Delayed elective total shoulder arthroplasty: causes and eventual outcomes.

PURPOSE: The purpose of this study is to identify risk factors for delays in planned total shoulder arthroplasty (TSA) and determine the perioperative outcomes of TSAs that experienced a delay. METHODS: The American College of Surgeons National Quality Improvement Program (NSQIP) database was queried from 2006 to 2019 for primary TSA. Delayed TSA was defined as surgery that occurred greater than one day after hospital admission. Patient demographics, comorbidities, and post-operative complications were collected and compared; the incidence of delayed TSA was analyzed. RESULTS: The delayed patients were older, had a higher BMI, a higher rate of recent prior major surgery, and more comorbidities. Delayed patients had higher rates of postoperative complications, return to the OR, and 30-day readmission. Between 2006 and 2019, the rate of delayed TSA decreased. CONCLUSION: Surgeons should take care to ensure that patients with comorbidities undergo thorough preoperative clearance to prevent same-day cancellations and postoperative complications.

An engineered human cardiac tissue model reveals contributions of systemic lupus erythematosus autoantibodies to myocardial injury.

Systemic lupus erythematosus (SLE) is a highly heterogenous autoimmune disease that affects multiple organs, including the heart. The mechanisms by which myocardial injury develops in SLE, however, remain poorly understood. Here we engineered human cardiac tissues and cultured them with IgG fractions containing autoantibodies from SLE patients with and without myocardial involvement. We observed unique binding patterns of IgG from two patient subgroups: (i) patients with severe myocardial inflammation exhibited enhanced binding to apoptotic cells within cardiac tissues subjected to stress, and (ii) patients with systolic dysfunction exhibited enhanced binding to the surfaces of viable cardiomyocytes. Functional assays and RNA sequencing (RNA-seq) revealed that IgGs from patients with systolic dysfunction exerted direct effects on engineered tissues in the absence of immune cells, altering tissue cellular composition, respiration and calcium handling. Autoantibody target characterization by phage immunoprecipitation sequencing (PhIP-seq) confirmed distinctive IgG profiles between patient subgroups. By coupling IgG profiling with cell surface protein analyses, we identified four pathogenic autoantibody candidates that may directly alter the function of cells within the myocardium. Taken together, these observations provide insights into the cellular processes of myocardial injury in SLE that have the potential to improve patient risk stratification and inform the development of novel therapeutic strategies.

Ulnar Collateral Ligament Repair With Internal Brace Using Linked Knotless Suture Anchors.

This article presents an adaptation of the internal brace ulnar collateral ligament (UCL) repair technique using knotless suture anchors, which shows promise for improved postsurgical functionality and a shortened recovery period in patients with UCL injuries. Traditional methods of UCL reconstruction often require a lengthy 12- to 18-month recovery period, presenting a significant challenge for athletes keen to return to their sport. The modified technique uses smaller sutures and drill holes, thereby eliminating the need for larger anchors and simplifying the surgical process. Furthermore, we provide a comprehensive exploration of the rehabilitation protocol involved after surgery, which includes various phases of physical therapy and use of the "thrower's ten" program to improve shoulder and elbow stability, strength, and mobility. This technique paves the way for a promising alternative to traditional UCL reconstruction or repair methods, with the potential to significantly enhance clinical outcomes, improve recovery times, and positively impact athletes' lives.

Stratification of the Minimal Clinically Important Difference, Substantial Clinical Benefit, and Patient Acceptable Symptomatic State after Total Shoulder Arthroplasty by Implant Type, Preoperative Diagnosis, and Sex.

BACKGROUND: Clinical significance, as opposed to statistical significance, has increasingly been utilized to evaluate outcomes after total shoulder arthroplasty (TSA). The purpose of this study was to identify thresholds of the minimal clinically important difference (MCID), substantial clinical benefit (SCB), and patient acceptable symptomatic state (PASS) for TSA outcome metrics and determine if these thresholds are influenced by prosthesis type (anatomic or reverse TSA), sex, or preoperative diagnosis. METHODS: A prospectively collected international multicenter database inclusive of 38 surgeons was queried for patients receiving a primary aTSA or rTSA between 2003 and 2021. Prospectively, outcome metrics including ASES, shoulder function score (SFS), SST, UCLA, Constant, VAS Pain, shoulder arthroplasty smart (SAS) score, forward flexion, abduction, external rotation, and internal rotation was recorded preoperatively and at each follow-up. A patient satisfaction question was administered at each follow-up. Anchor-based MCID, SCB, and PASS were calculated as defined previously overall and according to implant type, preoperative diagnosis, and sex. The percentage of patients achieving thresholds was also quantified. RESULTS: A total of 5,851 total shoulder arthroplasties including aTSA (n=2,236) and rTSA (n=3,615) were included in the study cohort. The following were identified as MCID thresholds for the overall (aTSA + rTSA irrespective of diagnosis or sex) cohort: VAS Pain (-1.5), SFS (1.2), SST (2.1), Constant (7.2), ASES (13.9), UCLA (8.2), SPADI (-21.5), and SAS (7.3), Abduction (13°), Forward elevation (16°), External rotation (4°), Internal rotation score (0.2). SCB thresholds for the overall cohort were: VAS Pain (-3.3), SFS (2.9), SST 3.8), Constant (18.9), ASES (33.1), UCLA (12.3), SPADI (-44.7), and SAS (18.2), Abduction (30°), Forward elevation (31°), External rotation (12°), Internal rotation score (0.9). PASS thresholds for the overall cohort were: VAS Pain (0.8), SFS (7.3), SST (9.2), Constant (64.2), ASES (79.5), UCLA (29.5), SPADI (24.7), and SAS (72.5), Abduction (104°), Forward elevation (130°), External rotation (30°), Internal rotation score (3.2). MCID, SCB, and PASS thresholds varied depending on preoperative diagnosis and sex. CONCLUSION: MCID, SCB, and PASS thresholds vary depending on implant type, preoperative diagnosis, and sex. A comprehensive understanding of these differences as well as identification of clinically-relevant thresholds for legacy and novel metrics is essential to assist surgeons in evaluating their patient's outcomes, interpreting the literature, and counseling their patients preoperatively regarding expectations for improvement. Given that PASS thresholds are fragile and vary greatly depending on cohort variability, caution should be exercised in conflating them across different studies.

Irreparable Subscapularis Tears: Current Tendon Transfer Options.

PURPOSE OF REVIEW: Irreparable subscapularis tears, especially in younger patients with higher functional demands, present a challenging entity. Pectoralis major and latissimus dorsi tendon transfers are commonly considered for surgical management of this pathology, yet no consensus exists regarding the superior option. The purpose of this article is to review the most current tendon transfer techniques for irreparable subscapularis tears. RECENT FINDINGS: For decades, transfer of the pectoralis major has been considered the gold standard technique for irreparable subscapularis tears. This transfer was found to reduce pain and improve functional outcome scores, yet range of motion and force of internal rotation were not maintained in long-term follow-up studies. The latissimus dorsi tendon transfer for the same indications has demonstrated biomechanical superiority in recent cadaveric studies with promising short-term results clinically. Both pectoralis major and latissimus dorsi tendon transfers improve outcomes of patients with irreparable subscapularis tears. Future comparative studies are still needed to determine superiority amongst techniques.

Experimentally Induced Peripheral Venous Congestion Exacerbates Inflammation, Oxidative Stress, and Neurohormonal and Endothelial Cell Activation in Patients With Systolic Heart Failure.

BACKGROUND: Venous congestion (VC) is a hallmark of symptomatic heart failure (HF) requiring hospitalization; however, its role in the pathogenesis of HF progression remains unclear. We investigated whether peripheral VC exacerbates inflammation, oxidative stress and neurohormonal and endothelial cell (EC) activation in patients with HF with reduced ejection fraction (HFrEF). METHODS AND RESULTS: Two matched groups of patients with HFrEF and with no peripheral VC vs without recent HF hospitalization were studied. We modeled peripheral VC by inflating a cuff around the dominant arm, targeting ∼ 30 mmHg increase in venous pressure (venous stress test [VST]). Blood and ECs were sampled before and after 90 minutes of VST. We studied 44 patients (age 53 ± 12 years, 32% female). Circulating endothelin-1, tumor necrosis factor-α, interleukin-6, isoprostane, angiotensin II (ang-2), angiopoietin-2, vascular cell adhesion molecule-1, and CD146 significantly increased after the VST. Enhanced endothelin-1 and angiopoietin-2 responses to the VST were present in patients with vs without recent hospitalization and were prospectively associated with incident HF-related events; 6698 messenger ribonucleic acid (mRNA probe sets were differentially expressed in ECs after VST. CONCLUSIONS: Experimental VC exacerbates inflammation, oxidative stress, neurohormonal and EC activation and promotes unfavorable transcriptome remodeling in ECs of patients with HFrEF. A distinct biological sensitivity to VC appears to be associated with high risk for HF progression.

Impact of opioid dependence on outcomes following total shoulder arthroplasty.

INTRODUCTION: The opioid epidemic is a well-established problem encountered in orthopedic surgery in the United States. Evidence in lower extremity total joint arthroplasty and spine surgery suggests a link between chronic opioid use and increased expense and rates of surgical complications. The purpose of this study was to study the impact of opioid dependence (OD) on the short-term outcomes following primary total shoulder arthroplasty (TSA). METHODS: A total of 58,975 patients undergoing primary anatomic and reverse TSA were identified using the National Readmission Database from 2015 to 2019. Preoperative opioid dependence status was used to divide patients into 2 cohorts, with 2089 patients being chronic opioid users or having opioid use disorders. Preoperative demographic and comorbidity data, postoperative outcomes, cost of admission, total hospital length of stay (LOS), and discharge status were compared between the 2 groups. Multivariate analysis was conducted to control for the influence of independent risk factors other than OD on postoperative outcomes. RESULTS: Compared to nonopioid-dependent patients, OD patients undergoing TSA had higher odds of postoperative complications including any complications within 180 days (odds ratio [OR] 1.4, 95% confidence interval [CI] 1.3-1.7), readmission within 180 days (OR 1.2, 95% CI 1.1-1.5), revision within 180 days (OR 1.7, 95% CI 1.4-2.1), dislocation (OR 1.9, 95% CI 1.3-2.9), bleeding (OR 3.7, 95% CI 1.5-9.4), and gastrointestinal complication (OR 14, 95% CI 4.3-48). Total cost ($20,741 vs. $19,643), LOS (1.8 ± 1.8 days vs. 1.6 ± 1.7 days), and likelihood for discharge to another facility or home with home health care (18 vs. 16% and 23% vs. 21%, respectively) were higher in patients with OD. CONCLUSION: Preoperative opioid dependence was associated with higher odds of postoperative complications, rates of readmission and revision, costs, and health care utilization following TSA. Efforts focused on mitigating this modifiable behavioral risk factor may lead to better outcomes, lower complications, and decreased associated costs.

Perioperative complications and outcomes in patients with paraplegia undergoing rotator cuff repair.

Background: Patients with paraplegia often experience chronic shoulder pain due to overuse. We sought to determine if these patients have an increased prevalence of perioperative complications and higher rates of re-admissions and rotator cuff re-tears relative to able-bodied controls following rotator cuff repair (RCR). Methods: We queried the NRD (2011-2018) to identify all patients undergoing primary RCR (n = 34,451) and identified cohorts of matched paraplegic and non-paraplegic patients (n = 194 each). We compared demographic factors, comorbidity profiles, perioperative complication rates, length of stay, revision rates, and re-admission rates between the two groups. Results: Patients with paraplegia had lower rates of chronic obstructive pulmonary disease (p = 0.02), hypertension (p = 0.007), congestive heart failure (p = 0.027), obesity (p < 0.001), and prior myocardial infarction (p = 0.01). Additionally, patients with paraplegia experienced higher rates of urinary tract infections (11.9% vs. 2.1%, p < 0.001), lower rates of acute respiratory distress syndrome (0% vs. 3.1%, p = 0.041), and had a longer length of stay (4-days vs. 1-day, p < 0.001). Revision rates were similar for the two groups. Conclusions: Compared to matched controls, patients with paraplegia were found to have similar demographic characteristics, less comorbidities, similar perioperative complication rates, and similar revision rates. These findings address a gap in the literature regarding surgical management of shoulder pain in patients with paraplegia by providing a matched comparison with a large sample size.

Angiopoietin-2 blockade suppresses growth of liver metastases from pancreatic neuroendocrine tumors by promoting T cell recruitment.

Improving the management of metastasis in pancreatic neuroendocrine tumors (PanNETs) is critical, as nearly half of patients with PanNETs present with liver metastases, and this accounts for the majority of patient mortality. We identified angiopoietin-2 (ANGPT2) as one of the most upregulated angiogenic factors in RNA-Seq data from human PanNET liver metastases and found that higher ANGPT2 expression correlated with poor survival rates. Immunohistochemical staining revealed that ANGPT2 was localized to the endothelial cells of blood vessels in PanNET liver metastases. We observed an association between the upregulation of endothelial ANGPT2 and liver metastatic progression in both patients and transgenic mouse models of PanNETs. In human and mouse PanNET liver metastases, ANGPT2 upregulation coincided with poor T cell infiltration, indicative of an immunosuppressive tumor microenvironment. Notably, both pharmacologic inhibition and genetic deletion of ANGPT2 in PanNET mouse models slowed the growth of PanNET liver metastases. Furthermore, pharmacologic inhibition of ANGPT2 promoted T cell infiltration and activation in liver metastases, improving the survival of mice with metastatic PanNETs. These changes were accompanied by reduced plasma leakage and improved vascular integrity in metastases. Together, these findings suggest that ANGPT2 blockade may be an effective strategy for promoting T cell infiltration and immunostimulatory reprogramming to reduce the growth of liver metastases in PanNETs.

The Obesity Paradox: A Nonlinear Relationship Between 30-Day Postoperative Complications and Body Mass Index After Total Shoulder Arthroplasty.

BACKGROUND: An inverse relationship coined the "obesity paradox" has been propositioned, in which body mass index (BMI) may be contradictorily protective in patients undergoing surgery or treatment of chronic disease. This study sought to investigate the BMI associated with the lowest rate of medical complications after total shoulder arthroplasty (TSA). METHODS: The American College of Surgeons National Surgical Quality Improvement Project database was queried to identify adults who underwent elective primary TSA between January 2012 and December 2020. Thirty-day postoperative medical complications were extracted, which included death, readmission, pneumonia, pulmonary embolism, renal failure, and cardiac arrest, among others. BMI was classified into five categories (underweight [BMI <18.5 kg/m 2 ], normal weight [BMI ≥18.5 and <25 kg/m 2 ], overweight [BMI ≥25 and <30 kg/m 2 ], obese [BMI ≥30 and <40 kg/m 2 ], and morbidly obese [BMI ≥40 kg/m 2 ]). We examined the risk of any 30-day postoperative complications and BMI categorically and on a continuous basis using multivariable logistic regression controlling for age, sex, procedure year, and comorbidities. RESULTS: Of the 31,755 TSAs, 84% were White, 56% were female, and the average age of patients was 69.2 ± 9.3 years. Thirty-day postoperative medical complications occurred in 4.53% (n = 1,440). When assessed on a continuous basis, the lowest risk was in patients with a BMI between 30 and 35 kg/m 2 . Underweight individuals (BMI <18.5 kg/m 2 ) had the highest postoperative complication rates overall. The probability of medical complications increased with age and was greater for female patients. CONCLUSION: The relationship between BMI and complication risk in TSA is nonlinear. A BMI between 30 and 35 kg/m 2 was associated with the lowest risk of medical complications after TSA, and BMI<18.5 kg/m 2 had the highest risk overall, indicating some protective aspects of BMI against 30-day medical complications. Thus, obesity alone should not preclude patients from TSA eligibility, rather surgical candidacy should be evaluated in the context of patients' overall health and likelihood of benefit from TSA. LEVEL OF EVIDENCE: III, Retrospective Comparative Study.

A pancreatic cancer mouse model with human immunity.

Pancreatic ductal adenocarcinoma (PDAC) is characterized by a tumor immune microenvironment (TIME) that promotes resistance to immunotherapy. A preclinical model system that facilitates studies of the TIME and its impact on the responsiveness of human PDAC to immunotherapies remains an unmet need. We report a novel mouse model, which develops metastatic human PDAC that becomes infiltrated by human immune cells recapitulating the TIME of human PDAC. The model may serve as a versatile platform to study the nature of human PDAC TIME and its response to various treatments.

Comparison of long-term clinical and radiological outcomes for cemented keel, cemented peg, and hybrid cage glenoids with anatomical total shoulder arthroplasty using the same humeral component.

Aims: The aim of this study was to longitudinally compare the clinical and radiological outcomes of anatomical total shoulder arthroplasty (aTSA) up to long-term follow-up, when using cemented keel, cemented peg, and hybrid cage peg glenoid components and the same humeral system. Methods: We retrospectively analyzed a multicentre, international clinical database of a single platform shoulder system to compare the short-, mid-, and long-term clinical outcomes associated with three designs of aTSA glenoid components: 294 cemented keel, 527 cemented peg, and 981 hybrid cage glenoids. Outcomes were evaluated at 4,746 postoperative timepoints for 1,802 primary aTSA, with a mean follow-up of 65 months (24 to 217). Results: Relative to their preoperative condition, each glenoid cohort had significant improvements in clinical outcomes from two years to ten years after surgery. Patients with cage glenoids had significantly better clinical outcomes, with higher patient-reported outcome scores and significantly increased active range of motion, compared with those with keel and peg glenoids. Those with cage glenoids also had significantly fewer complications (keel: 13.3%, peg: 13.1%, cage: 7.4%), revisions (keel: 7.1%, peg 9.7%, cage 3.5%), and aseptic glenoid loosening and failure (keel: 4.7%, peg: 5.8%, cage: 2.5%). Regarding radiological outcomes, 70 patients (11.2%) with cage glenoids had glenoid radiolucent lines (RLLs). The cage glenoid RLL rate was 3.3-times (p < 0.001) less than those with keel glenoids (37.3%) and 4.6-times (p < 0.001) less than those with peg glenoids (51.2%). Conclusion: These findings show that good long-term clinical and radiological outcomes can be achieved with each of the three aTSA designs of glenoid component analyzed in this study. However, there were some differences in clinical and radiological outcomes: generally, cage glenoids performed best, followed by cemented keel glenoids, and finally cemented peg glenoids.

Outcome and complication comparison for intramedullary nail versus open reduction internal fixation in humeral diaphyseal fractures for 2800 matched patient pairs utilizing the Nationwide Readmissions Database.

INTRODUCTION: Open reduction internal fixation (ORIF) and intramedullary nail fixation (IMN) are the predominant repair methods for operative treatment of humeral diaphyseal fractures; however, the optimal method is not fully elucidated. The purpose of this study was to analyze whether IMN or ORIF humeral diaphyseal surgeries result in a significantly higher prevalence of adverse outcomes and whether these outcomes were age dependent. We hypothesize there is no difference in reoperation rates and complications between IMN and ORIF for humeral diaphyseal fractures. METHODS: Data collected from 2015 to 2017 from the Nationwide Readmissions Database were evaluated to compare the prevalence of six adverse outcomes: radial nerve palsy, infections, nonunion, malunion, delayed healing, and revisions. Patients treated for a primary humeral diaphyseal fracture with either IMN or ORIF were matched and compared (n = 2,804 pairs). Patients with metastatic cancer were excluded. RESULTS: Following an ORIF procedure, there was a greater odds of undergoing revision surgery (p = 0.03) or developing at least one of the complications of interest (p = 0.03). In the age-stratified analysis, no significant differences were identified in the prevalence of adverse outcomes between the IMN and ORIF cohorts in the 0-19, 20-39, and 40-59 age groups. Patients who were 60 + had 1.89 times the odds of experiencing at least one complication and 2.04 times the odds of undergoing a revision after an ORIF procedure versus an IMN procedure (p = 0.03 for both). DISCUSSION: IMN and ORIF for humeral diaphyseal fractures are comparable in regard to complications revision rates in patients under the age of 60. Meanwhile, patients 60 + years show a statistically significant increase in the odds of undergoing revision surgery or experiencing complications following an ORIF. Since IMN appears to be more beneficial to older patients, being 60 + years old should be considered when determining fracture repair techniques for patients presenting with primary humeral diaphyseal fractures.

Impact of COVID-19 on clinical outcomes following total shoulder arthroplasty.

Background: The coronavirus (COVID-19) pandemic has introduced patient stressors and changes to perioperative protocols in total shoulder arthroplasty (TSA). The purpose of this study is to evaluate the short-term effects of the COVID-19 pandemic on various patient outcomes and satisfaction following elective TSA. Methods: A retrospective review was performed on 147 patients who underwent primary TSA at a single institution between June 2019 and December 2020. Patients were divided into 2 cohorts: pre-COVID (June 2019-March 2020; n = 74) and post-COVID (April 2020-December 2020; n = 73). No elective TSA were performed between 10 March 2020 and 23 April 2020 at our institution. Data were collected prospectively both pre- and postoperatively. Range of motion (ROM) testing included active abduction, internal rotation, and external rotation. Patient reported outcome measures (PROMs) included global shoulder function, Simple Shoulder Test, American Shoulder and Elbow Surgeons, Visual Analog Scale pain scoring systems, and patient satisfaction. ROM and PROMs were compared at preoperative, 3-month follow-up, and 12-month follow-up intervals. Operative time, length of stay (LOS), 90-day readmission, and 90-day reoperation were also compared. Results: There were no differences in baseline patient characteristics. The operative time, LOS, home discharge rate, readmission, and reoperation did not differ between groups. For both cohorts, the PROMs and ROM improved at each follow-up visit postoperatively. While preoperative abduction, internal rotation, and external rotation were significantly greater in the post-COVID group, all ROM measures were similar at 3-month and 12-month follow-up visits. There was no difference in pain, global function, Simple Shoulder Test, American Shoulder and Elbow Surgeons, or patient satisfaction between groups at all time intervals. Conclusions: Patients undergoing elective TSA amidst the COVID-19 pandemic demonstrate excellent PROMs, ROM, and high satisfaction up to 12-months postoperatively that are comparable to pre-pandemic standards. Operative time, LOS, discharge destination, as well as 90-day readmission and reoperation rates were not impacted by the pandemic. Patients can expect similar outcomes for TSA when comparing pre-COVID to post-COVID as the pandemic continues.

How using body mass index cutoffs to determine eligibility for total shoulder arthroplasty affects health care disparities.

BACKGROUND: The prevalence of obesity in the United States is continuously rising and is associated with increased morbidity, mortality, and health care costs. Body mass index (BMI) has been used as a risk stratification and counseling tool for patients undergoing total joint arthroplasty in an effort to focus on outcome-driven care. Although the use of BMI cutoffs may have benefits in minimizing complications when selecting patients for total shoulder arthroplasty (TSA), it may impact access to care for some patient populations and further increase disparities. The purpose of this study is to determine the implications of using BMI cutoffs on the eligibility for TSA among different ethnic and gender patient populations. METHODS: The American College of Surgeons National Surgical Quality Improvement Program database was queried to identify 20,872 patients who underwent anatomic and reverse TSA between 2015 and 2019. Patient demographics, including age, sex, race and ethnicity, and BMI, were compared between eligible and ineligible patients based on BMI for 5 cutoff values: 30, 35, 40, 45, and 50 kg/m2. RESULTS: Of the total patient population studied, the mean age was 69 years, 55% were female, and the mean BMI was 31 kg/m2. For all BMI subgroups, there were more ineligible than eligible patients who were female or Black (P < .001). The relative rate of eligibility for Black patients was lower in each BMI cutoff group, whereas the relative rate of eligibility for White and Asian patients was higher for each group. There were more eligible than ineligible Asian patients for BMI cutoffs of 30 and 35 kg/m2 (both P < .001), and there were no differences in eligibility and ineligibility in Hispanic patients (P > .05). Furthermore, White patients were more eligible than ineligible for all BMI cutoff groups (P < .001). CONCLUSIONS: Enforcing BMI cutoffs for access to TSA may limit the procedure for female or Black patients for all BMI cutoffs, thus furthering the health care disparities these populations already face. However, there are more eligible than ineligible White patients for all BMI cutoff groups, which indicates a disparity in the access to TSA based on sex and race. Physicians may inadvertently increase health care disparities observed in TSA if they use BMI as the sole risk stratification tool for patients, even though BMI has been known to increase complications after TSA. Moreover, orthopedic surgeons should only use BMI as one of many factors in a more holistic process when determining if a patient should undergo TSA.

DIAPH1 mediates progression of atherosclerosis and regulates hepatic lipid metabolism in mice.

Atherosclerosis evolves through dysregulated lipid metabolism interwoven with exaggerated inflammation. Previous work implicating the receptor for advanced glycation end products (RAGE) in atherosclerosis prompted us to explore if Diaphanous 1 (DIAPH1), which binds to the RAGE cytoplasmic domain and is important for RAGE signaling, contributes to these processes. We intercrossed atherosclerosis-prone Ldlr-/- mice with mice devoid of Diaph1 and fed them Western diet for 16 weeks. Compared to male Ldlr-/- mice, male Ldlr-/- Diaph1-/- mice displayed significantly less atherosclerosis, in parallel with lower plasma concentrations of cholesterol and triglycerides. Female Ldlr-/- Diaph1-/- mice displayed significantly less atherosclerosis compared to Ldlr-/- mice and demonstrated lower plasma concentrations of cholesterol, but not plasma triglycerides. Deletion of Diaph1 attenuated expression of genes regulating hepatic lipid metabolism, Acaca, Acacb, Gpat2, Lpin1, Lpin2 and Fasn, without effect on mRNA expression of upstream transcription factors Srebf1, Srebf2 or Mxlipl in male mice. We traced DIAPH1-dependent mechanisms to nuclear translocation of SREBP1 in a manner independent of carbohydrate- or insulin-regulated cues but, at least in part, through the actin cytoskeleton. This work unveils new regulators of atherosclerosis and lipid metabolism through DIAPH1.

Identification of Independent Predictors of Increased 90-Day Complication and Revision Rates Following Total Elbow Arthroplasty.

Introduction: Total elbow arthroplasty (TEA) is an increasingly popular surgical option for many debilitating conditions of the elbow. There currently exists a paucity of literature regarding patient and hospital factors that lead to inferior outcomes following TEA. The purpose of this study is to identify independent predictors of increased complication and revision rates following TEA. Methods: The National Readmissions Database (NRD) was queried from 2011 to 2018 to identify all cases of TEA (n = 8932). Relevant patient demographic factors, comorbidities, and hospital characteristics were identified and run in a univariate binomial logistic regression model. All significant variables were included in a multivariate binomial logistic regression model for data analysis. Results: Independent predictors of increased complication rates included age, female sex, Medicare and Medicaid payer status, medium bed-sized center, and 18 of 34 medical comorbidities (all P < .05). Independent predictors of increased revision rates included medium bed-sized centers, non-teaching hospital status, chronic pulmonary disease, depression, and pulmonary circulatory disorders (all P < .05). Conclusion: This study identified several patient and hospital characteristics that are independently associated with both increased complication and revision rates following TEA. This information can aid orthopedic surgeons during shared decision making when considering TEA in patients. Level of Evidence: Level III, retrospective cohort study.

Aseptic glenoid baseplate loosening after reverse total shoulder arthroplasty with a single prosthesis.

BACKGROUND: Early reverse total shoulder arthroplasty (rTSA) designs had high failure rates, mainly from loosening of the glenoid baseplate. The purpose of this study was to determine the incidence of aseptic glenoid baseplate loosening after primary rTSA using a contemporary medialized glenoid-lateralized humerus system and identify significant risk factors associated with loosening. METHODS: A total of 7162 patients underwent primary rTSA with a single-platform rTSA system between April 2007 and August 2021; of these primary rTSA patients, 3127 with a minimum 2-year follow-up period were identified. Patients with aseptic glenoid baseplate loosening were compared with all other primary rTSA patients without loosening. Univariate and multivariate analyses were performed to compare these cohorts and identify the demographic characteristics, comorbidities, operative parameters, and implant characteristics associated aseptic glenoid loosening after rTSA. Odds ratios (ORs) were calculated for each significant risk factor and for multiple combinations of risk factors. RESULTS: Irrespective of minimum follow-up, 53 of 7162 primary rTSA shoulders (31 female and 22 male shoulders) experienced aseptic glenoid loosening, for an overall rate of 0.74%. At latest (2-year minimum) follow-up, 30 of 3127 patients experienced aseptic glenoid loosening and showed significantly lower clinical scores, function, and active range of motion and higher pain scores than patients without loosening. Univariate analysis identified rheumatoid arthritis (P = .029; OR, 2.74) and diabetes (P = .028; OR, 1.84) as significant risk factors for aseptic glenoid loosening after rTSA, and multivariate analysis identified Walch glenoid types B2 (P = .002; OR, 4.513) and B3 (P = .002; OR, 14.804), use of expanded lateralized glenospheres (P = .025; OR, 2.57), and use of augmented baseplates (P = .001; OR, 2.50) as significant risk factors. CONCLUSION: The incidence of aseptic glenoid baseplate loosening was 0.74% for the evaluated medialized glenoid-lateralized humerus rTSA system. Numerous risk factors for aseptic loosening were identified, including rheumatoid arthritis, diabetes, Walch type B2 and B3 glenoids, posteriorly-superiorly augmented baseplates, and expanded lateralized glenospheres. Finally, analysis of multiple combinations of risk factors identified patients and implant configurations with the greatest risk of aseptic glenoid loosening.

Does glenohumeral offset affect clinical outcomes in a lateralized reverse total shoulder arthroplasty?

BACKGROUND: Reverse total shoulder arthroplasty (rTSA) exhibits high rates of success and low complication rates. rTSA has undergone numerous design adaptations over recent years, and lateralization of implant components provides theoretical and biomechanical benefits in stability and range of motion (ROM) as well as decreased rates of notching. However, the magnitude of implant lateralization and its effect on these outcomes is less well understood. The purpose of this study was to evaluate how increasing glenohumeral offset affects outcomes after rTSA, specifically in a lateralized humerus + medialized glenoid implant model. METHODS: Primary rTSA using a lateralized humeral + medialized glenoid implant model performed at a single academic institution between 2012 and 2018 were retrospectively reviewed. Patient-reported outcome (PRO) parameters and clinical outcomes including ROM were evaluated both pre- and postoperatively. Pre- and postoperative radiographs were analyzed for measurement of glenohumeral offset, defined as the acromial-tuberosity offset (ATO) distance on the anteroposterior radiograph. RESULTS: A total of 130 rTSAs were included in the analysis, with a mean follow-up of 35 mo. The mean postoperative absolute ATO was 16 mm, and the mean delta ATO (difference from pre- to postoperatively) was 4.6 mm further lateralized. Among all study patients, improvements in all ROM parameters and all PROs were observed from pre- to postoperative assessments. When assessing for the effects of lateralization on these outcomes, multivariate analysis failed to reveal a significant effect from the absolute postoperative ATO or the delta ATO on any outcome parameter. CONCLUSIONS: rTSA using a lateralized humeral + medialized glenoid implant model exhibits excellent clinical outcomes in ROM and PROs. However, the magnitude of lateralization as measured radiographically by the ATO did not significantly affect these outcomes; patients exhibited universally good outcomes irrespective of the degree of offset restoration.

Shoulder arthroplasty after prior anterior shoulder instability surgery: a matched cohort analysis.

PURPOSE: To evaluate the effect of prior anterior shoulder instability surgery (SIS) on the outcomes and complications of primary anatomic total shoulder arthroplasty (aTSA) and reverse total shoulder arthroplasty (rTSA). METHODS: Between 2007 and 2018, 38 primary total shoulder arthroplasties (TSA) (22 aTSA and 16 rTSA) with a prior SIS and a minimum of 2 years of follow-up were identified. This cohort was matched 1:3 based on age, sex, body mass index, year of surgery, and dominant shoulder. aTSA and rTSA were matched to patients with primary osteoarthritis (OA) and rotator cuff tear arthropathy (CTA), respectively. RESULTS: TSA produced similar postoperative pain, ROM, patient-reported outcome measures, complications, and revisions in those with prior SIS vs. controls. aTSA with prior SIS demonstrated worse final postoperative abduction (116° vs. 133°; P = 0.046) and abduction improvement (24° vs. 47°; P = 0.034) compared to OA controls. Both aTSA and rTSA with prior SIS demonstrated significant improvements from baseline across all metrics, with no significant differences between the groups. aTSA and rTSA with prior SIS demonstrated no differences to controls in complications (4.6% vs. 6.1%; P = .786 and 0% vs. 6.3%. P = .183) or revisions (4.6% vs. 4.6%; P = .999 and 0% vs. 4.2%; P = .279). CONCLUSIONS: TSA after prior SIS surgery can improve both pain and function without adversely increasing the rates of complications or revision surgery. When compared to patients without prior SIS, aTSA demonstrated worse abduction; however, all other functional differences remained statistically similar. LEVEL OF EVIDENCE: III; Retrospective Cohort Comparison; Treatment Study.