Predictors of Paroxysmal Atrial Fibrillation in Patients With a Cryptogenic Stroke: Selecting Patients for Long-Term Rhythm Monitoring.

BACKGROUND: After a cryptogenic stroke, patients will often require prolonged cardiac monitoring; however, the subset of patients who would benefit from long-term rhythm monitoring is not clearly defined. OBJECTIVE: Using significant predictors of AF using age, sex, comorbidities, baseline 12-lead electrocardiogram, short term rhythm monitoring and echocardiogram data, we created a risk score and compared it to previously published risk scores. METHODS: Patients admitted to Montefiore Medical Center between May 2017 and June 2022 with a primary diagnosis of cryptogenic stroke or TIA who underwent long-term rhythm monitoring with an implantable cardiac monitor were retrospectively analyzed. RESULTS: Variables positively associated with a diagnosis of clinically significant atrial fibrillation include age (p < 0.001), race (p = 0.022), diabetes status (p = 0.026), and COPD status (p = 0.012), the presence of atrial runs (p = 0.003), the number of atrial runs per 24 hours (p < 0.001), the total number of atrial run beats per 24 hours (p < 0.001) and the number of beats in the longest atrial run (p < 0.001), LA enlargement (p = 0.007) and at least mild mitral regurgitation (p = 0.009). We created a risk stratification score for our population, termed the "ACL score." The ACL score demonstrated superiority to the CHA2DS2-VASc score and comparability to the C2HEST score for predicting device-detected AF. CONCLUSION: The ACL score enables clinicians to better predict which patients are more likely to be diagnosed with device-detected AF after a cryptogenic stroke.

Fixation of Olecranon Fractures Using a Hybrid Intramedullary Screw and Tension Band Construct.

Introduction: Olecranon fractures are common injuries that require surgical intervention for optimal outcomes. Various fixation methods have been described in the literature, including the use of intramedullary proximal ulna screws in combination with tension band augmentation. Limited research has compared this hybrid technique to other established methods of fixation. This study compared complication and reoperation rates between multiple groups. Methods: A retrospective review was conducted on patients with olecranon fractures who underwent internal fixation at a level 1 trauma center between January 1st, 2013, and April 22nd, 2023. Data was collected using CPT codes, and patients were categorized into five groups based on the method of fixation received: no implant, tension band only, locking olecranon plate, intramedullary screw and tension band hybrid, and others. Variables such as patient demographics, Mayo fracture classification, open vs. closed injury, implant type, reoperation rates, and postoperative complications were recorded. Results: A total of 217 patients were included in the study. No difference was found with implant choice and reoperation rate (p = 0.461). There was a significant difference found with reoperation and fracture type (p = 0.027) and open fracture (p = 0.002). Conclusion: The primary findings of this study indicate no significant difference in implant choice and reoperation rates among the various fixation methods used for olecranon fractures. These findings suggest that the hybrid fixation technique, utilizing intramedullary proximal ulna screws in combination with tension band augmentation, is a viable and comparable treatment option when evaluated against other well-documented methods of fixation. This study also reiterates that severity of initial injury is often the most important factor related to poorer outcomes. Further discussion and analysis of the data will provide a comprehensive understanding of implications and recommendations for olecranon fracture fixation.

From Promise to Practice: Recent Growth in 30 Years of Tissue Engineering Commercialization.

This perspective, marking the 30th anniversary of the Tissue Engineering journal, discusses the exciting trends in the global commercialization of tissue engineering technology. Within a historical context, we present an evolution of challenges and a discussion of the last 5 years of global commercial successes and emerging market trends, highlighting the continued expansion of the field in the northeastern United States. This leads to an overview of the last 5 years' progress in clinical trials for tissue-engineered therapeutics, including an analysis of trends in success and failure. Finally, we provide a broad overview of preclinical research and a perspective on where the state-of-the-art lies on the horizon.

A Current Review in the Orthopedic Management of Osteonecrosis of the knee Secondary to Treatment of Pediatric Hematologic Malignancy.

Acute Lymphoblastic Leukemia is the most prevalent pediatric hematologic malignancy. The treatment for this illness has advanced significantly, now touting a 90% cure rate. Although these patients often become disease free, treatment can leave devastating effects that last long after their disease burden is alleviated. A commonly experienced result of treatment is osteonecrosis (ON), often occurring in weight bearing joints. Uncertainty exists in the optimal treatment of this cohort of patients. In this review, we describe the etiology and suspected pathogenesis of ON, as well as treatment options described in the literature.

Development of a patient specific cartilage graft using magnetic resonance imaging and 3D printing.

OBJECTIVES: The goal of this project was to develop and validate a patient-specific, anatomically correct graft for cartilage restoration using magnetic resonance imaging (MRI) data and 3-dimensional (3D) printing technology. The specific aim was to test the accuracy of a novel method for 3D printing and implanting individualized, anatomically shaped bio-scaffolds to treat cartilage defects in a human cadaveric model. We hypothesized that an individualized, anatomic 3D-printed scaffold designed from MRI data would provide a more optimal fill for a large cartilage defect compared to a generic flat scaffold. METHODS: Four focal cartilage defects (FCDs) were created in paired human cadaver knees, age <40 years, in the weight-bearing surfaces of the medial femoral condyle (MFC), lateral femoral condyle (LFC), patella, and trochlea of each knee. MRIs were obtained, anatomic grafts were designed and 3D printed for the left knee as an experimental group, and generic flat grafts for the right knee as a control group. Grafts were implanted into corresponding defects and fixed using tissue adhesive. Repeat post-implant MRIs were obtained. Graft step-off was measured as the distance in mm between the surface of the graft and the native cartilage surface in a direction perpendicular to the subchondral bone. Graft contour was measured as the gap between the undersurface of the graft and the subchondral bone in a direction perpendicular to the joint surface. RESULTS: Graft step-off was statistically significantly better for the anatomic grafts compared to the generic grafts in the MFC (0.0 â€‹± â€‹0.2 â€‹mm vs. 0.7 â€‹± â€‹0.5 â€‹mm, p â€‹< â€‹0.001), LFC (0.1 â€‹± â€‹0.3 â€‹mm vs. 1.0 â€‹± â€‹0.2 â€‹mm, p â€‹< â€‹0.001), patella (-0.2 â€‹± â€‹0.3 â€‹mm vs. -1.2 â€‹± â€‹0.4 â€‹mm, p â€‹< â€‹0.001), and trochlea (-0.4 â€‹± â€‹0.3 vs. 0.4 â€‹± â€‹0.7, p â€‹= â€‹0.003). Graft contour was statistically significantly better for the anatomic grafts in the LFC (0.0 â€‹± â€‹0.0 â€‹mm vs. 0.2 â€‹± â€‹0.4 â€‹mm, p â€‹= â€‹0.022) and trochlea (0.0 â€‹± â€‹0.0 â€‹mm vs. 1.4 â€‹± â€‹0.7 â€‹mm, p â€‹< â€‹0.001). The anatomic grafts had an observed maximum step-off of -0.9 â€‹mm and a maximum contour mismatch of 0.8 â€‹mm. CONCLUSION: This study validates a process designed to fabricate anatomically accurate cartilage grafts using MRI and 3D printing technology. Anatomic grafts demonstrated superior fit compared to generic flat grafts. LEVEL OF EVIDENCE: Level IV.

Designing Biomimetic 3D-Printed Osteochondral Scaffolds for Enhanced Load-Bearing Capacity.

Osteoarthritis is a debilitating chronic joint disorder that affects millions of people worldwide. Since palliative and surgical treatments cannot completely regenerate hyaline cartilage within the articulating joint, osteochondral (OC) tissue engineering has been explored to heal OC defects. Utilizing computational simulations and three-dimensional (3D) printing, we aimed to build rationale around fabricating OC scaffolds with enhanced biomechanics. First, computational simulations revealed that interfacial fibrils within a bilayer alter OC scaffold deformation patterns by redirecting load-induced stresses toward the top of the cartilage layer. Principal component analysis revealed that scaffolds with 800 µm long fibrils (scaffolds 8A-8H) possessed optimal biomechanical properties to withstand compression and shear forces. While compression testing indicated that OC scaffolds with 800 µm fibrils did not have greater compressive moduli than other scaffolds, interfacial shear tests indicated that scaffold 8H possessed the greatest shear strength. Lastly, failure analysis demonstrated that yielding or buckling models describe interfacial fibril failure depending on fibril slenderness S. Specifically for scaffolds with packing density n = 6 and n = 8, the yielding failure model fits experimental loads with S < 10, while the buckling model fitted scaffolds with S < 10 slenderness. The research presented provides critical insights into designing 3D printed interfacial scaffolds with refined biomechanics toward improving OC tissue engineering outcomes.

Spontaneous Resolution of Pediatric Varus Ankle Deformity: A Case Report.

Introduction: Distal tibia fractures are a common cause of physeal injuries that can subsequently cause deformity in pediatric populations. Limited literature exists supporting treatment strategies for varus deformities. In this study, we illustrate a unique case of premature physeal closure complicated by development of a varus ankle deformity treated with navigation guided physeal bar resection that spontaneously resolved without the requirement for guided growth. Case Report: A 6-year-old female presented to our clinic after development of a right ankle varus deformity measuring 14°. She had sustained a right Salter Harris type 3 distal tibia fracture 10 months prior and underwent fixation at an external facility. After undergoing navigation guided physeal bar resection, resolution of her deformity occurred without the use of guided growth. Conclusion: Spontaneous resolution of an ankle deformity is possible after a physeal bar resection. However, in these technically demanding procedures, it is important to optimize accuracy and results using preoperative bar mapping and intraoperative three-dimensional navigation.

Recycling transplanted organs: An exceptional case and literature review.

BACKGROUND: Recycling transplant kidneys, in other words using an allograft which has previously been transplanted in one recipient for transplant in a second recipient, can be a source of opportunity for expanding the pool of available grafts in the United States and beyond. SUMMARY: We describe a case of renal transplantation from a donor who had undergone a kidney transplant 3 years prior and had good graft function at the time of procurement. The recipient underwent transplantation uneventfully and to date has demonstrated excellent graft function. We also include a literature review of reported cases of recycled/retransplanted kidneys. KEY MESSAGES: -Recycling transplanted kidneys is a largely untapped resource which could help decrease the transplant waitlist. -Utilizing such kidneys does need special considerations in terms of procurement technique, backtable, crossmatch, recipient selection and follow-up.

Assessing ChatGPT's orthopedic in-service training exam performance and applicability in the field.

BACKGROUND: ChatGPT has gained widespread attention for its ability to understand and provide human-like responses to inputs. However, few works have focused on its use in Orthopedics. This study assessed ChatGPT's performance on the Orthopedic In-Service Training Exam (OITE) and evaluated its decision-making process to determine whether adoption as a resource in the field is practical. METHODS: ChatGPT's performance on three OITE exams was evaluated through inputting multiple choice questions. Questions were classified by their orthopedic subject area. Yearly, OITE technical reports were used to gauge scores against resident physicians. ChatGPT's rationales were compared with testmaker explanations using six different groups denoting answer accuracy and logic consistency. Variables were analyzed using contingency table construction and Chi-squared analyses. RESULTS: Of 635 questions, 360 were useable as inputs (56.7%). ChatGPT-3.5 scored 55.8%, 47.7%, and 54% for the years 2020, 2021, and 2022, respectively. Of 190 correct outputs, 179 provided a consistent logic (94.2%). Of 170 incorrect outputs, 133 provided an inconsistent logic (78.2%). Significant associations were found between test topic and correct answer (p = 0.011), and type of logic used and tested topic (p = < 0.001). Basic Science and Sports had adjusted residuals greater than 1.96. Basic Science and correct, no logic; Basic Science and incorrect, inconsistent logic; Sports and correct, no logic; and Sports and incorrect, inconsistent logic; had adjusted residuals greater than 1.96. CONCLUSIONS: Based on annual OITE technical reports for resident physicians, ChatGPT-3.5 performed around the PGY-1 level. When answering correctly, it displayed congruent reasoning with testmakers. When answering incorrectly, it exhibited some understanding of the correct answer. It outperformed in Basic Science and Sports, likely due to its ability to output rote facts. These findings suggest that it lacks the fundamental capabilities to be a comprehensive tool in Orthopedic Surgery in its current form. LEVEL OF EVIDENCE: II.

Utilization of the remote monitoring of cardiac implantable electronic devices in a diverse demographic cohort: Insights from a single-center observation.

BACKGROUND: Despite its clinical benefits, patient compliance to remote monitoring (RM) of cardiac implantable electronic devices (CIEDs) varies and remains under-studied in diverse populations. OBJECTIVE: We sought to evaluate RM compliance, clinical outcomes, and identify demographic and socioeconomic factors affecting RM in a diverse urban population in New York. METHODS: This retrospective cohort study included patients enrolled in CIED RM at Montefiore Medical Center between December 2017 and May 2022. RM compliance was defined as the percentage of days compliant to RM transmission divided by the total prescribed days of RM. Patients were censored when they were lost to follow-up or at the time of death. The cohorts were categorized into low (≤30%), intermediate (31-69%), and high (≥70%) RM compliance groups. Statistical analyses were conducted accordingly. RESULTS: Among 853 patients, median RM compliance was 55%. Age inversely affected compliance (p < .001), and high compliance was associated with guideline-directed medical therapy (GDMT) usage and implantable cardioverter defibrillator (ICD)/cardiac resynchronization defibrillator (CRTD) devices. The low-compliance group had a higher mortality rate and fewer regular clinic visits (p < .001) than high-compliance group. Socioeconomic factors did not significantly impact compliance, while Asians showed higher compliance compared with Whites (OR 3.67; 95% CI 1.08-12.43; p = .04). Technical issues were the main reason for non-compliance. CONCLUSION: We observed suboptimal compliance to RM, which occurred most frequently in older patients. Clinic visit compliance, optimal medical therapy, and lower mortality were associated with higher compliance, whereas insufficient understanding of RM usage was the chief barrier to compliance.

Frontiers in nonviral delivery of small molecule and genetic drugs, driven by polymer chemistry and machine learning for materials informatics.

Materials informatics (MI) has immense potential to accelerate the pace of innovation and new product development in biotechnology. Close collaborations between skilled physical and life scientists with data scientists are being established in pursuit of leveraging MI tools in automation and artificial intelligence (AI) to predict material properties in vitro and in vivo. However, the scarcity of large, standardized, and labeled materials data for connecting structure-function relationships represents one of the largest hurdles to overcome. In this Highlight, focus is brought to emerging developments in polymer-based therapeutic delivery platforms, where teams generate large experimental datasets around specific therapeutics and successfully establish a design-to-deployment cycle of specialized nanocarriers. Three select collaborations demonstrate how custom-built polymers protect and deliver small molecules, nucleic acids, and proteins, representing ideal use-cases for machine learning to understand how molecular-level interactions impact drug stabilization and release. We conclude with our perspectives on how MI innovations in automation efficiencies and digitalization of data-coupled with fundamental insight and creativity from the polymer science community-can accelerate translation of more gene therapies into lifesaving medicines.

A novel perfusion bioreactor promotes the expansion of pluripotent stem cells in a 3D-bioprinted tissue chamber.

While the field of tissue engineering has progressed rapidly with the advent of 3D bioprinting and human induced pluripotent stem cells (hiPSCs), impact is limited by a lack of functional, thick tissues. One way around this limitation is to 3D bioprint tissues laden with hiPSCs. In this way, the iPSCs can proliferate to populate the thick tissue mass prior to parenchymal cell specification. Here we design a perfusion bioreactor for an hiPSC-laden, 3D-bioprinted chamber with the goal of proliferating the hiPSCs throughout the structure prior to differentiation to generate a thick tissue model. The bioreactor, fabricated with digital light projection, was optimized to perfuse the interior of the hydrogel chamber without leaks and to provide fluid flow around the exterior as well, maximizing nutrient delivery throughout the chamber wall. After 7 days of culture, we found that intermittent perfusion (15 s every 15 min) at 3 ml min-1provides a 1.9-fold increase in the density of stem cell colonies in the engineered tissue relative to analogous chambers cultured under static conditions. We also observed a more uniform distribution of colonies within the tissue wall of perfused structures relative to static controls, reflecting a homogeneous distribution of nutrients from the culture media. hiPSCs remained pluripotent and proliferative with application of fluid flow, which generated wall shear stresses averaging ∼1.0 dyn cm-2. Overall, these promising outcomes following perfusion of a stem cell-laden hydrogel support the production of multiple tissue types with improved thickness, and therefore increased function and utility.

Three-Dimensional Printed Cellulose for Wound Dressing Applications.

Wounds are skin tissue damage due to trauma. Many factors inhibit the wound healing phase (hemostasis, inflammation, proliferation, and alteration), such as oxygenation, contamination/infection, age, effects of injury, sex hormones, stress, diabetes, obesity, drugs, alcoholism, smoking, nutrition, hemostasis, debridement, and closing time. Cellulose is the most abundant biopolymer in nature which is promising as the main matrix of wound dressings because of its good structure and mechanical stability, moisturizes the area around the wound, absorbs excess exudate, can form elastic gels with the characteristics of bio-responsiveness, biocompatibility, low toxicity, biodegradability, and structural similarity with the extracellular matrix (ECM). The addition of active ingredients as a model drug helps accelerate wound healing through antimicrobial and antioxidant mechanisms. Three-dimensional (3D) bioprinting technology can print cellulose as a bioink to produce wound dressings with complex structures mimicking ECM. The 3D printed cellulose-based wound dressings are a promising application in modern wound care. This article reviews the use of 3D printed cellulose as an ideal wound dressing and their properties, including mechanical properties, permeability aspect, absorption ability, ability to retain and provide moisture, biodegradation, antimicrobial property, and biocompatibility. The applications of 3D printed cellulose in the management of chronic wounds, burns, and painful wounds are also discussed.

Subtrochanteric fracture after femoral neck system of femoral neck fractures: a report of four cases.

BACKGROUND: The femoral neck system (FNS) is commonly used for internal fixation of femoral neck fractures and has shown promising results. However, we have observed cases of peri-implant subtrochanteric femur fractures associated with the use of FNS at our institution. This case series aims to investigate four cases of peri-implant subtrochanteric fractures in patients treated with the FNS implant for femoral neck fractures. CASE PRESENTATION: We reviewed 35 patients who underwent treatment with FNS for femoral neck fractures between January 2017 and December 2021 at our level 1 trauma institution. Among these patients, four cases of peri-implant subtrochanteric femur fractures were identified. In contrast, no such fractures occurred in patients treated with cannulated screws or dynamic hip screws (DHS). Interestingly, all four cases of peri-implant fractures were seen in patients with incomplete nondisplaced femoral neck fractures. Only one case involved an identifiable technical error. CONCLUSIONS: This case series sheds light on peri-implant subtrochanteric femur fractures as a previously unreported complication associated with the use of FNS for femoral neck fractures. These fractures were observed exclusively in patients with incomplete nondisplaced fractures who received FNS fixation. No similar complications were observed in patients treated with other types of fixation. This finding suggests the need for caution and further investigation when considering FNS as a treatment option for this specific fracture pattern. The identification of peri-implant subtrochanteric femur fractures as a potential complication of FNS usage in incomplete nondisplaced femoral neck fractures raises important considerations for clinical decision-making and patient management in orthopedic trauma.

Procalcitonin as a Predictor of Septic Knee Arthritis: A Retrospective Cohort Study.

INTRODUCTION: Differentiating septic arthritis from aseptic arthritis (AA) of the knee is difficult without arthrocentesis. Although procalcitonin (PCT) has shown diagnostic value in identifying bacterial infections, it has not been established as a reliable marker for identifying septic arthritis (SA). Recent studies have shown promise in the use of PCT as a useful systemic marker for identifying septic arthritis versus AA. This observational retrospective review compares PCT with routine inflammatory markers as a tool for differentiating septic arthritis versus AA in patients with acute, atraumatic knee pain. METHODS: Fifty-three consecutive patients (24 SA, 29 AA) were retrospectively reviewed at one institution with concern for SA. SA was diagnosed based on a physical examination, laboratory markers, and arthrocentesis. Laboratory indices were compared between the septic arthritis and AA groups. Data analysis was conducted to define sensitivity and specificity. Receiver operator characteristic curve analysis and regression were conducted to determine the best marker for acute SA of the knee. RESULTS: Using multiple logistic regression, bacteremia (OR 6.75 ± 5.75) was determined to be the greatest predictor of SA. On linear regression, concomitant bacteremia (coef 3.07 ± 0.87), SA (coef 2.18 ± 0.70), and the presence of pseudogout crystals (coef 1.80 ± 0.83) on microscopy predicted an increase in PCT. Using a PCT cutoff of 0.25 ng/mL yields a sensitivity of 91.7% and specificity of 55.2% for predicting SA; however, the ideal cutoff in our series was 0.32 ng/mL with a sensitivity of 79.2% and specificity of 72.4%. PCT was superior to the white blood cell count, erythrocyte sedimentation rate, and C-reactive protein in the area under the receiver-operating characteristic curve analysis. DISCUSSION: Procalcitonin seems to be the most sensitive and specific systemic marker in differentiating septic from AA.

4D Bioprinting via Molecular Network Contraction for Membranous Tissue Fabrication.

Generation of thin membranous tissues (TMT), such as the cornea, epidermis, and periosteum, presents a difficult fabrication challenge in tissue engineering (TE). TMTs consist of several cell layers that are less than 100 µm in thickness per layer. While traditional methods provide the necessary resolution for TMT fabrication, they require significant handling and incorporation of several layers is limited. Extrusion bioprinting offers precise control over deposition of different biomaterials and cell populations within the same construct but lacks the resolution to generate biomimetic TMTs. For the first time, a 4D bioprinting strategy that allows for the generation of cell-laden TMTs is developed. Anionic gelatin methacrylate (GelMA) hydrogels are treated with cationic poly-l-lysine (PLL), which induces charge attraction, microscale network collapse, and macroscale hydrogel shrinking. The impact of shrinking on hydrogel properties, print resolution, and cell viability is presented. Additionally, this work suggests that a novel mechanism is occurring, where PLL exhibits a contractile force on GelMA and PLL molecular weight drives GelMA shrinking capabilities. Finally, it is shown that this phenomenon can occur while maintaining an encapsulated cell population. These findings address a critical barrier by generating macroscale tissue structures with their microscale TMT counterparts in the same print.

Spiritual Well-Being and Related Factors in Children With Cancer.

Introduction: There are specific gaps that call for empirical research in the experiences of spiritual well-being among children 12 years old and younger with cancer. Understanding these relationships can help to develop holistic and family centered care in pediatric oncology wards. This study assessed the spiritual well-being of children with cancer in association with their general well-being, happiness, quality of life, pain intensity, and personal characteristics. Method: The data were collected in Lithuania between June 2020 and November 2021. Children with cancer (N = 81) who were hospitalized at pediatric oncology-hematology centers participated in the study. Inclusion criteria were age (from 5 to 12 years old), diagnosis of oncologic disease for the first time, and absence of other chronic diseases. The instruments used were: Feeling Good, Living Life; Oxford Happiness Questionnaire, Short Form; Well-Being Index; PedsQL™3.0 Cancer Module, and a Wong-Baker FACES® Pain Rating Scale. Results: Communal and personal domains of spiritual well-being had the highest scores among pediatric oncology patients while both dimensions of the transcendental domain scored lowest. Age, level of education, and family composition revealed differences in children's spiritual health, happiness, and well-being, and church attendance was significant for overall spiritual well-being and its transcendental domain on lived experience dimension. Happiness had the strongest effect on all four domains of spiritual well-being. Discussion: Children emphasized the importance of spiritual aspects to feel better to a greater extent than they experienced in their lives. Despite their young age, children were familiar with family traditions, that is, religious practice and church attendance, and followed them in a particular sociocultural context.