The effect of anterolateral ligament reconstruction on knee constraint: A computer model-based simulation study

Area of Science:

• Orthopedic surgery
• Biomechanics
• Sports medicine

Background:

• Anterolateral ligament reconstruction (ALLR) aims to restore knee constraint.
• Knee abduction (valgus) moment is analyzed under external loads.
• Influence of ALLR on knee stability is investigated.

Purpose of the Study:

• To determine the influence of anterolateral ligament reconstruction (ALLR) on knee constraint.
• To analyze knee abduction moment under anterior or internal rotational loads.
• To evaluate the effect of femoral attachment site on ALLR outcomes.

Main Methods:

• A 3D knee computer model from CT scans of a healthy male was used.
• Simulated groups included intact, ACL+Antero-Lateral Complex deficient, and ACL+ALL reconstructed knees.
• External anterior force (90-N) or internal rotation moment (5 Nm) was applied at various flexion angles (0-50°).

Main Results:

• Reconstructed knees showed significantly reduced anterior translation and internal rotation compared to deficient knees.
• ALLR with posterior and proximal femoral attachment sites, combined with ACL reconstruction, replicated intact knee mechanical behavior.
• Specific graft fixation sites were crucial for restoring normal knee kinematics.

Conclusions:

• Combined ACL and ALLR, when performed minimally invasively and anatomically, effectively prevents excessive anterior translation and internal rotation.
• Postero-proximal femoral tunnel fixation for ALL reconstruction does not lead to overconstraint of the lateral tibiofemoral compartment.
• Anatomically precise ALLR is key to restoring knee stability after combined ligament injuries.