病的骨折を起こした低リン血症性ビタミンD抵抗性クル病未治療成人例の一例

抄録

A 52-year-old man was admitted with medial neck fracture of the right femur. This fracture occurred when he stood up from a sitting position. He had a peculiar short stature.: 140cm in height; 59kg in weight with bilateral bow legs. Laboratory examinations showed hypophosphatemia with normocalcemia, increased level of serum alkalinephosphatase and normal levels of PTH, 25(OH)D3, and 1, 25(OH)₂D3. Radiological findings showed Looser's zone in the subtrochanteric region of the right femur, osteoarthritic changes in many joints and exostotic bone proliferations at the site of ligamentous and tendinous insertions.
The architecture of cancellous bone was atrophic with a coarse trabecular pattern. Histological examination showed the increase of osteoid. Therefore he was diagnosed as an untreated adult case of hypophosphatemic vit. D resistant rickets. We guess that the cause of this pathological fracture is weakness of the bone and increase of the shearing force on the femoral neck due to varus deformity of the femur. Failure of intestinal phosphate absorption may play a role in hypophosphatemia in this case.