title: A moderate-intensity static magnetic field enhances repair of cartilage damage in rabbits.
abstract: OBJECTIVE
  Electromagnetic fields have been proposed to enhance healing of cartilage defects by stimulation of chondrocyte proliferation, proteoglycan synthesis as well as decreasing pain and improving motion in osteoarthritic patients. However, the effects of a moderate-intensity static magnetic field on cartilage repair have not been investigated. This study tries to determine the effects of a moderate-intensity permanent magnetic field of 40 mT on cartilage repair.
  
  
  METHODS
  Defects of 3 mm in diameter and 6 mm in depth were made on the weight bearing surface of the right medial femoral condyle of 30 rabbits. The animals were divided randomly into three equal groups (magnet, sham and control). In the magnet group, cylindrical permanent magnets were implanted subcutaneously medial to the medial femoral condyle, while in the sham group the cylindrical ceramic were not magnetized, and nothing was implanted in controls. After 12 weeks of observation, Mankin's microscopic scoring was done on all specimens, and irregularity of surface characteristics, cell colonization, hypocellularity, cartilage matrix formation, and presence of empty lacunae were investigated.
  
  
  RESULTS
  Each of these characteristics showed significant differences in magnet group relative to control and sham groups (p <0.05). Mankin's score was 1.6 ± 0.6 in magnet group, 7.2 ± 1.6 in sham group and 7.7 ± 1 in control group (p <0.001).
  
  
  CONCLUSIONS
  [corrected] In this animal study, microscopic Mankin's scoring depicted histological improvement in cartilage of magnet group.
authors.affiliation: Bone & Joint Diseases Research Center, Shiraz University of Medical Sciences, Iran.
authors.forename: Fereidoon M
authors.initials: FM
authors.lastname: Jaberi
authors.forename: Sara
authors.initials: S
authors.lastname: Keshtgar
authors.forename: Alireza
authors.initials: A
authors.lastname: Tavakkoli
authors.forename: Ehsan
authors.initials: E
authors.lastname: Pishva
authors.forename: Bita
authors.initials: B
authors.lastname: Geramizadeh
authors.forename: Nader
authors.initials: N
authors.lastname: Tanideh
authors.forename: Mehrad M
authors.initials: MM
authors.lastname: Jaberi
mesh_terms: D000818:Animals; D002358:Cartilage, Articular / Q000473:pathology* / Q000502:physiology / Q000528:radiation effects*; D005260:Female; D007719:Knee Joint / Q000473:pathology; D060526:Magnetic Fields; D011817:Rabbits; D011897:Random Allocation; D014945:Wound Healing / Q000528:radiation effects*