Fig. 1.
From: Incidence and location of heterotopic ossification following hip arthroscopy
a, b Frog-leg lateral radiograph and 3D CT scan of a 19-year-old male patient, acquired 1 year after arthroscopic labral repair and acetabulofemoroplasty. Heterotopic ossification was classified as Brooker grade 2, with the largest measurement (width) being 21 mm. c, d Heterotopic ossification was located in anterolateral joint capsule and removed with arthroscopy. e Frog-leg lateral radiograph showed no evidence of heterotopic ossification at 2 year follow-up