Micro-CT Analysis of Bone Tunnel Area after Anterior Cruciate Ligament Reconstruction in the Animal Model / 中国运动医学杂志

ABSTRACT

Objective To assess the bone tunnel area at different times and sites of the tunnel after the anterior cruciate ligament(ACL) reconstruction in rabbits using Micro-CT.Methods Fifteen rabbits were performed ACL reconstruction using semitendinosus tendon autograft and randomly allocated into 3 groups and killed at 3,6,and 12 weeks after the operation.All samples undertook the micro-CT scanning(using SkyScan 1176,Bruker,U.S.A.) and were analyzed the areas of bone tunnels of femur and tibia after the 3-demension image rebuilding.For each tunnel,the area of the entrance,middle and exit of the tunnel were measured 3 times respectively and compared.Results The average area of the femoral tunnel did not change significantly with time,being 4.84 mm2,4.57 mm2 and 4.46 mm2 at 3,6 and 12 weeks after the operation(P=0.99).At the very beginning,the femoral tunnel area at the entrance was the biggest,while that of the middle was the smallest.Six weeks after the operation,significant differences were observed between the femoral tunnel area at the entrance and middle,as well as that between the exit and middle(P=0.0011,P=0.0106);However,12 weeks after the operation,significant differences were observed only between that at the entrance and middle(P=0.0227).The average tibial tunnel area increased significantly at 6 weeks(6.577 mm2) and decreased at 12 weeks(3.103 mm2) after the operation(P=0.0005).Moreover,no significant differences were observed in the average tibial tunnel area at different time points and sites(P＜0.05).At different sites,the average tibial tunnel area expanded at 6 weeks,and then declined at 12 weeks after the operation.Conclusion The bone tunnel area changes with time after the ACL reconstruction,first increasing followed by decreasing in the average tibial tunnel area.The femur and tibial tunnel have significant differences in the tunnel area at different sites,which change differently with time.The bone tunnel expansion after the anterior cruciate ligament reconstruction can be comprehensively measured repeatedly at different sites.