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Residual anterolateral rotatory laxity after anterior cruciate ligament (ACL) reconstruction (ACLR) has been shown to correlate with inferior outcomes. With further understanding of the importance of the anterolateral complex (ALC) in rotatory control of an ACL deficient knee, various methods of extraarticular augmentation procedures have been re-introduced. We describe our method of lateral extraarticular tenodesis (LET) in addition to a single bundle hamstring tendon (HT) ACLR. The addition of a LET has been shown in our recent randomized controlled trial in young patients at high risk of failure to significantly reduce the risk of graft rupture and persistent rotatory laxity 2 years after surgery.
Indications for LET:
Revision
where no other significant pathology needs to be addressed
Primary
All young active patients with HT ACLR
High-risk individuals with grade 2/3 pivot
<20 yrs old
Generalized Ligamentous Laxity
Recurvatum
Increased posterior tibial slope >12 degrees
Pivoting sport
The iliotibial band (ITB) graft should be harvested from the posterior half of the ITB so that it is closer to the attachment of the capsule-osseous layer of the ITB on the tibia. Care should be taken not to disrupt the most posterior fibers of the ITB as these represent the native capsulo-osseous layer (COL).
The graft should be sized to a maximum of 1 cm in width and at least 8 cm in length. Too wide a graft will lead to difficulties in passing it under the fibula collateral ligament (FCL), risking injury to the femoral original of the FCL. Too short a graft will also result in fixation difficulties at the anatomic insertion of the COL on the lateral metaphyseal flare of the lateral femoral condyle, just posterior and proximal to the FCL origin.
To aid in identification of the FCL, the knee can be placed into a figure of four position, placing the FCL under tension for easy identification by palpation.
At the femoral attachment site of the tenodesis, there is a small fat pad in the area proximal and lateral to the lateral gastrocnemius tendon. This fat pad should be cleared down to the femur with electrocautery as the superolateral geniculate artery and small veins are in close proximity. Adequate hemostasis should be achieved to prevent postoperative hematoma formation.
If a suspensory loop is used for the ACL graft femoral fixation, the button is typically in the area of femoral LET graft attachment, and care should be taken to avoid damaging the button.
During fixation, the ITB graft is held taut but not over-tensioned, with the knee in 60–70 degrees flexion and the tibia in neutral rotation. This is to avoid potential over-constraint of tibial internal rotation.
: Lateral Extraarticular Tenodesis
Anterior cruciate ligament reconstruction (ACLR) is performed with the objective of restoring knee stability and enabling patients to return to pivoting activities. Despite advancements in arthroscopic ACLR techniques, return to competitive sport has been reported to be as low as 44%. Conventional ACLR has not been shown to reliably restore normal tibiofemoral rotational kinematics, with residual rotatory laxity being demonstrated in many studies. This has been shown to correlate with poor outcomes and, in many cases, the subsequent need for revision surgery.
With the understanding of the importance of restoring the soft tissue stabilizers at the anterolateral corner of the knee, various methods of extraarticular augmentation, such as LET, were re-introduced in recent years, with the aim of improving knee rotational kinematics and stability. Biomechanical findings have demonstrated restoration of rotational stability with the addition of lateral extraarticular procedures to ACLR. , It has also been shown in a cadaveric study that the addition of LET to ACLR resulted in a reduction of ACL graft strain by 43%, possibly protecting the ACL graft while it heals and remodels during the ligamentization phase.
In addition to biomechanical evidence, a recent systematic review of 29 clinical studies reported significant reduction in anterolateral rotational laxity when LET was performed in combination with intra-articular ACLR. The addition of LET to a single bundle HT ACLR has also been shown in our recent randomized controlled trial in young patients at high risk of failure to significantly reduce the risk of graft rupture and persistent rotatory laxity 2 years after surgery. With clear evidence of the effectiveness of LET, we describe our method of LET to be performed in young patients at high risk of failure from an ACLR.
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