Katsuki Taguchi

Peculiar structures of the blood vessels forming the secondary ossification center in the rat femoral heads

To investigate the development of the blood vessels forming the secondary ossification center in the femoral heads of growing rats, we observed the specimens of the proximal femurs having vascular casts using both an optical and a scanning electron microscopy (SEM). Histologically, the vascular invasion occurred from the lateral part of the cartilaginous epiphysis, prior to the appearance of the ossification center. The vascular casts were prominent within the cellular spaces consisting of a few hypertrophic chondrocytes. The SEM study suggested that the vascular buds had peculiar structures and invaded the cartilaginous epithysis by breaking through the cellular spaces. The blood vessels budded out from the arch of the lateral epiphyseal vessels toward the femoral heads. The sizes of the large-caliber vascular buds of about 50 μm in diameter were similar to those of the cellular spaces, and they penetrated into the epiphysis by repeated merging and branching. Many deep impressions were noted on the surface of the vascular buds, and the tips showed the peculiar shape similar to a suction cup.

Tendency of Femoral Neck Fractures

953 patients over the age of 65 with femoral neck fractures from April, 1989 to March, 1999 were studied by clinical recordings to investigate the tendency at our hospital. The items investigated were age, sex, type of fracture, location of injury, gait performance before injury, complications, etc. The results were as follows;1. The number of patients and the average age have gradually increased year after year.2. In all patients with femoral neck fracture, the ratio of medial to lateral was 1:1.7 and in patients over the age of 90, the percentaye of lateral was higher.3. For medial, the percentage of indication of osteosynthesis was higher.4. The number of bilateral femoral neck fractures increased, and in female cases lateral fracture and gait disturbance were high.