title: Reliability of radiographic measures in infants with clubfoot treated with the Ponseti method.
abstract: OBJECTIVE
  The aim of this study was two-fold: (1) to determine if radiographic measures can be reliably made in infants being treated with the Ponseti method and (2) to document radiographic changes before and after Achilles tenotomy.
  
  
  METHODS
  A retrospective radiographic and chart review was performed on children with clubfoot treated by the Ponseti method at a single institution over a 10-year period. Five independent reviewers measured a series of angles from a lateral forced dorsiflexion radiograph taken prior to and following Achilles tenotomy. These measures were taken in triplicate to determine the intra- and inter-reader reliability of dorsiflexion, tibio-calcaneal, talo-calcaneal, and talo-first metatarsal angles.
  
  
  RESULTS
  Thirty-six subjects (56 feet) were treated with the Ponseti method and met the inclusion criteria. The median (range) age of patients at the time of tenotomy was 52 (34-147) days. The intra-reader reliability [intra-rater correlation coefficient (ICC)] for each of the measured angles pre- and post-tenotomy ranged from 0.933 to 0.995 and 0.864 to 0.995, respectively. Similarly, the inter-reader reliabilities (ICC) ranged from 0.727 for the pre-tenotomy (talo-calcaneal) to 0.950 for the post-tenotomy (talo-first metatarsal) angles. The mean differences between pre- and post-tenotomy radiographs were: dorsiflexion increase of 17°, tibio-calcaneal angle increase of 19°, talo-calcaneal angle increase of 9°, and talo-first metatarsal angle increase of 10° (p-value ≤0.001 for all measurements except the talo-first metatarsal angle, with a p-value of 0.001).
  
  
  CONCLUSIONS
  Reliable radiographic measures can be made from lateral dorsiflexion radiographs of clubfeet treated with the Ponseti method before and after Achilles tenotomy.
authors.affiliation: Department of Orthopedics and Rehabilitation, University of Wisconsin, American Family Children's Hospital, 1685 Highland Ave., Suite 6170-11D, Madison, WI, 53705, USA.
authors.forename: Catherine C
authors.initials: CC
authors.lastname: Zimmerman
authors.forename: Blaise A
authors.initials: BA
authors.lastname: Nemeth
authors.forename: Kenneth J
authors.initials: KJ
authors.lastname: Noonan
authors.forename: Timothy P
authors.initials: TP
authors.lastname: Vanderbilt
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Winston
authors.forename: Conor P
authors.initials: CP
authors.lastname: O'Halloran
authors.forename: Sarah A
authors.initials: SA
authors.lastname: Sund
authors.forename: Scott J
authors.initials: SJ
authors.lastname: Hetzel
authors.forename: Matthew A
authors.initials: MA
authors.lastname: Halanski