A New Algorithm for Extra-Articular Reinforcement in ACL Injury Based on Rotational Instability

Area of Science:

• Orthopedic Surgery
• Sports Medicine
• Biomechanics

Background:

• Anterior cruciate ligament (ACL) reconstructions are improving with extra-articular reinforcements.
• Anteromedial rotational instability (AMRI), caused by valgus and external tibial rotation, can occur with ACL injuries.
• Reinforcement in the anteromedial quadrant, along the anterior oblique ligament (AOL) topography, can address external rotation instability.

Purpose of the Study:

• To propose an algorithm for managing rotational instability in ACL-injured patients undergoing extra-articular reinforcement.
• To identify specific indications for anteromedial versus anterolateral reinforcement based on physical examination findings.

Main Methods:

• Physical examination under anesthesia, including pivot shift and anterior drawer in external rotation (ADER) tests, is crucial.
• An algorithm is proposed to guide the selection of anterolateral, anteromedial, or combined reinforcements.
• Patients with positive pivot shift (internal rotation instability) or hyperlaxity may benefit from anterolateral reinforcement.

Main Results:

• Isolated positive ADER test indicates a need for anteromedial reinforcement.
• Positive ADER and pivot shift suggest the potential benefit of combined medial and lateral extra-articular reinforcement.
• AMRI is a risk factor for ACL reconstruction failure and requires treatment.

Conclusions:

• Clinical examination under anesthesia should assess both internal and external rotational stability.
• Anteromedial reinforcement, specifically in the AOL topography, is a viable option for treating AMRI.
• The proposed algorithm aids in optimizing extra-articular reinforcement strategies for ACL reconstructions.