[Bone necrosis during osteomalacias].

On the basis of 3 personal cases, the authors study the characteristics of osteonecroses during osteomalacias. They compare their findings to those in the literature. Clinically, the location at the femoral head is predominant, with absence of pain and functional tolerance often noted. On the radiological level, the demineralization of the skeleton is not constant, and there are few Looser-Milkman striae. In the lower limbs the necrosis is always located in the supporting areas, showing a restricted surface with little or no perinecrotic condensation and an absence of bone sequestrum. The cartilage remains intact for long periods. A pathogenic interpretation is proposed: the increasingly fragile state of the bones causes a subchondral fatigue fracture. The malacia bone thus adapts itself to the mechanical constraints thus imposed on it.