title: The effect of ankle joint immobilization on lower limb venous flow.
abstract: BACKGROUND
  Below-knee cast immobilization is associated with an increased risk of developing deep vein thrombosis secondary to venous stasis. We investigated the effect of weight-bearing in a below-knee cast or pneumatic walking boot on lower limb venous blood flow.
  
  
  METHODS
  Duplex ultrasonography was used to measure venous blood flow in the popliteal vein of 10 healthy volunteers. Venous blood flow was measured while at rest, ambulating non-weight-bearing, partial weight-bearing, and full weight-bearing. Measurements were performed without ankle joint immobilization, with the ankle immobilized in a neutral cast, and with the ankle immobilized in a pneumatic walking boot in both neutral and equinus.
  
  
  RESULTS
  There was no significant reduction in venous blood flow measurements between full weight-bearing without ankle joint immobilization and full weight-bearing in a neutral cast or neutral pneumatic walking boot. However, venous blood flow was reduced when partial weight-bearing (50%) and when full weight-bearing in a pneumatic walking boot in equinus.
  
  
  CONCLUSIONS
  These results demonstrate that venous blood flow returned to normal levels when the subjects were permitted to fully bear weight in below-knee casts or walking boots, provided that the ankle joint was not in equinus.
  
  
  CONCLUSIONS
  Weight-bearing status and ankle joint position should be appreciated during decisions for the provision of chemical thromboprophylaxis.
authors.affiliation: Department of Orthopaedics, Epsom General Hospital, Surrey, UK jcraik82@gmail.com.
authors.forename: Johnathan D
authors.initials: JD
authors.lastname: Craik
authors.affiliation: Department of Orthopaedics, Epsom General Hospital, Surrey, UK.
authors.forename: Amanda
authors.initials: A
authors.lastname: Clark
authors.affiliation: Department of Orthopaedics, Epsom General Hospital, Surrey, UK.
authors.forename: James
authors.initials: J
authors.lastname: Hendry
authors.affiliation: Department of Orthopaedics, Epsom General Hospital, Surrey, UK.
authors.forename: Andrea H
authors.initials: AH
authors.lastname: Sott
authors.affiliation: Department of Orthopaedics, Epsom General Hospital, Surrey, UK.
authors.forename: Paul D
authors.initials: PD
authors.lastname: Hamilton
mesh_terms: D000328:Adult; D002370:Casts, Surgical; D005260:Female; D061826:Foot Orthoses; D006801:Humans; D007103:Immobilization; D007866:Leg / Q000098:blood supply*; D008297:Male; D008875:Middle Aged; D011152:Popliteal Vein / Q000502:physiology; D012039:Regional Blood Flow; D016474:Weight-Bearing / Q000502:physiology*
keywords: boot; cast; deep vein thrombosis