Evaluation of Preoperative Variables that Improve the Predictive Accuracy of the Risk Assessment and Prediction Tool in Primary Total Hip Arthroplasty.

INTRODUCTION: Discharge disposition after total joint arthroplasty may be predictable. Previous literature has attempted to improve upon models such as the Risk Assessment and Prediction Tool (RAPT) in an effort to optimize postoperative planning. The purpose of this study was to determine whether preoperative laboratory values and other previously unstudied demographic factors could improve the predictive accuracy of the RAPT. METHODS: All patients included had RAPT scores in addition to the following preoperative laboratory values: red blood cell count, albumin, and vitamin D. All values were recorded within 90 days of surgery. Demographic variables including marital status, American Society of Anesthesiologists (ASA) scores, body mass index, Charlson Comorbidity Index, and depression were also evaluated. Binary logistic regression was used to determine the significance of each factor in association with discharge disposition. RESULTS: Univariate logistic regression found significant associations between discharge disposition and all original RAPT factors as well as nonmarried patients (P < 0.001), ASA class 3 to 4 (P < 0.001), body mass index >30 kg/m2 (P = 0.065), red blood cell count <4 million/mm3 (P < 0.001), albumin <3.5 g/dL (P < 0.001), Charlson Comorbidity Index (P < 0.001), and a history of depression (P < 0.001). All notable univariate models were used to create a multivariate model with an overall predictive accuracy of 90.1%. CONCLUSIONS: The addition of preoperative laboratory values and additional demographic data to the RAPT may improve its PA. Orthopaedic surgeons could benefit from incorporating these values as part of their discharge planning in THA. Machine learning may be able to identify other factors to make the model even more predictive.

Does Surgical Approach Affect Dislocation Rate After Total Hip Arthroplasty in Patients Who Have Prior Lumbar Spinal Fusion? A Retrospective Analysis of 16,223 Cases.

BACKGROUND: Lumbar spinal fusion (LSF) is a risk factor for dislocation following total hip arthroplasty (THA). The effect of the surgical approach on this association has not been investigated. This study examined the association between the surgical approach and dislocation following THA in patients who had prior LSF. METHODS: We retrospectively reviewed 16,223 primary elective THAs at our institution from June 2011 to September 2022. Patients who had LSF prior to THA were identified using International Classification of Diseases (ICD) codes. Patients were stratified by LSF history, surgical approach, and intraoperative robot or navigation use to compare dislocation rates. There were 8,962 (55.2%) posterior, 5,971 (36.8%) anterior, and 1,290 (8.0%) laterally based THAs. Prior LSF was identified in 323 patients (2.0%). Binary logistic regressions were used to assess the association of patient factors with dislocation risk. RESULTS: There were 177 dislocations identified in total (1.1%). In nonadjusted analyses, the dislocation rate was significantly higher following the posterior approach among all patients (P = .003). Prior LSF was associated with a significantly higher dislocation rate in all patients (P < .001) and within the posterior (P < .001), but not the anterior approach (P = .514) subgroups. Multivariate regressions demonstrated anterior (OR [odds ratio] = 0.64, 95% CI [confidence interval] 0.45 to 0.91, P = .013), and laterally based (OR = 0.42, 95% CI 0.18 to 0.96, P = .039) approaches were associated with decreased dislocation risk, whereas prior LSF (OR = 4.28, 95% CI 2.38 to 7.69, P < .001) was associated with increased dislocation risk. Intraoperative technology utilization was not significantly associated with dislocation in the multivariate regressions (OR = 0.72, 95% CI 0.49 to 1.06, P = .095). CONCLUSIONS: The current study confirmed that LSF is a significant risk factor for dislocation following THA; however, anterior and laterally based approaches may mitigate dislocation risk in this population. In multivariate analyses, including surgical approach, LSF, and several perioperative variables, intraoperative technology utilization was not found to be significantly associated with dislocation risk.

Revision rate following unipolar versus bipolar hemiarthroplasty.

INTRODUCTION: There has been much debate on use of bipolar or unipolar femoral heads in hemiarthroplasty for the treatment of femoral neck fractures. The outcome of these implants should be studied in the America Joint Replacement Registry (AJRR). METHODS: All primary femoral neck fractures treated with hemiarthroplasty between January 2012 and June 2020 were searched in the AJRR. All cause-revision of unipolar and bipolar hemiarthroplasty and reasons for revision were assessed for these patients until June of 2023. RESULTS: There were no differences in number and reason for all cause revisions between unipolar and bipolar hemiarthroplasty (p = 0.41). Bipolar hemiarthroplasty had more revisons at 6 months postoperatively (p = 0.0281), but unipolar hemiarthroplasty had more revisions between 2 and 3 years (p = 0.0003), and after 3-years (p = 0.0085), as analysed with a Cox model. Patients with older age (HR = 0.999; 95% CI, 0.998-0.999; p = 0.0006) and higher Charlson Comorbidity Index (HR = 0.996; 95% CI, 0.992- 0.999; p = 0.0192) had a significant increase in revision risk. CONCLUSIONS: We suggest that surgeons should consider using bipolar prosthesis when performing hemiarthroplasty for femoral neck fracture in patients expected to live >2 years post injury.

It Takes a Village: An Interdisciplinary Approach to Preparing Internal Medicine Residents to Care for Patients at the Intersection of Women's Health, Gender-Affirming Care, and Health Disparities.

Objective: To create an interdisciplinary curriculum to teach key topics at the intersection of women's health, gender-affirming care, and health disparities to internal medicine (IM) residents. Materials and Methods: A core team of faculty from IM, Obstetrics and Gynecology, and Surgery partnered with faculty and fellows from other disciplines and with community experts to design and deliver the curriculum. The resulting curriculum consisted of themed half-day modules, each consisting of three to four inter-related topics, updated and repeated on an ∼3-year cycle. Health equity was a focus of all topics. Module delivery used diverse interactive learning strategies. Modules have been presented to ∼175 residents annually, beginning in 2015. To assess the curriculum, we used formative evaluation methods, using primarily anonymous, electronic surveys, and collected quantitative and qualitative data. Most surveys assessed resident learning by quantifying residents' self-reported comfort with skills taught in the module pre- and postsession. Results: Of 131 residents who completed an evaluation in 2022/23, 121 (90%) "somewhat" or "strongly" agreed with their readiness to perform a range of skills taught in the module. In all previous years where pre- and postsurveys were used to evaluate modules, we observed a consistent meaningful increase in the proportion of residents reporting high levels of comfort with the material. Residents particularly valued interactive teaching methods, and direct learning from community members and peers. Conclusion: Our interdisciplinary curriculum was feasible, valued by trainees, and increased resident learning. The curriculum provides a template to address equity issues across a spectrum of women's and gender-affirming care conditions that can be used by other institutions in implementing similar curricula.

Cell population growth kinetics in the presence of stochastic heterogeneity of cell phenotype.

Recent studies at individual cell resolution have revealed phenotypic heterogeneity in nominally clonal tumor cell populations. The heterogeneity affects cell growth behaviors, which can result in departure from the idealized uniform exponential growth of the cell population. Here we measured the stochastic time courses of growth of an ensemble of populations of HL60 leukemia cells in cultures, starting with distinct initial cell numbers to capture a departure from the uniform exponential growth model for the initial growth ("take-off"). Despite being derived from the same cell clone, we observed significant variations in the early growth patterns of individual cultures with statistically significant differences in growth dynamics, which could be explained by the presence of inter-converting subpopulations with different growth rates, and which could last for many generations. Based on the hypothesis of existence of multiple subpopulations, we developed a branching process model that was consistent with the experimental observations.

Cell Population Growth Kinetics in the Presence of Stochastic Heterogeneity of Cell Phenotype.

Recent studies at individual cell resolution have revealed phenotypic heterogeneity in nominally clonal tumor cell populations. The heterogeneity affects cell growth behaviors, which can result in departure from the idealized uniform exponential growth of the cell population. Here we measured the stochastic time courses of growth of an ensemble of populations of HL60 leukemia cells in cultures, starting with distinct initial cell numbers to capture a departure from the uniform exponential growth model for the initial growth ("take-off"). Despite being derived from the same cell clone, we observed significant variations in the early growth patterns of individual cultures with statistically significant differences in growth dynamics, which could be explained by the presence of inter-converting subpopulations with different growth rates, and which could last for many generations. Based on the hypothesis of existence of multiple subpopulations, we developed a branching process model that was consistent with the experimental observations.

Explicit effort may not influence perceptuomotor decision-making.

Many decisions that humans make are enacted by the action system. For example, humans use reach-to-grasp movements when making perceptuomotor decisions between and obtaining fruits of varying quality from a pile. Recent work suggests that the characteristics of each action alternative may influence the decision itself-there may be a bias away from making perceptuomotor alternatives associated with high effort when participants are unaware of the effort differences between responses. The present study examined if perceptuomotor decisions were influenced by explicit reaching effort differences. Neurotypical human participants were presented with random dot motion stimuli in which most dots moved in random directions and varying percentages of remaining dots moved coherently left- or rightward. Participants reported leftward motion judgements by performing leftward (or left hand) reaching movements and rightward motion judgements by performing rightward (or right hand) reaching movements. A resistance band was affixed to participants' wrists and to the table in different configurations. The configurations allowed for one movement/motion direction judgement to always require stretching of the band and, therefore, require relatively more effort. Across a set of experiments, the response context (i.e. selecting directions within a limb or selecting between limbs) and the effort difference between responses were manipulated. Overall, no experiment revealed a bias away from the perceptuomotor decision associated with high effort. Based on these results, it is concluded that, in this biomechanical context, explicit effort may not influence perceptuomotor decision-making and may point to a contextual influence of action effort on perceptuomotor decision-making.

Multifunctional human monoclonal antibody combination mediates protection against Rift Valley fever virus at low doses.

The zoonotic Rift Valley fever virus (RVFV) can cause severe disease in humans and has pandemic potential, yet no approved vaccine or therapy exists. Here we describe a dual-mechanism human monoclonal antibody (mAb) combination against RVFV that is effective at minimal doses in a lethal mouse model of infection. We structurally analyze and characterize the binding mode of a prototypical potent Gn domain-A-binding antibody that blocks attachment and of an antibody that inhibits infection by abrogating the fusion process as previously determined. Surprisingly, the Gn domain-A antibody does not directly block RVFV Gn interaction with the host receptor low density lipoprotein receptor-related protein 1 (LRP1) as determined by a competitive assay. This study identifies a rationally designed combination of human mAbs deserving of future investigation for use in humans against RVFV infection. Using a two-pronged mechanistic approach, we demonstrate the potent efficacy of a rationally designed combination mAb therapeutic.

The Impact of Hospital Exposures Prior to Total Knee Arthroplasty on Postoperative Outcomes.

Background: Total knee arthroplasty (TKA) procedures are expected to grow exponentially in the upcoming years, highlighting the importance of identifying preoperative risk factors that predispose patients to poor outcomes. The present study sought to determine if preoperative healthcare events (PHEs) influenced outcomes following TKA. Methods: This was a retrospective review of all patients who underwent TKA at a single institution from June 2011 to April 2022. Patients who had a PHE within 90 days of surgery, defined as an emergency department visit or hospital admission, were compared to patients with no history of PHE. Patients who underwent revision, nonelective, and/or bilateral TKA were excluded. Chi-squared analysis and independent sample t-tests were used to determine significant differences between demographic variables. All significant covariates were included in binary logistic regressions used to predict discharge disposition, 90-day readmission, and 1-year revision. Results: Of the 10,869 patients who underwent TKA, 265 had ≥1 PHE. Patients who had a PHE were significantly more likely to require facility discharge (odds ratio [OR]: 1.662; P = .001) than patients who did not have a PHE. Any PHE predisposed patients to significantly higher 90-day readmission rates (OR: 2.173; P = .002). Patients with ≥2 PHEs were at a significantly higher risk of 1-year revision (OR: 5.870; P = .004) compared to patients without a PHE. Conclusions: Our results demonstrate that PHEs put patients at significantly greater risk of facility discharge, 90-day readmission, and 1-year revision. Moving forward, consideration of elective surgery scheduling in the context of a recent PHE may lead to improved postoperative outcomes. Level III Evidence: Retrospective Cohort Study.

Giving and Receiving Meaningful Feedback in Orthopaedic Surgery Training.

The process of giving and receiving feedback in orthopaedic surgery training programs is distinctly unique from any other job. Trainees are required to meet certain milestones, and faculty are responsible for the caliber of surgical skills of their graduating trainees, yet there are rarely standardized practices and guidance for providing real-time feedback. Furthermore, institutional educational programs for faculty on giving meaningful feedback are lacking. The purpose of this article was to understand how feedback is defined, how to appropriately involve the learner in the process to foster active engagement rather than destructive thinking, and to characterize important principles that can elevate one's learning and self-reflection to the fullest potential.

Modulation of response activation leads to biases in perceptuomotor decision making.

Humans are constantly enacting motor responses based on perceptual judgments or decisions. Recent work suggests that accumulating evidence for a decision and planning the action to enact the decision are coupled. Further, decision commitment may occur when the action reaches its motor threshold. Across several experiments, this coupled perception-action account of perceptuomotor decision making was tested by determining if increasing response activation corresponding to one decision influenced the evidence needed to make that decision. Participants were presented with stimuli that contained varying ratios of yellow-to-blue squares and made a speeded left/right-hand response to report whether the stimulus had more yellow or blue squares, respectively. Response activation was modulated by presenting stimuli laterally on the screen-spatially compatible or incompatible with the color reports. When stimuli appeared leftward (spatially compatible with a left response/"yellow" report), the threshold for a "yellow" perceptuomotor decision was reduced-consistent with the hypothesis that increasing "yellow" response activation would lead to a "yellow" reporting bias. Further, when stimuli appeared rightward (spatially compatible with a right response/"blue" report), the threshold for a "blue" perceptuomotor decision was reduced. An additional experiment revealed that directional saccades occurring during the task were unlikely to account for biases. Overall, spatially induced response activation influenced the decision outcomes, providing support for a tightly coupled perception-action system underlying perceptuomotor decisions. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Staged Bilateral Total Hip Arthroplasty in a Patient With Larsen Syndrome.

Larsen syndrome is a rare genetic disorder characterized by weak connective tissues and various musculoskeletal abnormalities. This is a case report of a 39-year-old patient with Larsen syndrome who presented with over a decade of bilateral hip pain and difficulty ambulating. This patient has a prior history of bilateral congenital hip dislocations that were treated with open reduction and spica casting as a child with good result. Years later, she went on to develop bilateral hip osteoarthritis with significant remodeling of the proximal femur. The goal of this case presentation is to demonstrate the utility of total hip arthroplasty for this patient and discuss surgical challenges and considerations.

Return to Sport After Hip and Knee Arthroplasty: Counseling the Patient on Resuming an Active Lifestyle.

PURPOSEOF REVIEW: The purpose of this review is to summarize the available literature on the epidemiology, biomechanics, clinical outcomes, and complications of return to sport after TJA, as well as provide guidelines for patients' safe return to athletic activity. RECENT FINDINGS: As volume and indications for total joint arthroplasty (TJA) expand, arthroplasty candidates today are demographically younger, more physically active, and have higher expectations for postoperative function. Many TJA patients wish to resume sports activity that may theoretically place their reconstruction under more biomechanical stress and risk for early wear or failure. Recommendations for postoperative patient activity following TJA have historically largely been surgeon-dependent and in the context of evolving prosthetic design and surgical techniques. We endorse a three-tiered framework for return to sporting activities: (1) low-impact sports are generally recommended, (2) intermediate-impact sports are generally recommended with experience, and (3) high-impact sports are generally not recommended though activity-specific joint decisions between patient and surgeon can be made.

Systematic analysis of human antibody response to ebolavirus glycoprotein shows high prevalence of neutralizing public clonotypes.

Understanding the human antibody response to emerging viral pathogens is key to epidemic preparedness. As the size of the B cell response to a pathogenic-virus-protective antigen is poorly defined, we perform deep paired heavy- and light-chain sequencing in Ebola virus glycoprotein (EBOV-GP)-specific memory B cells, allowing analysis of the ebolavirus-specific antibody repertoire both genetically and functionally. This approach facilitates investigation of the molecular and genetic basis for the evolution of cross-reactive antibodies by elucidating germline-encoded properties of antibodies to EBOV and identification of the overlap between antibodies in the memory B cell and serum repertoire. We identify 73 public clonotypes of EBOV, 20% of which encode antibodies with neutralization activity and capacity to protect mice in vivo. This comprehensive analysis of the public and private antibody repertoire provides insight into the molecular basis of the humoral immune response to EBOV GP, which informs the design of vaccines and improved therapeutics.

Antigenic mapping and functional characterization of human New World hantavirus neutralizing antibodies.

Hantaviruses are high-priority emerging pathogens carried by rodents and transmitted to humans by aerosolized excreta or, in rare cases, person-to-person contact. While infections in humans are relatively rare, mortality rates range from 1 to 40% depending on the hantavirus species. There are currently no FDA-approved vaccines or therapeutics for hantaviruses, and the only treatment for infection is supportive care for respiratory or kidney failure. Additionally, the human humoral immune response to hantavirus infection is incompletely understood, especially the location of major antigenic sites on the viral glycoproteins and conserved neutralizing epitopes. Here, we report antigenic mapping and functional characterization for four neutralizing hantavirus antibodies. The broadly neutralizing antibody SNV-53 targets an interface between Gn/Gc, neutralizes through fusion inhibition and cross-protects against the Old World hantavirus species Hantaan virus when administered pre- or post-exposure. Another broad antibody, SNV-24, also neutralizes through fusion inhibition but targets domain I of Gc and demonstrates weak neutralizing activity to authentic hantaviruses. ANDV-specific, neutralizing antibodies (ANDV-5 and ANDV-34) neutralize through attachment blocking and protect against hantavirus cardiopulmonary syndrome (HCPS) in animals but target two different antigenic faces on the head domain of Gn. Determining the antigenic sites for neutralizing antibodies will contribute to further therapeutic development for hantavirus-related diseases and inform the design of new broadly protective hantavirus vaccines.

Cell Population Growth Kinetics in the Presence of Stochastic Heterogeneity of Cell Phenotype.

Recent studies at individual cell resolution have revealed phenotypic heterogeneity in nominally clonal tumor cell populations. The heterogeneity affects cell growth behaviors, which can result in departure from the idealized exponential growth. Here we measured the stochastic time courses of growth of an ensemble of populations of HL60 leukemia cells in cultures, starting with distinct initial cell numbers to capture the departure from the exponential growth model in the initial growth phase. Despite being derived from the same cell clone, we observed significant variations in the early growth patterns of individual cultures with statistically significant differences in growth kinetics and the presence of subpopulations with different growth rates that endured for many generations. Based on the hypothesis of existence of multiple inter-converting subpopulations, we developed a branching process model that captures the experimental observations.

Staged Bilateral Total Hip Arthroplasty in a 17-Year-Old With Type VI Mucopolysaccharidosis.

Mucopolysaccharidosis encompasses multiple lysosomal storage disorders that are relevant to the orthopedic surgeon as they lead to disruption in bone and cartilage development. These patients may present with early-onset joint pain, including end-stage hip arthritis warranting total hip replacement. The altered hip anatomy in this disorder is of specific importance to the arthroplasty surgeon as it presents challenges when reconstructing the proximal femur and acetabulum and informs implant choice. We present a 17-year-old patient with end-stage bilateral hip arthritis who underwent staged bilateral total hip arthroplasty. We discuss technical considerations in surgical technique and the consequences of acetabular and femoral deformity on implant selection.

Cementing a Monoblock Dual-Mobility Implant into a Fully Porous Cup in Revision Total Hip Arthroplasty to Address Hip Instability: Surgical Technique.

Background: The use of a cemented monoblock dual-mobility implant into a fully porous cup is indicated for patients with acetabular bone loss who have a high risk of postoperative hip instability. Patients undergoing lumbar fusion for sagittal spinal deformities have an increased risk of hip dislocation (7.1%) and should be assessed on sitting and standing radiographs1. Gabor et al. conducted a multicenter, retrospective study assessing the use of a cemented monoblock dual-mobility bearing in a porous acetabular shell in patients with acetabular bone loss and a high risk of hip instability2. Of the 38 patients, 1 (2.6%) experienced a postoperative dislocation that was subsequently treated with closed reduction without further dislocation. This surgical technique represents a favorable surgical option for patients with acetabular bone loss who are at risk for hip instability. In the example case described in the present video article, the patients had a history of dislocations, lumbar fusion, and evidence of Paprosky 3B acetabular defect; as such, the decision was made to revise to a porous shell and cement a monoblock dual-mobility implant. Description: With use of the surgeon's preferred approach, the soft tissue is dissected and the hip is aspirated. The hip is dislocated and a subgluteal pocket is made with use of electrocautery to mobilize the trunnion of the femoral stem to aid in acetabular exposure. The femoral component is assessed to ensure appropriate positioning with adequate anteversion. The acetabular component and any acetabular screws are removed. A "ream to fit" technique is performed in the acetabulum until bleeding bone is encountered, with minimal reaming performed in healthy bone from the posterior column. A trial prosthesis is placed within the acetabulum to evaluate if there is satisfactory fixation and if any augment is necessary. Care must be taken during reaming to ensure that enough bone is reamed to accommodate a porous shell that can fit the monoblock dual-mobility implant with a 2-mm cement mantle. Smaller porous shells measuring 56 mm are available for smaller defects but are often not utilized in cases of substantial acetabular bone loss. Fresh-frozen cancellous allograft is utilized to fill any contained defects. The revision porous shell with circumferential screw holes is utilized to allow for screw fixation posterosuperior and anterior toward the pubis. The implants are dried prior to placement of the cement. The cement is applied to the shell and the monoblock dual-mobility implant to ensure adequate coverage. Antibiotic-loaded cement can be utilized according to surgeon preference. Excess cement is removed under direct visualization while the cement is drying, and the position of the dual-mobility implant is adjusted in approximately 20° anteversion and 40° inclination. Stability is assessed after the cement cures, and intraoperative radiography can be performed to confirm cup positioning prior to closure. Any remaining capsule is closed, followed by closure of the remaining soft tissue in a layered fashion. Alternatives: A fully porous multi-hole jumbo cup with conventional polyethylene liner and femoral head can be utilized to increase the jump distance of the femoral head. Constrained, lipped, or offset polyethylene liners can be utilized if the shell is well fixed and a dual-mobility implant cannot be inserted. A cemented dual-mobility implant can be utilized in a well-fixed acetabular shell without evidence of loosening or osteolysis. Rationale: Dual-mobility implants have become increasingly utilized because of their advantages: (1) ability to decrease dislocation rate without increasing constraint and (2) increasing range of motion with reduced impingement risk2-8. These implants are particularly useful in the setting of revision cases with large acetabular bone defects. In a study of 76 patients with dual-mobility implants cemented into porous acetabular shells, Muthusamy et al. found that only 3.3% of patients experienced postoperative dislocations9. Moreover, acetabular cup survival was excellent, with 100% survival at 1 year and 96.2% at 2 years. Expected Outcomes: The use of a dual-mobility implant is a viable treatment option in cases of revision total hip arthroplasty, particularly those in which postoperative stability is a concern; monoblock dual-mobility implants cemented into porous shells are particularly useful in this setting2-8. These trends are similarly seen in patients treated with monoblock dual-mobility implants cemented into porous shells. Muthusamy et al. evaluated the use of this construct to treat instability or risk of hip dislocation in 76 hips, reporting a dislocation rate of 3.3% at 2 years. Additionally, the authors reported rates of all-cause acetabular survival from re-revision of 96.7% at 6 months, 93.3% at 1 year, and 89.7% at 2 years9. Physicians should be aware of the possibility for intra-prosthetic dislocations, as although this complication is rare, it has been reported in the literature7,10. Important Tips: In order to allow for circumferential coverage for fixation and ingrowth potential in cases with acetabular defects, the shell is typically impacted slightly vertical (45° to 50° of inclination) and in neutral version (0° to 5° of anteversion). Positioning can be adjusted to improve osseous contact and ingrowth as determined by the size and shape of the defect.The use of a drill guide for the locking screws allows limited degrees of variable screw angulation. In the revision setting, longer screws may be placed posterosuperior toward the sciatic notch or anteroinferior into the pubis. Surgeons should be aware of the anatomy and should predrill holes to reduce the risk of injury to surrounding neurovascular structures such as the obturator artery anteriorly.Any screw holes that are not filled should be covered with plastic hole covers in order to prevent cement from migrating behind the cup. Implants should be dried prior to the placement of the cement, and the cement should be applied to the shell and the dual-mobility implant to ensure adequate coverage.Utilize a monoblock dual-mobility implant that is designed for cementation in order to avoid implant dissociation from the acetabular shell.Remove all fibrous tissue that may hinder bony integration.Assess for pelvis discontinuity; pelvis discontinuity and acetabular bone loss are risk factors in the setting of any revision and should be properly assessed preoperatively and intraoperatively and managed accordingly.Avoid over-reaming and damage of the posterior column.Utilize a reamer or trial to assess defect size and need for augments.Place a compression screw where the cup is in contact with the bone in order to avoid tilting.Cover unused screw holes. Acronyms and Abbreviations: THA = total hip arthroplastyS/P = status postTKA = total knee arthroplastyCT = computed tomographyKM = Kaplan MeierDMC = dual-mobility cupPE = polyethylene.

Emergency department visits following total joint arthroplasty: do revisions present a higher burden?

AIMS: Although readmission has historically been of primary interest, emergency department (ED) visits are increasingly a point of focus and can serve as a potentially unnecessary gateway to readmission. This study aims to analyze the difference between primary and revision total joint arthroplasty (TJA) cases in terms of the rate and reasons associated with 90-day ED visits. METHODS: We retrospectively reviewed all patients who underwent TJA from 2011 to 2021 at a single, large, tertiary urban institution. Patients were separated into two cohorts based on whether they underwent primary or revision TJA (rTJA). Outcomes of interest included ED visit within 90-days of surgery, as well as reasons for ED visit and readmission rate. Multivariable logistic regressions were performed to compare the two groups while accounting for all statistically significant demographic variables. RESULTS: Overall, 28,033 patients were included, of whom 24,930 (89%) underwent primary and 3,103 (11%) underwent rTJA. The overall rate of 90-day ED visits was significantly lower for patients who underwent primary TJA in comparison to those who underwent rTJA (3.9% vs 7.0%; p < 0.001). Among those who presented to the ED, the readmission rate was statistically lower for patients who underwent primary TJA compared to rTJA (23.5% vs 32.1%; p < 0.001). CONCLUSION: ED visits present a significant burden to the healthcare system. Patients who undergo rTJA are more likely to present to the ED within 90 days following surgery compared to primary TJA patients. However, among patients in both cohorts who visited the ED, three-quarters did not require readmission. Future efforts should aim to develop cost-effective and patient-centred interventions that can aid in reducing preventable ED visits following TJA. Cite this article: Bone Jt Open 2022;3(7):543-548.

Human Monoclonal Antibodies to Escherichia coli Outer Membrane Protein A Porin Domain Cause Aggregation but Do Not Alter In Vivo Bacterial Burdens in a Murine Sepsis Model.

Escherichia coli is one of the most frequent human pathogens, increasingly exhibits antimicrobial resistance, and has complex interactions with the host immune system. E. coli exposure or infection can result in the generation of antibodies specific for outer membrane protein A (OmpA), a multifunctional porin. We identified four OmpA-specific naturally occurring antibodies from healthy human donor B cells and assessed their interactions with E. coli and OmpA. These antibodies are highly specific for OmpA, exhibiting no cross-reactivity to a strain lacking ompA and retaining binding to both laboratory and clinical isolates of E. coli in enzyme-linked immunosorbent assay (ELISA) and immunofluorescence assays. One monoclonal antibody (Mab), designated ECOL-11, is specific for the extracellular N-terminal porin domain of OmpA and induces growth phase-specific bacterial aggregation. This aggregation is not induced by the fragment antigen binding (Fab) form of the MAb, suggesting the importance of bivalency for this aggregating activity. ECOL-11 decreases adhesion and phagocytosis of E. coli by RAW 264.7 macrophage-like cells, possibly by inhibiting the adhesion functions of OmpA. Despite this in vitro phenotype, organ E. coli burdens were not altered by antibody prophylaxis in a murine model of lethal E. coli septic shock. Our findings support the importance of OmpA at the host-pathogen interface and begin to explore the implications and utility of E. coli-specific antibodies in human hosts.