[Four major fractures in elderly].

Fractures of proximal humerus, distal radius, proximal femur and vertebral body are common in elderly patients with osteoporosis. These so called "four major fractures in elderly" can be difficult to treat because of fragile bone. They can be treated either conservatively or surgically. Except for proximal femur fracture, conservative treatment is performed as first line therapy. To avoid complications associated with conservative treatment, surgical treatment has been developed and proves to be effective. However, the risk of surgical stress and the possibility of postoperative complication have to be estimated carefully before surgery. While fracture is treated, osteoporosis should also be treated in order to prevent another fracture.

Immunohistochemical analysis of osteoconductivity of beta-tricalcium phosphate and carbonate apatite applied in femoral and parietal bone defects in rats.

The feature of osteoconductivity, and expression of inductive BMP and transcription factors (Runx2 and Osterix) for osteoblast differentiation, which was related to conductive bone formation, were observed in experimentally created defects in rat femoral and parietal bones filled with beta-tricalcium phosphate (beta-TCP) or carbonate apatite (CAP). Femoral cortical bone defects were repaired by conductive bone formed by osteoblasts differentiated around beta-TCP and CAP, and immunohistochemical observation revealed that the osteoblasts expressed BMPs, Runx2, and Osterix. However, the repair in parietal bone defects was incomplete despite the beta-TCP and CAP filling. Only cells, which differentiated around beta-TCP or CAP, and formed conductive bone expressed BMPs, Runx2, and Osterix. These findings revealed that the osteoconductivity of calcium phosphate materials required the expression of BMPs as the prerequisite for Runx2 and Osterix expression. Therefore, it is suggested that when calcium phosphate ceramics are used as bone substitute materials, BMPs are essential for osteoconductivity.