title: Surgical blood loss during femoral rodding in children with osteogenesis imperfecta.
abstract: BACKGROUND
  Historically, patients with osteogenesis imperfecta (OI) have been reported to be at risk for significant surgical bleeding secondary to abnormalities in platelet function. By reviewing the operative blood loss in OI patients undergoing femoral osteotomies and rodding, we hoped to identify risk factors for excessive bleeding.
  
  
  METHODS
  A retrospective review of 22 patients with 52 inserted femoral rods was conducted under Institutional Review Board approval. Information concerning patients and procedures was collected. Associations with mean blood loss were made for categorical variables using the unpaired t-test and for continuous variables using correlation. Multivariate linear regression was used to test the influence of potential risk factors for excessive bleeding.
  
  
  RESULTS
  The mean blood loss was 197 cc (standard deviation [SD] 129 cc, range 10-500 cc). The adjusted mean blood loss (ratio of actual blood loss divided by the total predicted blood volume [Custer and Rau in "The Harriet Lane Handbook," 18th edn. Mosby-Elsevier, Philadelphia, p 382, 2009]) was 0.16 (SD 0.13, range 0.01-0.44). Six blood transfusions were required out of 42 cases for a transfusion rate of 14%. The mean blood loss in those patients who were transfused was 279 cc compared with 182 cc for those not transfused. There were no differences in the adjusted mean blood loss between acute fracture treatment versus elective reconstruction (P = 0.08), nor between primary rodding versus revision rodding (P = 0.66). Older patients tended to have lower adjusted mean blood loss, though this was not significant (P = 0.07). Increasing number of osteotomies tended to lead to increased adjusted mean blood loss (P = 0.05). There was no association between operative time and adjusted mean blood loss (P = 0.36). When adjusting for procedure characteristics, increasing age was associated with decreasing adjusted mean blood loss (P = 0.008).
  
  
  CONCLUSIONS
  Predicting blood loss for femoral rodding in patients with OI is difficult, with no differences between revision and primary procedures or elective versus trauma cases. The blood loss in our patients undergoing femoral rodding was manageable, and the transfusion rate was reasonably low. Although massive blood loss has been described in patients with OI in the literature, we found that femoral rodding did not pose excessive risk of transfusion in our OI population.
authors.affiliation: Department of Orthopaedic Surgery, The Johns Hopkins Hospital, 601 North Caroline Street #5232, Baltimore, MD, 21287-0882, USA.
authors.forename: Carmen P
authors.initials: CP
authors.lastname: Pichard
authors.forename: Raymond E
authors.initials: RE
authors.lastname: Robinson
authors.forename: Richard L
authors.initials: RL
authors.lastname: Skolasky
authors.forename: Neal S
authors.initials: NS
authors.lastname: Fedarko
authors.forename: Arabella I
authors.initials: AI
authors.lastname: Leet