Bone density of élite female athletes with stress fractures

To investigate whether stress fractures occurring in élite female athletes are related to reductions in bone mineral density (BMD), we measured BMD in nine athletes with such fractures and nine athletes without fractures who were matched for age, weight, height and sport. BMD was measured in three regions: upper limbs (distal radius), axial skeleton (lumbar spine) and lower limbs (femoral neck) by photon absorptiometry. The number of menses per year was significantly less (P less than 0.04) and the age of menarche was significantly delayed (mean +/- SD; 16.1 +/- 0.4 v. 14.4 +/- 1.5 years, P less than 0.02) in the fracture group compared with the non-fracture group. There was no significant difference in BMD between the two groups at any of the measurement sites. Moreover although the fractures occurred mainly in lower limb bones, at sites characterised by predominantly cortical bone, all athletes had femoral neck BMD values within the 95% confidence limits for normal non-athletic women. We conclude that stress fractures in élite female athletes are largely independent of BMD.