Low Bone Mineral Density of the Forearm and Femur among Postmenopausal Women with Metaphyseal Comminuted Fracture of the Distal Radius

Osteoporosis is characterized by bone loss and skeletal fragility and is likely to occur in postmenopausal women. Distal radius fracture is a type of fragility fractures associated with osteoporosis. Bone mineral density (BMD) refers to the amount of mineral in bone tissue and is an indicator of osteoporosis. This study aimed to investigate the relationship between the severity of distal radius comminution and the BMD of the healthy contralateral forearm and femur in postmenopausal women. Of 165 women who sustained low-energy trauma from falls on flat ground, forearm and femoral neck BMDs were measured in 155 and 163 participants, respectively. Evaluation of distal radius comminution was performed by computed tomography, and the severity is classified based on the degree of articular surface comminution and on the presence of metaphyseal comminution. We thus evaluated 165 cases of articular surface comminution (extra-articular, 43 cases; intra-articular simple, 91 cases; and intra-articular multifragment, 31 cases) and metaphysis comminution (metaphyseal simple, 58 cases; metaphyseal monocortical comminution on either the palmar or dorsal side, 82 cases; and metaphyseal bicortical comminution on the palmar and dorsal sides, 25 cases). There was no significant association between intra-articular comminution and BMD of the forearm and femur. By contrast, the participants with metaphyseal bicortical comminution showed lower BMD of the forearm and femur compared with other types of metaphysis comminution (p < 0.05). In conclusion, postmenopausal women who developed bicortical comminuted fractures of the distal radius tend to have lower femoral BMD, which may predispose them to future hip fractures.