Prevalence of Asymptomatic Talar Bone Marrow Edema in Professional Ballet Dancers: Preliminary Data From a 2-Year Prospective Study

BACKGROUND: Compared with symptomatic bone marrow edema (BME) associated with stress fractures, asymptomatic BME seen on magnetic resonance imaging (MRI) is a phenomenon that has been described in high-level athletes and is thought to be related to bone adaptation to biomechanical loading unique to each sport. However, the prevalence, natural history, and management of these lesions remain poorly understood, particularly in dance, which places tremendous stress on the feet and ankles. PURPOSES/HYPOTHESIS: The purposes of this study were to (1) determine the prevalence of asymptomatic BME in the talus before the start of the performance season, (2) identify contributing demographic and training factors, and (3) compare the radiological evidence of talar BME with validated functional foot and ankle scores. We hypothesized that talar BME would be highly prevalent among asymptomatic professional dancers. STUDY DESIGN: Case series; Level of evidence, 4. METHODS: A total of 14 professional ballet dancers (6 female and 8 male; mean age, 24 years) were included in this 2-year prospective study. For each participant, we recorded complete medical and surgical history along with scores on the Foot and Ankle Ability Measure (FAAM) and the Foot and Ankle Disability Index. Bilateral foot and ankle 3.0-T MRI scans without contrast were completed before the start of the performance season and were evaluated for BME of the talus using the Fredericson criteria. RESULTS: Evidence of talar BME was seen in 15 of the 28 (54%) ankles examined and in 9 of 14 (64%) dancers. We found that 6 dancers demonstrated bilateral talar BME, 3 dancers demonstrated unilateral BME, and 5 dancers demonstrated no evidence of BME. The most common location of BME was the posterior talus, seen in 8 of 15 (53%) ankles. No statistically significant differences were noted in dancers with versus those without talar BME with regard to functional scores, demographic characteristics, or weekly training hours. CONCLUSION: Asymptomatic talar BME was highly prevalent (64%) in professional ballet dancers and tended to occur posteriorly. Long-term clinical and radiographic follow-up is necessary to determine the natural history of these lesions.