Reconstructing the anterolateral ligament does not decrease rotational knee laxity in ACL-reconstructed knees.

Area of Science:

• Orthopedic surgery
• Biomechanics
• Sports medicine

Background:

• The anterolateral ligament (ALL) plays a role in knee stability, but its specific contribution to rotational laxity is not fully understood.
• Anterior cruciate ligament (ACL) injuries often occur with associated injuries, impacting overall knee joint stability.
• Understanding ligamentous interactions is crucial for effective surgical reconstruction techniques.

Purpose of the Study:

• To investigate the influence of the anterolateral ligament (ALL) on rotational knee laxity.
• To assess rotational knee laxity under axial rotational stress after sequential cutting and reconstruction of the anterior cruciate ligament (ACL) and ALL.
• To determine the efficacy of ALL reconstruction in reducing internal knee rotation.

Main Methods:

• Utilized radiostereometric analysis (RSA) on eight human donor legs.
• Measured anterior-posterior and rotational laxity at 0°, 30°, and 60° knee flexion.
• Applied a 4 Nm internal rotating force to the foot, comparing intact, ACL- and ALL-resected, and reconstructed states.

Main Results:

• Cutting the ALL in ACL-deficient knees significantly increased internal rotation at all tested flexion angles (0°, 30°, 60°).
• Internal rotation increased by 1.0°, 1.6°, and 2.5° at 0°, 30°, and 60° flexion, respectively, after ALL resection.
• ALL reconstruction in ACL-reconstructed knees did not lead to a significant decrease in internal rotation laxity.

Conclusions:

• The anterolateral ligament (ALL) acts as a significant stabilizer against internal rotation in ACL-deficient knees.
• Reconstruction of the ALL using a gracilis autograft did not effectively reduce internal rotational laxity in ACL-reconstructed knees.
• Current evidence does not support ALL reconstruction solely for decreasing internal knee laxity in ACL-reconstructed patients.