title: Effect of Casting Material on the Cast Pressure After Sequential Cast Splitting.
abstract: BACKGROUND
  Circumferential casting is a vital component of nonoperative fracture management. These casts are commonly valved to release pressure and decrease the risk of complications from swelling. However, little information exists regarding the effect of different casting supplies on the pressure within the cast.
  
  
  METHODS
  Seventy-five long-arm casts were performed on human volunteers, divided between 5 experimental groups with 15 casts in each groups. Testing groups consisted of 2 groups with a plaster short-arm cast overwrapped with fiberglass to a long arm with either cotton or synthetic cast padding. The 3 remaining groups included fiberglass long-arm casts with cotton, synthetic, or waterproof cast padding. A pediatric blood pressure cuff bladder was placed within the cast and inflated to 100 mm Hg. After inflation, the cast was sequentially released with pressure reading preformed after each stage. Order of release consisted of cast bivalve, cast padding release, and cotton stockinet release. After release, the cast was overwrapped with a loose elastic bandage. Difference in pressure readings were compared based upon the cast material.
  
  
  RESULTS
  Pressures within the cast were found to decrease with sequential release of cast. The cast type had no effect of change in pressure. Post hoc testing demonstrated that the type of cast padding significantly affected the cast pressures with waterproof padding demonstrating the highest pressure readings at all time-points in the study, followed by synthetic padding. Cotton padding had the lowest pressure readings at all time-points.
  
  
  CONCLUSIONS
  Type of cast padding significantly influences the amount of pressure within a long-arm cast, even after bivalving the cast and cutting the cast padding. Cotton cast padding allows for the greatest change in pressure.
  
  
  CONCLUSIONS
  Cotton padding demonstrates the greatest change in pressure within a long-arm cast after undergoing bivalve. Synthetic and waterproof cast padding should not be used in the setting of an acute fracture to accommodate swelling.
authors.affiliation: Department of Orthopaedic Surgery, Dwight D. Eisenhower Army Medical Center, Fort Gordon, GA.
authors.forename: Aaron
authors.initials: A
authors.lastname: Roberts
authors.forename: K Aaron
authors.initials: KA
authors.lastname: Shaw
authors.forename: Shawn E
authors.initials: SE
authors.lastname: Boomsma
authors.forename: Craig D
authors.initials: CD
authors.lastname: Cameron
mesh_terms: D002133:Calcium Sulfate; D002370:Casts, Surgical; D032561:Cotton Fiber; D005898:Glass; D064368:Healthy Volunteers; D006801:Humans; D007103:Immobilization / Q000295:instrumentation* / Q000379:methods; D011091:Polyesters; D011093:Polyethylene Terephthalates; D011140:Polyurethanes; D011312:Pressure
chemical_list: D011091:Polyesters; D011093:Polyethylene Terephthalates; D011140:Polyurethanes; C009753:fiberglass; C046709:Scotchcast; D002133:Calcium Sulfate