title: Intramedullary pressure and bone marrow fat intravasation in unreamed femoral nailing.
abstract: OBJECTIVE
  To investigate whether intramedullary pressure and bone marrow fat embolization are different in unreamed compared with conventional reamed femoral nailing. The null hypothesis is that there is no difference between the two techniques.
  
  
  METHODS
  A prospective consecutive nonrandomized clinical trial.
  
  
  METHODS
  Intramedullary pressure was measured in the distal femoral fracture fragment at the supracondylar region. Bone marrow fat intravasation was measured by means of the modified Gurd-test. Monitoring was carried out in 31 unreamed and eight reamed intramedullary femoral nailing procedures.
  
  
  RESULTS
  Intramedullary pressure increased in the unreamed group to 82 +/- 11 mm Hg during the insertion of 9-mm and 10-mm nails and in the reamed group to 396 +/- 85 mm Hg during reaming of the medullary cavity. Insertion of nails after reaming led to an increase in intramedullary pressure of 79 +/- 13 mm Hg. A positive correlation between fat intravasation and intramedullary pressure was found in each group (rs = 0.73), resulting in less liberation of bone marrow fat in the unreamed group than in the reamed group.
  
  
  CONCLUSIONS
  Intramedullary pressure increased significantly in the reamed more than in the unreamed group. Bone marrow fat intravasation depended on the rise in intramedullary pressure, and occurred less frequently in unreamed than in reamed intramedullary femoral fracture stabilization.
authors.affiliation: Trauma Centre Unfallkrankenhaus, Salzburg, Austria.
authors.forename: A
authors.initials: A
authors.lastname: Kröpfl
authors.forename: U
authors.initials: U
authors.lastname: Berger
authors.forename: H
authors.initials: H
authors.lastname: Neureiter
authors.forename: H
authors.initials: H
authors.lastname: Hertz
authors.forename: G
authors.initials: G
authors.lastname: Schlag
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001853:Bone Marrow; D001858:Bone Nails / Q000009:adverse effects*; D004620:Embolism, Fat / Q000175:diagnosis / Q000209:etiology*; D004867:Equipment Design; D005260:Female; D005264:Femoral Fractures / Q000145:classification / Q000209:etiology / Q000601:surgery*; D005594:Fracture Fixation, Intramedullary / Q000295:instrumentation*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D011312:Pressure; D011446:Prospective Studies