2.Additional Screw Added to the Femoral Neck System Could Enhance the Stability of Pauwel Type III Femoral Neck Fractures:a Finite Element Analysis
Yonghan CHA ; Sunghoon PARK ; Chang-Ho JUNG ; Jin-Woo KIM ; Jun-Il YOO ; Jung-Taek KIM ; Yongho JEON ; Kyeong Jin HAN
Clinics in Orthopedic Surgery 2025;17(2):204-215
Background:
This study explores effective fixation methods for Pauwel type III femoral neck fractures by evaluating the biomechanical benefits of adding a screw to the Femoral Neck System (FNS).
Methods:
Computed tomography (CT) scans of an 82-year-old female patient with an intertrochanteric fracture were used to establish a finite element femur model with heterogeneous material properties. Finite element models of Pauwel type III fractures were created with and without an additional screw. The central and inferior trajectories of the FNS bolt were examined separately and combined with an additional screw for virtual fixation. Walking and stair-climbing loads were applied.
Results:
With the addition of a screw, both peak maximum and minimum principal strains consistently stayed comparable or decreased in models with both central and inferior bolt trajectories, while the volume of elements with principal strain exceeding 1% decreased by more than half. The peak von Mises stress observed in the implants ranged from 215.7 to 359.3 MPa, remaining below the titanium alloy's yield strength of 800 MPa. For normal walking, the addition of a screw to the central bolt trajectory model decreased the fracture gap by 50.6% and reduced sliding distance by 8.6%. For the inferior bolt trajectory, the gap was reduced by 57.9% and sliding distance by 25.0%.Under stair-climbing conditions, these improvements were also evident; the central trajectory model saw a halved fracture gap and a 7.9% decrease in sliding distance, while the inferior trajectory model experienced a 55.7% gap reduction and a 27.2% decrease in sliding distance. The additional screw increased the area ratio of the fracture site experiencing interfragmentary compression 34%–39%, while the additional screw alleviated peak interfragmentary compression by 12%–18% under both normal walking and stair-climbing conditions.
Conclusions
The addition of a screw reduced the fracture gap, sliding distance, and peak interfragmentary compression, while increasing the area ratio of interfragmentary compression under both walking and stair-climbing loads, regardless of the FNS bolt trajectory, suggesting a better mechanical environment for fracture healing.
3.Comparing Stability, Gait, and Functional Score after 40-mm Dual-Mobility Hip Arthroplasty to 36-mm Head Hip Arthroplasty in Elderly Hip Fracture Patients
Yonghan CHA ; Sang-Yeob LEE ; Ji-Ho BAE ; Yang Jae KANG ; Ji-Hoon BAEK ; Joon Soon KANG ; Chan Ho PARK ; Shinjune KIM ; Jun-Il YOO
Clinics in Orthopedic Surgery 2025;17(1):62-70
Background:
This study aimed to compare the intraoperative stability and early clinical outcomes of 40-mm diameter dual mobility (DM)-total hip arthroplasty (THA) with 36-mm ceramic head (large head) THA in active elderly patients with hip fractures.
Methods:
A prospective randomized controlled trial was conducted from May 2022 to December 2022. Inclusion criteria were as follows: age ≥ 60 years, displaced femoral neck fracture, Koval grade 1 or 2, planned 54-mm acetabular component, and over 1-year follow-up. Intraoperative stability tests were performed on all patients (internal rotation at 45°, 60°, and 90° of hip fracture). Functional outcomes (Harris Hip Score and University of California, Los Angeles [UCLA] Score) were evaluated at 6 weeks and 3 months postoperatively. Gait analysis using artificial intelligence (AI) techniques was conducted at 3 months postoperatively.
Results:
The study included 36 DM-THA patients (mean age, 69.6 ± 2.2 years; 44% women) and 37 large head THA patients (mean age, 69.6 ± 1.2 years; 64% women). No statistically significant differences were observed in functional outcomes and hip range of motion between the 2 groups. However, there was a significant difference in the gait speed and stance-swing phase of the large head THA group and the DM-THA group: the DM-THA group demonstrated superior gait speed (2.85 ± 0.83 kph vs. 2.04 ± 1.04 kph, p = 0.003) and higher stance phase ratios (operated side: 63.57% ± 3.82% vs. 48.19% ± 5.50%, p < 0.001; opposite side: 62.77% ± 2.27% vs. 49.93% ± 6.94%, p < 0.001). In the stability test at 90° of hip flexion, the DM-THA group had a measurement of 48.40° ± 5.17°, while the large head THA group had a measurement of 30.94° ± 2.98° (p = 0.012). Despite the lack of statistical significance, the intraoperative stability test showed the dislocation angle was notably different between the groups in the hip flexion position of 60° (51.60° ± 6.09° in the DM-THA group and 40.00° ± 2.80° in the large head THA group, p = 0.072).
Conclusions
Superior results were observed in the intraoperative stability test and early recovery of gait after DM-THA compared to large head THA. We believe that DM-THA can be a useful surgical option for THA in elderly patients with hip fractures.
4.Effects of student human rights ordinances on mental health among middle and high school students in South Korea: a difference-in-differences analysis
Epidemiology and Health 2025;47(1):e2025011-
OBJECTIVES:
To actively protect and enhance students’ human rights, student human rights ordinances (SHROs) have been enforced in seven provinces in South Korea at different times since 2010. Although human rights are closely linked to mental health, there has been no research on the effectiveness of human rights legislation on adolescent mental health. This study evaluated the effects of SHROs on the mental health of middle and high school students.
METHODS:
Repeated cross-sectional data were used, including 1,148,257 respondents from the Korea Youth Risk Behavior Web-based Survey between 2006 and 2023. Probabilities of perceived stress, sleep insufficiency, depressive mood, suicide ideation, and suicide attempt in treated provinces were estimated through a difference-in-differences approach that accounts for treatment effect heterogeneity across groups over time.
RESULTS:
SHROs had no consistently significant effects on any mental health outcomes, except for slightly increased suicide ideation in total students (0.7%, 95% confidence interval 0.3% to 1.1%). Suicide attempts in total and male students and perceived stress and sleep insufficiency in female students tended to decrease, while other mental health outcomes tended to increase. Uncertainty in the effect estimates of SHROs increased for all mental health outcomes with possible violations of parallel trends, rendering originally significant effects insignificant.
CONCLUSIONS
SHROs failed to improve mental health of middle and high school students in treated provinces, possibly due to the absence of enforcement mechanisms. Further research is needed on the effectiveness of and effect mechanisms for legal measures to improve human rights on adolescent mental health.
5.Re-do laparoscopic common bile duct exploration for recurrent common bile duct stones: a single-center retrospective cohort study
In Ho LEE ; Seung Jae LEE ; Ju Ik MOON ; Sang Eok LEE ; Nak Song SUNG ; Seong Uk KWON ; In Eui BAE ; Seung Jae RHO ; Sung Gon KIM ; Min Kyu KIM ; Dae Sung YOON ; Won Jun CHOI ; In Seok CHOI
Annals of Surgical Treatment and Research 2025;108(5):310-316
Purpose:
Common bile duct (CBD) stone recurrence after laparoscopic CBD exploration (LCBDE) is relatively common. No studies have been conducted evaluating the safety and feasibility of re-do LCBDE in the treatment of recurrent CBD stones.
Methods:
This single-center retrospective study reviewed 340 consecutive patients who underwent LCBDE for CBD stones between January 2004 and December 2020. Patients with pancreatobiliary malignancies and those who underwent other surgical procedures were excluded.
Results:
Of the 340 included patients, 45 experienced a recurrence after a mean follow-up period of 24.2 months. Of them, 18 underwent re-do LCBDE, 20 underwent endoscopic intervention, 2 underwent radiologic intervention, and 5 underwent observation. Re-do LCBDE and initial LCBDE showed similar surgical outcomes in terms of operative time (113.1 minutes vs. 107.5 minutes, P = 0.515), estimated blood loss (42.5 mL vs. 49.1 mL, P = 0.661), open conversion rate (2.9% vs. 0%, P = 0.461), postoperative complication (15.3% vs. 22.2%, P = 0.430), and postoperative hospital stay (6.5 days vs. 6.4 days, P = 0.921). Comparing re-do LCBDE and nonsurgical treatment (endoscopic or radiologic), no statistically significant differences were noted in posttreatment complication (22.2% vs. 13.6%, P = 0.477), hospital stay (6.4 days vs.7.3 days, P = 0.607), and recurrence (50.0% vs. 36.4%, P = 0.385). The clearance rate was higher in the re-do LCBDE group than in the nonsurgical group (100% vs. 81.8%, P = 0.057).
Conclusion
Compared to initial LCBDE and endoscopic or radiological treatments, re-do LCBDE for recurrent CBD stones is a treatment option worth considering in selected patients.
6.Additional Screw Added to the Femoral Neck System Could Enhance the Stability of Pauwel Type III Femoral Neck Fractures:a Finite Element Analysis
Yonghan CHA ; Sunghoon PARK ; Chang-Ho JUNG ; Jin-Woo KIM ; Jun-Il YOO ; Jung-Taek KIM ; Yongho JEON ; Kyeong Jin HAN
Clinics in Orthopedic Surgery 2025;17(2):204-215
Background:
This study explores effective fixation methods for Pauwel type III femoral neck fractures by evaluating the biomechanical benefits of adding a screw to the Femoral Neck System (FNS).
Methods:
Computed tomography (CT) scans of an 82-year-old female patient with an intertrochanteric fracture were used to establish a finite element femur model with heterogeneous material properties. Finite element models of Pauwel type III fractures were created with and without an additional screw. The central and inferior trajectories of the FNS bolt were examined separately and combined with an additional screw for virtual fixation. Walking and stair-climbing loads were applied.
Results:
With the addition of a screw, both peak maximum and minimum principal strains consistently stayed comparable or decreased in models with both central and inferior bolt trajectories, while the volume of elements with principal strain exceeding 1% decreased by more than half. The peak von Mises stress observed in the implants ranged from 215.7 to 359.3 MPa, remaining below the titanium alloy's yield strength of 800 MPa. For normal walking, the addition of a screw to the central bolt trajectory model decreased the fracture gap by 50.6% and reduced sliding distance by 8.6%. For the inferior bolt trajectory, the gap was reduced by 57.9% and sliding distance by 25.0%.Under stair-climbing conditions, these improvements were also evident; the central trajectory model saw a halved fracture gap and a 7.9% decrease in sliding distance, while the inferior trajectory model experienced a 55.7% gap reduction and a 27.2% decrease in sliding distance. The additional screw increased the area ratio of the fracture site experiencing interfragmentary compression 34%–39%, while the additional screw alleviated peak interfragmentary compression by 12%–18% under both normal walking and stair-climbing conditions.
Conclusions
The addition of a screw reduced the fracture gap, sliding distance, and peak interfragmentary compression, while increasing the area ratio of interfragmentary compression under both walking and stair-climbing loads, regardless of the FNS bolt trajectory, suggesting a better mechanical environment for fracture healing.
7.Comparing Stability, Gait, and Functional Score after 40-mm Dual-Mobility Hip Arthroplasty to 36-mm Head Hip Arthroplasty in Elderly Hip Fracture Patients
Yonghan CHA ; Sang-Yeob LEE ; Ji-Ho BAE ; Yang Jae KANG ; Ji-Hoon BAEK ; Joon Soon KANG ; Chan Ho PARK ; Shinjune KIM ; Jun-Il YOO
Clinics in Orthopedic Surgery 2025;17(1):62-70
Background:
This study aimed to compare the intraoperative stability and early clinical outcomes of 40-mm diameter dual mobility (DM)-total hip arthroplasty (THA) with 36-mm ceramic head (large head) THA in active elderly patients with hip fractures.
Methods:
A prospective randomized controlled trial was conducted from May 2022 to December 2022. Inclusion criteria were as follows: age ≥ 60 years, displaced femoral neck fracture, Koval grade 1 or 2, planned 54-mm acetabular component, and over 1-year follow-up. Intraoperative stability tests were performed on all patients (internal rotation at 45°, 60°, and 90° of hip fracture). Functional outcomes (Harris Hip Score and University of California, Los Angeles [UCLA] Score) were evaluated at 6 weeks and 3 months postoperatively. Gait analysis using artificial intelligence (AI) techniques was conducted at 3 months postoperatively.
Results:
The study included 36 DM-THA patients (mean age, 69.6 ± 2.2 years; 44% women) and 37 large head THA patients (mean age, 69.6 ± 1.2 years; 64% women). No statistically significant differences were observed in functional outcomes and hip range of motion between the 2 groups. However, there was a significant difference in the gait speed and stance-swing phase of the large head THA group and the DM-THA group: the DM-THA group demonstrated superior gait speed (2.85 ± 0.83 kph vs. 2.04 ± 1.04 kph, p = 0.003) and higher stance phase ratios (operated side: 63.57% ± 3.82% vs. 48.19% ± 5.50%, p < 0.001; opposite side: 62.77% ± 2.27% vs. 49.93% ± 6.94%, p < 0.001). In the stability test at 90° of hip flexion, the DM-THA group had a measurement of 48.40° ± 5.17°, while the large head THA group had a measurement of 30.94° ± 2.98° (p = 0.012). Despite the lack of statistical significance, the intraoperative stability test showed the dislocation angle was notably different between the groups in the hip flexion position of 60° (51.60° ± 6.09° in the DM-THA group and 40.00° ± 2.80° in the large head THA group, p = 0.072).
Conclusions
Superior results were observed in the intraoperative stability test and early recovery of gait after DM-THA compared to large head THA. We believe that DM-THA can be a useful surgical option for THA in elderly patients with hip fractures.
8.Effects of student human rights ordinances on mental health among middle and high school students in South Korea: a difference-in-differences analysis
Epidemiology and Health 2025;47(1):e2025011-
OBJECTIVES:
To actively protect and enhance students’ human rights, student human rights ordinances (SHROs) have been enforced in seven provinces in South Korea at different times since 2010. Although human rights are closely linked to mental health, there has been no research on the effectiveness of human rights legislation on adolescent mental health. This study evaluated the effects of SHROs on the mental health of middle and high school students.
METHODS:
Repeated cross-sectional data were used, including 1,148,257 respondents from the Korea Youth Risk Behavior Web-based Survey between 2006 and 2023. Probabilities of perceived stress, sleep insufficiency, depressive mood, suicide ideation, and suicide attempt in treated provinces were estimated through a difference-in-differences approach that accounts for treatment effect heterogeneity across groups over time.
RESULTS:
SHROs had no consistently significant effects on any mental health outcomes, except for slightly increased suicide ideation in total students (0.7%, 95% confidence interval 0.3% to 1.1%). Suicide attempts in total and male students and perceived stress and sleep insufficiency in female students tended to decrease, while other mental health outcomes tended to increase. Uncertainty in the effect estimates of SHROs increased for all mental health outcomes with possible violations of parallel trends, rendering originally significant effects insignificant.
CONCLUSIONS
SHROs failed to improve mental health of middle and high school students in treated provinces, possibly due to the absence of enforcement mechanisms. Further research is needed on the effectiveness of and effect mechanisms for legal measures to improve human rights on adolescent mental health.
9.Effects of student human rights ordinances on mental health among middle and high school students in South Korea: a difference-in-differences analysis
Epidemiology and Health 2025;47(1):e2025011-
OBJECTIVES:
To actively protect and enhance students’ human rights, student human rights ordinances (SHROs) have been enforced in seven provinces in South Korea at different times since 2010. Although human rights are closely linked to mental health, there has been no research on the effectiveness of human rights legislation on adolescent mental health. This study evaluated the effects of SHROs on the mental health of middle and high school students.
METHODS:
Repeated cross-sectional data were used, including 1,148,257 respondents from the Korea Youth Risk Behavior Web-based Survey between 2006 and 2023. Probabilities of perceived stress, sleep insufficiency, depressive mood, suicide ideation, and suicide attempt in treated provinces were estimated through a difference-in-differences approach that accounts for treatment effect heterogeneity across groups over time.
RESULTS:
SHROs had no consistently significant effects on any mental health outcomes, except for slightly increased suicide ideation in total students (0.7%, 95% confidence interval 0.3% to 1.1%). Suicide attempts in total and male students and perceived stress and sleep insufficiency in female students tended to decrease, while other mental health outcomes tended to increase. Uncertainty in the effect estimates of SHROs increased for all mental health outcomes with possible violations of parallel trends, rendering originally significant effects insignificant.
CONCLUSIONS
SHROs failed to improve mental health of middle and high school students in treated provinces, possibly due to the absence of enforcement mechanisms. Further research is needed on the effectiveness of and effect mechanisms for legal measures to improve human rights on adolescent mental health.
10.Re-do laparoscopic common bile duct exploration for recurrent common bile duct stones: a single-center retrospective cohort study
In Ho LEE ; Seung Jae LEE ; Ju Ik MOON ; Sang Eok LEE ; Nak Song SUNG ; Seong Uk KWON ; In Eui BAE ; Seung Jae RHO ; Sung Gon KIM ; Min Kyu KIM ; Dae Sung YOON ; Won Jun CHOI ; In Seok CHOI
Annals of Surgical Treatment and Research 2025;108(5):310-316
Purpose:
Common bile duct (CBD) stone recurrence after laparoscopic CBD exploration (LCBDE) is relatively common. No studies have been conducted evaluating the safety and feasibility of re-do LCBDE in the treatment of recurrent CBD stones.
Methods:
This single-center retrospective study reviewed 340 consecutive patients who underwent LCBDE for CBD stones between January 2004 and December 2020. Patients with pancreatobiliary malignancies and those who underwent other surgical procedures were excluded.
Results:
Of the 340 included patients, 45 experienced a recurrence after a mean follow-up period of 24.2 months. Of them, 18 underwent re-do LCBDE, 20 underwent endoscopic intervention, 2 underwent radiologic intervention, and 5 underwent observation. Re-do LCBDE and initial LCBDE showed similar surgical outcomes in terms of operative time (113.1 minutes vs. 107.5 minutes, P = 0.515), estimated blood loss (42.5 mL vs. 49.1 mL, P = 0.661), open conversion rate (2.9% vs. 0%, P = 0.461), postoperative complication (15.3% vs. 22.2%, P = 0.430), and postoperative hospital stay (6.5 days vs. 6.4 days, P = 0.921). Comparing re-do LCBDE and nonsurgical treatment (endoscopic or radiologic), no statistically significant differences were noted in posttreatment complication (22.2% vs. 13.6%, P = 0.477), hospital stay (6.4 days vs.7.3 days, P = 0.607), and recurrence (50.0% vs. 36.4%, P = 0.385). The clearance rate was higher in the re-do LCBDE group than in the nonsurgical group (100% vs. 81.8%, P = 0.057).
Conclusion
Compared to initial LCBDE and endoscopic or radiological treatments, re-do LCBDE for recurrent CBD stones is a treatment option worth considering in selected patients.

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