3D-Printed Metaphyseal Cones in Revision Total Knee Arthroplasties: Excellent Survivorship of 740 Cones at 5 Years.

BACKGROUND: Porous metaphyseal cones are frequently utilized during revision total knee arthroplasty (TKA) procedures. The purpose of the present study was to evaluate 3D-printed metaphyseal cones used for revision TKA, with specific emphasis on implant survivorship, radiographic appearance, and clinical outcomes after short-term follow-up. METHODS: We identified 740 cones (498 tibial, 242 femoral) that had been inserted during 533 revision TKA procedures that had been performed at a single tertiary care academic institution. Aseptic loosening (n = 199), periprosthetic joint infection (PJI) (n = 183), and instability (n = 84) were the most common reasons for the index revision. Type-2B or 3 bone loss was present in 67% of the knees. The mean age was 66 years, the mean body mass index was 34 kg/m 2 , and 55% of the patients were female. Serial radiographs were reviewed. The mean duration of follow-up was 4 years. RESULTS: The 5-year cumulative incidence of cone revision for aseptic loosening was 1% (95% confidence interval [CI], 0% to 3%). The 5-year cumulative incidence of any cone revision or removal was 6% (95% CI, 4% to 9%). In total, 37 cones (19 femoral, 18 tibial) were revised, with PJI (n = 23; 14 recurrent), periprosthetic femoral fracture (n = 3), arthrofibrosis (n = 3), and aseptic loosening of the femoral component and femoral cone (n = 3) as the most common reasons for cone revision. The 5-year cumulative incidence of any TKA re-revision was 14% (95% CI, 11% to 18%). There were a total of 67 re-revisions, with PJI (n = 38), persistent drainage (n = 6), and extensor mechanism disruption (n = 3) being the most common reasons. Radiographically, 2 unrevised femoral cones and 1 unrevised tibial cone appeared to be possibly loose; all 3 cones were in knees with distal femoral replacements or hinged constructs. CONCLUSIONS: This large series showed that 3D-printed titanium metaphyseal cones were very durable at short-term follow-up, with a 5-year cumulative incidence of cone revision for aseptic loosening of 1%. PJI was the most common reason for cone revision and any revision. LEVEL OF EVIDENCE: Therapeutic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Contemporary Aseptic Revision Total Hip Arthroplasty in Patients ≤50 Years of Age: Results of >500 Cases.

BACKGROUND: There has been a paucity of long-term outcomes data on aseptic revision total hip arthroplasties (THAs) in the young adult population. The purpose of this study was to evaluate implant survivorship, complications, and clinical outcomes in a large cohort of contemporary aseptic revision THAs in patients ≤50 years of age at the time of the surgical procedure. METHODS: We identified 545 aseptic revision THAs performed at a single academic institution from 2000 to 2020 in patients who were 18 to 50 years of age. Patients who underwent conversion THAs and patients with a history of any ipsilateral hip infection were excluded. The mean age was 43 years, the mean body mass index (BMI) was 29 kg/m 2 , and 63% were female. The index indication for revision THA was aseptic loosening in 46% of cases, polyethylene wear or osteolysis in 28% of cases (all revisions of conventional polyethylene), and dislocation in 11% of cases. There were 126 hips (23%) that had undergone at least 1 previous revision (median, 1 revision [range, 1 to 5 revisions]). The mean follow-up was 10 years. RESULTS: In the entire cohort, the 20-year survivorship free of any re-revision was 76% (95% confidence interval [95% CI], 69% to 82%). There were 87 re-revisions, with 31 dislocations, 18 cases of aseptic loosening of the femoral component, and 16 periprosthetic joint infections (PJIs) being the most common reasons for re-revision. Dislocation as the indication for the index revision was associated with an increased risk of re-revision (hazard ratio, 2.9; p < 0.001). The 20-year survivorship free of any reoperation was 73% (95% CI, 66% to 78%). There were 75 nonoperative complications (14%), including 32 dislocations. The mean Harris hip score significantly improved (p < 0.001) from 65 preoperatively to 81 at 10 years postoperatively. CONCLUSIONS: Contemporary aseptic revision THAs in patients ≤50 years of age demonstrated a re-revision risk of approximately 1 in 4 at 20 years. Dislocation, aseptic loosening of the femoral component, and PJI were the most common reasons for re-revision. Index revision THAs for dislocation had a 3 times higher risk of re-revision. LEVEL OF EVIDENCE: Therapeutic Level III . See Instructions for Authors for a complete description of levels of evidence.

Meaning, trust, and belonging: Exploring the factors that foster elite forced migrant athletes' growth.

BACKGROUND AND PURPOSE: Researchers have highlighted elite refugee athletes' acculturation and sport-related challenges upon transitioning into host country sports systems. Using a strength-based approach, we aimed to broaden this view through exploring the internal and external factors that have fostered refugee athletes' abilities to find meaning and growth following their transitions into a national sports system. METHODOLOGY: Data collection began with an arts-based drawing activity which was then discussed in a conversational interview. Fourteen (n = 11 male, 3 female) national and international refugee athletes participated. The interviews were analyzed using a reflexive thematic analysis, a form of qualitative analysis used to derive commonalities that connect athletes' experiences. The data is represented through polyphonic vignettes (narrative featuring multiple perspectives) to safeguard athletes' anonymity whilst showcasing varying perspectives. RESULTS: Athletes were at various phases of growth at the time of the interviews. The primary internal factor that facilitated growth was responsibility to find and pursue meaning. External factors of trust and belonging, actualized through supporting elite athletes' personal differences, were external factors that fostered their abilities to find meaning. CONCLUSION: Elite refugee athletes' growth occurred at the nexus of individual responsibility, trusting relationships, and inclusive sport environments. The findings inform individual and environmental growth-based interventions for current and future elite athletes who face varying adversities within their sports contexts.

Draft genomes of 12 Bifidobacterium isolates from human IBD fecal samples.

Twelve Bifidobacterium strains were isolated from fecal samples of inflammatory bowel disease patients and matched "household control" individuals. These include the species Bifidobacterium adolescentis, Bifidobacterium animalis, Bifidobacterium breve, Bifidobacterium catenulatum, Bifidobacterium longum, and Bifidobacterium pseudocatenulatum.

AdipoRon reduces TGFß1-mediated collagen deposition in vitro and alleviates knee stiffness in vivo.

Arthrofibrosis, which causes joint motion restrictions, is a common complication following total knee arthroplasty (TKA). Key features associated with arthrofibrosis include myofibroblast activation, knee stiffness, and excessive scar tissue formation. We previously demonstrated that adiponectin levels are suppressed within the knee tissues of patients affected by arthrofibrosis and showed that AdipoRon, an adiponectin receptor agonist, exhibited anti-fibrotic properties in human mesenchymal stem cells. In this study, the therapeutic potential of AdipoRon was evaluated on TGFß1-mediated myofibroblast differentiation of primary human knee fibroblasts and in a mouse model of knee stiffness. Picrosirius red staining revealed that AdipoRon reduced TGFß1-induced collagen deposition in primary knee fibroblasts derived from patients undergoing primary TKA and revision TKA for arthrofibrosis. AdipoRon also reduced mRNA and protein levels of ACTA2, a key myofibroblast marker. RNA-seq analysis corroborated the anti-myofibrogenic effects of AdipoRon. In our knee stiffness mouse model, 6 weeks of knee immobilization, to induce a knee contracture, in conjunction with daily vehicle (DMSO) or AdipoRon (1, 5, and 25 mg/kg) via intraperitoneal injections were well tolerated based on animal behavior and weight measurements. Biomechanical testing demonstrated that passive extension angles (PEAs) of experimental knees were similar between vehicle and AdipoRon treatment groups in mice evaluated immediately following immobilization. Interestingly, relative to vehicle-treated mice, 5 mg/kg AdipoRon therapy improved the PEA of the experimental knees in mice that underwent 4 weeks of knee remobilization following the immobilization and therapy. Together, these studies revealed that AdipoRon may be an effective therapeutic modality for arthrofibrosis.

Psychological injury rehabilitation lags behind physical rehabilitation: Elite athletes' experiences and support within Chinese context.

This qualitative study was focused on two objectives: to explore (a) Chinese elite athletes' perceptions of their rehabilitation experiences after severe acute injuries, and (b) support strategies facilitating their return to competition. We interviewed 10 Chinese elite athletes through a semi-structured interview guide consisting of open questions and requests for information about the participants' injury and rehabilitation experiences. We utilized a reflexive thematic analysis to interpret participants' accounts. Two themes are presented to reveal the Chinese elite athletes' perceptions: (a) psychological injury rehabilitation lags behind physical rehabilitation and (b) post-injury psychological support within the CWNS.This study contributes to athlete rehabilitation scholarship by providing a unique Eastern, collective perspective embedded with the Chinese Whole Nation System (CWNS).

Crystal structure of domain of unknown function 507 (DUF507) reveals a new protein fold.

The crystal structure of the domain of unknown function family 507 protein from Aquifex aeolicus is reported (AaDUF507, UniProt O67633, 183 residues). The structure was determined in two space groups (C2221 and P3221) at 1.9 Å resolution. The phase problem was solved by molecular replacement using an AlphaFold model as the search model. AaDUF507 is a Y-shaped α-helical protein consisting of an anti-parallel 4-helix bundle base and two helical arms that extend 30-Å from the base. The two crystal structures differ by a 25° rigid body rotation of the C-terminal arm. The tertiary structure exhibits pseudo-twofold symmetry. The structural symmetry mirrors internal sequence similarity: residues 11-57 and 102-148 are 30% identical and 53% similar with an E-value of 0.002. In one of the structures, electron density for an unknown ligand, consistent with nicotinamide or similar molecule, may indicate a functional site. Docking calculations suggest potential ligand binding hot spots in the region between the helical arms. Structure-based query of the Protein Data Bank revealed no other protein with a similar tertiary structure, leading us to propose that AaDUF507 represents a new protein fold.

Engaging youth and parents in clinical pediatric research: A case-based example.

Background: Youth and parent engagement is a key component of clinical research. There are many ways to actively and meaningfully engage youth and parents as integral members of research teams, for example, through ad-hoc committees, advisory councils, or as co-leads on projects. When youth and parents are actively and meaningfully engaged in research projects, they share knowledge from their lived experiences to improve the quality and relevance of research. Methods: We describe a case-based example of engaging youth and parent research partners when co-designing a questionnaire to assess preferences for pediatric headache treatments, from both a researcher and youth/parent perspective. We also summarize best practices in patient and family engagement from the literature and pertinent guidelines to assist researchers with integrating patient and family engagement into their studies. Results: As researchers, we felt that the integration of a youth and parent engagement plan into our study significantly altered and strengthened questionnaire content validity. We encountered challenges throughout the process and detailed these experiences to help educate others about challenge mitigation and best practices in youth and parent engagement. As youth and parent partners, we felt that engaging in the process of questionnaire development was an exciting and empowering opportunity, and that our feedback was valued and integrated. Conclusions: By sharing our experience, we hope to catalyze thought and discussion around the importance of youth and parent engagement in pediatric research, with the goal of stimulating more appropriate, relevant, and high-quality pediatric research and clinical care in the future.

Novel requirements for HAP2-mediated gamete fusion in Tetrahymena.

The ancestral gamete fusion protein, HAP2, catalyzes sperm-egg fusion in a broad range of taxa dating to the last eukaryotic common ancestor. Remarkably, HAP2 orthologs are structurally related to the class II fusogens of modern-day viruses, and recent studies make clear that these proteins utilize similar mechanisms to achieve membrane merger. To identify factors that may regulate HAP2 activity, we screened mutants of the ciliate Tetrahymena thermophila for behaviors that mimic Δhap2 knockout phenotypes in this species. Using this approach, we identified two new genes, GFU1 and GFU2, whose products are necessary for the formation of membrane pores during fertilization and show that the product of a third gene, namely ZFR1, may be involved in pore maintenance and/or expansion. Finally, we propose a model that explains cooperativity between the fusion machinery on apposed membranes of mating cells and accounts for successful fertilization in T. thermophila's multiple mating type system.

Surgical tracheostomy in a patient with a stuck tracheal tube in situ.

The inability to extubate a patient's trachea due to a mechanical complication is rarely encountered in clinical practice. The risks of attempting to remove a stuck tracheal tube include laryngeal trauma, vocal cord injury and arytenoid dislocation, all of which have significant implications. Here, we report the case of a patient who was admitted to the intensive care unit for mechanical ventilation following liver transplant surgery. Her trachea was initially extubated on the second postoperative day, but she required further mechanical ventilation the following day and her trachea was re-intubated. Five days later, she was deemed suitable for tracheal extubation, but the formation of granulation tissue around the tracheal tube prevented its removal. A multi-disciplinary decision-making approach was taken when deciding to site a surgical tracheostomy. A flexible bronchoscope was used as an aid for safe placement. This facilitated safe extrication of the tracheal tube, which was freed by gentle manipulation both proximally and distally. We suspect that tracheal tube size may have been a factor in the development of the granulation tissue in this case. It is important to consider tracheal tube size in all patients, particularly if they require tracheal re-intubation or are likely to require mechanical ventilation for a prolonged period.

A Biodegradable, Polymer-Supported Oxygen Atom Transfer Reagent.

Biodegradable polymers are desirable to mitigate the environmental impact of plastic waste in the environment. Over the past several decades, the development of organocatalytic ring-opening polymerization (OROP) has made the synthesis of many new types of biodegradable polymers possible. In this research article, the first example of an oxygen atom transfer reagent pendant on a biodegradable polymer backbone is reported. The monomers for the polycarbonate backbone are sourced from the biodegradable 2,2-bis(hydroxymethyl) propionic acid molecule, and an iodoaryl group is installed pendant to the cyclic monomer for post-polymerization modification into an iodosylaryl oxygen atom transfer reagent. The key I-O bond is characterized by XPS spectroscopy, and a test reaction to triphenylphosphine demonstrates the ability of the polymer to engage in an oxygen atom transfer reaction with a substrate.

Incidence and distribution of ocular disorders in the first year of life.

PURPOSE: To describe the incidence and distribution of eye diseases affecting children in the first year of life in Olmsted County, Minnesota. METHODS: We conducted a population-based, retrospective medical record review of infants (≤1 year of age) residing in Olmsted County diagnosed with an ocular disorder from January 1, 2005, through December 31, 2014. RESULTS: A total of 4,223 infants were diagnosed with an ocular disorder, yielding an incidence of 20,242/100,000 births per year, or 1 in 4.9 live births (95% CI, 19,632-20,853). The median age at diagnosis was 3 months, and 2,179 (51.5%) were female. The most common diagnoses included conjunctivitis, in 2,175 (51.5%), nasolacrimal duct obstruction, in 1,432 (33.6%), and pseudostrabismus, in 173 (4.1%). Visual acuity was decreased in one or both eyes in 23 (0.5%) infants because of strabismus in 10 (43.5%) and cerebral visual impairment in 3 (13.0%). A majority of the infants (3,674 [86.9%]) were diagnosed and managed by a primary care provider, and 549 (13.0%) were evaluated and/or managed by an eye care provider. CONCLUSIONS: Although ocular disorders occurred in 1 in 5 infants in this cohort, most conditions were evaluated and managed by primary care providers. Understanding the incidence and distribution of ocular diseases among infants is useful for planning clinical resources.

Incidence and Clinical Characteristics of Infantile Conjunctivitis in a Western Population.

OBJECTIVE: To describe the incidence and clinical characteristics of conjunctivitis in the first year of life. DESIGN: Population-based cohort study. PARTICIPANTS: All infant (≤12 months of age) residents of Olmsted County, Minnesota, diagnosed with conjunctivitis from January 1, 2005, through December 31, 2014. METHODS: The medical records of all potential cases identified by the Rochester Epidemiology Project database were reviewed. MAIN OUTCOME MEASURES: Incidence rate and clinical features of infantile conjunctivitis. RESULTS: A total of 2175 infants were diagnosed during the 10-year period, yielding an incidence of 10,422 per 100,000 children or approximately 1 in 10 infants by 1 year of age. The mean age at diagnosis was 4.9 months (range, 1 day-12 months), and 1001 (46.0%) were female. Both eyes were involved in 1180 (54.3%), the right eye alone in 506 (23.3%), and 489 (22.5%) in the left. Five hundred seventy-six (26.5%) of the 2175 were diagnosed at ≤30 days of life, from which topical cultures were obtained in 111 (19.7%). Only 36 (32.4%) of the cultures showed bacterial agents, with Chlamydia present in 3. Treatment for infantile conjunctivitis, where recorded, included topical antibiotics in 523 (90.8%) and simple observation in 47 (8.2%). CONCLUSIONS: Conjunctivitis in the first year of life occurred in approximately 10% of infants in this population-based cohort. More than half involved both eyes, one-quarter were identified in the first 30 days of life, and sight-threatening infectious agents were rare.

Accuracy of the International Classification of Diseases, 9th Revision for Identifying Infantile Eye Disease.

PURPOSE: To determine the predictive value of International Classification of Diseases, 9th Revision (ICD-9) codes for identifying infantile eye diagnoses. METHODS: Population-based retrospective cohort study of all residents of Olmsted County, Minnesota diagnosed at ≤1 year of age with an ocular disorder. The medical records of all infants diagnosed with any ocular disorder from January 1, 2005, through December 31, 2014, were identified. To assess ICD-9 code accuracy, the medical records of all diagnoses with ≥20 cases were individually reviewed and compared to their corresponding ICD-9 codes. Main outcome measures included positive predictive value (PPV), negative predictive value (NPV), sensitivity, and specificity of ICD-9 codes. RESULTS: In a cohort of 5,109 infants with ≥1 eye-related ICD-9 code, 10 ocular diagnoses met study criteria. The most frequent diagnoses were conjunctivitis (N = 1,695) and congenital nasolacrimal duct obstruction (N = 1,250), while the least common was physiologic anisocoria (N = 23). The PPVs ranged from 8.3% to 88.0%, NPVs from 96.3% to 100%, sensitivity from 3.0% to 98.7%, and specificity from 72.6% to 99.9%. ICD-9 codes were most accurate at identifying physiologic anisocoria (PPV: 88.0%) and least accurate at identifying preseptal cellulitis (PPV: 8.3%). In eye specialists versus non-eye specialists, there was a significant difference in PPV of ICD-9 codes for conjunctivitis (26.8% vs. 63.9%, p < .001), pseudostrabismus (85.9% vs. 25.0%, p < .001), and physiologic anisocoria (95.5% vs. 33.3%, p = .002). CONCLUSION: The predictive value of ICD-9 codes for capturing infantile ocular diagnoses varied widely in this cohort. These findings emphasize the limitations of database research methodologies that solely utilize claims data to identify pediatric eye diseases.Abbreviations/Acronyms PPV: positive predictive value; NPV: negative predictive value; CNLDO: congenital nasolacrimal duct obstruction.

Tinea blepharitis and follicular conjunctivitis in a child.

Trichophyton tonsurans is a fungal species that frequently causes tinea capitis (ringworm), a skin infection found in children. We report a case of unilateral blepharoconjunctivitis due to tinea capitis in a previously healthy 8-year-old boy. Although no case of blepharitis or follicular conjunctivitis due to T. tonsurans has been previously reported, the findings are consistent with other rare causes of ringworm blepharitis. Emerging or chronic fungal blepharitis should be considered in the differential diagnosis of unilateral follicular conjunctivitis.

The key role of the latent N-H group in Milstein's catalyst for ester hydrogenation.

We previously demonstrated that Milstein's seminal diethylamino-substituted PNN-pincer-ruthenium catalyst for ester hydrogenation is activated by dehydroalkylation of the pincer ligand, releasing ethane and eventually forming an NHEt-substituted derivative that we proposed is the active catalyst. In this paper, we present a computational and experimental mechanistic study supporting this hypothesis. Our DFT analysis shows that the minimum-energy pathways for hydrogen activation, ester hydrogenolysis, and aldehyde hydrogenation rely on the key involvement of the nascent N-H group. We have isolated and crystallographically characterized two catalytic intermediates, a ruthenium dihydride and a ruthenium hydridoalkoxide, the latter of which is the catalyst resting state. A detailed kinetic study shows that catalytic ester hydrogenation is first-order in ruthenium and hydrogen, shows saturation behavior in ester, and is inhibited by the product alcohol. A global fit of the kinetic data to a simplified model incorporating the hydridoalkoxide and dihydride intermediates and three kinetically relevant transition states showed excellent agreement with the results from DFT.

The aluminum beverage tab and a soldier with chronic abdominal pain.

Since its introduction in the 1960s, the aluminum pull-tab has been an uncommon cause of aspiration and intestinal obstruction. In many cases, the inability to visualize aluminum on imaging studies delayed diagnosis and therapy or missed the foreign body altogether. Early reports of injury secondary to pull-tab ingestion or aspiration spurred the beverage industry to re-engineer the pop-tab in the 1980s. The new design meant to reduce injury by keeping the tab attached permanently to the can. Despite this innovation, the aluminum pop-tab continues to be a cause of injury. Here, we describe the inadvertent ingestion of an aluminum pop-tab by a 22-year-old patient that resulted in chronic intermittent abdominal distress due to recurrent bowel obstruction for 4 years. This case is unique in the length of delayed diagnosis and demonstrates the elusive nature of an aluminum foreign body.

Pseudostrabismus in the First Year of Life and the Subsequent Diagnosis of Strabismus.

PURPOSE: To report the population-based birth prevalence of pseudostrabismus in the first year of life and the subsequent diagnosis of strabismus. DESIGN: Retrospective population-based cohort study. METHODS: All residents of Olmsted County, Minnesota ≤1 year old diagnosed with pseudostrabismus from January 1, 2005 through December 31, 2014, were identified using a medical record linkage system that captures virtually all medical care provided in a single Midwestern United States county population. The birth prevalence of pseudostrabismus and the subsequent diagnosis of strabismus were assessed. RESULTS: A total of 184 infants were diagnosed with pseudostrabismus during the 10-year study period, which yielded a birth prevalence of 1 in 113 children in the first year of life. There were 165 (89.7%) infants initially diagnosed by a non-ophthalmology care provider (NOCP) and confirmed by an ophthalmologist, 13 (7.1%) patients were diagnosed by an ophthalmologist alone, and 6 (3.3%) patients were diagnosed by a NOCP alone. Eighty-eight (49.4%) infants had at least 1 follow-up visit with an ophthalmologist, and the median follow-up time from pseudostrabismus diagnosis to the last health care visit that included an eye examination was 7.7 years (interquartile range: 5.8 years). Nine (4.9%) of the 184 infants were subsequently diagnosed with strabismus at a mean age of 4.5 years (range: 1.3 to 8.7 years) (7 with esotropia and 2 with exotropia). CONCLUSION: Pseudostrabismus is a relatively frequent diagnosis in the first year of life. The prevalence of strabismus among infants with pseudostrabismus in this cohort was lower than those in previous reports and similar to strabismus rates reported in the same population.