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.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.
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.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.
6.Busulfan, Melphalan, and Etoposide (BuME) Showed an Equivalent Effect to Busulfan, Cyclophosphamide, and Etoposide (BuCE) as Conditioning Therapy for Autologous Stem Cell Transplantation in Patients with Relapsed or High-Risk Non-Hodgkin’s Lymphoma: A Multicenter Randomized Phase II Study bythe Consortium for Improving Survival of Lymphoma (CISL)
Kyoung Ha KIM ; Jae Hoon LEE ; Mark LEE ; Hoon-Gu KIM ; Young Rok DO ; Yong PARK ; Sung Yong OH ; Ho-Jin SHIN ; Won Seog KIM ; Seong Kyu PARK ; Jee Hyun KONG ; Moo-Rim PARK ; Deok-Hwan YANG ; Jae-Yong KWAK ; Hye Jin KANG ; Yeung-Chul MUN ; Jong-Ho WON
Cancer Research and Treatment 2023;55(1):304-313
Purpose:
High-dose chemotherapy followed by autologous stem cell transplantation (ASCT) is the standard management for relapsed or high-risk non-Hodgkin’s lymphoma (NHL). We reported the busulfan, melphalan, and etoposide (BuME) conditioning regimen was effective in patients with relapsed or high-risk NHL. Moreover, the busulfan, cyclophosphamide, and etoposide (BuCE) conditioning regimen has been used widely in ASCT for NHL. Therefore, based on these encouraging results, this randomized phase II multicenter trial compared the outcomes of BuME and BuCE as conditioning therapies for ASCT in patients with NHL.
Materials and Methods:
Patients were randomly assigned to receive either BuME (n=36) or BuCE (n=39). The BuME regimen was comprised of busulfan (3.2 mg/kg/day, intravenously) administered on days –7, –6, and –5, etoposide (400 mg/m2 intravenously) on days –5 and –4, and melphalan (50 mg/m2/day intravenously) on days –3 and –2. The BuCE regimen was comprised of busulfan (3.2 mg/kg/day intravenously) on days –7, –6, and –5, etoposide (400 mg/m2/day intravenously) on days –5 and –4, and cyclophosphamide (50 mg/kg/day intravenously) on days –3 and –2. The primary endpoint was 2-year progression-free survival (PFS).
Results:
Seventy-five patients were enrolled. Eleven patients (30.5%) in the BuME group and 13 patients (33.3%) in the BuCE group had disease progression or died. The 2-year PFS rate was 65.4% in the BuME group and 60.6% in the BuCE group (p=0.746). There were no non-relapse mortalities within 100 days after transplantation.
Conclusion
There were no significant differences in PFS between the two groups. Therefore, busulfan-based conditioning regimens, BuME and BuCE, may be important treatment substitutes for the BCNU-containing regimens.
7.Intensified First Cycle of Rituximab Plus Eight Cycles of Cyclophosphamide, Doxorubicin, Vincristine, and Prednisolone with Rituximab Chemotherapy for Advanced-Stage or Bulky Diffuse Large B-Cell Lymphoma: A Multicenter Phase II Consortium for Improving Survival of Lymphoma (CISL) Study
Yu Ri KIM ; Jin Seok KIM ; Won Seog KIM ; Hyeon Seok EOM ; Deok-Hwan YANG ; Sung Hwa BAE ; Hyo Jung KIM ; Jae Hoon LEE ; Suk-Joong OH ; Sung-Soo YOON ; Jae-Yong KWAK ; Chul Won CHOI ; Min Kyoung KIM ; Sung Young OH ; Hye Jin KANG ; Seung Hyun NAM ; Hyeok SHIM ; Joon Seong PARK ; Yeung-Chul MUN ; Cheolwon SUH ;
Cancer Research and Treatment 2023;55(4):1355-1362
Purpose:
This phase II, open-label, multicenter study aimed to investigate the efficacy and safety of a rituximab intensification for the 1st cycle with every 21-day of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP-21) among patients with previously untreated advanced-stage or bulky diffuse large B-cell lymphoma (DLBCL).
Materials and Methods:
Ninety-two patients with stage III/IV or bulky DLBCL from 21 institutions were administered 8 cycles of R-CHOP-21 with an additional one dose of rituximab intensification on day 0 of the 1st cycle (RR-CHOP). The primary endpoint was a complete response (CR) rate after 3 cycles of chemotherapy.
Results:
Among the 92 DLBCL patients assessed herein, the response rate after 3 cycles of chemotherapy was 88.0% (38.0% CR+50.0% partial response [PR]). After the completion of 8 cycles of chemotherapy, the overall response rate was observed for 68.4% (58.7% CR+9.8% PR). The 3-year progression-free survival rate was 64.0%, and the 3-year overall survival rate was 70.4%. Febrile neutropenia was one of the most frequent grade 3 adverse events (40.0%) and 5 treatment-related deaths occurred. Compared with the clinical outcomes of patients who received R-CHOP chemotherapy as a historical control, the interim CR rate was higher in male patients with RR-CHOP (20.5% vs. 48.8%, p=0.016).
Conclusion
Rituximab intensification on days 0 to the 1st cycle of the standard 8 cycles R-CHOP-21 for advanced DLBCL yielded favorable response rates after the 3 cycles of chemotherapy and acceptable toxicities, especially for male patients. ClinicalTrials.gov ID: NCT01054781.
8.Field evaluation of the safety and immunogenicity of a classical swine fever virus E2 subunit vaccine in breeding and nursery animals on Jeju Island, South Korea
Guehwan JANG ; Eun-Joo KIM ; Seong-Cheol CHO ; Sung-Up MOON ; Byeong Soo KIM ; Jinhee KIM ; Kyoung Ju JEONG ; Kyungok SONG ; Seong Hwan MUN ; Won-Myoung KANG ; Jonghoo LEE ; Changnam PARK ; Hyoung-Seok YANG ; Changhee LEE
Clinical and Experimental Vaccine Research 2022;11(3):264-273
Purpose:
Classical swine fever (CSF) reemerged on CSF-free Jeju Island where vaccination is not practiced by the unintentional injection of a live attenuated vaccine (modified live attenuated vaccines–low-virulence Miyagi [MLV-LOM]) in 2014. Since the Jeju provincial authority is considering adopting a voluntary immunization policy using a CSF-E2 subunit vaccine to combat LOM-derived CSF endemic, this study aimed to evaluate in Jeju herds.
Materials and Methods:
Two vaccination trials using the Bayovac CSF-E2 vaccine licensed for use in South Korea assessed the safety and humoral immunity of the CSF-E2 vaccine in breeding (trial 1) and nursery animals (trial 2) under farm application conditions.
Results:
Neither local nor systemic (including reproductive) adverse effects were objectively observed in pregnant sows and young piglets following a respective vaccination regime at pregnancy or weaning, respectively. Trial 1 showed that sows immunized with the CSF-E2 vaccine possessed high and consistent E2-specific and neutralizing antibody levels. The CSF-E2 vaccine-immunized pregnant sows subsequently conferred appropriate and steady passive immunity to their offspring. In trial 2, a double immunization scheme of the CSF-E2 vaccine in piglets at 40 and 60 days of age could elicit a consistent and long-lasting adequate antibody response. Additionally, the two trials detected no E rns -specific antibody responses, indicating that CSF-E2 vaccine can differentiate infected from vaccinated animals (DIVA).
Conclusion
Our trial data collectively provide invaluable information on applying the CSFE2 subunit vaccine to circumvent the possible drawbacks associated with the MLV-LOM concerning the safety, efficacy, and DIVA, in the LOM-endemic field farms and contribute to advanced CSF eradication on Jeju Island.
9.A Novel Robot-Assisted Kinematic Measure for Children with Attention-Deficit/Hyperactivity Disorder: A Preliminary Study
Aran MIN ; Johanna Inhyang KIM ; Hak Jong NOH ; Moon Sang KIM ; Hyo-Shin LEE ; Mun-Taek CHOI ; Kyuha LEE ; Jun-Ho SEO ; Ga Hyun LEE ; Seong-kyu KANG ; Dong Hyun AHN
Psychiatry Investigation 2021;18(7):645-651
Objective:
Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inattention, hyperactivity, and impulsivity. In contrast to neurocognitive measurements of inattention and impulsivity, there has been limited research regarding the objective measurement of hyperactivity in youths with ADHD. The purpose of the present study was to investigate the clinical effectiveness of a newly developed Robot-assisted Kinematic Measure for ADHD (RAKMA) in children with ADHD.
Methods:
In total, 35 children with ADHD aged 5 to 12 years and 50 healthy controls (HCs) were recruited, and the parents completed the Child Behavior Checklist and the Korean ADHD Diagnostic Scale. RAKMA performance was represented by RAKMA stimulus–response and hyperactivity variables. We compared the RAKMA performance of those with ADHD and with that of HCs and also investigated the correlation between the RAKMA variables and ADHD clinical scale scores.
Results:
Significant differences between the ADHD and HC groups were observed regarding most RAKMA variables, including correct reactions, commission errors, omission errors, reaction times, migration distance, and migration speed scores. Significant correlations were detected between various ADHD clinical scale scores and RAKMA variables.
Conclusion
The RAKMA was a clinically useful tool for objectively measuring hyperactivity symptoms in children with ADHD. Further studies with larger samples are warranted.
10.A Novel Robot-Assisted Kinematic Measure for Children with Attention-Deficit/Hyperactivity Disorder: A Preliminary Study
Aran MIN ; Johanna Inhyang KIM ; Hak Jong NOH ; Moon Sang KIM ; Hyo-Shin LEE ; Mun-Taek CHOI ; Kyuha LEE ; Jun-Ho SEO ; Ga Hyun LEE ; Seong-kyu KANG ; Dong Hyun AHN
Psychiatry Investigation 2021;18(7):645-651
Objective:
Attention-deficit/hyperactivity disorder (ADHD) is a neurodevelopmental disorder characterized by inattention, hyperactivity, and impulsivity. In contrast to neurocognitive measurements of inattention and impulsivity, there has been limited research regarding the objective measurement of hyperactivity in youths with ADHD. The purpose of the present study was to investigate the clinical effectiveness of a newly developed Robot-assisted Kinematic Measure for ADHD (RAKMA) in children with ADHD.
Methods:
In total, 35 children with ADHD aged 5 to 12 years and 50 healthy controls (HCs) were recruited, and the parents completed the Child Behavior Checklist and the Korean ADHD Diagnostic Scale. RAKMA performance was represented by RAKMA stimulus–response and hyperactivity variables. We compared the RAKMA performance of those with ADHD and with that of HCs and also investigated the correlation between the RAKMA variables and ADHD clinical scale scores.
Results:
Significant differences between the ADHD and HC groups were observed regarding most RAKMA variables, including correct reactions, commission errors, omission errors, reaction times, migration distance, and migration speed scores. Significant correlations were detected between various ADHD clinical scale scores and RAKMA variables.
Conclusion
The RAKMA was a clinically useful tool for objectively measuring hyperactivity symptoms in children with ADHD. Further studies with larger samples are warranted.

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