Pregnancy-related transient osteoporosis is a rare disease, usually accompanied by joint pain in the third trimester of pregnancy. It commonly involves the hip, but has also been encountered in other joints in the lower extremity. This condition can be diagnosed by magnetic resonance imaging but it can be mistaken for pain caused by pregnancy, childbirth, or breastfeeding, making rapid diagnosis and treatment difficult. If not treated properly, the condition can progress to fracture or avascular necrosis of the femoral head. Nevertheless, symptoms can be improved sufficiently with conservative treatment. if diagnosed approximately. This paper presents a case of transient osteoporosis of the hip and knee in pregnancy, which recovered completely after conservative treatment.

Purpose: To evaluate whether extended pelvic lymph node dissection (PLND) improves survival outcomes compared with standard PLND in patients with bladder cancer (BCa) undergoing radical cystectomy (RC), and to assess its potential benefits in patients with prior or concurrent radical nephroureterectomy (p/cRNU). Materials and Methods: A multicenter analysis included 2202 patients with BCa undergoing RC with standard or extended PLND at 11 tertiary centers from 2003 to 2023. Following propensity score matching, 659 pairs (n=1,318), including 128 patients with p/cRNU, were analyzed. Recurrence-free survival (RFS) was the primary outcome, while overall survival (OS), cancer-specific survival (CSS), and readmission rates were secondary outcomes. Survival analyses performed using Kaplan-Meier methods and clustered Cox models. Results: Extended PLND yielded significantly more lymph nodes than standard PLND (median: 27.0 vs. 17.0, p<0.001) but did not improve RFS, CSS, or OS in the overall cohort (all p>0.05). Extended PLND increased readmission rates (28.4% vs. 20.2%, p=0.001) and readmission risk (odds ratio, 1.57; 95% confidence interval [CI], 1.15–2.16, p=0.005). However, subgroup analysis revealed extended PLND significantly improved RFS in patients with p/cRNU (hazard ratio, 0.54; 95% CI, 0.38–0.77; p<0.001). Conclusion Extended PLND does not provide survival benefits for overall patient population and increases readmission risk but significantly improves RFS in patients with p/cRNU. Tailoring PLND extent based on upper tract disease status is recommended.

Purpose: Autologous arteriovenous fistulas (AVFs) are considered the gold standard for hemodialysis access, with outcomes largely dependent on the surgeon’s experience. Nevertheless, few studies have been conducted on the learning curve of junior vascular surgeons in AVF creation. This study aims to address this by examining the development of surgical skills among junior vascular surgeons. Materials and Methods: A retrospective analysis was conducted on 100 patients who underwent autologous AVF procedures performed by five junior surgeons between January 2018 and December 2023. To establish the cutoff number of cases for the learning curve, we examined the cubic spline curve using the hazard ratio for primary failure. Results: The cutoff number for operation cases was 15.33, and we divided the analysis into a pre-learning curve period (≤15 cases of AVF) and a post-learning curve period (>15 cases of AVF). The 1-year primary patency rate for AVF during the post-learning curve period was 84.0%, which was higher than the 65.5% rate observed during the pre-learning curve period. In a subgroup analysis based on AVF type, the radiocephalic fistula patient group demonstrated a significant increase in 1-year primary patency in the post-learning curve period compared to that in the pre-learning curve period (80.0% vs. 43.0%, log-rank P=0.033). In contrast, there was no significant difference in the primary patency rates between the post- and pre-learning curve periods in the brachiocephalic fistula patient group (90.0% vs. 89.2%, log-rank P=0.930). Conclusion Junior vascular surgeons demonstrated improved primary AVF patency beyond the learning curve benchmark in 15 patients, with particularly notable enhancements in radiocephalic fistulas.

Purpose: Autologous arteriovenous fistulas (AVFs) are considered the gold standard for hemodialysis access, with outcomes largely dependent on the surgeon’s experience. Nevertheless, few studies have been conducted on the learning curve of junior vascular surgeons in AVF creation. This study aims to address this by examining the development of surgical skills among junior vascular surgeons. Materials and Methods: A retrospective analysis was conducted on 100 patients who underwent autologous AVF procedures performed by five junior surgeons between January 2018 and December 2023. To establish the cutoff number of cases for the learning curve, we examined the cubic spline curve using the hazard ratio for primary failure. Results: The cutoff number for operation cases was 15.33, and we divided the analysis into a pre-learning curve period (≤15 cases of AVF) and a post-learning curve period (>15 cases of AVF). The 1-year primary patency rate for AVF during the post-learning curve period was 84.0%, which was higher than the 65.5% rate observed during the pre-learning curve period. In a subgroup analysis based on AVF type, the radiocephalic fistula patient group demonstrated a significant increase in 1-year primary patency in the post-learning curve period compared to that in the pre-learning curve period (80.0% vs. 43.0%, log-rank P=0.033). In contrast, there was no significant difference in the primary patency rates between the post- and pre-learning curve periods in the brachiocephalic fistula patient group (90.0% vs. 89.2%, log-rank P=0.930). Conclusion Junior vascular surgeons demonstrated improved primary AVF patency beyond the learning curve benchmark in 15 patients, with particularly notable enhancements in radiocephalic fistulas.

Purpose: Autologous arteriovenous fistulas (AVFs) are considered the gold standard for hemodialysis access, with outcomes largely dependent on the surgeon’s experience. Nevertheless, few studies have been conducted on the learning curve of junior vascular surgeons in AVF creation. This study aims to address this by examining the development of surgical skills among junior vascular surgeons. Materials and Methods: A retrospective analysis was conducted on 100 patients who underwent autologous AVF procedures performed by five junior surgeons between January 2018 and December 2023. To establish the cutoff number of cases for the learning curve, we examined the cubic spline curve using the hazard ratio for primary failure. Results: The cutoff number for operation cases was 15.33, and we divided the analysis into a pre-learning curve period (≤15 cases of AVF) and a post-learning curve period (>15 cases of AVF). The 1-year primary patency rate for AVF during the post-learning curve period was 84.0%, which was higher than the 65.5% rate observed during the pre-learning curve period. In a subgroup analysis based on AVF type, the radiocephalic fistula patient group demonstrated a significant increase in 1-year primary patency in the post-learning curve period compared to that in the pre-learning curve period (80.0% vs. 43.0%, log-rank P=0.033). In contrast, there was no significant difference in the primary patency rates between the post- and pre-learning curve periods in the brachiocephalic fistula patient group (90.0% vs. 89.2%, log-rank P=0.930). Conclusion Junior vascular surgeons demonstrated improved primary AVF patency beyond the learning curve benchmark in 15 patients, with particularly notable enhancements in radiocephalic fistulas.

Purpose: Autologous arteriovenous fistulas (AVFs) are considered the gold standard for hemodialysis access, with outcomes largely dependent on the surgeon’s experience. Nevertheless, few studies have been conducted on the learning curve of junior vascular surgeons in AVF creation. This study aims to address this by examining the development of surgical skills among junior vascular surgeons. Materials and Methods: A retrospective analysis was conducted on 100 patients who underwent autologous AVF procedures performed by five junior surgeons between January 2018 and December 2023. To establish the cutoff number of cases for the learning curve, we examined the cubic spline curve using the hazard ratio for primary failure. Results: The cutoff number for operation cases was 15.33, and we divided the analysis into a pre-learning curve period (≤15 cases of AVF) and a post-learning curve period (>15 cases of AVF). The 1-year primary patency rate for AVF during the post-learning curve period was 84.0%, which was higher than the 65.5% rate observed during the pre-learning curve period. In a subgroup analysis based on AVF type, the radiocephalic fistula patient group demonstrated a significant increase in 1-year primary patency in the post-learning curve period compared to that in the pre-learning curve period (80.0% vs. 43.0%, log-rank P=0.033). In contrast, there was no significant difference in the primary patency rates between the post- and pre-learning curve periods in the brachiocephalic fistula patient group (90.0% vs. 89.2%, log-rank P=0.930). Conclusion Junior vascular surgeons demonstrated improved primary AVF patency beyond the learning curve benchmark in 15 patients, with particularly notable enhancements in radiocephalic fistulas.

Purpose: Autologous arteriovenous fistulas (AVFs) are considered the gold standard for hemodialysis access, with outcomes largely dependent on the surgeon’s experience. Nevertheless, few studies have been conducted on the learning curve of junior vascular surgeons in AVF creation. This study aims to address this by examining the development of surgical skills among junior vascular surgeons. Materials and Methods: A retrospective analysis was conducted on 100 patients who underwent autologous AVF procedures performed by five junior surgeons between January 2018 and December 2023. To establish the cutoff number of cases for the learning curve, we examined the cubic spline curve using the hazard ratio for primary failure. Results: The cutoff number for operation cases was 15.33, and we divided the analysis into a pre-learning curve period (≤15 cases of AVF) and a post-learning curve period (>15 cases of AVF). The 1-year primary patency rate for AVF during the post-learning curve period was 84.0%, which was higher than the 65.5% rate observed during the pre-learning curve period. In a subgroup analysis based on AVF type, the radiocephalic fistula patient group demonstrated a significant increase in 1-year primary patency in the post-learning curve period compared to that in the pre-learning curve period (80.0% vs. 43.0%, log-rank P=0.033). In contrast, there was no significant difference in the primary patency rates between the post- and pre-learning curve periods in the brachiocephalic fistula patient group (90.0% vs. 89.2%, log-rank P=0.930). Conclusion Junior vascular surgeons demonstrated improved primary AVF patency beyond the learning curve benchmark in 15 patients, with particularly notable enhancements in radiocephalic fistulas.

Purpose: The appropriate evaluation of height and accurate estimation of bone age are crucial for proper assessment of the growth status of a child. We developed a bone age estimation program using a deep learning algorithm and established a model to predict the final adult height of Korean children. Materials and Methods: A total of 1678 radiographs from 866 children, for which the interpretation results were consistent between two pediatric endocrinologists, were used to train and validate the deep learning model. The bone age estimation algorithm was based on the convolutional neural network of the deep learning system. The test set simulation was performed by a deep learning program and two raters using 150 radiographs and final height data for 100 adults. Results: There was a statistically significant correlation between bone age interpreted by the artificial intelligence (AI) program and the reference bone age in the test set simulation (r=0.99, p<0.001). In the test set simulation, the AI program showed a mean absolute error (MAE) of 0.59 years and a root mean squared error (RMSE) of 0.55 years, compared with reference bone age, and showed similar accuracy to that of an experienced pediatric endocrinologist (rater 1). Prediction of final adult height by the AI program showed an MAE of 4.62 cm, compared with the actual final adult height. Conclusion We developed a bone age estimation program based on a deep learning algorithm. The AI-derived program demonstrated high accuracy in estimating bone age and predicting the final adult height of Korean children and adolescents.

Purpose: The survival benefit of neoadjuvant chemotherapy (NAC) prior to surgical resection in colorectal cancer with liver metastases (CRCLM) patients remains controversial. The aim of this study was to compare overall outcome of CRCLM patients who underwent NAC followed by surgical resection versus surgical treatment first. Methods: We retrospectively analyzed 429 patients with stage IV colorectal cancer with synchronous liver metastases who underwent simultaneous liver resection between January 2008 and December 2016. Using propensity score matching, overall outcome between 60 patients who underwent NAC before surgical treatment and 60 patients who underwent surgical treatment first was compared. Results: Before propensity score matching, metastatic cancer tended to involve a larger number of liver segments and the primary tumor size was bigger in the NAC group than in the primary resection group, so that a larger percentage of patients in the NAC group underwent major hepatectomy (P<0.001). After propensity score matching, demographic features and pathologic outcomes showed no significant differences between the 2 groups. In addition, there was no significant difference in short-term recovery outcomes such as postoperative morbidity (P=0.603) and oncologic outcome, including 3-year overall survival rate (P=0.285) and disease-free survival rate (P=0.730), between the 2 groups. Conclusion NAC prior to surgical treatment in CRCLM is considered a safe treatment that does not increase postoperative morbidity, and its impact on oncologic outcome was not inferior.

Purpose: The survival benefit of neoadjuvant chemotherapy (NAC) prior to surgical resection in colorectal cancer with liver metastases (CRCLM) patients remains controversial. The aim of this study was to compare overall outcome of CRCLM patients who underwent NAC followed by surgical resection versus surgical treatment first. Methods: We retrospectively analyzed 429 patients with stage IV colorectal cancer with synchronous liver metastases who underwent simultaneous liver resection between January 2008 and December 2016. Using propensity score matching, overall outcome between 60 patients who underwent NAC before surgical treatment and 60 patients who underwent surgical treatment first was compared. Results: Before propensity score matching, metastatic cancer tended to involve a larger number of liver segments and the primary tumor size was bigger in the NAC group than in the primary resection group, so that a larger percentage of patients in the NAC group underwent major hepatectomy (P<0.001). After propensity score matching, demographic features and pathologic outcomes showed no significant differences between the 2 groups. In addition, there was no significant difference in short-term recovery outcomes such as postoperative morbidity (P=0.603) and oncologic outcome, including 3-year overall survival rate (P=0.285) and disease-free survival rate (P=0.730), between the 2 groups. Conclusion NAC prior to surgical treatment in CRCLM is considered a safe treatment that does not increase postoperative morbidity, and its impact on oncologic outcome was not inferior.