Pulmonary Effects of Fixation of a Fracture with a Plate Compared with Intramedullary Nailing. A Canine Model of Fat Embolism and Fracture Fixation

• Published in: Journal of bone and joint surgery. American volume 1997-07, Vol.79 (7), p.984-96
• Main Authors: SCHEMITSCH, EMIL H, JAIN, RINA, TURCHIN, DIANA C, MULLEN, J BRENDAN, BYRICK, ROBERT J, ANDERSON, GAIL I, RICHARDS, ROBIN R
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Bone Plates - adverse effects; Dogs; Embolism, Fat - etiology; Fracture Fixation, Intramedullary - adverse effects; Fractures, Bone - complications; Fractures, Bone - therapy; Hypertension, Pulmonary - etiology; Medical sciences; Methylmethacrylate; Methylmethacrylates - analysis; Orthopedic surgery; Pulmonary Edema - etiology; Pulmonary Embolism - etiology; Surgery (general aspects). Transplantations, organ and tissue grafts. Graft diseases
• ISSN: 0021-9355; 1535-1386
• DOI: 10.2106/00004623-199707000-00004

Fat-embolism syndrome and pulmonary dysfunction may develop in multiply injured patients who have a fracture of a long bone. Although early fixation of a fracture is beneficial, intramedullary nailing may exacerbate pulmonary dysfunction by causing additional embolization of marrow fat. We examined the pulmonary effects of the timing and method of fixation of a fracture in a canine fat-embolism model. Fat embolism was induced in forty-one adult dogs by reaming the ipsilateral femur and tibia followed by pressurization of the intramedullary canal. The animals were divided into a control group of eight dogs that had induction of fat embolism alone and an experimental group of thirty-three dogs that had induction of fat embolism and internal fixation of a transverse fracture of the middle of the contralateral femoral shaft. In the control group, four dogs each were killed four hours and twenty-four hours after induction of fat embolism. In the experimental group, a femoral fracture was created and fixation was performed four hours after embolic showering in fifteen animals and twenty-four hours after embolization in eighteen animals. The two experimental groups were subdivided according to the method of fixation of the fractureeleven dogs each had application of a plate, nailing without reaming, and nailing with reaming. The pulmonary arterial pressure and the alveolar-arterial gradient were measured preoperatively, during induction of fat embolism, and as long as one hour after fixation of the fracture but before the animal was killed. The lungs, brain, and kidneys were examined for pathological and physiological evidence of intravascular fat. The intravascular fat persisted for twenty-four hours after induction of pulmonary fat embolism. Pulmonary arterial pressure remained elevated at four hours after the embolic showering, before creation and fixation of the fracture. By twenty-four hours after the induction of fat embolism, pulmonary arterial pressure had returned to the baseline level. Neither the creation nor the fixation of the fracture affected pulmonary arterial pressure. In the animals that had fixation of a fracture four hours after embolization, both nailing with reaming and nailing without reaming produced alveolar-arterial gradients that were higher than the baseline values, whereas fixation with a plate did not change the alveolar-arterial gradient significantly from the baseline value. In addition, the alveolar-arterial gradients in the anima