Unusual Cause of Lumbar Pain in Elite Sports: Two Case Reports of Sacral Stress Fractures

› Nonspecific lower back and buttock pain can significantly limit performance in athletes and can be of different origins. Sacral stress fractures are a rare and, in many cases, undiagnosed cause of lower back pain, which can lead to a substantial loss of time before a full return-to-sports is achieved with full athletic performance. › The main risk factors of sacral stress fractures include repetitive full weight-bearing activities, short-term increases in exercise intensity or duration, and excessive energy deficit. Knowledge of the injury pattern, high clinical suspicion, and early MRI examination lead to a timely diagnosis. Therapeutically, load reduction with avoidance of high impact activities for at least 6 weeks is indicated initially, followed by dosed and progressive load increase. In parallel, supplementation with calcium and vitamin D is recommended. Athletes with recurrent stress fractures, regardless of region, should be evaluated for a “Female Athlete Triad” or its male counterpart, as well as endocrinologic risk factors. Preventive measures are possible for stress fractures but are not specific to sacral stress fractures. › We describe two clinical case scenarios, one of a professional soccer player and one of an elite track and field athlete with sacral stress fractures as the cause of nonspecific lumbar pain.