Clin Biomech (Bristol). 2026 May 14;137:106870. doi: 10.1016/j.clinbiomech.2026.106870. Online ahead of print.
ABSTRACT
BACKGROUND: Rupture of the anterior cruciate ligament is a well-known cause of knee instability. However, even after reconstruction, some patients continue to experience residual instability, which has raised interest in the anterolateral ligament as a secondary stabilizer of the knee. This study aimed to investigate in-vivo knee kinematics during level walking after combined single-bundle anterior cruciate and anterolateral ligament reconstruction to assess restoration of normal knee kinematics.
METHODS: Ten individuals who underwent combined reconstruction and ten healthy controls participated in treadmill gait trials using a biplanar fluoroscopic imaging system. The subject-specific 3D model and tibiofemoral kinematics were reconstructed using a statistical shape and intensity model and 2D3D registration. Tibial kinematics were compared among operated, contralateral, and healthy knees using statistical parametric mapping and a cumulative-change analysis.
FINDINGS: The operated knees exhibited significantly increased anterior tibial translation throughout 17-85% of the stance phase compared with both contralateral and normal knees (p < 0.05). Internal tibial rotation was also significantly greater in operated knees during early stance (15-37%) compared with normal knees. Cumulative changes in internal-external rotation and anterior-posterior translation during early stance were significantly increased in operated knees than in contralateral and normal knees.
INTERPRETATION: Anatomical single-bundle reconstructions combined with anterolateral ligament reconstruction do not fully restore normal joint kinematics. Increased anterior translation and internal rotation persist, indicating residual instability. These findings support rotational laxity of single-bundle techniques and suggest the potential need to address dynamic instability.
PMID:42150244 | DOI:10.1016/j.clinbiomech.2026.106870
