title: Expression of vascular endothelial growth factor on chondrocytes increases with osteoarthritis - an animal experimental investigation.
abstract: OBJECTIVE
  To evaluate the expression of VEGF by chondrocytes of hyaline cartilage during the course of osteoarthritis (OA).
  
  
  METHODS
  In 12 white New Zealand rabbits the anterior cruciate ligament (ACL) was resected to create an anterior instability of the knee. In 12 control rabbits only a sham operation without resection of the ACL was done. Four animals of each group were killed at 3, 6, and 12 weeks. The load bearing area was evaluated histologically according to Mankin and by immunostaining for VEGF.
  
  
  RESULTS
  In the experimental group, histological grades of OA showed a positive linear correlation with the time after surgery. Immunostaining showed an increased expression of VEGF in the control group after 3 weeks, which dropped to normal after 6 weeks. There was no difference in the progression of OA between control and experimental groups after 3 weeks, but a significant difference was seen after 6 (p=0,01) and 12 (p=0,05) weeks. A significant positive correlation between VEGF expression and the histological grade of OA was found (r = 0.767; p<0.01).
  
  
  CONCLUSIONS
  An increase of VEGF expressing chondrocytes occurs during time course of OA.
authors.affiliation: Sporthopaedicum Straubing, Germany.
authors.forename: C O
authors.initials: CO
authors.lastname: Tibesku
authors.forename: K
authors.initials: K
authors.lastname: Daniilidis
authors.forename: A
authors.initials: A
authors.lastname: Skwara
authors.forename: J
authors.initials: J
authors.lastname: Paletta
authors.forename: T
authors.initials: T
authors.lastname: Szuwart
authors.forename: S
authors.initials: S
authors.lastname: Fuchs-Winkelmann