Abstract
The present study was planned to evaluate the efficacy of tendon derived hydrogel and hyaluronic acid in repair of experimentally induced superficial digital flexor tendon defect in rams, ultrasonographically with detection of vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) in blood. Thirty six adult rams were divided randomly into three equal groups: First group (control group) rams were subjected to partial removal of the superficial digital flexor tendon (SDFT), second group (tendon derived hydrogel group): rams were subjected to the same procedure as mentioned in first group except that the tendon defect was filled with tendon derived hydrogel directly, while third group (hyaluronic acid group): same procedure as in first group but the tendon defect was filled with hyaluronic acid directly. Clinically there was no pain, no infection, no signs of rejection and all wounds had healed completely in all rams, normal body temperature, except for the swelling which appeared in the first group in one ram at 30 days post operatively and two rams in third group at 60 days post operatively, all animals were able to stand and showed normal gait. Ultrasonographic results at 120th day post operation in first group showed, hypoechoic to hyperechoic regions at the site of the defect. At the same period for the second group the sonogram showed, well-aligned echoic tendon structure, while in the third group at the same period there were hypoechoic areas at the site of the defect. The results of bFGF and VEGF detection showed significant differences between the periods in first group at P≤0.05, while in second and third groups there were significant differences at P≤0.01for bFGF. The results of detection VEGF showed, significant differences in the mean values among the periods at P≤0.01in first group, also second group there was significant differences at P≤0.01. And in third group there was a significant difference at P≤0.05. Also there were significant differences among all groups P≤0.01in at 60th day postoperatively. In conclusion the tendon derived hydrogel matrix and the hyaluronic acid have a regenerative effect in repair of tendons injuries, but the superiority is for tendon derived hydrogel matrix

Key words: Tendon, Growth factors, Tendon derived hydrogel, ultrasound of tendon, Hyaluronic acid.