title: Effect of intermittent pneumatic soft-tissue compression on fracture-healing in an animal model.
abstract: BACKGROUND
  The fracture-healing process is closely related to blood supply. Intermittent pneumatic compression of the surrounding soft tissue may alter blood flow and, therefore, modify the healing process. The object of the present study was to evaluate the effect of intermittent pneumatic compression on fracture-healing in an animal model.
  
  
  METHODS
  Unilateral, transverse, mid-tibial osteotomies with a 3-mm gap were performed in thirty rabbits. The osteotomy site was stabilized with a double-bar external fixator. The femoral vein was ligated to induce venous stasis. Beginning on the fourth postoperative day, fifteen rabbits were treated with intermittent pneumatic compression with use of four rubber balloons, two around the distal part of the calf and two around the midpart of the calf, for one hour daily for four weeks (the study group) and fifteen rabbits were not treated with intermittent pneumatic compression (the control group). Peripheral computerized tomographic examination was performed biweekly to measure callus area and mineral content at the fracture gap. At eight weeks, the rabbits were killed, and the biomechanical properties of the healing fractures were evaluated with a torsional test.
  
  
  RESULTS
  An increase in callus area and mineral content at the osteotomy gap was observed in the study group, compared with the values in the control group, starting four weeks after the index procedure. At six weeks, the rabbits treated with intermittent pneumatic compression exhibited, on the average, a 32.2% larger callus area (p = 0.035) and a 49.7% higher mineral content (p = 0.01) at the osteotomy site compared with the values in the control group. The torsional stiffness, maximum torque, angular displacement at maximum torque, and energy required to failure of specimens in the study group were an average of 27.0% (p = 0.05), 61.5% (p = 0.0001), 35.4% (p = 0.0003), and 110.8% (p = 0.0001) higher, respectively, than those in the control group at eight weeks.
  
  
  CONCLUSIONS
  Intermittent pneumatic compression enhanced callus mineralization and development and it improved the biomechanical properties of a healing osteotomy site in the rabbit tibia.
authors.affiliation: The J. Vernon Luck Sr. M.D. Orthopaedic Research Center at Orthopaedic Hospital/University of California at Los Angeles, USA. spark@laoh.ucla.edu
authors.forename: Sang-Hyun
authors.initials: SH
authors.lastname: Park
authors.forename: Mauricio
authors.initials: M
authors.lastname: Silva
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D004195:Disease Models, Animal; D016267:External Fixators; D005260:Female; D017102:Fracture Healing / Q000502:physiology*; D005597:Fractures, Open / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D005676:Gravity Suits; D011817:Rabbits; D013977:Tibia / Q000098:blood supply / Q000000981:diagnostic imaging / Q000503:physiopathology; D013978:Tibial Fractures / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D014057:Tomography, X-Ray Computed; D014102:Torsion Abnormality; D014689:Venous Insufficiency / Q000000981:diagnostic imaging / Q000503:physiopathology