Association between Bone Mineral Density and Fracture Characteristics in the 5th Metatarsal Bone Base Fracture in Elderly for Prediction of Osteoporotic Fracture

BACKGROUND: This study aimed to analyze the correlation between bone mineral density (BMD) and the type of 5th metatarsal fracture, as well as to demonstrate whether there is a difference in radiological findings (heel alignment angle [HAA], heel moment arm [HMA], and metatarsus angle) between fracture types. METHODS: A total of 87 patients were enrolled in the study and allocated into 3 groups: the Zone 1 group (N=36), the Zone 2 group (N=33), and the Zone 3 group (N=18). The participants’ demographic data, T-scores, existing fracture or osteoporosis medications, and radiologic parameters including HAA, HMA, and metatarsus adductus angle were analyzed and compared. RESULTS: There was a significant difference between the mean age of the participants, with the highest age in the Zone 1 group and the lowest in the Zone 3 group. Regarding the history of concurrent fracture or osteoporosis medications, there was no significant difference between the 3 groups. Similarly, no significant difference was observed between the 3 groups about the BMD values. In contrast, the HAA was statistically significant in all groups with a positive correlation of −8.9 in the Zone 1 group, a negative correlation of 3.55 in the Zone 2 group, and an inverse relationship of 6.1 in the Zone 3 group. The metatarsus adductus angle was significantly higher in the Zone 3 group than the Zone 1 and Zone 2 groups. CONCLUSIONS: The location of a 5th metatarsal bone fracture is not significantly associated with BMD. However, mechanical influences, such as hindfoot varus or forefoot adductus, have a significant correlation with fracture types.