Comparison of anterior and rotatory laxity using navigation between single- and double-bundle ACL reconstruction: prospective randomized trial

Abstract

To prospectively assess the anterior tibial translation and rotational kinematics of the knee joint as well as the clinical outcome after single-bundle (SB) and double-bundle (DB) anterior cruciate ligament (ACL) reconstruction. Forty-two patients randomly underwent single-bundle (Group SB, n=21) or double-bundle (Group DB, n=21) ACL reconstruction using hamstring tendon autografts. Anterior tibial translation and rotatory laxity were measured prior to and after fixation of the graft during reconstruction under the guidance of a navigation system. Clinical outcome measurements included the evaluation of the joint stability and functional status. Anterior tibial translation and rotatory laxity were improved significantly at all degrees of knee flexion in both groups. The postoperative total rotation (sum of internal and external rotation) at 30° and 60° (26.6° vs. 24.0°; 28.7° vs. 25.1°) as well as postoperative change in external rotation at 60° (-1.4° vs. -4.6°), and a change in total rotation at 30° and 60° (-7.0° vs. -11.5°; -6.1° vs. -8.9°) differed between the two groups, with better stability in the DB group. At 2years follow-up, IKDC subjective satisfaction score was significantly different between two groups (70.9 vs. 79.6), while manual and instrumented laxity, pivot shift tests, modified Lysholm score, Tegner activity score, thigh muscle strengths were not different. Correlation analysis showed little correlations between anterior laxity tests at follow-up, and the kinematic variables measured by navigation during surgery while pivot shift test, IKDC subjective satisfaction score, modified Lysholm score, and Tegner activity score were mainly correlated with navigation-measured rotations in both groups. The kinematic tests in this study found evidence suggesting that the DB ACL reconstruction improved rotatory laxity better than the SB ACL reconstruction at 30° and 60° of flexion, but there was no difference in functional outcome at 2years follow-up between SB and DB groups. Prospective comparative study, Level II.