to 2020 between the ages of 12 and 93. INTERVENTION: Chest x-ray performed postoperatively. MAIN OUTCOME MEASUREMENT: Presence of acute postoperative pneumothorax. RESULTS: Of the 236 patients who underwent surgery, 189 (80%) patients received a CXR postoperatively and 7 (3%) patients experienced respiratory symptoms. All patients who had respiratory symptoms received a postoperative CXR. Those who did not receive a CXR postoperatively did not experience any respiratory complications. Two patients in the cohort had a postoperative pneumothorax, which was present preoperatively and unchanged in size postoperatively. Both of these patients were managed with general anesthesia and endotracheal intubation for surgery. The most common finding on CXR postoperatively was atelectasis. The cost of a portable CXR can be upward of $594 when including technology, personnel fees, and radiologic interpretation. CONCLUSION: Postoperative chest x-rays after clavicle open reduction and internal fixation did not detect any acute postoperative pneumothorax in asymptomatic patients. It is not cost-effective to routinely get chest x-rays in patients after open-reduction internal fixation of clavicle fractures. In our study, of the 189 chest x-rays performed, only 7 patients experienced postoperative respiratory symptoms. Our health care system as a total could have saved upward of $108,108 in total for these patients because they may have been considered nonreimbursable by an insurance provider. LEVEL OF EVIDENCE: Diagnostic Level IV. See Instructions for Authors for a complete description of levels of evidence.

Cellular transformation promotes the incorporation of docosahexaenoic acid into the endolysosome-specific lipid bis(monoacylglycerol)phosphate in breast cancer.

Bis(monoacylglycero)phosphates (BMPs), a class of lipids highly enriched within endolysosomal organelles, are key components of the lysosomal intraluminal vesicles responsible for activating sphingolipid catabolic enzymes. While BMPs are understudied relative to other phospholipids, recent reports associate BMP dysregulation with a variety of pathological states including neurodegenerative diseases and lysosomal storage disorders. Since the dramatic lysosomal remodeling characteristic of cellular transformation could impact BMP abundance and function, we employed untargeted lipidomics approaches to identify and quantify BMP species in several in vitro and in vivo models of breast cancer and comparative non-transformed cells and tissues. We observed lower BMP levels within transformed cells relative to normal cells, and consistent enrichment of docosahexaenoic acid (22:6) fatty acyl chain-containing BMP species in both human- and mouse-derived mammary tumorigenesis models. Our functional analysis points to a working model whereby 22:6 BMPs serve as reactive oxygen species scavengers in tumor cells, protecting lysosomes from oxidant-induced lysosomal membrane permeabilization. Our findings suggest that breast tumor cells might divert polyunsaturated fatty acids into BMP lipids as part of an adaptive response to protect their lysosomes from elevated reactive oxygen species levels, and raise the possibility that BMP-mediated lysosomal protection is a tumor-specific vulnerability that may be exploited therapeutically.

Exposure to DMSO during infancy alters neurochemistry, social interactions, and brain morphology in long-evans rats.

INTRODUCTION: Dimethyl sulfoxide (DMSO) is a widely used solvent to dissolve hydrophobic substances for clinical uses and experimental in vivo purposes. While usually regarded safe, our prior studies suggest changes to behavior following DMSO exposure. We therefore evaluated the effects of a five-day, short-term exposure to DMSO on postnatal infant rats (P6-10). METHODS: DMSO was intraperitoneally injected for five days at 0.2, 2.0, and 4.0 ml/kg body mass. One cohort of animals was sacrificed 24 hr after DMSO exposure to analyze the neurometabolic changes in four brain regions (cortex, hippocampus, basal ganglia, and cerebellum) by hydrophilic interaction liquid chromatography. A second cohort of animals was used to analyze chronic alterations to behavior and pathological changes to glia and neuronal cells later in life (P21-P40). RESULTS: 164 metabolites, including key regulatory molecules (retinoic acid, orotic acid, adrenic acid, and hypotaurine), were found significantly altered by DMSO exposure in at least one of the brain regions at P11 (p < .05). Behavioral tests showed significant hypoactive behavior and decreased social habits to the 2.0 and 4.0 ml DMSO/kg groups (p < .01). Significant increases in number of microglia and astrocytes at P40 were observed in the 4.0 ml DMSO/kg group (at p < .015.) CONCLUSIONS: Despite short-term exposure at low, putatively nontoxic concentrations, DMSO led to changes in behavior and social preferences, chronic alterations in glial cells, and changes in essential regulatory brain metabolites. The chronic neurological effects of DMSO exposure reported here raise concerns about its neurotoxicity and consequent safety in human medical applications and clinical trials.

The Emerging and Diverse Roles of Bis(monoacylglycero) Phosphate Lipids in Cellular Physiology and Disease.

Although understudied relative to many phospholipids, accumulating evidence suggests that bis(monoacylglycero)phosphate (BMP) is an important class of regulatory lipid that plays key roles in lysosomal integrity and function. BMPs are rare in most mammalian tissues, comprising only a few percent of total cellular lipid content, but are elevated in cell types such as macrophages that rely heavily on lysosomal function. BMPs are markedly enriched in endosomal and lysosomal vesicles compared to other organelles and membranous structures, and their unique sn-1:sn-1' stereoconfiguration may confer stability within the hydrolytic lysosomal environment. BMP-enriched vesicles serve in endosomal-lysosomal trafficking and function as docking structures for the activation of lysosomal hydrolytic enzymes, notably those involved in the catabolic breakdown of sphingolipids. BMP levels are dysregulated in lysosomal storage disorders, phospholipidosis, metabolic diseases, liver and kidney diseases and neurodegenerative disorders. However, whether BMP alteration is a mediator or simply a marker of pathological states is unclear. Likewise, although BMP acyl chain composition may be altered with disease states, the functional significance of specific BMP species remains to be resolved. Newly developed tools for untargeted lipidomic analysis, together with a deeper understanding of enzymes mediating BMP synthesis and degradation, will help shed further light on the functional significance of BMPs in cellular physiology and pathology.