title: Is it worthwhile to routinely ultrasound screen children with idiopathic clubfoot for hip dysplasia?
abstract: OBJECTIVE
  Patients with idiopathic clubfoot are considered at increased risk for having developmental dysplasia of the hips (DDH). However, the studies showing this association have been relatively small. Many clinicians who treat idiopathic clubfoot routinely screen the hips of these patients with ultrasound or radiograph due to the concerns of increased risk of DDH. We evaluated a large clubfoot population to determine the risk of DDH and compare this to a population of children without clubfoot. We also evaluated if the clubfoot patients found to have DDH would have been discovered by standard DDH screening.
  
  
  METHODS
  We identified infants in 3 states (MA, NY, NC), who were reported to each state's birth defects registry as having a clubfoot. A second cohort of infants without clubfoot was also identified as a control group. Mothers of these children were contacted to be included in the study, and a computer-assisted telephone interview was administered by one of the study nurses, including questions about treatment of DDH. The child's median age at interview was 7 months. Mothers of clubfoot cases were also contacted for follow-up at mean age of 3.3 years.
  
  
  RESULTS
  Families of 677 patients with clubfoot and 2037 controls were interviewed. A total of 5/677 (0.74%) patients with clubfoot and 5/2037 (0.25%) controls reported having their infant treated with a brace or harness for hip problems (P=0.134). Of the patients with clubfoot, 2 of them did not need treatment for their DDH and 2 would have been discovered by standard hip screening. Follow-up study at 3.3 years of age found no serious late hip dysplasia.
  
  
  CONCLUSIONS
  Treatment of DDH was uncommon in all children; the higher proportion in infants with clubfoot was not statistically different than controls. Of the patients with clubfoot and DDH, standard hip screening would have been appropriate and others did not need treatment. These data suggest that routine hip ultrasound or radiographic screening of idiopathic clubfoot patients is not necessary unless indicated by the standard infant hip screening.
  
  
  METHODS
  Level 3 study.
authors.affiliation: *Department of Orthopaedic Surgery, Boston Children's Hospital †Department of Orthopaedic Surgery, Harvard Medical School ‡Slone Epidemiology Center, Boston University, Boston, MA.
authors.forename: Susan T
authors.initials: ST
authors.lastname: Mahan
authors.forename: Mahsa M
authors.initials: MM
authors.lastname: Yazdy
authors.forename: James R
authors.initials: JR
authors.lastname: Kasser
authors.forename: Martha M
authors.initials: MM
authors.lastname: Werler
mesh_terms: D016022:Case-Control Studies; D002648:Child; D003025:Clubfoot / Q000150:complications / Q000000981:diagnostic imaging*; D005260:Female; D006618:Hip Dislocation, Congenital / Q000150:complications / Q000000981:diagnostic imaging*; D006801:Humans; D007223:Infant; D008297:Male; D008403:Mass Screening / Q000379:methods*; D018570:Risk Assessment; D012307:Risk Factors; D014463:Ultrasonography