1.Delayed Retroperitoneal Hematoma Following Intradiscal Electrothermal Therapy: A Case Report of a Rare Complication
Jun-Yong CHA ; Yun-Young PARK ; Jin-Uk KIM ; Jun-Ho LEE ; Seong-Hwan MUN ; Gun AHN ; Il-Tae JANG
The Nerve 2026;12(1):36-40
Intradiscal electrothermal therapy (IDET) is a minimally invasive procedure used to treat discogenic back pain and offers an alternative to surgical intervention in selected patients. Although it is generally considered safe, rare but significant complications can occur and may be difficult to diagnose because their symptoms overlap with those of other spinal conditions. We describe the case of a 69-year-old woman who presented with severe lower back and left buttock pain that was unresponsive to conservative treatment. Magnetic resonance imaging revealed disc bulging with a high-intensity zone at the L4–5 and L5–S1 levels. IDET was performed at the L4–5 level, resulting in initial pain relief. However, the patient returned 7 days later with recurrent pain. Despite undergoing percutaneous epidural neuroplasty at the left L5–S1 level, a medial branch block, and a piriformis muscle block, her symptoms persisted. Further evaluation with spinal computed tomography revealed a retroperitoneal hematoma near the left psoas muscle. Referred pain from the hematoma mimicked discogenic pain, resulting in delayed diagnosis and unnecessary interventions. The patient remained hemodynamically stable and gradually improved with conservative management alone. This case highlights retroperitoneal hematoma as a rare complication of IDET and emphasizes the importance of accurate and timely diagnosis in patients with persistent or worsening symptoms after spinal procedures. Clinicians should consider non-discogenic sources of pain when treatment outcomes deviate from expected patterns.
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.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.Evidence‑based Korean guidelines for the clinical management of multiple myeloma: addressing 12 key clinical questions
Sung‑Hoon JUNG ; Youngil KOH ; Min Kyoung KIM ; Jin Seok KIM ; Joon Ho MOON ; Chang‑Ki MIN ; Dok Hyun YOON ; Sung‑Soo YOON ; Je‑Jung LEE ; Chae Moon HONG ; Ka‑Won KANG ; Jihyun KWON ; Kyoung Ha KIM ; Dae Sik KIM ; Sung Yong KIM ; Sung‑Hyun KIM ; Yu Ri KIM ; Young Rok DO ; Yeung‑Chul MUN ; Sung‑Soo PARK ; Young Hoon PARK ; Ho Jin SHIN ; Hyeon‑Seok EOM ; Sang Eun YOON ; Sang Mee HWANG ; Won Sik LEE ; Myung‑won LEE ; Jun Ho YI ; Ji Yun LEE ; Ji Hyun LEE ; Ho Sup LEE ; Sung‑Nam LIM ; Jihyang LIM ; Ho‑Young YHIM ; Yoon Hwan CHANG ; Jae‑Cheol JO ; Jinhyun CHO ; Hyungwoo CHO ; Yoon Seok CHOI ; Hee jeong CHO ; Ari AHN ; Jong Han CHOI ; Hyun Jung KIM ; Kihyun KIM
Blood Research 2025;60():9-
Multiple myeloma (MM), a hematological malignancy, is characterized by malignant plasma cell proliferation in the bone marrow. Recent treatment advances have significantly improved patient outcomes associated with MM.In this study, we aimed to develop comprehensive, evidence-based guidelines for the diagnosis, prognosis, and treat‑ ment of MM. We identified 12 key clinical questions essential for MM management, guiding the extensive literature review and meta-analysis of the study. Our guidelines provide evidence-based recommendations by integrating patient preferences with survey data. These recommendations include current and emerging diagnostic tools, thera‑ peutic agents, and treatment strategies. By prioritizing a patient-centered approach and rigorous data analysis, these guidelines were developed to enhance MM management, both in Korea and globally.
8.Introduction to the forensic research via omics markers in environmental health vulnerable areas (FROM) study
Jung-Yeon KWON ; Woo Jin KIM ; Yong Min CHO ; Byoung-gwon KIM ; Seungho LEE ; Jee Hyun RHO ; Sang-Yong EOM ; Dahee HAN ; Kyung-Hwa CHOI ; Jang-Hee LEE ; Jeeyoung KIM ; Sungho WON ; Hee-Gyoo KANG ; Sora MUN ; Hyun Ju YOO ; Jung-Woong KIM ; Kwan LEE ; Won-Ju PARK ; Seongchul HONG ; Young-Seoub HONG
Epidemiology and Health 2024;46(1):e2024062-
This research group (forensic research via omics markers in environmental health vulnerable areas: FROM) aimed to develop biomarkers for exposure to environmental hazards and diseases, assess environmental diseases, and apply and verify these biomarkers in environmentally vulnerable areas. Environmentally vulnerable areas—including refineries, abandoned metal mines, coal-fired power plants, waste incinerators, cement factories, and areas with high exposure to particulate matter—along with control areas, were selected for epidemiological investigations. A total of 1,157 adults, who had resided in these areas for over 10 years, were recruited between June 2021 and September 2023. Personal characteristics of the study participants were gathered through a survey. Biological samples, specifically blood and urine, were collected during the field investigations, separated under refrigerated conditions, and then transported to the laboratory for biomarker analysis. Analyses of heavy metals, environmental hazards, and adducts were conducted on these blood and urine samples. Additionally, omics analyses of epigenomes, proteomes, and metabolomes were performed using the blood samples. The biomarkers identified in this study will be utilized to assess the risk of environmental disease occurrence and to evaluate the impact on the health of residents in environmentally vulnerable areas, following the validation of diagnostic accuracy for these diseases.
9.Introduction to the forensic research via omics markers in environmental health vulnerable areas (FROM) study
Jung-Yeon KWON ; Woo Jin KIM ; Yong Min CHO ; Byoung-gwon KIM ; Seungho LEE ; Jee Hyun RHO ; Sang-Yong EOM ; Dahee HAN ; Kyung-Hwa CHOI ; Jang-Hee LEE ; Jeeyoung KIM ; Sungho WON ; Hee-Gyoo KANG ; Sora MUN ; Hyun Ju YOO ; Jung-Woong KIM ; Kwan LEE ; Won-Ju PARK ; Seongchul HONG ; Young-Seoub HONG
Epidemiology and Health 2024;46(1):e2024062-
This research group (forensic research via omics markers in environmental health vulnerable areas: FROM) aimed to develop biomarkers for exposure to environmental hazards and diseases, assess environmental diseases, and apply and verify these biomarkers in environmentally vulnerable areas. Environmentally vulnerable areas—including refineries, abandoned metal mines, coal-fired power plants, waste incinerators, cement factories, and areas with high exposure to particulate matter—along with control areas, were selected for epidemiological investigations. A total of 1,157 adults, who had resided in these areas for over 10 years, were recruited between June 2021 and September 2023. Personal characteristics of the study participants were gathered through a survey. Biological samples, specifically blood and urine, were collected during the field investigations, separated under refrigerated conditions, and then transported to the laboratory for biomarker analysis. Analyses of heavy metals, environmental hazards, and adducts were conducted on these blood and urine samples. Additionally, omics analyses of epigenomes, proteomes, and metabolomes were performed using the blood samples. The biomarkers identified in this study will be utilized to assess the risk of environmental disease occurrence and to evaluate the impact on the health of residents in environmentally vulnerable areas, following the validation of diagnostic accuracy for these diseases.
10.Association between Age-Related Macular Degeneration and Arthritis: Data from the Korean National Health and Nutrition Examination Survey for 2017 and 2018
Jun Sung NAH ; Junho MUN ; Kyoung Lae KIM ; Yong-Kyu KIM ; Youn Joo CHOI ; Sung Pyo PARK ; Kyeong Ik NA
Annals of Optometry and Contact Lens 2024;23(4):171-177
Purpose:
We examined the association between age-related macular degeneration (AMD) and arthritis.
Methods:
Using data from the Korea National Health and Nutrition Examination Survey for 2017 and 2018, we conducted a complex sample analysis of 6,993 individuals with recorded information on AMD, as well as the diagnosis and treatment of osteoarthritis (OA) and rheumatoid arthritis (RA). We compared the diagnosis and treatment of arthritis between the AMD and control groups using logistic regression analysis, with a specific focus on the treatment among patients with arthritis.
Results:
In the AMD group (n = 1,118) and the control group (n = 5,875), univariate logistic regression analysis showed substantial differences in the diagnosis and treatment of OA and RA. However, after adjusting for age, alcohol consumption, diabetes mellitus, and hypertension in multivariate logistic regression analysis, these differences were no longer substantial. Among patients with OA (n = 246 in the AMD group and n = 821 in the control group), there was a significant association between AMD and OA treatments (odds ratio 1.511, 95% confidence interval 1.051-2.172).
Conclusions
Patients diagnosed with and treated for OA had a higher likelihood of concurrent AMD than those who did not receive treatment. Therefore, ophthalmic examinations and closer monitoring are recommended for these patients.

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