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.Efficacy and Safety of Metformin and Atorvastatin Combination Therapy vs. Monotherapy with Either Drug in Type 2 Diabetes Mellitus and Dyslipidemia Patients (ATOMIC): Double-Blinded Randomized Controlled Trial
Jie-Eun LEE ; Seung Hee YU ; Sung Rae KIM ; Kyu Jeung AHN ; Kee-Ho SONG ; In-Kyu LEE ; Ho-Sang SHON ; In Joo KIM ; Soo LIM ; Doo-Man KIM ; Choon Hee CHUNG ; Won-Young LEE ; Soon Hee LEE ; Dong Joon KIM ; Sung-Rae CHO ; Chang Hee JUNG ; Hyun Jeong JEON ; Seung-Hwan LEE ; Keun-Young PARK ; Sang Youl RHEE ; Sin Gon KIM ; Seok O PARK ; Dae Jung KIM ; Byung Joon KIM ; Sang Ah LEE ; Yong-Hyun KIM ; Kyung-Soo KIM ; Ji A SEO ; Il Seong NAM-GOONG ; Chang Won LEE ; Duk Kyu KIM ; Sang Wook KIM ; Chung Gu CHO ; Jung Han KIM ; Yeo-Joo KIM ; Jae-Myung YOO ; Kyung Wan MIN ; Moon-Kyu LEE
Diabetes & Metabolism Journal 2024;48(4):730-739
Background:
It is well known that a large number of patients with diabetes also have dyslipidemia, which significantly increases the risk of cardiovascular disease (CVD). This study aimed to evaluate the efficacy and safety of combination drugs consisting of metformin and atorvastatin, widely used as therapeutic agents for diabetes and dyslipidemia.
Methods:
This randomized, double-blind, placebo-controlled, parallel-group and phase III multicenter study included adults with glycosylated hemoglobin (HbA1c) levels >7.0% and <10.0%, low-density lipoprotein cholesterol (LDL-C) >100 and <250 mg/dL. One hundred eighty-five eligible subjects were randomized to the combination group (metformin+atorvastatin), metformin group (metformin+atorvastatin placebo), and atorvastatin group (atorvastatin+metformin placebo). The primary efficacy endpoints were the percent changes in HbA1c and LDL-C levels from baseline at the end of the treatment.
Results:
After 16 weeks of treatment compared to baseline, HbA1c showed a significant difference of 0.94% compared to the atorvastatin group in the combination group (0.35% vs. −0.58%, respectively; P<0.0001), whereas the proportion of patients with increased HbA1c was also 62% and 15%, respectively, showing a significant difference (P<0.001). The combination group also showed a significant decrease in LDL-C levels compared to the metformin group (−55.20% vs. −7.69%, P<0.001) without previously unknown adverse drug events.
Conclusion
The addition of atorvastatin to metformin improved HbA1c and LDL-C levels to a significant extent compared to metformin or atorvastatin alone in diabetes and dyslipidemia patients. This study also suggested metformin’s preventive effect on the glucose-elevating potential of atorvastatin in patients with type 2 diabetes mellitus and dyslipidemia, insufficiently controlled with exercise and diet. Metformin and atorvastatin combination might be an effective treatment in reducing the CVD risk in patients with both diabetes and dyslipidemia because of its lowering effect on LDL-C and glucose.
7.Study Design and Protocol for a Randomized Controlled Trial to Assess Long-Term Efficacy and Safety of a Triple Combination of Ezetimibe, Fenofibrate, and Moderate-Intensity Statin in Patients with Type 2 Diabetes and Modifiable Cardiovascular Risk Factors (ENSEMBLE)
Nam Hoon KIM ; Juneyoung LEE ; Suk CHON ; Jae Myung YU ; In-Kyung JEONG ; Soo LIM ; Won Jun KIM ; Keeho SONG ; Ho Chan CHO ; Hea Min YU ; Kyoung-Ah KIM ; Sang Soo KIM ; Soon Hee LEE ; Chong Hwa KIM ; Soo Heon KWAK ; Yong‐ho LEE ; Choon Hee CHUNG ; Sihoon LEE ; Heung Yong JIN ; Jae Hyuk LEE ; Gwanpyo KOH ; Sang-Yong KIM ; Jaetaek KIM ; Ju Hee LEE ; Tae Nyun KIM ; Hyun Jeong JEON ; Ji Hyun LEE ; Jae-Han JEON ; Hye Jin YOO ; Hee Kyung KIM ; Hyeong-Kyu PARK ; Il Seong NAM-GOONG ; Seongbin HONG ; Chul Woo AHN ; Ji Hee YU ; Jong Heon PARK ; Keun-Gyu PARK ; Chan Ho PARK ; Kyong Hye JOUNG ; Ohk-Hyun RYU ; Keun Yong PARK ; Eun-Gyoung HONG ; Bong-Soo CHA ; Kyu Chang WON ; Yoon-Sok CHUNG ; Sin Gon KIM
Endocrinology and Metabolism 2024;39(5):722-731
Background:
Atherogenic dyslipidemia, which is frequently associated with type 2 diabetes (T2D) and insulin resistance, contributes to the development of vascular complications. Statin therapy is the primary approach to dyslipidemia management in T2D, however, the role of non-statin therapy remains unclear. Ezetimibe reduces cholesterol burden by inhibiting intestinal cholesterol absorption. Fibrates lower triglyceride levels and increase high-density lipoprotein cholesterol (HDL-C) levels via peroxisome proliferator- activated receptor alpha agonism. Therefore, when combined, these drugs effectively lower non-HDL-C levels. Despite this, few clinical trials have specifically targeted non-HDL-C, and the efficacy of triple combination therapies, including statins, ezetimibe, and fibrates, has yet to be determined.
Methods:
This is a multicenter, prospective, randomized, open-label, active-comparator controlled trial involving 3,958 eligible participants with T2D, cardiovascular risk factors, and elevated non-HDL-C (≥100 mg/dL). Participants, already on moderate-intensity statins, will be randomly assigned to either Ezefeno (ezetimibe/fenofibrate) addition or statin dose-escalation. The primary end point is the development of a composite of major adverse cardiovascular and diabetic microvascular events over 48 months.
Conclusion
This trial aims to assess whether combining statins, ezetimibe, and fenofibrate is as effective as, or possibly superior to, statin monotherapy intensification in lowering cardiovascular and microvascular disease risk for patients with T2D. This could propose a novel therapeutic approach for managing dyslipidemia in T2D.
8.Efficacy and Safety of Lurasidone vs. Quetiapine XR in Acutely Psychotic Patients With Schizophrenia in Korea: A Randomized, Double-Blind, Active-Controlled Trial
Se Hyun KIM ; Do-Un JUNG ; Do Hoon KIM ; Jung Sik LEE ; Kyoung-Uk LEE ; Seunghee WON ; Bong Ju LEE ; Sung-Gon KIM ; Sungwon ROH ; Jong-Ik PARK ; Minah KIM ; Sung Won JUNG ; Hong Seok OH ; Han-yong JUNG ; Sang Hoon KIM ; Hyun Seung CHEE ; Jong-Woo PAIK ; Kyu Young LEE ; Soo In KIM ; Seung-Hwan LEE ; Eun-Jin CHEON ; Hye-Geum KIM ; Heon-Jeong LEE ; In Won CHUNG ; Joonho CHOI ; Min-Hyuk KIM ; Seong-Jin CHO ; HyunChul YOUN ; Jhin-Goo CHANG ; Hoo Rim SONG ; Euitae KIM ; Won-Hyoung KIM ; Chul Eung KIM ; Doo-Heum PARK ; Byung-Ook LEE ; Jungsun LEE ; Seung-Yup LEE ; Nuree KANG ; Hee Yeon JUNG
Psychiatry Investigation 2024;21(7):762-771
Objective:
This study was performed to evaluate the efficacy and safety of lurasidone (160 mg/day) compared to quetiapine XR (QXR; 600 mg/day) in the treatment of acutely psychotic patients with schizophrenia.
Methods:
Patients were randomly assigned to 6 weeks of double-blind treatment with lurasidone 160 mg/day (n=105) or QXR 600 mg/day (n=105). Primary efficacy measure was the change from baseline to week 6 in Positive and Negative Syndrome Scale (PANSS) total score and Clinical Global Impressions severity (CGI-S) score. Adverse events, body measurements, and laboratory parameters were assessed.
Results:
Lurasidone demonstrated non-inferiority to QXR on the PANSS total score. Adjusted mean±standard error change at week 6 on the PANSS total score was -26.42±2.02 and -27.33±2.01 in the lurasidone and QXR group, respectively. The mean difference score was -0.91 (95% confidence interval -6.35–4.53). The lurasidone group showed a greater reduction in PANSS total and negative subscale on week 1 and a greater reduction in end-point CGI-S score compared to the QXR group. Body weight, body mass index, and waist circumference in the lurasidone group were reduced, with significantly lower mean change compared to QXR. Endpoint changes in glucose, cholesterol, triglycerides, and low-density lipoprotein levels were also significantly lower. The most common adverse drug reactions with lurasidone were akathisia and nausea.
Conclusion
Lurasidone 160 mg/day was found to be non-inferior to QXR 600 mg/day in the treatment of schizophrenia with comparable efficacy and tolerability. Adverse effects of lurasidone were generally tolerable, and beneficial effects on metabolic parameters can be expected.
9.Efficacy and Safety of DA-8010, a Novel M3 Antagonist, in Patients With Overactive Bladder: A Randomized, Double-Blind Phase 2 Study
Hee Seo SON ; Cheol Young OH ; Myung-Soo CHOO ; Hyeong Gon KIM ; Joon Chul KIM ; Kyu-Sung LEE ; Dong Gil SHIN ; Sung Yong CHO ; Seong Jin JEONG ; Ju Tae SEO ; Hana YOON ; Hong Sang MOON ; Jang Hwan KIM
International Neurourology Journal 2022;26(2):119-128
Purpose:
DA-8010 is a novel muscarinic M3 receptor antagonist with significant selectivity for bladder over salivary gland in preclinical studies. We evaluated the clinical efficacy and safety of DA-8010 in overactive bladder (OAB) patients.
Methods:
This phase 2, randomized, double-blind, parallel-group, active reference- and placebo-controlled trial was conducted at 12 centers in South Korea (NCT03566134). Patients aged ≥19 years with OAB symptoms for ≥3 months were enrolled. Three hundred six patients (30.07% male) were randomized to 12 weeks of treatment among 4 groups; 2 experimental groups (DA-8010 2.5 or 5 mg), an active reference group (solifenacin 5 mg), and a placebo group. The change from the baseline of (=∆) 24-hour frequency at 12 weeks (primary endpoint), episodes of urgency, overall/urgency urinary incontinence, average/ maximum voided volume, nocturia, and patients’ subjective responses were analyzed.
Results:
In the full analysis set, the mean (standard deviation) [median] values for ∆ 24-hour frequency at 12 weeks were -1.01 (2.44) [-1.33] for placebo, -1.22 (2.05) [-1.33] for DA-8010 2.5 mg, and -1.67 (2.25) [-1.67] for DA-8010 5 mg; DA-8010 5 mg showed a significant decrease compared with placebo (P=0.0413). At 4 and 8 weeks, both DA-8010 2.5 mg (P=0.0391 at 4 weeks, P=0.0335 at 8 weeks) and DA-8010 5 mg (P=0.0001 at 4 weeks, P=0.0210 at 8 weeks) showed significant decrease in ∆ 24-hour frequency compared with placebo. DA-8010 5 mg achieved a significant decrease in ∆ number of urgency episodes, compared with placebo at 4 (P=0.0278) and 8 (P=0.0092) weeks. Adverse drug reactions (ADRs) were observed in 3.95% of placebo, 6.67% of DA-8010 2.5 mg, 18.42% of DA-8010 5 mg, and 17.33% of solifenacin 5 mg groups. No serious ADRs were observed in any patient.
Conclusions
Both DA-8010 2.5 mg and 5 mg showed therapeutic efficacy for OAB without serious ADRs. Therefore, both dosages of DA-8010 can advance to a subsequent large-scale phase 3 trial.
10.Fates of retained hepatic segment IV and its prognostic impact in adult split liver transplantation using an extended right liver graft
Yong-Kyu CHUNG ; Shin HWANG ; Chul-Soo AHN ; Ki-Hun KIM ; Deok-Bog MOON ; Tae-Yong HA ; Gi-Won SONG ; Dong-Hwan JUNG ; Gil-Chun PARK ; Young-In YOON ; Woo-Hyoung KANG ; Hwui-Dong CHO ; Jin Uk CHOI ; Minjae KIM ; Sang Hoon KIM ; Byeong-Gon NA ; Sung-Gyu LEE
Annals of Surgical Treatment and Research 2021;101(1):37-48
Purpose:
When splitting a liver for adult and pediatric graft recipients, the retained left medial section (S4) will undergo ischemic necrosis and the right trisection graft becomes an extended right liver (ERL) graft. We investigated the fates of the retained S4 and its prognostic impact in adult split liver transplantation (SLT) using an ERL graft.
Methods:
This was a retrospective analysis of 25 adult SLT recipients who received split ERL grafts.
Results:
The mean model for end-stage liver disease (MELD) score was 27.3 ± 10.9 and graft-recipient weight ratio (GRWR) was 1.98 ± 0.44. The mean donor age was 26.5 ± 7.7 years. The split ERL graft weight was 1,181.5 ± 252.8 g, which resulted in a mean GRWR of 1.98 ± 0.44. Computed tomography of the retained S4 parenchyma revealed small ischemic necrosis in 16 patients (64.0%) and large ischemic necrosis in the remaining 9 patients (36.0%). No S4-associated biliary complications were developed. The mean GRWR was 1.87 ± 0.43 in the 9 patients with large ischemic necrosis and 2.10 ± 0.44 in the 15 cases with small ischemic necrosis (P = 0.283). The retained S4 parenchyma showed gradual atrophy on follow-up imaging studies. The amount of S4 ischemic necrosis was not associated with graft (P = 0.592) or patient (P = 0.243) survival. A MELD score of >30 and pretransplant ventilator support were associated with inferior outcomes.
Conclusion
The amount of S4 ischemic necrosis is not a prognostic factor in adult SLT recipients, probably due to a sufficiently large GRWR.

Result Analysis
Print
Save
E-mail