title: The effect of early hyaluronic acid delivery on the development of an acute articular cartilage lesion in a sheep model.
abstract: BACKGROUND
  Partial-thickness articular cartilage lesions occur with knee trauma and may progress to osteoarthritis. This study evaluates the effectiveness of hyaluronic acid on cartilage healing after acute knee injury in sheep.
  
  
  OBJECTIVE
  Early administration of hyaluronic acid to an acute cartilage injury will prevent chondrocyte death and improve cartilage metabolism.
  
  
  METHODS
  Controlled laboratory study.
  
  
  METHODS
  A 10 x 10 mm partial-thickness articular cartilage lesion was created on the medial condyle of 16 adult sheep stifles (hindlimbs). Eight sheep received intra-articular hyaluronic acid injections at days 0, 8, and 15, and 8 controls received saline. Contralateral stifles were nonoperated controls. All sheep were sacrificed at 12 weeks after surgery. Synovial fluid was drawn before surgery and after euthanasia for collagen II, nitric oxide, and interleukin-1 beta analysis. The medial condyle was analyzed by gross appearance, confocal laser microscopy for cell viability, histologic analysis for cartilage morphology, and dimethylmethylene blue assay for proteoglycan.
  
  
  RESULTS
  At 12 weeks, histologic analysis revealed that the hyaluronic acid group had significantly better scores than the saline group (P = .001). The hyaluronic acid group had significantly greater glycosaminoglycan content than the saline group (P = .011), and showed a trend of reduced chondrocyte death compared with the saline group (P = .07). Synovial fluid showed no significant differences between the groups in collagen II, nitric oxide, and interleukin-1 beta levels.
  
  
  CONCLUSIONS
  The results demonstrated that early administration of hyaluronic acid shows a significant improvement in cartilage histologic analysis and increased glycosaminoglycan content after acute traumatic cartilage injury.
  
  
  CONCLUSIONS
  Early hyaluronic acid treatment for acute partial-thickness articular cartilage lesions may decrease or delay articular degeneration.
authors.affiliation: Division of Sports Medicine, Department of Orthopaedics, Miller School of Medicine, University of Miami, Miami, FL 33136, USA. kaplan@med.miami.edu
authors.forename: Lee D
authors.initials: LD
authors.lastname: Kaplan
authors.forename: Yan
authors.initials: Y
authors.lastname: Lu
authors.forename: Jonathan
authors.initials: J
authors.lastname: Snitzer
authors.forename: Brett
authors.initials: B
authors.lastname: Nemke
authors.forename: Zhengling
authors.initials: Z
authors.lastname: Hao
authors.forename: Steven
authors.initials: S
authors.lastname: Biro
authors.forename: William
authors.initials: W
authors.lastname: Albiero
authors.forename: Herman F
authors.initials: HF
authors.lastname: Stampfli
authors.forename: Mark
authors.initials: M
authors.lastname: Markel
authors.forename: Charles
authors.initials: C
authors.lastname: Popkin
authors.forename: Samuel Z
authors.initials: SZ
authors.lastname: Baum
mesh_terms: D000818:Animals; D002357:Cartilage Diseases / Q000188:drug therapy*; D002358:Cartilage, Articular / Q000293:injuries* / Q000503:physiopathology; D018450:Disease Progression; D005260:Female; D006820:Hyaluronic Acid / Q000008:administration & dosage* / Q000494:pharmacology*; D007719:Knee Joint / Q000473:pathology; D023421:Models, Animal; D020370:Osteoarthritis, Knee / Q000517:prevention & control; D012038:Regeneration; D012756:Sheep; D014947:Wounds and Injuries / Q000503:physiopathology / Q000628:therapy
chemical_list: D006820:Hyaluronic Acid