[Fractures of the calcaneus during fluoride therapy of osteoporosis].

Two cases of calcaneum "stress" fractures are reported. The fracture, which was unilateral in the first case and bilateral in the second, occurred 15 and 18 months respectively after the initiation of fluoride treatment for osteoporosis. The simultaneous discovery of thyrotoxicosis in the second patient suggests that the role of hyperthyroidism in the occurrence of these fractures be discussed in addition to that of fluoride treatment.