: Bony atrophy around the components following total knee arthroplasty TKA is often observed by radiography. To investigate the underlying cause of this incidence, we sought to quantitatively evaluate postoperative bone changes around the total knee components using dual-energy X-ray absorptiometry DXA over time. A retrospective study was conducted to compare bone mineral density BMD around the components in 22 patients pre-operatively and at 1, 3, 6, 12, and 24 months after cementless TKA for the treatment of osteoarthritis. In the coronal view, the medial tibia showed that a signi cant decrease in BMD at 12 months compared with 1 month after surgery P 0.05 , while the sagittal view showed that a signi cant decrease in BMD only at the anterior femoral condyle at 24 months compared with 1 month postoperatively P 0.05 . TKA improved the leg alignment and load-bearing axis in all patients, but we found that BMD tended to decrease on the medial side of the tibia and the anterior femoral condyle area over time following surgery. Our results suggest that recreating proper valgus alignment of the knee joint provides physiological balancing and condition. A larger prospective study is warranted.

We report a case of an 82-year-old woman with senile dementia who was hospitalized at a specialist dementia hospital for 10 months. She had swelling of the left shoulder joint, subcutaneous hematoma in the left upper arm, and anemia was noted on blood examination. Her serum hemoglobin level was lower than normal at 4.6 g/dL, but there was no sign of gastrointestinal disease or gastrointestinal bleeding, and her stool specimens were negative for occult blood. Hematoma subsequently appeared on her chest and back. She had a low activation level of factor VIII (<1%), a high concentration of acquired inhibitors of factor VIII (18.5 BU/mL), and prolonged activated partial thromboplastin time (83.1 seconds). The possibility of drug-induced anemia or hematoma were ruled out. We diagnosed acquired hemophilia A (AHA), and suspected that this was the cause of her hematomas. We began treatment of her AHA with oral prednisolone and intravenous infusion of factor VIII. The bleeding improved, but she later died due to bacterial pneumonia. AHA is very rare, with a reported annual incidence of 0.1/100,000 in Japan. However, it is necessary to consider such a rare disease when we encounter bleeding in elderly patients.