Magnetic resonance imaging of the ankle in female ballet dancers en pointe
Background: Ballet dancers require extreme range of motion of the ankle, especially weight-bearing maximum plantar flexion (en pointe). In spite of a high prevalence of foot and ankle injuries in ballet dancers, the anatomy and pathoanatomy of this position have not been sufficiently studied in weight-bearing. Magnetic resonance imaging (MRI) is a beneficial method for such study. Purpose: To develop an MRI method of evaluating the ankles of female ballet dancers standing en pointe and to assess whether pathological findings from the MR images were associated with ankle pain reported by the subjects. Material and Methods: Nine female ballet dancers (age, 21 +/- 2.9 years; dance experience, 16 +/- 4.1 years; en pointe dance experience, 7 +/- 4.9 years) completed an ankle pain visual analog scale questionnaire and underwent T1- and T2-weighted scans using a 0.25 T open MRI device. The ankle was scanned in three positions: supine with full plantar flexion, standing with the ankle in anatomical position, and standing en pointe. Results: Obtaining MR images of the ballet dancers en pointe was successful in spite of limitations imposed by the difficulty of remaining motionless in the en pointe position during scanning. MRI signs of ankle pathology and anatomical variants were observed. Convergence of the posterior edge of the tibial plafond, posterior talus, and superior calcaneus was noted in 100% of cases. Widened anterior joint congruity and synovitis/joint effusion were present in 71% and 67%, respectively. Anterior tibial and/or talar spurs and Stieda's process were each seen in 44%. However, clinical signs did not always correlate with pain reported by the subjects. Conclusion: This study successfully established an ankle imaging technique for ballet dancers en pointe that can be used in the future to assess the relationship between en pointe positioning and ankle pathoanatomy in ballet dancers.