Augmentation of Anterolateral Structures of the Knee Causes Undesirable Tibiofemoral Cartilage Contact in Double-Bundle Anterior Cruciate Ligament Reconstruction—A Randomized In-Vivo Biomechanics Study

Purpose To analyze the in vivo tibiofemoral cartilage contact patterns in knees undergoing double-bundle anterior cruciate ligament reconstruction(DB-ACLR) with or without anterolateral structure augmentation (ALSA). Methods Twenty patients with an ACL-ruptured knee and a healthy contralateral side were included. Nine patients received an isolated DB-ACLR (DB-ACLR group), and 11 patients had a DB-ACLR with ALSA (DB+ALSA group). At 1-year follow-up, a combined computed tomography, magnetic resonance imaging, and dual fluoroscopy imaging system analysis was used to capture a single-legged lunge of both the operated and healthy contralateral side. Tibiofemoral contact points (CPs) of the medial and lateral compartments were compared. CP locations were expressed as anteroposterior (AP, +/–) and medial–lateral (ML, –/+) values according to the tibia. Results In the DB-ACLR knees, no significant differences were found in CPs when compared with the healthy contralateral knees (P ≥ .31). However, in the DB+ALSA knees, the CPs in the lateral compartment had a significantly more anterior (mean AP: operative, –2.8 mm, 95% confidence interval [CI] –5.0 to–0.7 vs healthy, –5.0 mm, 95% CI –6.7 to –3.2; P = .006) and lateral (mean ML: operative, 23.2 mm, 95% CI 21.9-24.5 vs healthy, 21.8 mm, 95% CI 20.2-23.3; P = .013) location. The CPs in the medial compartment were located significantly more posterior (mean AP: operative, –3.4, 95% CI –5.0 to –1.9 vs healthy, –1.3, 95% CI –2.6 to –0.1; P = .006) and lateral (mean ML: operative, –21.3, 95% CI –22.6 to –20.0 vs healthy, –22.6, 95% CI –24.2 to –21.0; P = .021). Conclusions DB-ACLR restored the tibiofemoral cartilage contact mechanics to near-normal values at 1-year follow-up. Adding the ALSA to the DB-ACLR resulted in significantly altered tibiofemoral cartilage contact locations in both the medial and lateral compartments. Clinical Relevance In DB-ACLR knees, the addition of an ALSA may be unfavorable as it caused significantly changed arthrokinematics.