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.

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.

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.

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.

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.

Purpose: To report a case of suprasellar Rathke's cleft cyst accompanying visual field defect found in a patient complaining of decreased visual acuity after cataract surgery.Case Summary: A 62-year-old male patient who showed a best-corrected visual acuity (BCVA) of 0.6 after left eye cataract surgery visited our hospital two months after surgery with decreased vision. He showed a best corrected visual acuity of 0.2, did not have relative afferent pupillary defect, and there were no specific findings on fundus examination. In the full field perimetry test, partial visual field loss in superior temporal quadrants were found in both eyes, being more prominent in left eye. In ganglion cell layer measurements using optical coherence tomography, a symmetric thinning in the thickness of the nasal ganglion cell layer was observed in both eyes, which was consistent with the visual field test. It was discovered that a liquid solid mass with a diameter of 21 mm in the upper part of the pituitary gland was compressing the optic chiasm in orbit magnetic resonance imaging. The patient was then referred to neurosurgery for pituitary surgery using transsphenoidal approach and diagnosed with Rathke's cleft cyst on histopathologic examination. Three months after surgery, the BCVA has increased to 0.5 and the visual field test showed no scotoma. Conclusions We report a case that Rathke's cleft cyst above the sella turcica inducing visual disturbances, emphasizing the importance of early detection and treatment through neuroophthalmological evaluation in a patient presenting with unexplained visual impairment.

Purpose: Several studies have evaluated the impact of sarcopenic obesity (SO) on postoperative complications, including postoperative pancreatic fistula (POPF), in patients undergoing pancreatoduodenectomy (PD). Previous studies have shown that SO increases POPF, but it remains unclear whether SO increases postoperative complications. In this study, we aimed to determine the relationship between SO and immediate postoperative complications. Methods: From January 2005 to December 2019, the medical records of patients who underwent PD for periampullary cancer were retrospectively reviewed. Skeletal muscle index (SMI) and visceral fat area (VFA) were calculated from preoperative computed tomography images. Patients with high VFA were classified as obese, while those with low SMI were classified as sarcopenic. Patients were divided into 4 groups: normal group, sarcopenia only group, obesity only group, and SO group. Postoperative outcomes were compared between groups, and factors affecting postoperative complications were analyzed by multivariate analysis. Results: Normal group (n = 176), sarcopenia only group (n = 130), obesity only group (n = 207), and SO group (n = 117) were analyzed retrospectively. SO group had significantly more frequent major complications compared to the normal group (P = 0.006), as well as a significantly more frequent clinically relevant POPF compared to the other groups (P = 0.002). In multivariate analysis, SO was an independent risk factor for major complications (P = 0.008) and clinically relevant POPF (P = 0.003). Conclusion SO is a factor associated with poor immediate postoperative outcomes after PD for periampullary cancer.