title: The effects of low-intensity ultrasound on medial collateral ligament healing in the rabbit model.
abstract: BACKGROUND
  Ruptured medial collateral ligaments are capable of healing over time, but biomechanical and biochemical properties remain inferior to normal tissue. Low-intensity ultrasound may improve healing.
  
  
  OBJECTIVE
  Medial collateral ligaments treated with ultrasound will demonstrate superior healing.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  Twenty-one late-adolescent male rabbits underwent bilateral ligament transection. One ligament from each rabbit received ultrasound treatment every other day for 6 total treatments. Contralateral ligaments received sham treatments. After 3 or 6 weeks, ligaments were evaluated biomechanically and assayed for collagen concentration and the relative proportions of types I and III collagen.
  
  
  RESULTS
  Areas of sonicated specimens were significantly larger (10.6% +/- 4.90%) at 6 weeks. Ultimate load (39.5% +/- 17.0%), ultimate displacement (24.5% +/- 8.0%), and energy absorption (69.1% +/- 22.0%) were significantly higher for sonicated specimens at 6 weeks. No significant biomechanical differences were observed at 3 weeks. The relative proportion of type I collagen was significantly higher in sonicated ligaments at 3 weeks (8.61% +/- 4.0%) and 6 weeks (6.91% +/- 3.0%). No significant differences in collagen concentration were observed at either 3 or 6 weeks.
  
  
  CONCLUSIONS
  Subtle improvement with ultrasound treatment may be apparent by 3 weeks after injury, suggested by increased proportion of type I collagen. Ultrasound appears to improve some structural properties and to modestly increase scar cross-sectional area and type I collagen present at 6 weeks after injury in this model.
  
  
  CONCLUSIONS
  Ultrasound treatments after ligament injury may facilitate earlier return to activities and decrease risk of reinjury.
authors.affiliation: Virginia Commonwealth University, Department of Physical Therapy, School of Allied Health, 1200 East Broad Street, PO Box 980224, Richmond, VA 23298-0224, USA.
authors.forename: Karen J
authors.initials: KJ
authors.lastname: Sparrow
authors.forename: Sheryl D
authors.initials: SD
authors.lastname: Finucane
authors.forename: John R
authors.initials: JR
authors.lastname: Owen
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Wayne
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D017888:Medial Collateral Ligament, Knee / Q000000981:diagnostic imaging*; D011817:Rabbits; D014464:Ultrasonic Therapy; D014463:Ultrasonography; D014945:Wound Healing