Summary: | 博士 === 國立陽明大學 === 醫學工程研究所 === 99 === ACL tear is a common injury. The incidence of late developed arthritic change remains high. Post-traumatic kinematic change is thought to be the major cause of joint degeneration. The details in 6-degree-of-freedom kinematic changes after ACL injury are important to the treatment protocols.
Adding an additional graft in ACL reconstruction, the double-bundle ACL reconstruction technique becomes more complicated. There are many techniques discussed in literatures, including the flexion angle of the knee during bundle fixation, the initial graft force, and the numbers of tunnels. However, few literature reports about graft fixation sequence.
Utilizing dual fluoroscopic imaging system(DFIS), we measured the 6-degree-of-freedom tibiofemoral kinematic changes after ACL injury. In ACL deficient knees, the tibia tends to shift more anteriorly. It also experienced greater valgus rotation and medial translation. These kinematic changes after ACL injury could lead to abnormal tibiofemoral cartilage contact during daily walking, which may cause joint degeneration.
By analyzing two similar in-vitro biomechanical studies of double-bundle anterior cruciate ligament (ACL)reconstructions, we found that even the grafts were fixed using similar initial tensions and at similar flexion angles, the sequence of fixing the two grafts in a double-bundle ACL reconstruction could dramatically alter the in-situ forces in the grafts.
Finally, Meta-analysis of ten included studies that reported anteroposterior laxity demonstrated the both single and double bundle treatment options for ACL injury results in similar anteroposterior knee joint laxity at time-zero. No conclusive evidence on the superiority of one reconstruction technique over the other in terms of rotation laxity can be obtained.
Surgical or conservative treatments aimed at correcting the abnormalities are necessary to prevent further degenerative process of the ACL injured knees. In surgical treatment, double-bundle ACL reconstruction has not yet shown their superiority over single-bundle technique. It also seems more complicate as we know. More comprehensive study in surgical parameter is needed.
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