Effects of Anterolateral Structure Augmentation on the In Vivo Kinematics of Anterior Cruciate Ligament–Reconstructed Knees

Abstract

Background: Double-bundle anterior cruciate ligament (ACL) reconstruction (ACLR) is a well-known treatment that restores the stability of ACL-deficient knees. However, some isolated ACL-reconstructed knees ultimately show rotatory laxity and develop osteoarthritis. Whether combined ACLR with anterolateral structure (ALS) augmentation (ALSA) can provide better improvement in the in vivo knee rotational kinematics remains unknown. Hypothesis: When compared with isolated double-bundle ACLR, combined double-bundle ACLR with ALSA can improve knee in vivo rotational kinematics and provide better restoration of knee kinematics. Study Design: Controlled laboratory study. Methods: Sixteen patients with unilateral ACL injury were randomly divided into 2 groups to receive either combined double-bundle ACLR and ALSA (ALSA group) or isolated double-bundle ACLR (ACLR group). All patients performed a single-leg lunge using the operative and nonoperative/contralateral legs under dual-fluoroscopic imaging system surveillance during a hospital visit at a minimum 1 year (12-13 months) of follow-up to assess the 6 degrees of freedom knee kinematics. Functional evaluation using the Lysholm and Marx rating scales and clinical examinations were also performed. Results: From full extension to approximately 90° of knee flexion at 5° intervals, the mean ± SD internal rotation of the reconstructed knees in the ALSA group (1.5°± 0.9°) was significantly smaller than that of the contralateral knees (8.2°± 1.9°; P = .008). The ALSA group knees also showed significantly ( P = .045) more medial translation than the contralateral knees. In the ACLR group, the mean internal rotation of the reconstructed knee (6.0°± 2.1°) was significantly smaller than that of the contralateral knees (8.9°± 0.6°; P < .001). At full extension, the tibia was significantly more externally rotated than that of the contralateral legs (0.5°± 7.4° vs 7.6°± 3.4°, P = .049). Conclusion: When compared with isolated double-bundle ACLR, double-bundle ACLR augmented with ALS reconstruction resulted in anterolateral rotatory overconstraint during the lunge motion. Clinical Relevance: Additional ALSA of double-bundle ACL-reconstructed knees overconstrained rotatory stability. Therefore, the use of ALSA for ACL-reconstructed knees should be considered with caution for patients with ACL deficiency and anterolateral rotatory instability. Longer-term follow-up to evaluate long-term outcomes and altered kinematics over time is recommended.

Effects of Anterolateral Structure Augmentation on the In Vivo Kinematics of ACL-Reconstructed Knees: Letter to the Editor

“…The second point is the lack of presurgical kinematic data. Chen et al 3 claim that tibial medial translation could be potentially attributable to the potential lateral resistance of the LET on the lateral side of the knee; however, we disagree with this statement. Previous studies found a more medial tibial position in ACL-injured knees.…”

“…Despite these considerations, we again congratulate Chen et al 3 for their valuable study that undoubtedly contributes to the recent literature about LET and permits us to debate such a key topic in sports medicine.…”

“…We read with great interest the paper titled “Effects of Anterolateral Structure Augmentation on the In Vivo Kinematics of Anterior Cruciate Ligament-Reconstructed Knees” by Chen et al, 3 and we would like to congratulate the authors on the high quality of the study performed.…”

“…The third point is related to the technical aspect of the LET performed by Chen et al 3 : in their paper, there is no mention of tensioning devices that could have helped the surgeon at achieving a correct anterolateral ligament (ALL) graft tension. Since the “rediscovering” of the ALL by Claes and colleagues, 4 the knee anterolateral aspect has been widely investigated, and many efforts have been made in biomechanical evaluation of modern versions of the LET.…”

Effects of Anterolateral Structure Augmentation on the In Vivo Kinematics of ACL-Reconstructed Knees: Response

“…We sincerely appreciate Agostinone et al’s insightful comments on our recent controlled laboratory study using the dual-fluoroscopic imaging tracking technique. Our study 7 finally included 15 patients to compare the in vivo kinematics between combined double-bundle anterior cruciate ligament reconstruction (ACLR) and anterolateral structure (ALS) augmentation (ALSA) and isolated double-bundle ACLR. We concluded that when compared with isolated double-bundle ACLR, double-bundle ACLR with ALSA resulted in anterolateral rotatory overconstraint during the lunge motion.…”