High fat diet consumption induces fat accumulation in the liver. An understanding of when liver fat accumulation begins is important for exploring the mechanisms underlying fatty liver. The aim of this study was to investigate the processes of fat accumulation in the liver during high fat diet consumption with or without exercise using computed tomography (CT). Male 6 week old C57BL/6J mice were randomly assigned to the normal diet or high fat diet group. After 6 weeks, mice in the high-fat diet group were further divided into voluntary wheel exercise (HFD+Ex) and no exercise (HFD) groups. We measured body weight, food intake and locomotor activity in all mice. Liver fat accumulation was measured by CT scan weekly. Blood and tissue sampling was performed at the end of the experimental period. Following the 6 week exercise period, total body, mesenteric fat and liver weight in the HFD+Ex group were significantly lower than those in the HFD group. Alanine aminotransferase levels improved in HFD+Ex mice compared with those of HFD mice. The hounsfield unit value in HFD mice decreased between 3 and 8 weeks, suggesting that liver fat accumulation accelerated during this period. In contrast this decrease was not observed one week after exercise in HFD+Ex mice. These results suggest that liver fat accumulation estimated by CT was not observed until the 3rd week of high fat feeding while the effects of voluntary wheel exercise appeared immediately.

Background: No study has compared flat and elevated-rim polyethylene liners in terms of stress distribution on the bearing surface. The purpose of this study was to investigate the difference in stress distribution between flat and elevated-rim polyethylene liners. Methods: A stress analysis was performed by using the 3-dimensional finite element method. The cup was placed at an open angle of 20°, the flat liner and the liner with a 10° elevation was placed at inclination angles of 80°, 70°, and 60°. Results: Compared with the 60° flat liner, the 80° and 70° flat liners showed higher stress at the liner edge. In the elevated-rim liner, the stress was high at the liner edge along the cup edge. When the von Mises equivalent stress was applied to each element of the liner, the high stress area (volume) was the largest for the 80° flat liner, second largest for the 80° elevated-rim liner, and third largest for the 70° flat liner. The average contact pressure also followed the same order. Conclusions Elevated-rim liners affect the stress distribution by increasing the area of contact. However, since elevated-rim liners exhibit high stress at the cup edge, they are likely to result in new problems including liner failure. These findings could aid surgeons in the selection of liners and determination of revision methods such as isolated liner exchange vs. acetabular cup revision for a well-fixed metal cup with a higher inclination angle in revision total hip arthroplasty.

Knee rotationplasty is a surgery wherein the rotated ankle serves as the new knee joint after resecting the original knee joint and lesion. However, details of postoperative rehabilitation treatment in a convalescent rehabilitation ward are not well-known. Therefore, we reported the rehabilitation progress of a 36-year-old man who underwent knee rotationplasty in the convalescent rehabilitation ward. In the early postoperative period, the surgery required no weight bearing on the operated lower limb until bone healing. Even during this period, we conducted physical therapies such as joint range of motion training and muscle strength training as outpatient rehabilitation therapy. After being admitted to the convalescent rehabilitation ward, physical therapy was intensified and the patient's rotationplasty prosthesis was then fabricated and fitted by a prosthetist and orthotist. The patient was discharged 80 days after his hospitalization and could eventually walk stably with his prosthesis and returned to work. In Japan, the length of stay in a convalescent rehabilitation ward is limited. If patients are provided with enough physical therapy during the postoperative course and rotationplasty prosthesis by a skilled prosthetist and orthotist, rehabilitation treatment after knee rotationplasty can achieve good results in a convalescent rehabilitation ward.

The importance of off the job training in surgical education are widely recognized. The Japanese Board of Cardiovascular Surgery has required a board candidate to do at least 30 hours of off the job training from 2017. U-40 Basic Lecture Course are held annually for young cardiovascular surgeon to learn about basic surgical skills. U-40 Advanced Lecture Course was started to provide opportunity to have more advanced hands-on lecture for young cardiovascular surgeon. However, after the COVID-19 pandemic, the opportunity to hold hands-on seminars are highly limited. In such circumstances, we held a hybrid hands-on seminar. We report details about the hybrid hands-on seminar.