title: Low-intensity pulsed ultrasound (LIPUS) and pulsed electromagnetic field (PEMF) treatments affect degeneration of cultured articular cartilage explants.
abstract: OBJECTIVE
  Articular cartilage has some capacity for self-repair. Clinically used low-intensity pulsed ultrasound (LIPUS) and pulsed electromagnetic field (PEMF) treatments were compared in their potency to prevent degeneration using an explant model of porcine cartilage.
  
  
  METHODS
  Explants of porcine cartilage and human osteoarthritic cartilage were cultured for four weeks and subjected to daily LIPUS or PEMF treatments. At one, two, three and four weeks follow-up explants were prepared for histological assessment or gene expression (porcine only).
  
  
  RESULTS
  Non-treated porcine explants showed signs of atrophy of the superficial zone starting at one week. Treated explants did not. In LIPUS-treated explants cell clusters were observed. In PEMF-treated explants more hypertrophic-like changes were observed at later follow up. Newly synthesized tissue was present in treated explants. Gene expression profiles did indicate differences between the two methods. Both methods reduced expression of the aggrecan and collagen type II gene compared to the control. LIPUS treatment of human cartilage samples resulted in a reduction of degeneration according to Mankin scoring. PEMF treatment did not.
  
  
  CONCLUSIONS
  LIPUS or PEMF prevented degenerative changes in pig knee cartilage explants. LIPUS reduced degeneration in human cartilage samples. LIPUS treatment seems to have more potency in the treatment of osteoarthritis than PEMF treatment.
authors.affiliation: West China College of Stomatology, Department of Orthodontics, Sichuan University, Chengdu, Sichuan, China.
authors.forename: Lijun
authors.initials: L
authors.lastname: Tan
authors.forename: Yijin
authors.initials: Y
authors.lastname: Ren
authors.forename: Theo G
authors.initials: TG
authors.lastname: van Kooten
authors.forename: Dirk W
authors.initials: DW
authors.lastname: Grijpma
authors.forename: Roel
authors.initials: R
authors.lastname: Kuijer
mesh_terms: D053674:Aggrecans / Q000378:metabolism; D000818:Animals; D002358:Cartilage, Articular / Q000473:pathology*; D024043:Collagen Type II / Q000378:metabolism; D020869:Gene Expression Profiling; D006801:Humans; D007719:Knee Joint / Q000473:pathology; D055909:Magnetic Field Therapy; D010003:Osteoarthritis / Q000473:pathology / Q000628:therapy*; D013552:Swine; D014464:Ultrasonic Therapy / Q000379:methods*; D000069453:Ultrasonic Waves; D014945:Wound Healing / Q000502:physiology
chemical_list: D053674:Aggrecans; D024043:Collagen Type II