title: MR Imaging in Postreduction Assessment of Developmental Dysplasia of the Hip: Goals and Obstacles.
abstract: Developmental dysplasia of the hip is a spectrum disorder of hip development that ranges in severity from abnormal acetabular morphology to complete hip dislocation. While treatment with a Pavlik harness is highly effective in infants younger than 6 months, older infants and children and those with orthotic failure often warrant surgical reduction and placement of a spica cast, which limits subsequent imaging evaluation. Magnetic resonance (MR) imaging has been described in the evaluation of the adequacy of hip reduction for more than 2 decades, but the practice is still not widespread and is performed routinely at relatively few centers. MR imaging is a robust tool for outcome assessment after hip reduction and placement of a spica cast, facilitating multiplanar confirmation of concentric reduction independent of an ossific nucleus or orthopedic hardware. Excellent image contrast of soft tissues allows identification of obstacles to concentric reduction, which may be extra-articular or intra-articular. Extra-articular obstacles include tightening of the adductor muscles and tightening of the iliopsoas tendon with constriction of the joint capsule. Intra-articular obstacles include limbus formation, labral inversion, an enlarged pulvinar, and hypertrophy of the ligamentum teres and/or the transverse acetabular ligament. Intravenous contrast material administration may demonstrate altered epiphyseal blood flow and help identify patients at risk for early ischemia. Imaging technique and image interpretation can be optimized to facilitate the performance of postreduction MR imaging studies where they may be of benefit. (©)RSNA, 2016.
authors.affiliation: From the Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pa (D.G.R., S.S., D.J.); and Department of Radiology and Imaging, Hospital for Special Surgery, New York, NY (E.A.B., D.N.M.).
authors.forename: Daniel G
authors.initials: DG
authors.lastname: Rosenbaum
authors.affiliation: From the Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pa (D.G.R., S.S., D.J.); and Department of Radiology and Imaging, Hospital for Special Surgery, New York, NY (E.A.B., D.N.M.).
authors.forename: Sabah
authors.initials: S
authors.lastname: Servaes
authors.affiliation: From the Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pa (D.G.R., S.S., D.J.); and Department of Radiology and Imaging, Hospital for Special Surgery, New York, NY (E.A.B., D.N.M.).
authors.forename: Eric A
authors.initials: EA
authors.lastname: Bogner
authors.affiliation: From the Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pa (D.G.R., S.S., D.J.); and Department of Radiology and Imaging, Hospital for Special Surgery, New York, NY (E.A.B., D.N.M.).
authors.forename: Diego
authors.initials: D
authors.lastname: Jaramillo
authors.affiliation: From the Department of Radiology, Children's Hospital of Philadelphia, Philadelphia, Pa (D.G.R., S.S., D.J.); and Department of Radiology and Imaging, Hospital for Special Surgery, New York, NY (E.A.B., D.N.M.).
authors.forename: Douglas N
authors.initials: DN
authors.lastname: Mintz
mesh_terms: D002648:Child; D002675:Child, Preschool; D003287:Contrast Media; D005271:Femur Head Necrosis / Q000000981:diagnostic imaging; D006618:Hip Dislocation, Congenital / Q000000981:diagnostic imaging* / Q000628:therapy*; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008279:Magnetic Resonance Imaging / Q000379:methods*; D009989:Orthotic Devices; D010027:Osteotomy; D012307:Risk Factors
chemical_list: D003287:Contrast Media