[Anterior cruciate ligament reconstruction with double-bundle artificial ligament based on four-dimensional impingement free mechanism: a comparative study with single-bundle reconstruction].

OBJECTIVE: To investigate the surgical method of anterior cruciate ligament (ACL) reconstruction with double-bundle artificial ligaments based on four-dimensional impingement free mechanism, and to compare its short-term effectiveness with traditional single-bundle reconstruction.

METHODS: A retrospective analysis was performed on the clinical data of 45 patients with complete ACL rupture who met the selection criteria and were treated between October 2022 and October 2025. Based on anatomical measurement results and surgical technique selection, patients were divided into a single-bundle reconstruction group (29 cases, receiving traditional over-the-top isometric single-bundle reconstruction) and a double-bundle reconstruction group [16 cases, receiving four-dimensional impingement free ACL double-bundle reconstruction (over-the-top anteromedial bundle+low posterolateral bundle)]. Baseline data-including age, injured side, cause of injury, concomitant meniscus injury, and preoperative Lysholm score, International Knee Documentation Committee (IKDC) score, and Tegner score-showed no significant difference between the two groups ( P>0.05); however, the difference in gender distribution between the two groups was significant ( P<0.05). Operation time, complications, knee range of motion, and the results of the Lachman test, anterior drawer test, and pivot-shift test were recorded. Knee function was evaluated using the Lysholm, IKDC, and Tegner scores preoperatively and at last follow-up, and the proportion of patients returning to pre-injury sports activity levels was calculated. Postoperative three-dimensional CT was performed to evaluate bone tunnel placement and graft-to-tunnel congruence.

RESULTS: Operations were successfully completed in both groups, with the operation time in the double-bundle reconstruction group being significantly longer than that in the single-bundle reconstruction group ( P<0.05). All patients were followed up 6-13 months, with an average of 8.5 months. Patients in both groups resumed immediate postoperative knee range of motion reached 0°-135°, and normal independent walking at 2 weeks postoperatively. At last follow-up, the Lachman test and anterior drawer test were negative in all patients; the pivot-shift test was negative in all cases in the double-bundle reconstruction group, whereas 3 cases (all grade Ⅰ) were positive in the single-bundle reconstruction group, with no significant difference in the positive rate of the pivot-shift test between the two groups ( P>0.05). At last follow-up, the proportion of patients returning to pre-injury sports activity levels was significantly higher in the double-bundle reconstruction group than in the single-bundle reconstruction group ( P<0.05). Both the IKDC and Tegner scores showed significant improvement compared with preoperative values in the two groups ( P<0.05), while the Lysholm scores showed no significant difference when compared with preoperative values ( P>0.05). There was no significant difference in the pre- to post-operative change values of each score between the two groups ( P>0.05). Postoperative three-dimensional CT demonstrated that the distance between the margins of the anterior and posterior bone tunnels in the double-bundle reconstruction group was more than 5 mm, with no evidence of tunnel fracture or posterior cruciate ligament impingement; MRI showed favorable graft morphology without signs of impingement. During the follow-up, no severe complications such as graft laxity, rupture, or synovitis occurred in either group.

CONCLUSION: Under the guarantee of strict anatomical screening, artificial ligament double-bundle reconstruction based on four-dimensional impingement free mechanism shows a favorable clinical trend in restoring rotational stability, with pivot-shift control superior to that of single-bundle reconstruction. Combined with a higher rate of return to sports, it holds significant clinical value for athletic populations seeking early, high-quality rehabilitation. However, strict indication screening based on individualized anatomical conditions is essential for this surgical procedure.