Background: Tibiotalocalcaneal (TTC) arthrodesis is a viable salvage option for failed total ankle arthroplasty (TAA), but it is typically a complex procedure associated with a high complication rate. This study analyzed outcomes of salvage TTC arthrodesis using a retrograde intramedullary (IM) nail without subtalar joint preparation after failed TAA. Methods: This study included 18 patients (18 ankles) who underwent TTC arthrodesis without subtalar joint preparation for failed TAA from July 2008 to March 2023 and were followed up for at least 2 years. Visual analog scale pain scores and Ankle Osteoarthritis Scale pain and disability scores were used to assess functional outcomes. Radiographic union, time to union, complications, and clinical success—defined as pain improvement without the need for revision surgery or amputation—were also evaluated. Results: The mean follow-up duration after TTC arthrodesis was 79.8 months (range, 26–199 months). Tibiotalar joint union was achieved in 13 ankles (72.2%) at a mean of 7.5 months after TTC arthrodesis. Subtalar joint union was achieved in 7 ankles (38.9%). All functional scores improved significantly from preoperatively to the last follow-up. The overall clinical success rate was 83.3% (15 ankles). Conclusions TTC arthrodesis using a retrograde IM nail without subtalar joint preparation produced favorable outcomes in patients with failed TAA. No complications associated with the subtalar joint were observed in any patient during follow-up. Therefore, TTC arthrodesis using a retrograde IM nail without subtalar joint preparation may be a considerable salvage option for failed TAA.

Background: Degenerative lumbar scoliosis (DLS) alters spinal anatomy, impacting the feasibility and dimensions of surgical corridors for oblique lumbar interbody fusion (OLIF). This study aimed to compare the morphometric characteristics of OLIF corridors between patients with left- and right-apex curves, focusing on corridor dimensions, psoas muscle asymmetry, and segmental artery positioning. Methods: A retrospective analysis of 80 patients with DLS (left apex: n = 43; right apex: n = 37) was conducted. Corridor angles and distances, psoas muscle cross-sectional areas, and segmental artery locations were measured at L2–3, L3–4, and L4–5 using T2-weighted magnetic resonance imaging (MRI). Multivariate regression analysis identified key anatomical predictors of corridor variation at L2–3. Results: Regardless of the apex direction, the left-sided corridor was consistently larger across all levels. Corridor angles were significantly greater on the left side in both groups (left apex: L2–3, 39.7° vs. 13.5°; L3–4, 38.3° vs. 11.9°; L4–5, 38.6° vs. 6.9°;right apex: L2–3, 53.7° vs. 18.1°; L3–4, 43.1° vs. 18.5°; L4–5, 28.6° vs. 11.9°). Psoas muscle areas were larger on the concave side of the curve (left apex: 125.7 mm2 vs. 67.9 mm2 ; right apex: 125.4 mm2 vs. 77.4 mm2 ). Segmental artery positioning exhibited curvedependent asymmetry at L2–3 (left apex: 8.8 mm vs. 7.9 mm; right apex: 9.6 mm vs. 8.0 mm). Multivariate regression analysis revealed that in the left apex group, the left psoas area (β = −0.132) and segmental artery distances were significant predictors of corridor angle variation (R2 = 0.517). In the right apex group, psoas asymmetry (β = 0.123) and sagittal alignment (β = −0.851) were associated with corridor differences. Conclusions OLIF corridors in DLS patients demonstrate consistent left-sided dominance, regardless of apex direction. Psoas muscle asymmetry and segmental artery positioning contribute to corridor variations. While the left-sided approach remains standard, right-sided access may be feasible in select cases, particularly at L4–5. These findings provide insights for optimizing preoperative planning and surgical decision-making in DLS patients.

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: The absence of standardized clinical minimum inhibitory concentration (MIC) breakpoints for Helicobacter pylori infection has resulted in inconsistent resistance definitions, even within the same research group in Korea. Therefore, establishing epidemiological cutoff values (ECOFFs) is essential for standardization. Methods: The MIC distributions for antibiotics commonly used against H. pylori infection in South Korea were analyzed from 2015 to 2023. A total of 5,925 primary H. pylori isolates were collected from five data sources, and MIC values were determined using the serial 2-fold agar dilution method. The ECOFFinder program was used to establish ECOFFs for six antibiotics. Results: The tentative ECOFFs for amoxicillin and clarithromycin were 0.125 μg/mL. The ECOFFs for levofloxacin, metronidazole, and tetracycline were 0.5, 8.0, and 0.25 μg/mL, respec-tively. The ECOFF for rifabutin could not be determined due to insufficient data. On the basis of these ECOFFs, the resistance rate was 17.9% for amoxicillin, 31.9% for clarithromycin, 40.9% for levofloxacin, 24.7% for metronidazole, and 11.5% for tetracycline. Conclusions This comprehensive analysis defined regional antibiotic resistance patterns and established Korea-specific ECOFFs, providing a foundation for determining clinical breakpoints and optimizing H. pylori eradication strategies.

Purpose: To develop and validate an artificial intelligence (AI)-based personalized outcome prediction model for upper-urinary tract urothelial carcinoma patients undergoing radical nephroureterectomy. Materials and Methods: Data from patients who underwent radical nephroureterectomy between 2010 and 2020 across three hospitals were retrospectively analyzed. A model was developed using one tertiary center’s data and externally validated with data from two other hospitals. An AI model using XGBoost as risk estimator and bootstrapped Weibull Accelerated Failure Time model for 10-year survival probability was employed. Hyperparameter tuning used Optuna method. Model efficacy was assessed using concordance index, average Brier score, D-calibration, and six-month interval time-dependent area under the curve (AUC). Results: Of 1,039 patients, 627 qualified after excluding 50 with neoadjuvant chemotherapy. Model development used 564 patients (507 training, 57 test) with 9:1 stratified random split, plus 63 for internal validation and 362 for external validation. Significant parameters included preoperative glomerular filtration rate (p<0.001), hydroureteronephrosis (p=0.013), pathological N stage (p<0.001), concurrent carcinoma in situ (p<0.001), disease progression (p<0.001), and survival rate (p<0.001). Disease-free survival (DFS) model’s concordance index: internal validation 0.789, external validations 0.734 and 0.771. Overall survival (OS) model’s concordance index: internal validation 0.819, external validations 0.780 and 0.771. Mean time-dependent AUC was 0.66–0.77 for DFS and 0.67–0.80 for OS during 10-year periods. Conclusions AI-based model effectively predicts disease-free and OS outcomes for upper-urinary tract urothelial carcinoma patients with post-radical nephroureterectomy, showcasing robust performance across multicenter settings.

A unified consensus statement on medication-related osteonecrosis of the jaw (MRONJ) has not yet been established among the Asian member countries or regions of the Asian Federation of Osteoporosis Societies (AFOS). This study aimed to develop a consensus on MRONJ in patients with osteoporosis across these countries and regions. In this study, the term “Asia-Pacific” refers specifically to the Asian member countries and regions of AFOS. A structured survey consisting of nine MRONJ-related questions was distributed across 10 countries and regions to assess the level of agreement and summarize regional perspectives. In addition, a manual literature review and voting were conducted to evaluate the current evidence on MRONJ. The key aspects of MRONJ, including definition, staging, diagnosis, pathogenesis, risk factors, management, and prevention, were generally consistent among the AFOS countries and regions. The annual incidence and incidence rate of MRONJ associated with low-dose antiresorptive therapy in patients with osteoporosis ranged from 0.025% to 0.136% and 21 to 283 cases per 100,000 person-years, respectively. However, evidence regarding the benefits of drug discontinuation before dental surgery, such as tooth extraction, remains insufficient. Large-scale, multinational studies across AFOS countries and regions are warranted to determine the incidence of MRONJ better and evaluate the impact of antiresorptive drug discontinuation before dental procedures. These findings may contribute to the devel opment of effective evidence-based strategies for preventing MRONJ in patients with osteoporosis.

Purpose: Brain magnetic resonance imaging (MRI) is commonly performed to exclude secondary causes of pediatric headache. Incidental findings are detected in approximately one-fifth of scans, and nonspecific white matter lesions (WMLs) have been reported in 0.7% to 47% of pediatric patients with headache. However, the natural history of these lesions remains unclear. This study aimed to determine the prevalence and radiologic course of WMLs in pediatric patients with headache. Methods: We retrospectively reviewed the clinical and MRI data of pediatric patients who underwent brain MRI for headache at a single tertiary-care center between September 2006 and July 2023. Patients with neurological or systemic conditions known to cause WMLs were excluded. MRI findings and clinical characteristics were analyzed descriptively. Results: Among the 515 enrolled patients (mean age, 10.7 years), abnormal MRI findings were observed in 126 (24.5%), including nonspecific WMLs in eight (1.6%). Most lesions were supratentorial (seven of eight), with a mean maximum diameter of 10.0 mm (range, 4.3 to 24.9). Follow-up MRI was available for three patients; two demonstrated interval increases in lesion extent on repeat imaging. During the same period, headache frequency or severity also increased, but no new neurological deficits were documented. Conclusion Nonspecific WMLs were rare in pediatric patients with headache. In a small subset with limited follow-up, interval radiologic changes were observed without neurological deterioration. Larger prospective studies are needed to clarify the natural history and clinical significance of WMLs in pediatric headache.

Purpose: Exanthem subitum (ES), most commonly caused by human herpesvirus 6B (HHV-6B), is a prevalent febrile illness in infants and toddlers. Previous studies have suggested a possible association between HHV-6B infection and an increased risk of complex febrile seizures (CFS). Given that CFS may prompt additional diagnostic procedures to rule out serious neurological disorders, we compared the clinical characteristics and management of patients with and without ES. Methods: We retrospectively reviewed the medical records of 141 children younger than two years of age who experienced their first febrile seizure between March 2013 and August 2024 at a tertiary medical center. We collected demographic, clinical, and laboratory data and compared clinical profiles between children diagnosed with ES and those without ES. Results: Twenty-eight children (19.9%) were clinically diagnosed with ES. Although the frequency of CFS did not significantly differ between the ES and non-ES groups (42.9% vs. 28.3%, P=0.172), children with ES were more likely to undergo lumbar puncture (42.9% vs. 11.5%, P<0.001) and receive empiric intravenous antibiotics for suspected central nervous system infection (39.3% vs. 10.6%, P<0.001). Conclusion Despite the typically benign and self-limiting nature of ES, febrile seizures occurring in the context of ES appear to be associated with more aggressive diagnostic and therapeutic interventions. The development of rapid, noninvasive diagnostic assays for HHV-6B may help reduce unnecessary procedures and promote more judicious management.