Kouhei Murase

Impact load transmission of the knee joint-influence of leg alignment and the role of meniscus and articular cartilage

OBJECTIVE The objective of this study was to evaluate load transmission in the cancellous bone of the tibia under static and impact load.BACKGROUND. Abnormal transmission of loads may result in osteoarthritis and fractures. However, the role of the cancellous bone in these processes is not well understood.METHODS. The compressive stresses in the subchondral bone, epiphysis and diaphysis of the tibia of porcine knees were measured under static and impact load using mini-pressure transducers. The tests were performed using a drop-tower type testing machine in neutral, varus and valgus alignments. Tests were repeated after meniscectomy and again after removing the articular cartilage.RESULTS. In the intact knee in all alignments, the highest stress on the medial side was found in the epiphysis, and in the subchondral bone on the lateral side. After meniscectomy, a significant increase was observed in the stress in the subchondral bone on both sides. After the articular cartilage was also removed, the stress in the subchondral bone increased again, but slightly.CONCLUSION. The importance of the meniscus in load transmission is supported by this study. The contribution of the articular cartilage to load transmission is less than that of the meniscus.Relevance. The patterns of static and dynamic load transmission observed in this study correlate with the sites of insufficiency fractures of the medial tibial plateau and traumatic lateral tibial plateau fractures observed clinically. Examination of the load transmission is key to a more complete understanding of the causes of osteoarthritis and tibial plateau fractures.

Investigation breasts' form and internal structure by wearing a brassiere from MRI images

Purpose – The breast is composed of two main types of soft tissues: glandular tissue and adipose tissue. Wearing a brassiere makes them deform easily. In order to design comfortable brassieres by which the body shape is adjusted, it is important to clarify the relationship between the breast deformation and the internal structure of the breast. The purpose of this paper is to assess a method to determine the structure inside the breast. Breast shape comparison was performed to assess the relationship between the external deformation caused by wearing a brassiere and the internal structure of the breast.Design/methodology/approach – The subjects were five adult females. The breast MRI imaging in the sitting position was carried out using the vertical MRI systems under bare breasts condition and under wearing a brassiere condition. By creating 3D images from the MRI images obtained, the internal structure of the breast was determined. The 3D images under the wearing brassiere conditions were superimposed on...