Morphological Changes in the Infrapatellar Fat Pad During Walking Detected by Dynamic Ultrasound in Healthy Volunteers.

Aim This study aimed to verify specific morphological changes in the infrapatellar fat pad (IFP) during walking in healthy young participants. Methods A total of 17 healthy young participants (mean age, 22.8 ± 0.9 years) were recruited in this cross-sectional study. The IFP was evaluated using ultrasonography in three conditions: supine, standing, and walking. The IFP value was described as the thickness of the distal section of the IFP. Additionally, in the walking condition, the IFP was captured in video mode on ultrasonography, and its dynamics were recorded. The waveform of the IFP was produced using the sequence of the IFP thickness on each image. The morphological change of IFP (ΔIFP) was calculated in the IFP waveform and was shown as the difference in IFP thickness between the maximum and minimum at the beginning of the early stance phase. Moreover, kinematics and kinetic data were evaluated using a three-dimensional motion system, and the knee flexion angle (KFA) and knee flexion moment (KFM) were obtained. Results The thickness of the IFP during walking was significantly greater than that during the supine and standing conditions (p < 0.001 for both). The IFP waveform during walking showed a gradual increase during the stance phase and a decrease during the swing phase of the gait cycle. ΔIFP was 1.35 ± 0.42 mm and significantly correlated with the KFM (r = 0.59, p = 0.007). Conclusions Dynamic ultrasonography revealed a specific morphological change in the IFP during walking, which correlated with the KFM.

Study protocol of the ASTOP trial: A multicenter, randomized, double-blind, placebo-controlled trial of presurgical aspirin administration for the prevention of thromboembolic complications of coil embolization for ruptured aneurysms.

RATIONALE: Thromboembolism is a serious complication of endovascular treatment for ruptured cerebral aneurysms. The administration of antiplatelet agents before endovascular treatment for ruptured cerebral aneurysms may reduce the risk of thromboembolic complications. AIM: This study aimed to assess the safety and efficacy of preoperative aspirin administration in endovascular treatment for ruptured cerebral aneurysms. SAMPLE SIZE ESTIMATES: Assuming a 15% incidence rate of both intraoperative thromboembolic morbidity and symptomatic ischemic lesions on magnetic resonance imaging diffusion-weighted imaging scans assessed by an Independent Review Committee, a sample size of 484 will be required to detect a 10% improvement with aspirin administration with 90% power using the Pearson's chi-square test at a two-sided significance level of 2.5% for each primary outcome, after accounting for a 5% dropout rate. METHODS AND DESIGN: ASTOP is a multicenter, randomized, double-blind, placebo-controlled clinical trial. A total of 484 patients with ruptured cerebral aneurysms receiving coil embolization within 72 h of onset will be randomly assigned 1:1 to receive 200 mg of aspirin or placebo before the procedure. STUDY OUTCOMES: The primary outcomes will be the incidence rates of intraoperative thromboembolic complications and symptomatic ischemic lesions on magnetic resonance imaging diffusion-weighted imaging scans evaluated by the Independent Review Committee. The secondary outcomes will be the incidence rate of cerebral ischemic events and all bleeding events within 14 days of enrollment and functional outcomes defined by the modified Rankin Scale score at 90 days. DISCUSSION: This trial will provide valuable data on the role of antiplatelet agents during endovascular treatment for ruptured cerebral aneurysms. TRIAL REGISTRATION: Registration: Japan Registry of Clinical Trials, Identifier: jRCTs031210421.

Evaluation under loading detects medial meniscus extrusion in patients with reconstructed anterior cruciate ligament and restricted knee extension.

PURPOSE: Some patients who undergo anterior cruciate ligament (ACL) reconstruction experience abnormal mechanical stress in the meniscus. Medial meniscal extrusion (MME) is reflected in the pathological condition of the meniscus, which expands owing to repetitive mechanical stress. Thus, the effect of the reconstructed ACL on increasing MME under weight-bearing conditions remains unclear. This study investigated the effect of ACL reconstruction on meniscal extrusion under non-weight-bearing and weight-bearing conditions. METHODS: Seventeen patients who underwent unilateral ACL reconstruction (ACL group) and 20 age-matched healthy volunteers (control group) were enrolled. Ultrasonography was performed in the supine, standing, and walking positions in preoperative and postoperative ACL patients. MME during walking was evaluated based on the dynamic behavior of extrusion, and kinetic and kinematic data were synchronously obtained. Moreover, the ACL group underwent magnetic resonance imaging (MRI) evaluation at two points: preoperatively and 12 months postoperatively, and the ultrasound findings were compared. RESULTS: MME in the supine position measured using both ultrasonography and MRI was not significantly different preoperatively and postoperatively in the ACL group. However, postoperative MME and dynamic behavior of extrusion under standing and walking conditions were significantly higher than those in the preoperative state (dynamic behavior: 0.9 ± 0.4 mm preoperatively, 1.2 ± 0.4 mm postoperatively). Moreover, the deficits in knee extension during walking persisted postoperatively and were significantly higher than those in the control group. CONCLUSION: MME in patients with ACL reconstruction including meniscus repair was different under mechanical stress compared to the non-weight bearing condition.

Individuals with asymptomatic hallux valgus exhibit altered foot kinematics during gait regardless of their foot posture.

BACKGROUND: A flatfoot has been believed to be closely associated with the development of hallux valgus; however, the association is still controversial. Abnormal foot kinematics has been identified as a possible risk factor for the development of hallux valgus, but it remains unclear whether foot posture contributes to abnormal foot kinematics. This is the first study to investigate the differences in foot kinematics during gait between individuals with and without hallux valgus, while controlling for foot posture. METHODS: Twenty-five females with hallux valgus and 25 healthy females aged 18 to 22 were recruited. Foot posture was measured using normalized navicular height truncated and the leg-heel angle. Foot kinematic and kinetic data during gait were recorded by a three-dimensional motion capture system. To investigate the characteristics of foot kinematics in individuals with hallux valgus while controlling for foot posture, we used a propensity score matching method. The matching was obtained by using the 1:1 nearest-neighbor procedure and a caliper width of 0.2. FINDINGS: Twelve pairs were matched. Individuals with hallux valgus had significantly increased midfoot dorsiflexion from 56% to 80% during stance phase, rearfoot eversion from 53% to 71%, and forefoot abduction from 5% to 29% compared with control. INTERPRETATION: Individuals with hallux valgus have a flexible foot that cannot suppress the dynamic deformation of the rearfoot and midfoot during gait. To suppress the development of hallux valgus, interventions that aim to prevent dynamic deformations of the rearfoot and midfoot during gait may be necessary, regardless of their static foot posture.

Safety and Efficacy of Management for Intraprocedural Rupture During Endovascular Treatment for Intracranial Aneurysms.

BACKGROUND AND OBJECTIVES: Although intraprocedural rupture (IPR) is rare, it is a devastating complication of endovascular treatment (EVT) for intracranial aneurysms. Very few studies have been conducted on IPR, and the safety and efficacy of management techniques of IPR have not been investigated. METHODS: Patients who experienced IPR during EVT between 2013 and 2022 were enrolled from a multicenter observational registry. We examined the safety and efficacy of the management of IPR using imaging markers, including increased hemorrhage and ischemic lesions, which were evaluated using postoperative computed tomography and diffusion-weighted imaging, respectively. RESULTS: Of the 3269 EVTs for intracranial aneurysms, 74 patients who experienced IPR (2.26%) were analyzed. Fifty-five patients (3.36%) experienced IPR among 1636 EVT cases for ruptured aneurysms. Multivariate analysis revealed that increased hemorrhage was significantly associated with poor outcomes (odds ratio [OR], 6.37 [95% CI, 1.00-40.51], P = .050), whereas ischemic lesions were not. Regarding management techniques of IPR, antihypertensive medication use was significantly associated with increased hemorrhage (OR, 14.16 [95% CI, 2.35-85.34], P = .004). Heparin reversal was an independent factor for ischemic lesions (OR, 8.92 [95% CI, 1.54-51.58], P = .014). CONCLUSION: Although the setting of IPR may be miscellaneous, and optimal management varies depending on individual cases, heparin reversal might be associated with ischemic complications, and its role in the successful hemostasis in IPR during EVT for ruptured aneurysms remains unclear.

Additive Effects of Esaxerenone, a Nonsteroidal Mineralocorticoid Receptor Blocker, on Cardioplegic Arrest in Rat Hearts.

PURPOSE: Esaxerenone, a mineralocorticoid receptor blocker, attenuates global ischemia-induced myocardial damage and coronary endothelial dysfunction. This study aimed to determine whether esaxerenone exerted cardioprotective effects against cardioplegic arrest in Wistar rat hearts. METHODS: Isolated male Wistar rat hearts aerobically perfused via the Langendorff method for 20 min were randomly allocated to the Control (n = 6; perfused for an additional 10 min and subjected to no treatment) or Esax (n = 6; perfused with 0.1 µmol/L esaxerenone in perfusate for 10 min before ischemia) groups. Hearts in both groups were perfused with St. Thomas' Hospital No. 2 solution (STH2) for 2 min and subjected to 28 min of global ischemia. The recovery of left ventricular developed pressure (LVDP) and total troponin T leakage were measured after reperfusion. RESULTS: The final recovery of LVDP (expressed as a percentage of pre-ischemic value) in the Control and Esax groups was 50.8 ± 3.5% and 62.1 ± 5.6%, respectively (p <0.05, Esax vs. Control). The total troponin T leakage in the Control and Esax groups was 138.8 ± 18.5 ng/g heart wt and 74.3 ± 18.6 ng/g heart wt, respectively (p <0.05, Esax vs. Control). CONCLUSION: The administration of esaxerenone before cardioplegic arrest enhanced the cardioprotective effect exerted by STH2.

Efficacy of endovascular treatment for distal anterior cerebral artery aneurysms: A multicenter observational study.

OBJECTIVES: Distal anterior cerebral artery (DACA) aneurysms account for 1%-9% of all intracranial aneurysms. Microsurgical treatment is generally preferred for DACA aneurysms; however, it presents challenges owing to the anatomical complexities. Advances in neuro-interventional techniques have yielded promising results. This study aims to compare the clinical outcomes of DACA aneurysms treated with microsurgery and endovascular treatment (EVT) to elucidate the efficacy of EVT. MATERIALS AND METHODS: A multicenter observational registry comprising 16 stroke centers was utilized for this study. Data was retrospectively and prospectively analyzed from 166 patients with DACA aneurysms in our database, which included 4,552 consecutive patients with ruptured or unruptured intracranial aneurysms who underwent microsurgical or endovascular treatment between January 2013 and December 2021. RESULTS: Surgical clipping was performed in 115 patients, and 51 underwent coil embolization. The median follow-up duration was 15.3 months. No significant differences were observed in patient characteristics between the two treatment modalities. There were no differences in complication-related morbidity between the microsurgical treatment and EVT groups in either unruptured (10.5% vs. 9.1%, p=1.00) or ruptured aneurysms (5.2% vs. 6.9%, p=0.66). Coil embolization resulted in higher recurrence and retreatment rates than surgical clipping did, especially for ruptured aneurysms (2.6% vs. 27.6%, p<0.01). CONCLUSIONS: Endovascular treatment is an alternative to microsurgery for DACA aneurysms especially in unruptured cases or the patients who have difficulty undergoing craniotomy due to their general condition, albeit with considerations for higher recurrence and retreatment rates, particularly in ruptured cases. Close follow-up is crucial for the effective management of these challenges. Further studies are needed to refine the treatment strategies for DACA aneurysms.

A novel technique for H-shaped reinforcement of double-barreled aorta in surgical treatment of chronic aortic dissection.

Anastomosis of the prosthetic graft to the double-barreled aorta with intimal flap fenestration is a useful technique in surgery for chronic aortic dissection. Conversely, anastomosis to the false lumen's outer wall is prone to complications such as pseudoaneurysms, but little is known about the technique of reinforcing the double-barreled aorta. In this report, we describe a surgical case of chronic aortic dissection in which an H-shaped prosthetic graft was sutured to both aortic lumens, including the intimal flap, to prevent complications at the anastomosis site.

Preemptive Embolization of Abdominal Aortic Aneurysm Sac Side Branch Arteries Promotes Early Sac Shrinkage after Endovascular Aneurysm Repair 1.

BACKGROUND: The association between the occlusion rate of the side branch arteries branching from the abdominal aortic aneurysm sac and aneurysm sac shrinkage is unclear. We aimed to evaluate the efficacy of preemptive embolization of multiple side branch arteries branching from the abdominal aortic aneurysm sac in early aneurysm sac shrinkage after endovascular aneurysm repair. METHODS: Patients undergoing endovascular aneurysm repair of abdominal aortic aneurysms, with or without preemptive embolization of multiple side branch arteries, including the inferior mesenteric artery and lumbar arteries, between January 2016 and August 2021, were retrospectively evaluated. Preemptive embolization was introduced at our institution in January 2018 and has been performed in all patients who undergo endovascular aneurysm repair since then. We compared occlusion rates of the side branch arteries, frequency of type 2 endoleaks, changes in aneurysm sac size, percentage of aneurysm sac size decrease, and frequency of reduction in the aneurysm sac diameter by > 5 mm. RESULTS: The study included 43 patients in the embolization group and 20 in the nonembolization group. Preemptive embolization was successfully performed without any ischemic complications. The total occlusion rate of side branch arteries was significantly higher in the embolization group than in the nonembolization group (70.2% vs. 29.3%, P < 0.05). At 24 months of follow-up, the type 2 endoleak frequency was significantly lower in the embolization group than in the nonembolization group (6.9% vs. 31.6%, P < 0.05). The frequency of reduction in the aneurysm sac diameter by > 5 mm was significantly higher in the embolization group than in the nonembolization group at 24 months (62.1% vs. 31.6% P < 0.05). The optimal cutoff value for the total occlusion rate of the side branch arteries to achieve reduction in the aneurysm sac diameter by > 5 mm at 24 months, after endovascular aneurysm repair, was 66.7% in all patients (area under the curve = 0.634; sensitivity = 62.5%; specificity = 70.8%). These findings suggest that occluding 66.7% or more of the side branch arteries may result in early aneurysmal shrinkage. CONCLUSIONS: Preemptive embolization of multiple side branch arteries, branching from the abdominal aortic aneurysm sac, may contribute to early aneurysm sac shrinkage; this may serve as a marker for fewer late complications after endovascular aneurysm repair.

Validity of the Cost-Effectiveness of Middle Meningeal Artery Embolization Following Hematoma Evacuation for Initial Chronic Subdural Hematoma.

BACKGROUND: Despite numerous articles about middle meningeal artery embolization (MMAE) highlighting its efficacy and safety for recurrent chronic subdural hematoma (CSDH), the appropriateness of adjunctive MMAE after hematoma evacuation for initial CSDH remains unclear from a cost-effectiveness perspective. METHODS: Patients with CSDH were enrolled in this study and were prospectively divided into 2 groups: the "conventional treatment" group, which was treated with hematoma evacuation alone, and the "MMAE" group, which was treated with adjunctive MMAE after hematoma evacuation. The proportion of patients requiring retreatment, length of hospital stay, economic costs, and modified Rankin Score were compared between the 2 groups. RESULTS: In this study, 53 cases were included, with 30 classified into the conventional treatment group and 23 classified into the MMAE group. In the conventional treatment group, the proportion of patients who required surgical retreatment was higher than that in the MMAE group (16.7% vs. 8.7%). The relative risk was 0.522 (95% confidence interval, 0.111-2.45). Although the addition of MMAE increased the cost per hospitalization by 26%, the increase in cost per patient was limited to 12%, owing to the reduction in patients who relapsed and required a second hospitalization. The increase in cost was not statistically significant. The MMAE group had a significantly higher proportion of patients with favorable outcomes (modified Rankin Score 0-2) (56.7% vs. 87.0%, P = 0.0328). CONCLUSIONS: By minimizing the increase in hospitalization days and procedure costs, MMAE following hematoma evacuation for initial CSDH could decrease the retreatment rate and balance the total medical costs associated with MMAE.

Pulmonary mediastinal actinomycosis with "pound cake sign" on magnetic resonance imaging mimicking an infiltrative malignant tumor: A case report.

Actinomycosis is a rare chronic suppurative granulomatous disease. Surgical biopsy is often performed in patients with chest actinomycosis because malignancy is suspected in most cases. A 62-year-old man presented to our hospital with fever and exertional dyspnea that had persisted for several months. Contrast-enhanced computed tomography showed an irregularly shaped mass with contrast enhancement in the anterior mediastinum and consolidation in the left upper lung lobe contiguous with this mass, as well as multiple nodules in both lungs. The pulmonary artery trunk was stenotic and surrounded by the mass, and the right heart system was enlarged. Thoracoscopic biopsy was performed but failed to yield a diagnosis. Contrast-enhanced computed tomography after one month revealed an increased mass and worsening right heart strain. 18F-FDG (fluorodeoxyglucose) positron emission tomography/computed tomography and contrast-enhanced magnetic resonance imaging also suggested a malignant tumor, and an open chest biopsy was performed. No malignant cells were identified and actinomycetes were detected by histopathology and bacterial culture. The patient was treated with antibiotics, following which his contrast-enhanced computed tomography findings and general condition improved.

Contact aspiration for basilar artery occlusion safely reduces the puncture-to-recanalization time.

OBJECTIVE: Effective thrombectomies in the posterior circulation remain controversial. Previous reports have demonstrated the superiority of contact aspiration in anterior circulation. Aspiration catheters and stent retrievers are often used alone on a global scale, while combined techniques are commonly used in Japan. This study evaluated the effect of first-line contact aspiration with other strategies for the treatment of basilar artery occlusion. METHODS: The primary outcome was the frequency of the first-pass effect, and the secondary outcome was the time from puncture to the first-pass effect. A multicenter observational registry including 16 Japanese stroke centers was used. Between December 2013 and February 2021, enrolled patients underwent endovascular thrombectomy for basilar artery occlusion. The efficacy of contact aspiration compared to other methods (including stent retrievers and combined techniques) was evaluated. RESULTS: Eighty-four patients were included, all of whom had achieved effective recanalization. Twenty-six patients were treated with contact aspiration, 13 with combined technique, and 45 with stent retrievers. The two groups: contact aspiration and non-contact aspiration, had different backgrounds. Both had similar frequencies of effective recanalization and first-pass effects. The contact aspiration group experienced better functional outcomes without statistical significance, while this strategy was significantly associated with a shorter puncture-to-recanalization time (38 vs. 55 minutes, P=0.036). In particular, in the 55 patients with the first-pass effect, multivariate Cox proportional hazard analysis showed that contact aspiration was significantly associated with a shorter time from puncture to first-pass effect, independent of age and etiology of large-artery atherosclerosis (hazard ratio 2.02, 95% confidence intervals 1.10-3.69, P=0.023). CONCLUSION: This study suggested that contact aspiration for basilar artery occlusion may shorten the puncture-to-first-pass effect, compared to stent retrievers and combined techniques.

Chemical ablation of the left ventricular endocardium reduces ventricular fibrillation inducibility in acute ischemic canine heart.

Objective: Ventricular fibrillation remains as the major cause of death in patients with acute myocardial infarction. Effects of trans-atrial chemical ablation of the left ventricular (LV) endocardium with Lugol's solution on ventricular fibrillation inducibility and ventricular conduction were examined in canines with acute myocardial ischemia. Materials and Methods: Chemical ablation of the LV endocardium with Lugol's solution or normal saline was preformed through a left atrial appendage in 14 canines 30 min after occlusion of the left anterior coronary artery. Results: Ventricular fibrillation threshold decreased after the coronary artery occlusion and increased after endocardial chemical ablation. There was a significant difference in the ventricular fibrillation threshold after chemical ablation between with Lugol's solution and with normal saline (25.9 ± 9.2 mA vs. 11.3 ± 2.7 mA, p < .01). QRS width significantly increased from 88 ± 4msec to 116 ± 5msec (p < .01) after the chemical ablation with Lugol's solution, and the activation map of the ventricles demonstrated a left bundle branch block ventricular conduction pattern. Histological examination of the LV endocardium showed lymphocyte infiltration for a depth of 1 mm. Conclusions: Chemical ablation of the LV endocardium with Lugol's solution injures endocardial conduction system and increases ventricular fibrillation threshold in the early phase of myocardial ischemia in canines. The procedure may be useful in suppressing intractable ventricular tachyarrhythmias in patients with acute myocardial ischemia.

Temporary meniscus extrusion is caused by cumulative stress from uphill and downhill tasks in healthy volunteers.

Purpose: Excessive mechanical stress accumulates and causes knee injury. Meniscal extrusion is a key factor in detecting the reaction to cumulative mechanical stress. The accumulation of stress strongly depends on environmental conditions such as flat ground or uphill/downhill, and accumulates in knee compartments; only a few studies have reported the effects of different environments on lateral and medial meniscus extrusion. This study aimed to investigate the effects of cumulative uphill/downhill stress on the meniscal extrusion in each compartment. Methods: A total of 30 healthy volunteers with 30 affected knees were involved in this cohort study (mean age, 22.0 ± 1.1 years; men, n = 14). The participants were divided into flat-walking, uphill/downhill-walking, and uphill/downhill-jogging groups and their numbers of steps taken were recorded during the effort. Moreover, medial and lateral meniscal extrusions during walking were evaluated using ultrasound three times, before and after efforts (T1) and (T2), and one day after efforts (T3), respectively. Results: In the flat-walking group, no significant differences were observed between the follow-up periods. Conversely, in the uphill/downhill-walking and jogging groups, the medial meniscus extrusion at T2 was significantly higher than that at T1. Conversely, the medial meniscus extrusion at T3 was significantly lower than that at T2. By contrast, the lateral meniscus did not show any difference between the follow-up periods in any group. Conclusion: Temporary extrusion of the meniscus occurred after uphill/downhill tasks in healthy volunteers, and its reaction was observed only in the medial meniscus.

Safety and outcomes of surgical treatment of atrial fibrillation in emergency surgery cases.

BACKGROUND: Recent developments in surgical devices, including left atrial appendage closure, have enabled surgeons to perform aggressive operations for atrial fibrillation (AF). However, the outcomes of AF surgery in emergent cases have not been extensively studied. OBJECTIVE AND METHODS: The present study aimed to investigate the effectiveness of AF surgery in emergency surgery cases associated with cardiovascular events. We enrolled 18 patients who underwent various types of AF surgery due to emergencies, including acute aortic dissection (n = 6), acute myocardial infarction (n = 5), bleeding due to perforation from radiofrequency catheter ablation (n = 4), acute mitral regurgitation (n = 2), and cardiac tumor (n = 1). Four and ten patients underwent the full maze procedure and pulmonary vein isolation, respectively. Ganglionated plexi ablation was also performed in three patients as part of a combined procedure. The left atrial appendage was solely closed in four patients. RESULTS: There was no surgical mortality or major adverse cardiac and cerebrovascular events in our patient series. The rates of freedom of recurrence of AF or atrial tachycardia at 1 and 3 years were 92.9% and 82.5%, respectively. After a mean follow-up period of 46.7 ± 25.8 months, no thromboembolism events were observed in the patients. Furthermore, no cardiovascular death was recorded. CONCLUSION: The surgical procedures for AF are safe and effective in cases requiring emergency surgery.

Lithium-ion battery electrode properties of hydrogen boride.

Recently, hydrogen boride (HB) with a pseudo-two-dimensional sheet structure was successfully synthesized, and it is theoretically predicted to have high potential as a negative electrode material for alkali metal ion batteries, making it a promising new candidate. This study represents the first experimental examination of the negative electrode properties of HB. HB was synthesized via cation exchange from MgB2. The confirmation of HB synthesis was achieved through various spectroscopic experiments, including synchrotron radiation X-ray diffraction and X-ray photoelectron spectroscopy, in addition to direct observation using transmission electron microscopy. The HB electrode was prepared by mixing the HB powder sample with conductive additive carbon black and a polymer binder. A test cell was assembled with the HB electrode as the working electrode, and lithium metal as the counter and reference electrodes, and its battery electrode properties were evaluated. Although reversible charge-discharge curves with good reversibility were observed, the reversible capacity was 100 ± 20 mA h g-1 which is significantly smaller than the theoretical predictions. Nitrogen gas adsorption experiments were performed on the HB powder sample to determine the specific surface area indicating that the HB sheets were stacked together. It is plausible to consider that this stacking structure led to a reduced lithium-ion storage capacity compared to the theoretical predictions.

Effect of lateral wedge length on knee adduction moment reduction mechanics during gait.

Lateral wedge insole (LWI) wear is a well-known conservative treatment for patients with knee osteoarthritis and is expected to decrease knee joint loading. Although the effect of LWI length on knee adduction moment (KAM) has been investigated, the biomechanical mechanism has not been fully investigated. Twelve healthy young subjects walked in the laboratory with and without 2 different lengths of LWIs. Three-dimensional motion analysis was performed to calculate the first and second peaks and impulses of the KAM during the stance phase. In addition, the knee-ground reaction force lever arm (KLA) and center of pressure (COP), ankle eversion moment, and ankle eversion angle were calculated. The first peak of KAM was lower, COP was displaced outward, and KLA was shorter with both LWIs attached. On the other hand, the second peak of KAM was lower with longer LWIs, COP was displaced outward, and KLA was shorter. The KAM impulse was significantly smaller in the condition with longer LWI than in the other conditions with smaller ankle eversion motion; longer LWI induced COP to the lateral side through the stance phase and kept KLA short, thus reducing the KAM impulse.

Medial meniscus extrusion during gait is associated with decrease in knee rotation in early-stage knee osteoarthritis.

BACKGROUND: In patients with medial knee osteoarthritis (OA), medial meniscus extrusion during gait is aggravated by mechanical stress, such as knee adduction moment (KAM). Conversely, the decrease in the range of knee rotation during stance phase is also one of the important issues in early knee OA, whereas the correlation between medial meniscus extrusion and knee rotation during gait are unclear. RESEARCH QUESTION: To investigate the correlation between increase in medial meniscus extrusion and range of knee rotation during gait in patients with early- and late-stage of knee OA. METHODS: Forty patients with medial knee OA were enrolled and divided into early- and late-OA group by Kellgren-Lawrence grading scale. During gait tasks, the extent of medial meniscus extrusion was measured using ultrasonography and kinetic/kinematic data were measured using three-dimensional motion analysis system. The correlation between medial meniscus extrusion and the range of knee rotation or KAM were evaluated in the overall, early-, and late- OA groups. RESULTS: A significant negative correlation was observed between an increase in medial meniscus extrusion and range of knee rotation angle in early-OA group only. However, an increase in medial meniscus extrusion significantly correlated with the second KAM peak in the overall and early-OA groups. SIGNIFICANCE: The decrease in range of knee rotation during stance phase may be associated with the increase in medial meniscus extrusion during gait in patients with early knee OA.

[Modification of Maze Procedure in Nippon Medical School:Striving Towards Restoration of Sinus Rhythm with Physiological Activation of Atria].

Atrial fibrillation surgery is beneficial for restoring sinus rhythm and maintaining the physiological atrial contraction to prevent left atrial thrombus formation. The radial procedure, a good alternative to the maze procedure, has been performed at Nippon Medical School;it was designed to maintain physiological atrial excitation and blood flow. The design reduces the incision line and avoids conduction delay in the atrium through the use of ablation devices and intraoperative mapping of atrial excitation patterns. In addition, it preserves sinus node function and cardiac conduction pathway;this could prevent postoperative pacemaker implantation.