Background: The Dejour classification is widely accepted for grading the severity of trochlear dysplasia. However, whether it serves as a reliable prognostic marker for patellar instability surgery or a guide for clinical decision-making has yet to be established. Medial patellofemoral ligament (MPFL) reconstruction, with or without tibial tubercle osteotomy (TTO), yields comparable outcomes across Dejour grades. Nonetheless, we hypothesized that specific trochlear parameters would be more significant predictors of surgical results. Methods: This study included patients who underwent MPFL reconstruction, with or without TTO, for recurrent patellar dislocation at a single institution between 2010 and 2023. Patients with at least 1 year of follow-up were included. Preoperative demographics, radiographic measurements such as sulcus angle, lateral trochlear inclination (LTI), and trochlear depth, patient-reported outcome measures (PROMs), and intraoperative findings including cartilage status were analyzed. Severe trochlear dysplasia (STD) was categorized as Dejour B/D, while non-STD encompassed all other cases, and these 2 groups were compared. Postoperative PROMs were assessed at 1 year postoperatively and at the final follow-up. A noninferiority test was performed using Kujala, Lysholm, and International Knee Documentation Committee (IKDC) scores, with the inferiority margin defined by the minimal clinically important difference (MCID). Linear relationships between LTI, a widely used indicator of trochleoplasty, and PROMs were evaluated. Additionally, differences in the proportion of patients achieving MCID, substantial clinical benefit, and patient-acceptable symptom state were analyzed using odds ratios. Results: Forty-two knees (41 patients) were finally enrolled. Radiographic measurements, except for LTI at the most proximal trochlea, showed no significant differences between the STD and non-STD groups. Clinical outcomes also demonstrated no significant differences between the 2 groups, and noninferiority was confirmed. When analyzed based on LTI, no differences in PROMs were observed at the postoperative 1 year. However, at the final follow-up (mean, 37.27 months), the most proximal trochlear LTI showed significant correlations with both Kujala and Knee Injury and Osteoarthritis Outcome Score over the follow-up period. Conclusions MPFL reconstruction, with or without TTO, leads to similar clinical improvements for STD classified by Dejour criteria. However, when assessed using proximal LTI, dysplasia’s role as a prognostic factor should be considered.

Background: The etiology of adolescent idiopathic scoliosis is multifactorial, and the influence of lifestyle factors such as sleep is not clearly understood. Differences in scoliosis incidence between urban and rural areas have been reported, but the contributing factors remain unclear. Therefore, this study investigated the association between sleep patterns and the incidence of idiopathic scoliosis and explored whether these patterns contribute to the observed urban-rural disparity. Methods: This retrospective study utilized data from the Korea Children and Youth Panel Survey (2010–2016) and the Health Insurance Review and Assessment Service for 4,693 students (age, 7–18 years). Various lifestyle factors including sleep patterns, learning time, and activity times, were compared between urban and rural areas, and a correlation analysis was performed between these factors and the age-specific incidence of idiopathic scoliosis. Results: Urban students, who exhibited higher idiopathic scoliosis incidence rates, tended to have later bedtimes and shorter total sleep durations than rural students. Longer learning hours were also observed in urban areas. Significant correlations were found between idiopathic scoliosis incidence and bedtime (p = 0.031), total sleep time (p = 0.026), and changes in total sleep time (p = 0.011). Conclusions Our findings indicate that later bedtimes and shorter sleep durations may contribute to idiopathic scoliosis development in children and adolescents. The higher idiopathic scoliosis incidence in urban students than in rural students could be partially explained by these sleep pattern differences, highlighting the need for further research into the role of sleep in scoliosis onset and prevention.

Background/Aims: Biliary tract cancer (BTC) is a rare malignancy with poor prognosis. We investigated genomic determinants of clinical benefit from gemcitabine, cisplatin, and nab-paclitaxel (GAP) versus gemcitabine and cisplatin (GC) in advanced BTC. Methods: Clinical and genomic data using TruSight Oncology 500 were analyzed from patients treated with GAP (N=198) or GC (N=89) as first-line therapy. Results: With a median follow-up of 33.0 months, GAP modestly improved progression-free survival (PFS) (hazard ratio [HR] 0.764; 95% confidence interval [CI] 0.591–0.989) without significant overall survival (OS) difference compared to GC. Genomic profiling revealed frequent alterations in TP53 (35.2%), KRAS (16.4%), SMAD4 (10.5%), and TNFRSF14 (10.5%), involving RTK/RAS (44.3%), TP53 (41.8%), and PI3K (20.2%) pathways. Single-gene mutations did not predict treatment benefit. However, pathway-level analysis identified PI3K pathway activation as significantly associated with inferior PFS (HR 2.148; 95% CI 1.478–3.124) and OS (HR 2.096; 95% CI 1.413–3.109) in patients receiving GAP, an effect not observed with GC. Importantly, GAP conferred clinical benefit only in patients without PI3K pathway activation, while no survival advantage was seen in those with such alterations (Pinteraction=0.023 for PFS, Pinteraction=0.003 for OS). Similar results were obtained in the independent validation cohort treated with GAP (N=103) or GC (N=64) for BTC. Conclusions Genomic profiling using next-generation sequencing identified PI3K pathway activation as key molecular determinant that differentiates patient outcomes between GAP and GC treatments in advanced BTC.

Induced pluripotent stem cells (iPSCs) are a promising cell source for regenerative medicine. Clinical applications require a large number of functional red blood cells (RBCs), making it essential to ensure the proliferation of actively dividing, nucleated erythroblasts derived from iPSCs. Small molecules can enhance the efficiency and frequency of iPSC-derived cell differentiation. Sirtuin 1, a key enzyme in multiple biological processes, has been implicated in enhancing iPSC-derived cell differentiation. However, the specific effects of Sirtuin 1 on erythroblast proliferation from iPSCs remain unclear. Here, we developed a protocol to examine the effects of Sirtuin 1 on erythroblasts after endothelial-to-hematopoietic transition (EHT). We found that Sirtuin 1 activation increased the frequency of CD71＋CD235a＋erythroblasts at the early stage after EHT, suggesting a role for Sirtuin 1 in the proliferation of these specified erythroblasts. These findings reveal that Sirtuin 1 activation benefits erythroblast proliferation and could be considered for translational application in large-scale RBC culture.

Purpose: Triple-negative breast cancer (TNBC) is a frequent phenotype of BRCA-mutanttumors. Tumors with BRCAness may show characteristics of BRCA-mutant tumors and respond to similar treatments. Next-generation sequencing is an efficient and cost-effective method for simultaneously sequencing multiple cancer susceptibility genes, surpassing conventional Sanger testing. Methods: A total of 148 women with TNBC were recruited from December 2015 to November 2018, as part of a sub-analysis based on the PEARLY trial data. Of them, 103 patients received neoadjuvant chemotherapy (NCT). The targeted genes related to hereditary cancers were sequenced using the 65-gene germline next-generation sequencing (gNGS) panel pathogenic and likely pathogenic variants (P&LPs) were determined by Sanger sequencing. We examined the occurrence of pathologic complete remission (ypCR) in patients with P&LPs. Results: The patients’ median age was 47 years (range, 27–69 years). Twenty (13.7%) of 148 patients had P&LP in six genes, including BARD1 (n = 2), BRCA1 (n = 9), BRCA2 (n = 5), CHEK2 (n = 1), RAD51C (n = 1), and RAD51D (n = 2). Among the 103 patients with NCT, 43 (41.7%) achieved ypCR (P&LPs; 9 individuals vs. non-variants; 34 individuals). Among the 103 patients with NCT, 14 (9.3%) had P&LPs. Nine of 14 patients with P&LPs, including BARD1 (n = 2), BRCA1 (n = 4), BRCA2 (n = 1), RAD51C (n = 1), and RAD51D (n = 1), achieved ypCR, showing a trend toward statistical significance (p = 0.066). Conclusion Germline P&LP mutations in TNBC patients can be detected by gNGS. This panel test can identify BRCA and BRCAness mutations that may predict ypCR in TNBC.

Background: Left bundle branch block (LBBB) significantly increases the risk of left ventricular systolic dysfunction (LVSD) due to cardiac dyssynchrony. Although artificial intelligence–enabled electrocardiography (AI-ECG) mod‑ els show promise in detecting LVSD, their performance in LBBB patients remains underexplored. We hypothesized that an AI-ECG model clinically validated for detecting LVSD would accurately detect LVSD and predict future clinical outcomes in LBBB patients. Methods: In this retrospective multicenter study, 5,689 expert-validated LBBB ECGs collected from 2,813 patients between 2016 and 2024 were analyzed using a previously developed and validated AI-ECG model. LVSD was defined as an ejection fraction of ≤ 40%. Model performance was assessed using the area under the receiver operating char‑ acteristic curve (AUROC), the area under the precision-recall curve (AUPRC), sensitivity, and specificity. Patients were stratified into high- and low-risk groups based on a threshold that achieved 90% sensitivity. A Kaplan–Meier analysis was used to compare clinical outcomes. Results: Among the 2,813 LBBB patients (mean age, 70.7 years; male sex, 43.7%), hypertension and a history of heart failure were common. The AiTiALVSD model showed strong diagnostic performance for LVSD (AUROC, 0.930 [95% CI, 0.924–0.937]; AUPRC, 0.913 [95% CI, 0.902–0.923]; sensitivity, 0.979; specificity, 0.473). During the mean follow-up of 4.1 years, high-risk patients had significantly higher hazards than low-risk patients for all-cause mortality (adjusted hazard ratio [HR], 1.87; 95% CI, 1.53–2.28), implantable cardioverter defibrillator/cardiac resynchronization therapy implantation (adjusted HR, 15.2; 95% CI, 7.51–30.77), and cardiovascular hospitalization (adjusted HR, 1.11; 95% CI, 0.96–1.28). Conclusions AiTiALVSD effectively detects LVSD and stratifies long-term cardiovascular risk in LBBB patients, support‑ ing its clinical utility for early detection and patient management.

Purpose: Preterm birth remains a leading cause of long-term neurodevelopmental impairment, yet early evaluations frequently underestimate subsequent deficits. This study examined longitudinal neurodevelopmental trajectories across gestational age groups and identified predictors of developmental delay. Methods: A retrospective cohort of 532 preterm children, stratified by gestational age, was followed from the neonatal period to early preschool age. Neurodevelopment was assessed using the Korean version of the Bayley Scales of Infant and Toddler Development, Third Edition at 8–12 months (n=481), 13–24 months (n=118), and 25–42 months (n=100). Longitudinal trajectories were analyzed using general linear models, and predictors of developmental delay were identified through multivariable logistic regression. Results: During the first year, motor scores differed significantly across gestational age groups, with extremely preterm infants showing the lowest values. By the third to fourth years of life, cognitive and language scores diverged markedly, with extremely preterm children exhibiting the steepest decline and additional deficits in motor and adaptive behavior domains. Lower gestational age remained an independent predictor of both cognitive and language delay at early preschool age, while no independent predictors were identified for motor, social-emotional, or adaptive behavior outcomes. Conclusion Neurodevelopmental outcomes in preterm children follow dynamic, domain-specific trajectories influenced by gestational age and developmental timing. Motor delays are most evident in infancy, whereas cognitive and language impairments emerge by early preschool age. Gestational age remains a consistent predictor of later delay, emphasizing the need for longitudinal, gestational age–stratified monitoring and early, targeted intervention.

Background: Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is among the most important multidrug-resistant pathogens causing bloodstream infections (BSIs).Cefotaximase (CTX-M) enzymes are the most common and highly diverse ESBL family in E.coli. CTX-M-15 in group CTX-M-1 and CTX-M-14 in group CTX-M-9 are the most extensively disseminated enzymes. Multidrug-resistant E. coli strains complicate empirical therapy and increase healthcare burden globally and in Korea. We investigated the molecular epidemiology, sequence types (STs), and ESBL genotypes of E. coli bloodstream isolates in Korea and identified clinical risk factors for cefotaxime resistance. Methods: We collected all non-duplicated isolates of E. coli and related clinical information from patients with BSIs at eight sentinel hospitals in the Korean Global Antimicrobial Resistance Surveillance System (Kor-GLASS) collection network during 2017–2021. Duplicate isolates were removed to ensure representativeness of the data. Antimicrobial susceptibility was tested using disk diffusion tests, and multilocus sequence typing and betalactamase genotyping were performed. Results: Among 9,232 E. coli blood isolates, resistance rates to cefotaxime and ceftazidime were 36.4% and 11.4%, respectively. Among the clinical factors, age > 65 yrs (adjusted odds ratio [aOR], 1.36), hospital-origin infection (aOR, 2.55), and admission type (intensive care unit [ICU] vs. general ward; aOR, 1.34) were significant cefotaxime resistance risk factors. ST131 was the most prevalent among cefotaxime-resistant E. coli (64.8%, 2,180/3,363), followed by ST1193 (5.3%, N = 177), and ST69 (5.1%, N = 170).ST131, ST648, ST405, and ST410 cefotaxime-resistant E. coli isolates frequently harbored blaCTX-M-15, whereas ST1193 and ST68 showed a high proportion of blaCTX-M-27 carriers, and most ST457 and ST5150 isolates carried blaCTX-M-55. Conclusions Continuous monitoring of ESBL-producing E. coli is required to prevent further dissemination, guide empirical therapy, inform infection control policies, and ensure early detection of multidrug-resistant clones with the potential for widespread transmission.

A medial closing wedge supramalleolar osteotomy, along with corrections for pes plano-valgus, including medial displacement calcaneal osteotomy, and deltoid ligament repair or reconstruction, is most commonly considered for the joint-preserving surgery of valgus ankle arthritis. In cases of ‘opposing coronal plane deformities,’ however, where the tibial plafond is varus-aligned to the long axis of the tibia and the ground, while the talus is conversely valgus-aligned, medial closing wedge supramalleolar osteotomy may paradoxically risk exacerbating the valgus ankle arthritis. This paper reports the radiological and clinical outcomes of an otherwise healthy, physically active 55-year-old male patient with valgus ankle arthritis and opposing coronal-plane deformities, along with a literature review. The patient underwent joint-preserving surgery consisting of lateral closing wedge supramalleolar osteotomy, fibular osteotomy, medial displacement calcaneal osteotomy, and deltoid ligament augmentation with suture tape. This paper discusses the critical considerations and surgical precautions necessary when deciding on joint-preserving procedures for valgus ankle arthritis.

Purpose: To investigate the clinical characteristics, onset timing, and anatomical and functional outcomes of MEK inhibitor–associated retinopathy (MEKAR) in Korean patients receiving systemic MEK inhibitor therapy. Methods: This retrospective study included 16 patients diagnosed with MEKAR between January 2011 and August 2025. Best-corrected visual acuity (BCVA), central macular thickness (CMT), subfoveal choroidal thickness (CT), and optical coherence tomography (OCT) findings were evaluated at baseline, at MEKAR onset, and at final follow-up. Results: Mean age was 57.8 ± 10.6 years, with a male predominance (68.8%). Colorectal cancer was the most common primary malignancy (56.3%), followed by lung cancer and malignant melanoma (18.7% each). MEKAR developed after a median of 3.3 weeks (IQR, 1.9–4.4 weeks) following therapy initiation, and the median time to initial improvement was 2.4 weeks (IQR, 1.3–8.1 weeks). At onset, 62.6% of patients reported ocular symptoms, while 37.4% were asymptomatic. OCT showed reversible retinal changes, most commonly ellipsoid zone thickening (68.8%) and focal subretinal fluid (43.8%), all of which resolved completely. CMT increased transiently at onset compared with baseline (p = 0.002) and normalized at final follow-up (p < 0.001), with no baseline–final difference (p = 0.489). CT remained stable (p = 0.159). BCVA was preserved, with a median of 0.00 logMAR at baseline, onset and final follow-up. Patients undergoing dose modification or interruption showed faster improvement than those continuing therapy (median, 9 vs. 81 days; p = 0.004). One patient showed multiple recurrent episodes, all of which resolved without visual deterioration. Conclusions MEKAR developed early after treatment initiation and followed a transient, fully reversible course with preserved visual function. Although dose modification accelerated anatomical recovery, long-term outcomes remained favorable even with continued therapy, supporting close monitoring and individualized management rather than routine interruption, particularly in mild or asymptomatic cases.