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Biomedical subjects

J Umehara

Publications and source records attributed to J Umehara.

4 recordsLinked to original sources
PubMed1999

Influence of tibial bone quality on loosening of the tibial component in total knee arthroplasty for rheumatoid arthritis: long-term results.

This study examined the relationship between the bone quality of the proximal tibia, which was quantitatively investigated by histomorphometric method at the time of total knee arthroplasty, and the occurrence of loosening of an all-polyethylene tibial component in nine rheumatoid arthritis patients. Despite severe osteoporosis, there was no loosening after 12.8 years. These results suggest that even severe osteoporosis does not influence the occurrence of loosening of a cemented, all-polyethylene tibial component in rheumatoid patients with low activity levels. We recommend the use of all-polyethylene tibial component for low-activity patients.

Adult↗
PubMed1995

Proximal tibiofibular joint: a radiographic and computed tomographic study.

In 671 knees of 351 patients, the proximal tibiofibular joint was radiologically investigated. To clearly detect the contour of the joint, radiographs were obtained under fluoroscopic control with the lower extremity internally rotated. The contour was classified into three types: the joint lines of both tibia and fibula are straight (A); the joint line of the fibula is convex (B); the joint line of the tibia is convex (C). The rotation and the inclination of the joint were measured. Of the 671 knees, CT examination was also carried out in 51 knees. The obliquity of the joint was measured and the location of the fibula as related to the tibia was evaluated by CT. We also examined the relationships between the contour and the rotation, inclination, obliquity of the joint and the location of the fibula, and determined the characteristics of type B and C as compared with type A. The characteristics of type B were as follows: (1) this type was mainly seen in younger patients, (2) the rotation was the lowest and the inclination was the highest among the three types, (3) in CT the joint line was more saggital and the fibula was located more anteriorly. The characteristics of type C were as follows: (1) this type was seen in older patients, (2) the rotation was the highest and the inclination was the lowest among the three types, (3) in CT the joint line was more frontal and the fibula was located more posteriorly.

Adolescent↗