[Effect of local basic fibroblast growth factor and 5-fluorouracil on accelerating healing and preventing tendon adhesion after flexor tendon repair].

OBJECTIVE: To assess the effect of basic fibroblast growth factor (bFGF) and 5-fluorouracil (5-FU) applied topically on the tendon adhesion and the healing 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 flexor digitorum profundus tendons of the third right toes were transected and sutured directly. The repair site in group A was given 0.6 microL fibrin sealant (FS). In group B, the repair site was given 0.6 microL 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 repaired tendon. At 8 weeks, the adhesion degree was lighter in group C than in group B (P < 0.05), but there was no significant difference in the adhesion degree between group A and groups B, C (P > 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 < 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 < 0.05); however, it was significantly more than that of group A in the tendon parenchyma (P < 0.05), and no significant difference was observed when compared with that of group B (P > 0.05). At 8 weeks, no difference was found among 3 groups (P > 0.05). The collagen fiber content of group A was significantly less than that of group B at 4 and 8 weeks (P < 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 < 0.05); however, no significant difference was found between 2 groups at 8 weeks (P > 0.05). The collagen fiber content of group A was significantly less than that of group C in the parenchyma at 4 and 8 weeks (P < 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 < 0.05), but no significant difference in the parenchyma was observed between 2 groups (P > 0.05). The biomechanical tests showed that the gliding 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 x 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 gliding excursion of the tendon and the work of flexion among 3 groups (P < 0.05) and in the ultimate tensile strength of the tendon between group A and groups B, C (P < 0.05), but there was no significant difference in the ultimate tensile strength of the tendon between group B and group C (P > 0.05).

CONCLUSION: Local single-use bFGF and 5-FU can not only effectively promote the healing of flexor tendon, but also significantly reduce tendon adhesion.