Clinical outcomes after 1 versus 2-3 lines of neoadjuvant therapy in stage III inflammatory breast cancer.

PURPOSE: Many stage III inflammatory breast cancer (IBC) patients experience a sufficient response to first-line (1L) neoadjuvant chemotherapy (NAC) to allow surgery, while some require additional NAC. We evaluated the pathologic complete response (pCR), breast cancer-free survival (BCFS) and overall survival (OS) among patients requiring 1 vs. 2-3 lines (L) of NAC prior to surgery. METHODS: Stage III IBC patients from 2 institutions who received 1L or 2-3L of NAC prior to surgery were identified. Hormone receptor and HER2 status, grade, and pCR were evaluated. BCFS and OS were evaluated by the Kaplan-Meier method. Multivariable Cox models were utilized to estimate the hazard ratio (HR). RESULTS: 808 eligible patients (1997-2020) were identified (median age 51 years, median follow-up 69 months). 733 (91%) had 1L and 75 (9%) had 2-3L of NAC. Grade III, triple-negative and HER2-positive disease were more prevalent in 2-3L patients. 178 (24%) 1L and 14 (19%) 2-3L patients had pCR. 376 1L patients and 41 2-3L patients had recurrences. The 5-year BCFS was worse for the 2-3L group (33 vs. 46%, HR = 1.37; 95% CI 0.99-1.91). However, in 192 patients with a pCR, BCFS was similar (76 vs. 83% in 1L vs. 2-3L, respectively). There were 308 deaths (276 among 1L and 32 among 2-3L patients). The 5-year OS in 1L vs. 2-3L was 60 vs. 53% (HR = 1.32, 95% CI 0.91-1.93). CONCLUSIONS: Among stage III IBC patients, pCR rates were similar, irrespective of the NAC lines number, and BCFS and OS were comparable with pCR after 1L and 2-3L.

Femoral Component Design Is Associated With the Risk of Periprosthetic Femur Fracture After Cementless THA in Patients 65 Years or Older.

BACKGROUND: Periprosthetic femur fracture is a known complication after THA. The associated risk of cementless femoral component design for periprosthetic femur fracture in a registry population of patients older than 65 years has yet to be clearly identified. QUESTIONS/PURPOSES: (1) Is femoral stem geometry associated with the risk of periprosthetic femur fracture after cementless THA? (2) Is the presence or absence of a collar on cementless femoral implant designs associated with the risk of periprosthetic femur fracture after THA? METHODS: We analyzed American Joint Replacement Registry data from 2012 to March 2020. Unique to this registry is the high use of cementless femoral stems in patients 65 years and older. We identified 266,040 primary cementless THAs during the study period in patients with a diagnosis of osteoarthritis and surgeries linked to supplemental Centers for Medicare and Medicaid data where available. Patient demographics, procedure dates, and reoperation for periprosthetic femur fracture with revision or open reduction and internal fixation were recorded. The main analysis was performed comparing the Kheir and Chen classification: 42% (112,231 of 266,040) were single-wedge, 22% (57,758 of 266,040) were double-wedge, and 24% (62,983 of 266,040) were gradual taper/metadiaphyseal-filling cementless femoral components, which yielded a total of 232,972 primary cementless THAs. An additional analysis compared cementless stems with collars (20% [47,376 of 232,972]) with those with collarless designs (80% [185,596 of 232,972]). A Cox proportional hazard regression analysis with the competing risk of death was used to evaluate the association of design and fracture risk while adjusting for potential confounders. RESULTS: After controlling for the potentially confounding variables of age, sex, geographic region, osteoporosis or osteopenia diagnosis, hospital volume, and the competing risk of death, we found that compared with gradual taper/metadiaphyseal-filling stems, single-wedge designs were associated with a greater risk of periprosthetic femur fracture (HR 2.9 [95% confidence interval (CI) 2.2 to 3.9]; p < 0. 001). Compared with gradual taper/metadiaphyseal-filling stems, double-wedge designs showed an increased risk of periprosthetic femur fracture (HR 3.0 [95% CI 2.2 to 4.0]; p < 0. 001). Collarless stems showed an increased risk of periprosthetic fracture compared with collared stems (HR 7.8 [95% CI 4.1 to 15]; p < 0. 001). CONCLUSION: If cementless femoral fixation is used for THA in patients 65 years or older, surgeons should consider using gradual taper/metadiaphyseal-filling and collared stem designs because they are associated with a lower risk of periprosthetic femur fracture. Future investigations should compare gradual taper/metadiaphyseal-filling and collared cementless designs with cemented fixation in this population. LEVEL OF EVIDENCE: Level III, therapeutic study.

The molecular characterization of antibody binding to a superantigen-like protein from a commensal microbe.

Microorganisms have coevolved diverse mechanisms to impair host defenses. A major one, superantigens, can result in devastating effects on the immune system. While all known superantigens induce vast immune cell proliferation and come from opportunistic pathogens, recently, proteins with similar broad specificity to antibody variable (V) domain families were identified in a commensal microbiota. These proteins, identified in the human commensal Ruminococcus gnavus, are called immunoglobulin-binding protein (Ibp) A and B and have been shown to activate B cells in vitro expressing either human VH3 or murine VH5/6/7. Here, we provide molecular and functional studies revealing the basis of this Ibp/immunoglobulin (Ig) interaction. The crystal structure and biochemical assays of a truncated IbpA construct in complex with mouse VH5 antigen-binding fragment (Fab) shows a binding of Ig heavy chain framework residues to the Ibp Domain D and the C-terminal heavy chain binding domain (HCBD). We used targeted mutagenesis of contact residues and affinity measurements and performed studies of the Fab-IbpA complex to determine the stoichiometry between Ibp and VH domains, suggesting Ibp may serve to cluster full-length IgA antibodies in vivo. Furthermore, in vitro stimulation experiments indicate that binding of the Ibp HCBD alone is sufficient to activate responsive murine B cell receptors. The presence of these proteins in a commensal microbe suggest that binding a broad repertoire of immunoglobulins, particularly in the gut/microbiome environment, may provide an important function in the maintenance of host/microbiome homeostasis contrasting with the pathogenic role of structurally homologous superantigens expressed by pathogens.

Decreasing Hip Offset in Total Hip Arthroplasty Results in Decreased Physical Function Scores.

BACKGROUND: Acetabular and femoral offset play an important role in total hip arthroplasty (THA) for postoperative stability and biomechanical function. However, it is unknown whether offset impacts patient-reported outcomes (PROs). This study evaluated patients undergoing direct anterior (DA) THA with the hypothesis that patients who have a decrease in hip offset postoperatively would have lower physical function scores and higher pain interference. METHODS: There were 499 patients who underwent DA THA at a single tertiary academic institution who were retrospectively evaluated. Preoperative and postoperative hip offset was measured by 2 reviewers using the Sundsvall method on standing anteroposterior pelvis radiographs. Postoperative changes in hip offset were categorized as increased (> 5 mm), matched (within 5 mm of the preoperative offset measurement), or decreased ( >5 mm). Postoperative PROs with a minimum 1-year follow-up were recorded. A one-way analysis of variance was utilized to compare postoperative pain and PROs between groups. RESULTS: Patients who had decreased offset had the lowest mean postoperative physical function scores at 39.4 (8.0), followed by the increased offset group at 42.2 (10.4) and the matched offset group at 42.8 (9.8) (P < .01). There were significant differences in postoperative physical function scores between matched offset (42.8) and decreased offset (39.4) groups (P < .01), as well as between increased offset (42.2) and decreased offset (39.4) groups (P = .04). There was no difference between matched and increased offset cohorts. CONCLUSIONS: Our data suggests that reducing hip offset may result in worse physical function scores compared to those who have matched or increased hip offset. This should be considered intraoperatively, and efforts should be made to avoid reduced offset even in the presence of hip stability.

Dual Mobility Articulation in Total Hip Arthroplasty: Mixed Femoral and Acetabular Components are a Feasible Option.

BACKGROUND: The utilization of a different manufacturer for the prosthetic femoral head and the polyethylene insert in dual mobility (DM) for total hip arthroplasty (THA) may be necessary, especially in the revision setting. However, there is no data in the literature about this application. This study evaluated the outcomes of mixed manufacturer components, with the hypothesis that there would be no difference in measured outcomes compared to matched components. METHODS: The DM articulations implanted during THA revision were retrospectively reviewed from 2011 to 2017. The study group was then stratified into 2 cohorts: matching components or mixed components. Of 130 hips included in the study with DM articulations with average follow-up of 7 years, 103 had mixed and 27 had matching manufacturer components. Rates of all cause reoperation and revision, intraprosthetic dislocation, dislocation, and aseptic loosening were compared using Chi-squared and Fisher's exact test; survival analysis was also performed. RESULTS: Matched and mixed manufacturer implants had no significant difference between all cause reoperation (33 versus 25.2%), dislocation (14.8 versus 7.7%), and aseptic loosening (3.7 versus 3.9%), respectively. Higher rates of intraprosthetic dislocation (11 versus 0.97%) were observed in the matching component cohort. Survival analysis showed similar outcomes at 2, 5, and 10 years. CONCLUSIONS: Mixed-component DM articulations show similar results compared to matching components. The off-label use of mixed manufacture DM articulation in THA is a feasible and safe option in the correct patient. Furthermore, when encountering a well-fixed femoral stem or acetabular shell, the use of a mixed component DM articulations may reduce the morbidity for the patient and prevent revision of all components.

Inferior Outcomes for Patients Transferred Between Surgical Stages for Knee Periprosthetic Joint Infection.

BACKGROUND: Periprosthetic joint infection (PJI) in total knee arthroplasty may result in 2-stage revision surgery. There are limited data describing outcomes when the first stage is completed at an outside hospital and the patient is referred to a tertiary center. We hypothesized that patients have greater success when both surgeries occur at a single center. METHODS: There were 25 knee PJI patients who presented with an antibiotic spacer and had a minimum 2-year follow-up who were retrospectively identified at a single tertiary referral center from 2014 to 2021. A cohort matched for age, sex, body mass index, Elixhauser comorbidity measure, spacer type, infectious organism, and year of surgery was established with patients who had both stages completed at the investigating institution. Modified Delphi success criteria of no subsequent surgery or reinfection with any species were compared. RESULTS: The transferred group demonstrated a treatment success of 40% compared to 84% in the continuous group (P < .01). The transferred group was more likely to have an additional procedure between stages (44 versus 8%, P < .01), with a higher number of surgeries after primary total knee arthroplasty (4.8 versus 3.0, P < .01), between stages (1.4 versus 0.2, P < .01), and after second stage (0.8 versus 0.2, P = .03). The transferred group had longer durations between stages (20.1 versus 7.0 weeks, P < .01). CONCLUSION: Patients who have PJIs transferred between stages demonstrated higher treatment failure. Surgeons should consider transfer early with a goal of continuous management by a single institution.

Does Medically Supervised Weight Loss Prior to Total Knee Arthroplasty Improve Patient-Reported Pain and Physical Function?

BACKGROUND: Weight loss is commonly recommended before total knee arthroplasty (TKA) despite inconsistent evidence for better outcomes. This study sought to examine the impacts of preoperative weight loss on patient-reported and adverse outcomes among TKA patients supervised by a medical weight management clinic. METHODS: This study retrospectively analyzed patients who underwent medical weight management supervision within 18 months before TKA comparing patients who did and did not have clinically relevant weight loss. Preoperative body mass indices, demographics, Patient-Reported Outcomes Measurement Information System physical function and pain interference scores, pain intensity scores, and adverse outcomes were extracted. Multivariable linear regressions were performed to determine if preoperative weight loss correlated with patient-reported outcomes after controlling for confounders. RESULTS: There were 90 patients, 75.6% women, who had a mean age of 65 years (range, 42-82) and were analyzed. There were 51 (56.7%) patients who underwent clinically relevant weight loss with a mean weight loss of 10.4% and experienced no difference in adverse outcomes. Preoperative weight loss predicted significantly improved 3-month postoperative physical function (ß = 15.2 [13.0-17.3], P < .001), but not pain interference (ß = -18.9 [-57.1-19.4], P = .215) or pain intensity (ß = -1.8 [-4.9-1.2], P = .222) scores. CONCLUSION: We found that medically supervised preoperative weight loss predicted improvement in physical function 3 months after TKA. This weight loss caused no major adverse effects. Further research is needed to understand the causal relationships between preoperative weight loss, medical supervision, and outcome after TKA and to elucidate potential longer-term benefits in a larger sample.

Timing of Renal Transplant Prior to Total Knee Arthroplasty Impacts 90-Day Postoperative Outcomes.

BACKGROUND: Renal transplant (RT) patients are at increased risk for complications after total knee arthroplasty (TKA); however, it is unknown if the time from RT to TKA influences such risks. This study evaluated RT patients undergoing primary TKA at various time intervals after transplant. We hypothesized that increased time between RT and TKA would decrease the risk of complications after TKA. METHODS: There were 499 RT patients in a national database undergoing subsequent primary TKA from 2010 to 2020. Patients were stratified by intervals of less than 1 year, between 1 and 2 years, and more than 2 years from RT to TKA. Medical complications up to 90 days, readmissions, and 2-year revisions were compared via univariable and multivariable analyses. RESULTS: Patients who underwent TKA less than 1 year after RT were associated with higher 90-day medical complications when compared to those who underwent TKA 1 to 2 years after RT (odds ratio [OR] 0.4, confidence interval [CI] 0.2 to 0.8, P = .01) and more than 2 years (OR 0.3, CI 0.2 to 0.7, P < .01) after RT. Acute kidney injury and blood transfusion were the most common complications. The TKAs performed 2 years after RT were less likely to have 90-day readmissions when compared to TKAs performed less than 1 year after RT (OR 0.4, CI: 0.2 to 0.9, P < .01). However, time from RT to TKA did not increase the risk of revision at 2 years (P > .30). CONCLUSIONS: Patients undergoing TKA within 1 year of RT have an increased risk of 90-day postoperative medical complications and readmissions, but the time interval from RT does not appear to affect revision risk. These findings suggest waiting 1 year after RT before proceeding with TKA may be advantageous.

Continuation of Oral Antidiabetic Medications Was Associated With Better Early Postoperative Blood Glucose Control Compared to Sliding Scale Insulin After Total Knee Arthroplasty.

BACKGROUND: This study evaluated blood glucose (BG), creatinine levels, metabolic issues, length of stay (LOS), and early postoperative complications in diabetic primary total knee arthroplasty (TKA) patients. It examined those who continued home oral antidiabetic medications and those who switched to insulin postoperatively. The hypothesis was that continuing home medications would lead to lower BG levels without metabolic abnormalities. METHODS: Patients who had diabetes who underwent primary TKA from 2013 to 2022 were evaluated retrospectively. Diabetic patients who were not on home oral antidiabetic medications or who were not managed as an inpatient postoperatively were excluded. Patient demographics and laboratory tests collected preoperatively and postoperatively as well as 90-day emergency department visits and 90-day readmissions, were pulled from electronic records. Patients were grouped based on inpatient diabetes management: continuation of home medications versus new insulin coverage. Acute postoperative BG control, creatinine levels, metabolic abnormalities, LOS, and early postoperative complications were compared between groups. Multivariable regression analyses were performed to measure associations. RESULTS: A total of 867 primary TKAs were assessed; 703 (81.1%) patients continued their home oral antidiabetic medications. Continuing home antidiabetic medications demonstrated lower median maximum inpatient BG (180.0 mg/dL versus 250.0 mg/dL; P < .001) and median average inpatient BG (136.7 mg/dL versus 173.7 mg/dL; P < .001). Logistic regression analyses supported the presence of an association (odds ratio = 17.88 [8.66, 43.43]; P < .001). Proportions of acute kidney injury (13.5 versus 26.7%; P < .001) were also lower. There was no difference in relative proportions of metabolic acidosis (4.4 versus 3.7%; P = .831), LOS (2.0 versus 2.0 days; P = .259), or early postoperative complications. CONCLUSIONS: Continuing home oral antidiabetic medications after primary TKA was associated with lower BG levels without an associated worsening creatinine or increase in metabolic acidosis. LEVEL III EVIDENCE: Retrospective Cohort Study.

The Posterior Approach is Associated With Lower Total Encounter and 90-Day Costs When Compared to the Direct Anterior Approach.

BACKGROUND: The clinical impact of the surgical approach in total hip arthroplasty (THA) has been widely reviewed. This study evaluated the total encounter and 90-day costs of THA for 2 surgical approaches (posterior [P] and direct anterior [DA]) in 1 tertiary health system. METHODS: This is a retrospective review of 2,101 THAs (1,092 P and 1,009 DA) by 4 surgeons (2 with the highest volume of DA and P, respectively) from 2017 to 2022 at 1 academic center. Demographics, comorbidities, operative time, length of hospital stay, 90-day hospital returns, and complications were compared. The total encounter cost and 90-day postoperative cost were itemized. Multivariable regression analyses evaluated associations with increased cost at each time point. RESULTS: The DA cohort had a higher median encounter cost ($8,348.66 versus 7,332.42, P < .01), resulting from higher intraoperative (P < .01) and radiology (P < .01) expenses. Regression analyses demonstrated the DA was independently associated with increased encounter costs (odds ratio 1.1; 95% confidence interval 1.1 to 1.1; P < .01). There was a higher incidence of 90-day emergency department visits in the DA cohort (16 versus 12%, P = .02), with a trend toward increased readmissions. There was no difference in 90-day reoperations. Median 90-day cost was higher in the DA cohort ($126.99 versus 0.00, P < .01), and regression analyses demonstrated the DA had an association with increased 90-day cost (odds ratio 2.2; 95% confidence interval 1.5 to 3.0; P < .01). CONCLUSIONS: Despite a younger patient population, the DA was independently associated with increased encounter and 90-day costs in a single academic hospital system. This study may underestimate the cost difference, as capital costs such as specialized tables were not analyzed.

Unsuspected Positive Intraoperative Cultures in Aseptic Revision Knee Arthroplasty: Prevalence, Management, and Infection-Free Survivorship.

BACKGROUND: The purpose of this study was to evaluate the management and outcomes of aseptic revision total knee arthroplasty (arTKA) with unsuspected positive cultures (UPCs) compared to those with sterile cultures. METHODS: The institutional database at a single tertiary center was retrospectively reviewed for arTKA from January 2013 to October 2023. Patients who met Musculoskeletal Infection Society criteria for periprosthetic joint infection (PJI) based on available preoperative infectious workup, received antibiotic spacers, or did not have at least 1 year of follow-up were excluded. Patients were stratified based on intraoperative cultures into 4 cohorts: sterile cultures, 1 UPC, ≥ 2 UPCs with different organisms, and ≥ 2 UPCs with the same organism. Univariable analyses were used to compare these groups. Kaplan-Meier survivorship analysis assessed infection-free survival at 5 years, and Cox proportional hazards regressions were used to evaluate factors that influence infection-free survival. A total of 691 arTKAs at a mean follow-up of 4.2 years were included in the study. Of these, 49 (7.1%) had 1 UPC with a new organism, 10 (1.4%) had ≥2 UPCs of the same organism, and 2 (0.2%) had ≥2 UPCs with different organisms. RESULTS: Postoperative antibiotics were prescribed to 114 (16.5%) patients-13 (26.5%) with 1 UPC, 6 (60.0%) with ≥2 UPCs of the same organism, and 0 (0.0%) of patients who had ≥2 UPCs of different organisms. There were no differences in infection-free survival at 5 years between patients who had sterile cultures and 1 UPC (96 versus 89%; P = .39) nor between sterile cultures and ≥2 UPCs of different organisms (96 versus 100%; P < .72). However, patients who had ≥2 UPCs of the same organism had significantly worse infection-free survival at 5 years compared to patients who had sterile cultures (58 versus 96%; P < .001). Cox proportional hazards regression suggested that when adjusting for covariates, an American Society of Anesthesiologists classification of ≥3 (hazard ratio [HR] = 3.1; P = .007), ≥2 UPCs of the same organism (HR = 11.0; P < .001), 1 UPC (HR = 4.2; P = .018), and arTKA with hinge constructs (HR = 4.1; P = .008) were associated with increased risk of rerevision for PJI. CONCLUSIONS: Patients who had 1 UPC or ≥2 UPCs with different organisms had similar infection-free survival at 5 years as patients who had sterile cultures. However, patients who had ≥2 UPCs of the same organism had significantly worse infection-free survival at 5 years. Overall, 1 UPC or ≥2 UPCs of the same organism at the time of arTKA may suggest the patient is at higher risk of rerevision for PJI. More studies are needed to determine what interventions can be implemented to mitigate this risk.

Ultracongruent Polyethylene Liners Do Not Affect Survival of Total Knee Arthroplasty for Valgus Deformity.

BACKGROUND: Valgus knee deformity is observed in nearly 10% of patients undergoing total knee arthroplasty (TKA). The degree of polyethylene constraint required to balance a valgus knee remains controversial, and historically, posterior-stabilized (PS) designs have been favored. This study evaluated the survivorship of TKA done in valgus knees based on implant design and specifically compared posterior-stabilized (PS) and ultracongruent (UC) liners. METHODS: A total of 549 primary TKAs performed on valgus knees by fellowship-trained arthroplasty surgeons from 2013 to 2019 were reviewed. Demographics, comorbidities, degrees of preoperative deformity, implants used, and all-cause revisions until final follow-up were recorded. Cox regression analyses evaluated survival to all-cause revision in each cohort. The mean follow-up was 4.9 years (range, 2 to 9). RESULTS: There were 403 UC liners compared to 146 PS liners. There was no difference in patient age (68 versus 67 years; P = .30), body mass index (30.9 versus 30.4; P = .36), or degree of deformity (8.6 versus 8.8 degrees; P = .75) between the cohorts. At final follow-up, there were 5 revisions in the PS cohort (3.4%) versus 11 revisions in the UC cohort (2.7%) (P = .90). The most common reason for revision in both cohorts was periprosthetic joint infection (4 PS; 8 UC). Multivariable regression analyses controlling for age, body mass index, Elixhauser comorbidity score, sex, and degree of deformity demonstrated UC polyethylene liners were not associated with revision (hazard ratio 0.76; 95% confidence interval [CI] 0.26 to 2.21; P = .62). There was no difference in eight-year survivorship to all-cause revision, including aseptic and septic failure. CONCLUSIONS: Alternative polyethylene liners from the historically utilized PS liners for TKA for valgus deformity did not reduce survivorship. With modern polyethylene designs, UC inserts can be utilized for this deformity without increasing the risk of failure.

Preoperative Risk Factors for Lymphedema in Inflammatory Breast Cancer.

BACKGROUND: Prophylactic lymphatic bypass or LYMPHA (LYmphatic Microsurgical Preventive Healing Approach) is increasingly offered to prevent lymphedema following breast cancer treatment, which develops in up to 47% of patients. Previous studies focused on intraoperative and postoperative lymphedema risk factors, which are often unknown preoperatively when the decision to perform LYMPHA is made. This study aims to identify preoperative lymphedema risk factors in the high-risk inflammatory breast cancer (IBC) population. METHODS: Retrospective review of our institution's IBC program database was conducted. The primary outcome was self-reported lymphedema development. Multivariable logistic regression analysis was performed to identify preoperative lymphedema risk factors, while controlling for number of lymph nodes removed during axillary lymph node dissection (ALND), number of positive lymph nodes, residual disease on pathology, and need for adjuvant chemotherapy. RESULTS: Of 356 patients with IBC, 134 (mean age: 51 years, range: 22-89 years) had complete data. All 134 patients underwent surgery and radiation. Forty-seven percent of all 356 patients (167/356) developed lymphedema. Obesity (body mass index > 30) (odds ratio [OR]: 2.7, confidence interval [CI]: 1.2-6.4, p = 0.02) and non-white race (OR: 4.5, CI: 1.2-23, p = 0.04) were preoperative lymphedema risk factors. CONCLUSION: Patients with IBC are high risk for developing lymphedema due to the need for ALND, radiation, and neoadjuvant chemotherapy. This study also identified non-white race and obesity as risk factors. Larger prospective studies should evaluate potential racial disparities in lymphedema development. Due to the high prevalence of lymphedema, LYMPHA should be considered for all patients with IBC.

Photogeneration of Spin Quintet Triplet-Triplet Excitations in DNA-Assembled Pentacene Stacks.

Singlet fission (SF), an exciton-doubling process observed in certain molecular semiconductors where two triplet excitons are generated from one singlet exciton, requires correctly tuned intermolecular coupling to allow separation of the two triplets to different molecular units. We explore this using DNA-encoded assembly of SF-capable pentacenes into discrete π-stacked constructs of defined size and geometry. Precise structural control is achieved via a combination of the DNA duplex formation between complementary single-stranded DNA and the local molecular geometry that directs the SF chromophores into a stable and predictable slip-stacked configuration, as confirmed by molecular dynamics (MD) modeling. Transient electron spin resonance spectroscopy revealed that within these DNA-assembled pentacene stacks, SF evolves via a bound triplet pair quintet state, which subsequently converts into free triplets. SF evolution via a long-lived quintet state sets specific requirements on intermolecular coupling, rendering the quintet spectrum and its zero-field-splitting parameters highly sensitive to intermolecular geometry. We have found that the experimental spectra and zero-field-splitting parameters are consistent with a slight systematic strain relative to the MD-optimized geometry. Thus, the transient electron spin resonance analysis is a powerful tool to test and refine the MD-derived structure models. DNA-encoded assembly of coupled semiconductor molecules allows controlled construction of electronically functional structures, but brings with it significant dynamic and polar disorders. Our findings here of efficient SF through quintet states demonstrate that these conditions still allow efficient and controlled semiconductor operation and point toward future opportunities for constructing functional optoelectronic systems.

Insights into the origins of inverted circular dichroism in thin films of a chiral side chain polyfluorene.

We synthesized a fluorene-bithiophene co-polymer with chiral side chains (cPFT2) and investigated its chiroptical properties via synchotronradiation circular dichroism. We observed that thin films of the polymer display an intense circular dichroism (CD) upon annealing, which is of opposite handedness to the CD reported for similar polyfluorenes bearing the same enantiomeric chiral side chain. We then contrast the properties of this polymer with chiral side chain fluorene homopolymer (cPF) and observe large differences in their thin film morphology. Using photoluminescence spectroscopy, we uncover evidence of polymer chain bending in cPFT2, which is further supported by theoretical calculations, and propose an explanation for the observed inverted optical activity.

Music as an alternative self-regulation strategy to snack foods following a negative mood induction in 5-7-year-old children: Interactions with parental use of food as a reward.

This study aimed to extend studies that have looked at snack food consumption following a negative mood induction, and examine whether listening to a happy song would counteract these effects in children. A second aim was to examine whether parental feeding practices (use of food as a reward and the use of food to regulate emotions) and child Body Mass Index (BMI) would moderate any differences. Eighty 5-7-year-old children took part in a negative mood induction and were then assigned to either a happy music condition or a silent control condition. The weight (g) consumed of four snack foods was measured (fruit hearts, crisps, chocolate biscuits, and breadsticks). Parents filled in baseline measures of feeding practices. There were no significant differences in food consumption between conditions. There was, however, a significant interaction between the high use of food as a reward and the condition on the amount of food eaten. In particular, following a negative -mood induction, those children whose parents reported using food as a reward and who were in the silent condition ate significantly more snack foods. There were no significant interactions with child BMI or with parental use of food to regulate emotions. This research suggests that the use of certain parental strategies may influence how children respond to novel emotion regulation techniques. Further research is needed to evaluate the best types of music to regulate emotions in children, and whether parents can be encouraged to replace maladaptive feeding practices with more adaptive non-food practices.

A Multicenter Prospective Investigation on Patient Physical and Mental Health After Girdlestone Resection Arthroplasty.

BACKGROUND: Girdlestone resection arthroplasty is a salvage procedure for hip periprosthetic joint infection (PJI) that controls infection and reduces chronic pain, but may result in limited postoperative joint function. The aim of this study was to assess physical function and mental health after Girdlestone. METHODS: This was a multicenter, prospective study evaluating patients with Girdlestone. The Prosthesis Evaluation Questionnaire (PEQ) and patient-reported outcomes measurement information system (PROMIS) global physical health and mental health surveys were administered postoperatively via telephone. The PEQ consists of four scales (ie, ambulation, frustration, perceived response, and social burden) with scores ranging from 0 to 10. The PROMIS measures generated T-scores (mean: 50, standard deviation: 10) that enable comparison to the general population. RESULTS: Thirty-five patients completed all surveys. The average time from procedure to survey completion was 6 years (range, 1 to 20). The median scores for the ambulation, frustration, perceived response, and social burden scales of the PEQ were 0.0 [interquartile range: 0-4.1], 6.0 [3.0-9.3], 9.0 [7.2-10.0], and 7.5 [4.3-9.5]. The median raw scores of the PROMIS global physical health and mental health were 11.91 [interquartile range: 9-14] and 14.0 [10.0-16.0]. These corresponded to average T scores of 39.7 (standard error : 4.3) for physical health and 46.1 (standard error: 3.8) for mental health, which were 10.3 points and 3.9 points below the average score in the United States general population, respectively. CONCLUSION: Girdlestone can have a substantial negative impact on physical functions; however, mental health and social interaction may be only moderately affected. These outcomes can be used to guide patient expectations, as this procedure may be necessary in certain salvage scenarios.

Short Course of Oral Antibiotic Treatment After Two-Stage Exchange Arthroplasty Appears to Decrease Early Reinfection.

BACKGROUND: Recent evidence has suggested a benefit to extended postoperative prophylactic oral antibiotics after two-stage exchange arthroplasty for treatment of periprosthetic joint infections. We sought to determine reinfection rates with and without a short course of oral antibiotics after two-stage exchange procedures. METHODS: A retrospective review identified patients undergoing two-stage exchange arthroplasty for periprosthetic joint infection of the hip or knee. Patients were excluded if they failed a prior two-stage exchange, had positive cultures at reimplantation, prolonged intravenous antibiotics postoperatively, and/or life-long suppression. This resulted in 444 reimplantations (210 hips and 234 knees). Patients were divided into three cohorts based on the duration of oral antibiotics after reimplantation: no antibiotics (102), ≤2 weeks (266), or >2 weeks (76). The primary endpoint was reinfection within 1 year of reimplantation. RESULTS: Within 1 year of reimplantation, there were 34 reinfections. In the no-antibiotic, ≤ 2-week, and >2-week cohorts the reinfection rates were 14.1, 7.0, and 6.4%, respectively. Multivariate Cox regression showed a reduced reinfection rate in the ≤2-week cohort relative to no antibiotics (hazard ratio [HR]: 0.38, P = .01). While the smaller cohort with >2 weeks of antibiotics did not significantly reduce the reinfection rate (HR: 0.41, P = .12), when combined with the ≤2-week cohort, use of oral antibiotics had an overall reduction of the reinfection rate (HR: 0.39, P = .01). CONCLUSIONS: These data support the hypothesis that a short course of oral antibiotics after reimplantation decreases the 1-year reinfection rate. Future randomized studies should seek to examine the efficacy of different durations of oral antibiotics to reduce reinfection. LEVEL OF EVIDENCE: Prognostic Level IV.

Accelerated Discharge After Aseptic Revision Total Hip Arthroplasty Does Not Predict Inferior 30-Day Outcomes.

BACKGROUND: Perioperative advancements have made outpatient primary total hip arthroplasty (THA) a viable option for patients. This study evaluated the feasibility of expedited discharge after revision THA and compared 30-day outcomes to patients who had prolonged inpatient hospitalizations. The authors hypothesized that expedited discharge would not result in inferior 30-day outcomes. METHODS: Aseptic revision THAs in a national database were reviewed from 2013 to 2020. THAs were stratified by hospital length of stay (LOS) more or less than 24 hours. Demographics, comorbidities, preoperative laboratory values, American Society of Anesthesiology (ASA) scores, operative times, components revised, 30-day readmissions, and reoperations were compared. Multivariable analyses evaluated predictors of discharge prior to 24 hours, 30-day readmissions, and reoperations. Of 17,044 aseptic revision THAs, 211 were discharged within 24 hours. RESULTS: Accelerated discharge patients were younger, mean age 63 years (range, 20-92) versus 66 years (range, 18-94) (P < .01) had lower body mass index, mean 28.7 (range, 18.3-46.4) versus 29.9 (range, 17.3-52.5) (P = .01), and ASA scores (ASA, 1-2; 40.4-57.8%) (P < .01). Components revised had no association with LOS (P = .39); however, operative times were shorter and mean 100 minutes (range, 35-369) versus 139 minutes (range, 24-962) (P < .01) in accelerated discharge patients. Accelerated discharge patients had lower readmission rates (P < .01) but no difference in reoperation rates (P = .06). CONCLUSION: Discharge less than 24 hours after revision THA is a feasible option for the correct patient and further efforts to decrease LOS should be evaluated.

The Removal of Total Hip Arthroplasty From the Inpatient-Only List has Improved Patient Selection and Expanded Optimization Efforts.

BACKGROUND: On January 1, 2020, the Centers for Medicare and Medicaid Services removed total hip arthroplasty (THA) from the Inpatient-Only (IPO) list. This study evaluated patient demographics and comorbidities, preoperative optimization efforts, and 30-day outcomes of patients undergoing outpatient THA before and after IPO removal. The authors hypothesized that patients undergoing THA post-IPO removal would have improved optimization of modifiable risk factors and equivalent 30-day outcomes. METHODS: There were 17,063 outpatient THAs in a national database stratified by surgery performed before (2015 to 2019: 5,239 patients) and after IPO (2020: 11,824 patients) removal. Demographics, comorbidities, and 30-day outcomes were compared with univariable and multivariable analyses. Preoperative optimization thresholds were established for the following modifiable risk factors: albumin, creatinine, hematocrit, smoking history, and body mass index. The percentage of patients who fell outside the thresholds in each cohort were compared. RESULTS: Patients undergoing outpatient THA post-IPO removal were significantly older; mean age 65 years (range, 18 to 92) versus 62 (range, 18 to 90) years (P < .01), with a higher percentage of American Society of Anesthesiologists scores 3 and 4 (P < .01). There was no difference in 30-day readmissions (P = .57) or reoperations (P = 1.00). A significantly lower percentage of patients fell outside the established threshold for albumin (P < .01) post-IPO removal, and trended towards lower percentages for hematocrit and smoking status. CONCLUSION: The removal of THA from the IPO list expanded patient selection for outpatient arthroplasty. Preoperative optimization is critical to minimize postoperative complications, and the current study demonstrates that 30-day outcomes have not worsened post-IPO removal.