Objective To assess the effect of basic fibroblast growth factor (bFGF) and 5-fluorouracil (5-FU) appl ied topically on the tendon adhesion and the heal ing process after the flexor tendon repair in Leghorn chickens. Methods Ninety male Leghorn chickens (weighing 3.0-3.5 kg) were randomly divided into 3 groups, with 30 chickens in each group. The flexordigitorum profundus tendons of the third right toes were transected and sutured directly. The repair site in group A was given 0.6 μL fibrin sealant (FS). In group B, the repair site was given 0.6 μL FS containing 500 ng bFGF. In group C, before the tendons were transected, they had been soaked in 5-FU solution, and then the same treatment as group B was given. Six specimens of the third toe were harvested to perform the macroscopical and histological examinations at 1, 2, 4, and 8 weeks, respectively, and to perform the biomechanical test at 8 weeks. Results All animals survived until the experiment was completed. All incisions healed smoothly. No rupture occurred in the reparied tendon. At 8 weeks, the adhesion degree was l ighter in group C than in group B (P lt; 0.05), but there was no significant difference in the adhesion degree between group A and groups B, C (P gt; 0.05). At 1, 2, and 4 weeks after operation, the number of fibroblast cells of group A was significantly less than that of group B (P lt; 0.05), and the number of fibroblast cells of group C was significantly less than that of group A and group B in the tendon sheath and epitenon (P lt; 0.05); however, it was significantly more than that of group A in the tendon parenchyma (P lt; 0.05), and no significant difference was observed when compared with that of group B (P gt; 0.05). At 8 weeks, no difference was found among 3 groups (P gt; 0.05). The collagen fiber content of group A was significantly less than that of group B at 4 and 8 weeks (P lt; 0.05). In the sheath and epitenon, the collagen fiber content of group A was significantly more than that of group C at 4 weeks (P lt; 0.05); however, no significant difference was found between 2 groups at 8 weeks (P gt; 0.05). The collagen fiber content of group A wassignificantly less than that of group C in the parenchyma at 4 and 8 weeks (P lt; 0.05). At all time points, the collagen fiber content of group B was significantly more than that of group C in the sheath and epitenon (P lt; 0.05), but no significant difference in the parenchyma was observed between 2 groups (P gt; 0.05). The biomechanical tests showed that the gl iding excursion of the tendon in groups A, B, and C was (3.51 ± 0.56), (2.84 ± 0.42), and (4.56 ± 0.59) mm, respectively; the work of flexion was (14.08 ± 1.85), (20.62 ± 3.52), and (10.91 ± 1.53) N.mm, respectively; and the ultimate tensile strength of the tendon was (11.26 ± 1.83), (15.02 ± 2.20), and (14.40 ± 1.57) N, respectively. There were significant differences in the gl iding excursion of the tendon and the work of flexion among 3 groups (P lt; 0.05) and in the ultimate tensile strength of the tendon between group A and groups B, C (P lt; 0.05), but there was no significant difference in the ultimate tensile strength of the tendon between group B and group C (P gt; 0.05). Conclusion Local single-use bFGF and 5-FU can not only effectively promote the heal ing of flexor tendon, but also significantly reduce tendon adhesion.
Objective To explore the effects of exogenous basic fibroblast growth factor (bFGF) on insheathed tendon healing and adhesion formation. Methods Ninety Leghorn chickens were randomly divided into 3 groups (groups A, B and C), 30 animals for each group, and the right third digitorum longus tendon of the chicken was transected to make defect models. In group A, the tendon was sutured in situ after transection. In group B, the tendon was sutured after 0.6 μl fibrin sealant (FS) was applied at repair site. In group C, the tendon was sutured after 0.6 μl FS mixed with 500 ng bFGF was appliedat repair site. At 1, 2, 4 and 8 weeks after operation, the tendons of 6 chickens in each group were harvested for morphological and histological evaluation. Six specimens of each group was obtained for biomechanical test at 8 weeks. Results The gross observation showed that the differences of grading of tendon adhesion were not significant between groups A, B, and C 8 weeks after operation(Pgt;0.05). Histological evaluation showedthat there were no significant differences in fibroblast counting and the content of collagen fibers between groups A and B(P＞0.05). The angiogenesis, fibroblast proliferation and collagen production in the sheath, epitendon and parenchyma at repair site in group C occurred earlier and were more than those in groups A and B, showing significant differences (Plt;0.05). The biomechanical tests showed that the gliding excursionof the tendon in group A, B and C were 3.44±0.43、3.51±0.56 and 2.84±0.42 mm respectively; the work of flexion were 14.87±1.72、14.08±1.85 and 20.62±3.52 Nmm respectively; the ultimate tensile strength of the tendon was10.34±1.45，11.26±1.83 and 15.02±2.20 N respectively; showing no significant differences between groups A and B(Pgt;0.05), but showing significant differences between group C and groups A, B(Plt;0.05). Conclusion The exogenous bFGF at tendon repair site can facilitate insheathed tendon healing, but also increase the tendon adhesion formation.