[1] Univ Penn, Dept Radiol & Orthopaed Surg, Perelman Sch Med, Philadelphia, PA USA
[2] Univ Penn, Dept Radiol, Perelman Sch Med, Philadelphia, PA USA
[3] Univ Penn, Dept Orthopaed Surg, Perelman Sch Med, Philadelphia, PA USA
[4] Univ Penn, Philadelphia, PA USA
[5] Perelman Sch Med, Philadelphia, PA USA
[6] Univ Virginia, Charlottesville, VA USA
[7] Univ Penn, Perelman Sch Med, Ctr Res FOP & Related Disorders, Dept Orthoped Surg, Philadelphia, PA USA
[8] Univ Penn, Perelman Sch Med, Ctr Res FOP & Related Disorders, Dept Med, Philadelphia, PA USA