THE INCIDENCE of stress fractures of the os calcis has been previously reported as low. Records of the German Army Hospitals for the year 1935 through 1936 indicated that of 590 stress fractures only four were observed in the os calcis.1 Carlson and Wertz2 reported a series of 70 stress fractures of which 66 occurred in the metatarsal, three were noted in the femur, and one was observed in the calcaneus. Hullinger3 presented 71 calcaneal stress fractures demonstrated in 53 patients; bilateral involvement was indicated in 18 patients (34%). Bilateral involvement was noted in 11 patients (35% ) reported by Winfield and Dennis4 who observed 42 calcaneal stress fractures in 31 patients. Winfield and Dennis4 and Hullinger3 did not report the incidence of calcaneal stress fractures with respect to the total number of stress fractures involving all sites.
The patients in this series