1.Influence of Patellar Implant Shape on Patellofemoral Contact Pressure Using Finite Element Analysis
Hun Sik CHO ; Hyoung-Taek HONG ; Hyuck Min KWON ; Yong-Gon KOH ; Seong-Mun HWANG ; Kwan Kyu PARK ; Kyoung-Tak KANG
Yonsei Medical Journal 2025;66(6):383-389
Purpose:
This study focused on analyzing the contact pressure and area on different patellar component designs in total knee arthroplasty (TKA) to evaluate biomechanics related to the patellofemoral (PF) joint.
Materials and Methods:
The patellar components studied included the dome design, modified dome design, and anatomical design implants. Using finite element analysis and mechanical testing, the pressure and area were evaluated. The first loading condition was simulated at flexion angles of 0°, 15°, 45°, 90°, 120°, and 150°. The second loading condition was simulated for a clinically relevant scenario, involving a 2-mm medial shift at a flexion angle of 45°.
Results:
For both the modified dome and anatomical designs, the contact area and pressure increased with the flexion angle. The dome design reached its maximum contact area at a flexion angle of 120°. Among the designs, the anatomical design had the largest contact area and a lower contact pressure compared to the dome and modified dome designs. However, when a medial shift of 2 mm was simulated at a 45° flexion angle, which can occur clinically, the anatomical design showed edge contact, leading to higher contact pressure and reduced contact area. In contrast, the modified dome design demonstrated the lowest contact pressure and the greatest contact area under the same shifted conditions.
Conclusion
These findings suggest that the design of the patellar component significantly affects patellar biomechanics and stability. Specifically, the modified dome design showed improved biomechanical effects in clinically relevant scenarios. Therefore, patellar components with a modified dome design are expected to better manage PF joint pain and reduce complications in TKA.
2.Male preference for TERT alterations and HBV integration in young-age HBV-related HCC: implications for sex disparity
Jin Seoub KIM ; Hye Seon KIM ; Kwon Yong TAK ; Ji Won HAN ; Heechul NAM ; Pil Soo SUNG ; Sung Won LEE ; Jung Hyun KWON ; Si Hyun BAE ; Jong Young CHOI ; Seung Kew YOON ; Jeong Won JANG
Clinical and Molecular Hepatology 2025;31(2):509-524
Background/Aims:
Hepatocellular carcinoma (HCC) exhibits significant sex disparities in incidence, yet its molecular mechanisms remain unclear. We explored the role of telomerase reverse transcriptase (TERT) genetic alterations and hepatitis B virus (HBV) integration, both known major contributors to HCC, in sex-specific risk for HBV-related HCC.
Methods:
We examined 310 HBV-related HCC tissues to investigate sex-specific TERT promoter (TERT-pro) mutations and HBV integration profiles, stratified by sex and age, and validated with single-cell RNA sequencing (scRNA-seq) data.
Results:
Tumors predominantly exhibited TERT-pro mutations (26.0% vs. 0%) and HBV-TERT integration (37.0% vs. 3.0%) compared to non-tumorous tissues. While TERT-pro mutations increased with age in both sexes, younger males (≤60 years) showed marked predominance compared to younger females. Males had significantly more HBV integrations at younger ages, while females initially had fewer integrations that gradually increased with age. Younger males' integrations showed significantly greater enrichment in the TERT locus compared to younger females, alongside a preference for promoters, PreS/S regions, and CpG islands. Overall, TERT genetic alterations were significantly sex-differential in younger individuals (75.3% in males vs. 23.1% in females) but not in older individuals (76.9% vs. 83.3%, respectively). These alterations were associated with increased TERT expression. The skewed TERT abnormalities in younger males were further corroborated by independent scRNA-seq data.
Conclusions
Our findings highlight the critical role of TERT alterations and HBV integration patterns in the male predominance of HCC incidence among younger HBV carriers, offering insights for future exploration to optimize sex-specific patient care and HCC surveillance strategies.
3.Influence of Patellar Implant Shape on Patellofemoral Contact Pressure Using Finite Element Analysis
Hun Sik CHO ; Hyoung-Taek HONG ; Hyuck Min KWON ; Yong-Gon KOH ; Seong-Mun HWANG ; Kwan Kyu PARK ; Kyoung-Tak KANG
Yonsei Medical Journal 2025;66(6):383-389
Purpose:
This study focused on analyzing the contact pressure and area on different patellar component designs in total knee arthroplasty (TKA) to evaluate biomechanics related to the patellofemoral (PF) joint.
Materials and Methods:
The patellar components studied included the dome design, modified dome design, and anatomical design implants. Using finite element analysis and mechanical testing, the pressure and area were evaluated. The first loading condition was simulated at flexion angles of 0°, 15°, 45°, 90°, 120°, and 150°. The second loading condition was simulated for a clinically relevant scenario, involving a 2-mm medial shift at a flexion angle of 45°.
Results:
For both the modified dome and anatomical designs, the contact area and pressure increased with the flexion angle. The dome design reached its maximum contact area at a flexion angle of 120°. Among the designs, the anatomical design had the largest contact area and a lower contact pressure compared to the dome and modified dome designs. However, when a medial shift of 2 mm was simulated at a 45° flexion angle, which can occur clinically, the anatomical design showed edge contact, leading to higher contact pressure and reduced contact area. In contrast, the modified dome design demonstrated the lowest contact pressure and the greatest contact area under the same shifted conditions.
Conclusion
These findings suggest that the design of the patellar component significantly affects patellar biomechanics and stability. Specifically, the modified dome design showed improved biomechanical effects in clinically relevant scenarios. Therefore, patellar components with a modified dome design are expected to better manage PF joint pain and reduce complications in TKA.
4.Influence of Patellar Implant Shape on Patellofemoral Contact Pressure Using Finite Element Analysis
Hun Sik CHO ; Hyoung-Taek HONG ; Hyuck Min KWON ; Yong-Gon KOH ; Seong-Mun HWANG ; Kwan Kyu PARK ; Kyoung-Tak KANG
Yonsei Medical Journal 2025;66(6):383-389
Purpose:
This study focused on analyzing the contact pressure and area on different patellar component designs in total knee arthroplasty (TKA) to evaluate biomechanics related to the patellofemoral (PF) joint.
Materials and Methods:
The patellar components studied included the dome design, modified dome design, and anatomical design implants. Using finite element analysis and mechanical testing, the pressure and area were evaluated. The first loading condition was simulated at flexion angles of 0°, 15°, 45°, 90°, 120°, and 150°. The second loading condition was simulated for a clinically relevant scenario, involving a 2-mm medial shift at a flexion angle of 45°.
Results:
For both the modified dome and anatomical designs, the contact area and pressure increased with the flexion angle. The dome design reached its maximum contact area at a flexion angle of 120°. Among the designs, the anatomical design had the largest contact area and a lower contact pressure compared to the dome and modified dome designs. However, when a medial shift of 2 mm was simulated at a 45° flexion angle, which can occur clinically, the anatomical design showed edge contact, leading to higher contact pressure and reduced contact area. In contrast, the modified dome design demonstrated the lowest contact pressure and the greatest contact area under the same shifted conditions.
Conclusion
These findings suggest that the design of the patellar component significantly affects patellar biomechanics and stability. Specifically, the modified dome design showed improved biomechanical effects in clinically relevant scenarios. Therefore, patellar components with a modified dome design are expected to better manage PF joint pain and reduce complications in TKA.
5.Male preference for TERT alterations and HBV integration in young-age HBV-related HCC: implications for sex disparity
Jin Seoub KIM ; Hye Seon KIM ; Kwon Yong TAK ; Ji Won HAN ; Heechul NAM ; Pil Soo SUNG ; Sung Won LEE ; Jung Hyun KWON ; Si Hyun BAE ; Jong Young CHOI ; Seung Kew YOON ; Jeong Won JANG
Clinical and Molecular Hepatology 2025;31(2):509-524
Background/Aims:
Hepatocellular carcinoma (HCC) exhibits significant sex disparities in incidence, yet its molecular mechanisms remain unclear. We explored the role of telomerase reverse transcriptase (TERT) genetic alterations and hepatitis B virus (HBV) integration, both known major contributors to HCC, in sex-specific risk for HBV-related HCC.
Methods:
We examined 310 HBV-related HCC tissues to investigate sex-specific TERT promoter (TERT-pro) mutations and HBV integration profiles, stratified by sex and age, and validated with single-cell RNA sequencing (scRNA-seq) data.
Results:
Tumors predominantly exhibited TERT-pro mutations (26.0% vs. 0%) and HBV-TERT integration (37.0% vs. 3.0%) compared to non-tumorous tissues. While TERT-pro mutations increased with age in both sexes, younger males (≤60 years) showed marked predominance compared to younger females. Males had significantly more HBV integrations at younger ages, while females initially had fewer integrations that gradually increased with age. Younger males' integrations showed significantly greater enrichment in the TERT locus compared to younger females, alongside a preference for promoters, PreS/S regions, and CpG islands. Overall, TERT genetic alterations were significantly sex-differential in younger individuals (75.3% in males vs. 23.1% in females) but not in older individuals (76.9% vs. 83.3%, respectively). These alterations were associated with increased TERT expression. The skewed TERT abnormalities in younger males were further corroborated by independent scRNA-seq data.
Conclusions
Our findings highlight the critical role of TERT alterations and HBV integration patterns in the male predominance of HCC incidence among younger HBV carriers, offering insights for future exploration to optimize sex-specific patient care and HCC surveillance strategies.
6.Influence of Patellar Implant Shape on Patellofemoral Contact Pressure Using Finite Element Analysis
Hun Sik CHO ; Hyoung-Taek HONG ; Hyuck Min KWON ; Yong-Gon KOH ; Seong-Mun HWANG ; Kwan Kyu PARK ; Kyoung-Tak KANG
Yonsei Medical Journal 2025;66(6):383-389
Purpose:
This study focused on analyzing the contact pressure and area on different patellar component designs in total knee arthroplasty (TKA) to evaluate biomechanics related to the patellofemoral (PF) joint.
Materials and Methods:
The patellar components studied included the dome design, modified dome design, and anatomical design implants. Using finite element analysis and mechanical testing, the pressure and area were evaluated. The first loading condition was simulated at flexion angles of 0°, 15°, 45°, 90°, 120°, and 150°. The second loading condition was simulated for a clinically relevant scenario, involving a 2-mm medial shift at a flexion angle of 45°.
Results:
For both the modified dome and anatomical designs, the contact area and pressure increased with the flexion angle. The dome design reached its maximum contact area at a flexion angle of 120°. Among the designs, the anatomical design had the largest contact area and a lower contact pressure compared to the dome and modified dome designs. However, when a medial shift of 2 mm was simulated at a 45° flexion angle, which can occur clinically, the anatomical design showed edge contact, leading to higher contact pressure and reduced contact area. In contrast, the modified dome design demonstrated the lowest contact pressure and the greatest contact area under the same shifted conditions.
Conclusion
These findings suggest that the design of the patellar component significantly affects patellar biomechanics and stability. Specifically, the modified dome design showed improved biomechanical effects in clinically relevant scenarios. Therefore, patellar components with a modified dome design are expected to better manage PF joint pain and reduce complications in TKA.
7.Male preference for TERT alterations and HBV integration in young-age HBV-related HCC: implications for sex disparity
Jin Seoub KIM ; Hye Seon KIM ; Kwon Yong TAK ; Ji Won HAN ; Heechul NAM ; Pil Soo SUNG ; Sung Won LEE ; Jung Hyun KWON ; Si Hyun BAE ; Jong Young CHOI ; Seung Kew YOON ; Jeong Won JANG
Clinical and Molecular Hepatology 2025;31(2):509-524
Background/Aims:
Hepatocellular carcinoma (HCC) exhibits significant sex disparities in incidence, yet its molecular mechanisms remain unclear. We explored the role of telomerase reverse transcriptase (TERT) genetic alterations and hepatitis B virus (HBV) integration, both known major contributors to HCC, in sex-specific risk for HBV-related HCC.
Methods:
We examined 310 HBV-related HCC tissues to investigate sex-specific TERT promoter (TERT-pro) mutations and HBV integration profiles, stratified by sex and age, and validated with single-cell RNA sequencing (scRNA-seq) data.
Results:
Tumors predominantly exhibited TERT-pro mutations (26.0% vs. 0%) and HBV-TERT integration (37.0% vs. 3.0%) compared to non-tumorous tissues. While TERT-pro mutations increased with age in both sexes, younger males (≤60 years) showed marked predominance compared to younger females. Males had significantly more HBV integrations at younger ages, while females initially had fewer integrations that gradually increased with age. Younger males' integrations showed significantly greater enrichment in the TERT locus compared to younger females, alongside a preference for promoters, PreS/S regions, and CpG islands. Overall, TERT genetic alterations were significantly sex-differential in younger individuals (75.3% in males vs. 23.1% in females) but not in older individuals (76.9% vs. 83.3%, respectively). These alterations were associated with increased TERT expression. The skewed TERT abnormalities in younger males were further corroborated by independent scRNA-seq data.
Conclusions
Our findings highlight the critical role of TERT alterations and HBV integration patterns in the male predominance of HCC incidence among younger HBV carriers, offering insights for future exploration to optimize sex-specific patient care and HCC surveillance strategies.
8.Influence of Patellar Implant Shape on Patellofemoral Contact Pressure Using Finite Element Analysis
Hun Sik CHO ; Hyoung-Taek HONG ; Hyuck Min KWON ; Yong-Gon KOH ; Seong-Mun HWANG ; Kwan Kyu PARK ; Kyoung-Tak KANG
Yonsei Medical Journal 2025;66(6):383-389
Purpose:
This study focused on analyzing the contact pressure and area on different patellar component designs in total knee arthroplasty (TKA) to evaluate biomechanics related to the patellofemoral (PF) joint.
Materials and Methods:
The patellar components studied included the dome design, modified dome design, and anatomical design implants. Using finite element analysis and mechanical testing, the pressure and area were evaluated. The first loading condition was simulated at flexion angles of 0°, 15°, 45°, 90°, 120°, and 150°. The second loading condition was simulated for a clinically relevant scenario, involving a 2-mm medial shift at a flexion angle of 45°.
Results:
For both the modified dome and anatomical designs, the contact area and pressure increased with the flexion angle. The dome design reached its maximum contact area at a flexion angle of 120°. Among the designs, the anatomical design had the largest contact area and a lower contact pressure compared to the dome and modified dome designs. However, when a medial shift of 2 mm was simulated at a 45° flexion angle, which can occur clinically, the anatomical design showed edge contact, leading to higher contact pressure and reduced contact area. In contrast, the modified dome design demonstrated the lowest contact pressure and the greatest contact area under the same shifted conditions.
Conclusion
These findings suggest that the design of the patellar component significantly affects patellar biomechanics and stability. Specifically, the modified dome design showed improved biomechanical effects in clinically relevant scenarios. Therefore, patellar components with a modified dome design are expected to better manage PF joint pain and reduce complications in TKA.
9.Efficacy and safety of sofosbuvir–velpatasvir and sofosbuvir–velpatasvir–voxilaprevir for hepatitis C in Korea: a Phase 3b study
Jeong HEO ; Yoon Jun KIM ; Sung Wook LEE ; Youn-Jae LEE ; Ki Tae YOON ; Kwan Soo BYUN ; Yong Jin JUNG ; Won Young TAK ; Sook-Hyang JEONG ; Kyung Min KWON ; Vithika SURI ; Peiwen WU ; Byoung Kuk JANG ; Byung Seok LEE ; Ju-Yeon CHO ; Jeong Won JANG ; Soo Hyun YANG ; Seung Woon PAIK ; Hyung Joon KIM ; Jung Hyun KWON ; Neung Hwa PARK ; Ju Hyun KIM ; In Hee KIM ; Sang Hoon AHN ; Young-Suk LIM
The Korean Journal of Internal Medicine 2023;38(4):504-513
Despite the availability of direct-acting antivirals (DAAs) for chronic hepatitis C virus (HCV) infection in Korea, need remains for pangenotypic regimens that can be used in the presence of hepatic impairment, comorbidities, or prior treatment failure. We investigated the efficacy and safety of sofosbuvir–velpatasvir and sofosbuvir–velpatasvir–voxilaprevir for 12 weeks in HCV-infected Korean adults. Methods: This Phase 3b, multicenter, open-label study included 2 cohorts. In Cohort 1, participants with HCV genotype 1 or 2 and who were treatment-naive or treatment-experienced with interferon-based treatments, received sofosbuvir–velpatasvir 400/100 mg/day. In Cohort 2, HCV genotype 1 infected individuals who previously received an NS5A inhibitor-containing regimen ≥ 4 weeks received sofosbuvir–velpatasvir–voxilaprevir 400/100/100 mg/day. Decompensated cirrhosis was an exclusion criterion. The primary endpoint was SVR12, defined as HCV RNA < 15 IU/mL 12 weeks following treatment. Results: Of 53 participants receiving sofosbuvir–velpatasvir, 52 (98.1%) achieved SVR12. The single participant who did not achieve SVR12 experienced an asymptomatic Grade 3 ASL/ALT elevation on day 15 and discontinued treatment. The event resolved without intervention. All 33 participants (100%) treated with sofosbuvir–velpatasvir–voxilaprevir achieved SVR 12. Overall, sofosbuvir–velpatasvir and sofosbuvir–velpatasvir–voxilaprevir were safe and well tolerated. Three participants (5.6%) in Cohort 1 and 1 participant (3.0%) in Cohort 2 had serious adverse events, but none were considered treatment-related. No deaths or grade 4 laboratory abnormalities were reported. Conclusions: Treatment with sofosbuvir–velpatasvir or sofosbuvir–velpatasvir–voxilaprevir was safe and resulted in high SVR12 rates in Korean HCV patients.
10.Persistence of intrahepatic hepatitis B virus DNA integration in patients developing hepatocellular carcinoma after hepatitis B surface antigen seroclearance
Jeong Won JANG ; Jin Seoub KIM ; Hye Seon KIM ; Kwon Yong TAK ; Heechul NAM ; Pil Soo SUNG ; Si Hyun BAE ; Jong Young CHOI ; Seung Kew YOON ; Lewis R. ROBERTS
Clinical and Molecular Hepatology 2021;27(1):207-218
Background/Aims:
The role of hepatitis B virus (HBV) integration into the host genome in hepatocarcinogenesis following hepatitis B surface antigen (HBsAg) seroclearance remains unknown. Our study aimed to investigate and characterize HBV integration events in chronic hepatitis B (CHB) patients who developed hepatocellular carcinoma (HCC) after HBsAg seroclearance.
Methods:
Using probe-based HBV capturing followed by next-generation sequencing technology, HBV integration was examined in 10 samples (seven tumors and three non-tumor tissues) from seven chronic carriers who developed HCC after HBsAg loss. Genomic locations and patterns of HBV integration were investigated.
Results:
HBV integration was observed in six patients (85.7%) and eight (80.0%) of 10 tested samples. HBV integration breakpoints were detected in all of the non-tumor (3/3, 100%) and five of the seven (71.4%) tumor samples, with an average number of breakpoints of 4.00 and 2.43, respectively. Despite the lower total number of tumoral integration breakpoints, HBV integration sites in the tumors were more enriched within the genic area. In contrast, non-tumor tissues more often showed intergenic integration. Regarding functions of the affected genes, tumoral genes with HBV integration were mostly associated with carcinogenesis. At enrollment, patients who did not remain under regular HCC surveillance after HBsAg seroclearance had a large HCC, while those on regular surveillance had a small HCC.
Conclusions
The biological functions of HBV integration are almost comparable between HBsAg-positive and HBsAgserocleared HCCs, with continuing pro-oncogenic effects of HBV integration. Thus, ongoing HCC surveillance and clinical management should continue even after HBsAg seroclearance in patients with CHB.

Result Analysis
Print
Save
E-mail