[An experimental study on anterior cruciate ligament reconstruction with remnants and remaining bundle preservation]

To investigate whether anterior cruciate ligament (ACL) reconstruction with the remnants and the remaining bundle preservation is beneficial for the revascularization of the graft or not.

Animal models of the ACL reconstruction in 18 healthy New Zealand White rabbits (2-3 months old) were made using about 2.5 cm long extensor digitorum longus tendon and randomly divided into three groups (n=6): remnants debridement group (group A), remnants preservation group (group B) and remaining bundle preservation group (group C). The histological examination was made after 2, 4 and 8 weeks of operation. The intravascular injection of ink was used to observe the revascularization of the graft. The specimens were stained with HE method to observe the histological changes of the graft.

All the animals were in good condition and had good knee functions in the observation period. There was no new vessel in groups A and B at 2 and 4 weeks postoperatively. And new vessels were observed in the synovium of the graft in group C. The areas of the vessels in group C were (505 +/- 27) pixels at 2 weeks and (624 +/- 23) pixels at 4 weeks. At 8 weeks postoperatively new vessels were observed in all the three groups. The new vessel areas of groups A, B and C were (674 +/- 65), (836 +/- 76) and (1219 +/- 146) pixels, respectively. The vessel areas of group C were significantly bigger than those of groups A and B (P < 0.05). The vessel area of group B was significantly bigger than that of group A (P < 0.05). The fibroblast amount in group B was significantly more than that in group A at 2 and 4 weeks postoperatively (P < 0.05). But there was no significant difference between them at 8 weeks postoperatively (P > 0.05). The fibroblast amount of group C was significantly more than that of group A (P < 0.05) at each observation time postoperatively. At 2 and 4 weeks postoperatively, the fibroblast amount of group C was significantly more than that of group B (P < 0.05), but there was no significant difference between them at 8 weeks postoperatively (P > 0.05).

ACL reconstruction with remnants and remaining bundle preservation is beneficial for the early revascularization and fibroblasts growing of the graft. So the course of necrosis, regeneration and remodeling of the graft is shortened.