Tibiofemoral relationship following anatomic triple-bundle anterior cruciate ligament reconstruction

Purpose

The purpose of this study was to investigate the tibiofemoral relationship sequentially before and after anatomic triple-bundle (TB) anterior cruciate ligament (ACL) reconstruction in the same patients.

Methods

Nine patients with complete unilateral ACL rupture participated in this study. Anatomic TB ACL reconstruction was performed using autogenous semitendinosus tendon grafts. Computed tomography images were obtained before surgery as well as 3 weeks and 6 months afterwards. During image acquisition, the patient’s knees were fully extended in the supine position. Using three-dimensional computer models, anterior–posterior and medial–lateral displacement of the tibia relative to the femur were evaluated for each period, as were internal–external and varus–valgus rotation, followed by calculation of side-to-side differences in parameters. As the control group, 7 healthy volunteers were evaluated.

Results

The tibia was located anteriorly by 1.4 ± 0.9 mm and rotated internally by 2.1 ± 1.7° before surgery, while the tibia was located posteriorly by 2.0 ± 1.2 mm and rotated externally by 3.4 ± 3.5° 3 weeks after surgery. Six months after surgery, there was no significant difference between the patient and control groups.

Conclusions

The anteriorly located and internally rotated tibia in ACL-deficient knees was over-constrained (posterior displacement and external rotation) 3 weeks after anatomic TB ACL reconstruction, but returned to the normal position 6 months afterwards. Therefore, anatomic tunnel placement, appropriate initial tension, and moderate rehabilitation can be the key for return to the normal tibiofemoral relationship after ACL reconstruction.

Level of evidence

Therapeutic study, Level IV.