Background: When positioning the acetabular component for total hip arthroplasty (THA) in patients with sequelae of LeggCalvé-Perthes disease (LCPD), elevating the center of rotation (COR) of the hip is often unavoidable. We aimed to compare the outcomes between the preserved and elevated COR groups in patients with sequelae of LCPD. Methods: We enrolled 53 patients who underwent primary THA for sequelae of LCPD between 2006 and 2019. Patients were divided into 2 groups based on the postoperative COR position: 19 in the preserved COR group and 34 in the elevated COR group.The mean elevation of COR was 2.7 mm (range, 0–5.0 mm) in the preserved COR group and 8.1 mm (range, 6.0–12.0 mm) in the elevated COR group. Radiological outcomes, such as osteolysis and implant loosening, were evaluated. Additionally, reoperation, perioperative complications, limping gait, pelvic obliquity, and the modified Harris hip score (mHHS) were assessed. Results: There were no significant differences in radiological or clinical outcomes between the 2 groups. Neither osteolysis nor implant loosening was observed, and no reoperations were required. Intraoperative periprosthetic femoral fractures occurred in 3 cases (6%), but no cases of sciatic nerve palsy were observed. Residual limping gait was noted in 10 patients (19%), and pelvic obliquity persisted in 8 patients (15%). At the last follow-up, the mean mHHS was 89.2. Conclusions The 5–17-year follow-up results of primary cementless THA in patients with sequelae of LCPD were satisfactory.Furthermore, a moderate elevation of the COR, with a mean of 8.1 mm (range, 6.0–12.0 mm), did not significantly affect the outcomes of THA in these patients. Therefore, a moderate elevation of the COR can be considered an acceptable option for patients undergoing THA with sequelae of LCPD.

Background/Aims: The optimal vascular access strategy for very elderly patients initiating hemodialysis (HD) remains unclear. Arteriovenous fistulas (AVFs) offer long-term benefits but may be limited due to vascular aging. This study evaluated vascular access outcomes in patients aged ≥ 80 years. Methods: We conducted a retrospective cohort study using data from the Korean National Health Insurance Service between 2008 and 2019. Patients aged ≥ 80 years who initiated HD with a newly created AVF or arteriovenous graft (AVG) were included. Primary outcomes were primary, assisted primary, and secondary patency. The secondary outcome was all-cause mortality. Outcomes were compared using Kaplan–Meier analysis and multivariable Cox regression. Results: Among 8,487 patients, 5,124 (60.4%) received AVFs (AVF group) and 3,363 (39.6%) received AVGs (AVG group). AVFs were associated with significantly lower rates of patency loss across all definitions. The adjusted hazard ratios (HRs) for AVG vs. AVF were 1.76 (95% confidence interval [CI], 1.67–1.86) for primary patency loss, 1.90 (95% CI, 1.77–2.03) for assisted primary, and 3.18 (95% CI, 2.81–3.61) for secondary patency loss. All-cause mortality was also higher in the AVG group (adjusted HR, 1.24; 95% CI, 1.17–1.30). Conclusions In this large-scale study, AVF use was associated with superior patency and lower mortality compared with AVG in patients aged ≥ 80 years. These findings suggest that AVF remains a beneficial option for appropriately selected elderly patients and that age alone should not be a primary barrier to its creation.

Purpose: This developmental study explored the conceptual feasibility and applicability of a metaverse-based clinical assessment platform as a complementary tool to conventional objective structured clinical examinations in undergraduate medical education. Methods: A targeted literature review and expert consensus process were conducted to identify domains of clinical competence in which metaverse technologies could provide added value. Based on these findings, prototype virtual patient simulations were developed within a metaverse environment. Large language models (LLMs) were integrated to support dynamic, interactive history-taking simulations, and pilot modules for physical examination were also created. Results: Integration of LLMs into virtual patient scenarios enabled realistic, context-sensitive medical interviews, facilitating interactive dialogue between examinees and simulated patients. In contrast, physical examination modules faced technical limitations, particularly in replicating procedures requiring tactile or haptic feedback, such as palpation and percussion. Nevertheless, the metaverse environment enabled delivery of consistent and reproducible scenarios, supporting objective assessment of communication and diagnostic reasoning skills. Conclusion Metaverse-based simulations augmented by LLMs offer a promising approach to scalable and standardized clinical assessment, particularly within cognitive and interpersonal competency domains. Although current technological constraints limit the fidelity of physical examination simulations, rapid advancements in immersive and haptic technologies may help overcome these barriers in the near future. Further research is needed to evaluate the educational efficacy, validity, and feasibility of deploying such platforms in summative, high-stakes assessment contexts.

Purpose: We aimed to investigate how genetic predisposition to drinking and gastric cancer (GC) modifies the association between alcohol consumption and GC risk in the Korean population. Materials and Methods: Polygenic risk scores for GC (PRS-GC) and alcohol consumption (PRS-Alcohol) were formulated using genome-wide association results from BioBank Japan. Validation was performed using Korean cohorts (SNUBH-GENIE cohort), incorporating 8,846 controls and 531 patients with GC. Subsequently, these PRSs were applied to an independent Korean cohort of 67,771 participants, including 313 patients with GC during the follow-up for 14 years (KoGES cohort). Results: In KoGES cohort, the influence of alcohol consumption on GC risk was significantly altered by the PRS-GC and exhibited a synergistic interaction effect. PRS-Alcohol itself shows a negative correlation with GC risk. However, when actual alcohol consumption significantly exceeded genetically predicted levels, the risk of alcohol-related GC was notably increased (adjusted hazard ratio, 1.32; 95% confidence interval, 1.01 to 1.72). Heavy drinkers in the high–PRS-GC/low–PRS-Alcohol group had a 2.16 times higher risk of GC than non-to-light drinkers, which was prominent in males. Conclusion Korean drinkers with higher PRS-GC who consume alcohol more than genetically predicted levels are susceptible to GC. PRS-GC and PRS-Alcohol may be beneficial for assessing the impact of alcohol consumption on GC risk in Koreans.

Purpose: The male predominance in the incidence of gastric cancer (GC) is established; however, sex differences in the prognosis of GC remain controversial. As such, this study analyzed the prognosis of patients with GC based on age and sex. Materials and Methods: Data from 14,739 patients diagnosed with GC at Seoul National University Bundang Hospital between 2003 and 2023 were analyzed. Baseline characteristics, histological types of GC, overall and GC-specific survival rates (age and stage stratification), and associated risk factors were analyzed. Results: Females were significantly younger (p < 0.001) and exhibited more gastric body cancers (p < 0.001) and tumors with diffuse-type or poorly differentiated histology (p < 0.001) than males. Females exhibited an advantage over males in terms of overall survival (p=0.004), but not in GC-specific survival. However, age stratification revealed significant sex differences, that females < 50 years of age exhibited survival disadvantages (p < 0.001); however, this trend was reversed with age, and females > 60 years exhibited survival advantages (p < 0.001) for both overall and GC-specific survival. This may be explained by the lower ratio of diffuse-type GC as females age. Furthermore, in the analysis according to stage, females with stage IV disease exhibited significant survival disadvantages, with significantly younger age and a higher proportion of diffuse-type GC which exhibits aggressive features, resulting in poorer survival than in males. Conclusion Age and stage stratification revealed significant differences in survival between the sexes, which can be helpful for public health strategies.

Background/Aims: To determine the effectiveness of tyrosine kinase inhibitor (TKI) plus reduced-intensity therapy in adult patients with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL), this retrospective study compared treatment outcomes and induction mortality according to backbone regimen intensity. Methods: The data of 132 patients diagnosed with Ph-positive ALL were retrospectively collected from five centers. Patients received imatinib plus intensive chemotherapy (modified VPD, KALLA1407, or hyper-CVAD) or reduced-intensity chemotherapy (EWALL) for curative purposes. This study analyzed 117 patients, of which 35,22,46, and 14 received modified VPD, KALLA1407, hyper-CVAD, and EWALL, respectively. All patients used imatinib as a TKI. Results: The median age of the patients who received reduced-intensity chemotherapy was 64.4 years, while that of the patients with intensive regimens was 47.5 years. There was no induction death in the reduced-intensity group, while nine patients died in the intensive therapy group. Major molecular response achievement tended to be higher in the intensive chemotherapy group than in the reduced-intensity group. More patients in the intensive chemotherapy group received allogeneic stem cell transplantation (allo-SCT). There was no statistically significant difference in long-term survival between the two groups in terms of relapse-free survival and overall survival rates. Conclusions When imatinib plus reduced-intensity therapy was used as a frontline treatment, there was no inferiority in obtaining complete remission compared to imatinib plus intensive chemotherapy or significant difference in long-term survival. Since imatinib plus reduced-intensity therapy has limitations in obtaining a deep molecular response, proceeding to allo-SCT should be considered.

Background: Active surveillance (AS) has emerged as a viable management strategy for low-risk papillary thyroid microcarcinoma (PTMC), following pioneering trials at Kuma Hospital and the Cancer Institute Hospital in Japan. Numerous prospective cohort studies have since validated AS as a management option for low-risk PTMC, leading to its inclusion in thyroid cancer guidelines across various countries. From 2016 to 2020, the Multicenter Prospective Cohort Study of Active Surveillance on Papillary Thyroid Microcarcinoma (MAeSTro) enrolled 1,177 patients, providing comprehensive data on PTMC progression, sonographic predictors of progression, quality of life, surgical outcomes, and cost-effectiveness when comparing AS to immediate surgery. The second phase of MAeSTro (MAeSTro-EXP) expands AS to low-risk papillary thyroid carcinoma (PTC) tumors larger than 1 cm, driven by the hypothesis that overall risk assessment outweighs absolute tumor size in surgical decision-making. Methods: This protocol aims to address whether limiting AS to tumors smaller than 1 cm may result in unnecessary surgeries for low-risk PTCs detected during their rapid initial growth phase. By expanding the AS criteria to include tumors up to 1.5 cm, while simultaneously refining and standardizing the criteria for risk assessment and disease progression, we aim to minimize overtreatment and maintain rigorous monitoring to improve patient outcomes. Conclusion This study will contribute to optimizing AS guidelines and enhance our understanding of the natural course and appropriate management of low-risk PTCs. Additionally, MAeSTro-EXP involves a multinational collaboration between South Korea and Australia. This cross-country study aims to identify cultural and racial differences in the management of low-risk PTC, thereby enriching the global understanding of AS practices and their applicability across diverse populations.

Objective: To evaluate the safety and efficacy of coil embolization of venous segments in patients with Type IIa pelvic arteriovenous malformations (AVMs). Materials and Methods: A retrospective study was performed on 13 patients (median age, 43 years, range 20–62 years, 7 males) who underwent transvenous coil embolization for Type IIa pelvic AVM (characterized by multiple arterioles shunting to focal venous segments of a single draining vein) without the use of additional liquid embolic agents from March 2017 to February 2023. Treatment outcomes were analyzed based on clinical evaluations, post angiography findings, and follow-up CT. Results: Fourteen procedures were performed on 13 patients. Except in one patient, all treatments were completed in a single session. Transvenous access was employed in 10 procedures, whereas direct puncture was used in four sessions. The embolization procedures used an average of 55.7 ± 58.5 coils (range, 7–238) and lasted an average of 127.3 ± 39.5 minutes.The technical success rate was 92.9% (of 13/14). All patients reported symptom improvement. Follow-up CT scans showed complete occlusion of the AVM without recurrence in ten of the 13 patients. There was one minor adverse event: a small retroperitoneal hemorrhage, likely related to direct puncture, which resolved spontaneously. No other adverse events were observed. Conclusion Coil embolization of the draining vein segment, without the use of additional liquid embolic agents is a safe and effective method for managing Type IIa pelvic AVM.

Background/Aims: To determine the effectiveness of tyrosine kinase inhibitor (TKI) plus reduced-intensity therapy in adult patients with newly diagnosed Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL), this retrospective study compared treatment outcomes and induction mortality according to backbone regimen intensity. Methods: The data of 132 patients diagnosed with Ph-positive ALL were retrospectively collected from five centers. Patients received imatinib plus intensive chemotherapy (modified VPD, KALLA1407, or hyper-CVAD) or reduced-intensity chemotherapy (EWALL) for curative purposes. This study analyzed 117 patients, of which 35,22,46, and 14 received modified VPD, KALLA1407, hyper-CVAD, and EWALL, respectively. All patients used imatinib as a TKI. Results: The median age of the patients who received reduced-intensity chemotherapy was 64.4 years, while that of the patients with intensive regimens was 47.5 years. There was no induction death in the reduced-intensity group, while nine patients died in the intensive therapy group. Major molecular response achievement tended to be higher in the intensive chemotherapy group than in the reduced-intensity group. More patients in the intensive chemotherapy group received allogeneic stem cell transplantation (allo-SCT). There was no statistically significant difference in long-term survival between the two groups in terms of relapse-free survival and overall survival rates. Conclusions When imatinib plus reduced-intensity therapy was used as a frontline treatment, there was no inferiority in obtaining complete remission compared to imatinib plus intensive chemotherapy or significant difference in long-term survival. Since imatinib plus reduced-intensity therapy has limitations in obtaining a deep molecular response, proceeding to allo-SCT should be considered.