Pathophysiology of Femoral Fractures in Hypophosphatasia.
Hypophosphatasia, a rare genetic disease, causes spontaneous femoral fractures that resemble those in osteopetrosis, not typical osteomalacia. This paradox offers new insights into the complex pathophysiology of bone abnormalities in this disease.
This review examines the pathophysiology of femoral fractures in adults with hypophosphatasia (HPP), a rare genetic disorder characterized by low tissue-nonspecific alkaline phosphatase (TNAP) activity. While HPP can cause osteomalacia, the spontaneous femoral fractures in adults with moderate HPP resemble those seen in osteopetrosis, where bone becomes excessively dense and brittle. The review explores the anatomical, molecular, and biochemical bone abnormalities that contribute to this paradox, offering new insights into the disease. Further research is needed to investigate the nanoscale crystal structure of the bone and abnormalities in fracture healing and bone resorption in HPP patients with femoral fractures.