Lateral Extra-Articular Tenodesis as an Adjunct to ACL Reconstruction

Abstract

Background:

Lateral extra-articular tenodesis (LET) is a surgical technique used to decrease the risk of anterior cruciate ligament reconstruction (ACLR) failure by supplementing internal rotational stability and reducing pivot shift.

Indications:

A growing body of literature indicates that LET should be performed for patients under 25 years, those with increased posterior tibial slope and ligamentous laxity, and elite athletes in cutting and/or pivoting sports. Additional indications include patients with grade 2 pivot shift or greater and those with a history of anterior cruciate ligament graft failure.

Technique Description:

Surgeon preference determines LET and ACLR sequence. Anatomic landmarks are identified and marked. A 5-cm incision is made in line with the iliotibial (IT) band from Gerdy's tubercle toward the lateral epicondyle. Dissection is carried to the IT band. Approximately 1 cm from the posterior border of the IT band, a full-thickness graft of 7 to 8 cm in length and 1 cm in width is harvested proximally and then whipstitched. A varus stress applies ligamentous tension and aids in lateral collateral ligament (LCL) identification. The LCL is dissected out, and the graft is passed underneath it. An all-suture anchor placed approximately 1 to 2 cm proximal and posterior to the lateral epicondyle and the knee is positioned in neutral rotation and at approximately 60° of flexion. The graft is passed inside the suture loop with an additional knot tied over the top using the needled suture. The IT band is then repaired side to side. Remaining subcutaneous tissue and skin are closed in standard fashion based on the order of the surgery.

Results:

In the STABILITY randomized controlled trial, 2-year outcomes demonstrated a clinically and statistically significant decrease in clinical failure from 40% to 25% and graft rupture rate from 11% to 4% with the addition of LET to ACLR with hamstring autograft. Similar return-to-sport rate was seen between cohorts. A meta-analysis of 6 studies examining ACLR versus ACLR + LET in individuals undergoing primary ACLR reported a reduced incidence of graft failure and postoperative anterolateral rotatory instability.

Discussion/Conclusion:

LET is a technique that can help reduce the risk of ACLR failure. Our technique employs a knotless suture anchor to confer anterolateral rotatory stability in the setting of ACLR.

Patient Consent Disclosure Statement:

The author(s) attests that consent has been obtained from any patient(s) appearing in this publication. If the individual may be identifiable, the author(s) has included a statement of release or other written form of approval from the patient(s) with this submission for publication.

Graphical Abstract

This is a visual representation of the abstract.

Video Transcript

Lateral extra-articular tenodesis or LET as an adjunct to anterior cruciate ligament (ACL) reconstruction (ACLR).

Relevant disclosures are noted on this slide.

Background

LET is a surgical technique that is employed to confer additional internal rotation stability in patients considered high risk for ACLR failure or graft rupture. The technique we describe here uses the iliotibial (IT) band autograft that is dissected out and rerouted underneath the lateral collateral ligament (LCL) and fixed to the distal femur using an all-suture anchor. ³ Studies have found a reduced rupture and clinical failure rate in patients undergoing ACLR with LET in comparison to ACLR alone.^4-6

The anterolateral complex comprises the anterolateral ligament (ALL), IT band, and anterolateral joint capsule. When injured, there is anterolateral rotatory instability that can be clinically seen as increased translation of the lateral knee compartment during the pivot-shift test (ie, a grade 2 or 3 pivot shift).

Indications

The LET uses a portion of the IT band to reconstruct an injured anterolateral complex or to provide additional anterolateral stability. Indications for LET include patients at high risk for graft failure, including patients <25 years of age, those with posterior tibial slope >12°, patients with ligamentous laxity (Beighton score >4), athletes who participate in cutting or pivoting sports, patients with a history of ACL failure with a technically well-done ACLR, and those with a grade 2 pivot shift or more.

When planning for a concomitant LET, it is important to identify appropriate patient factors for indications as previously mentioned.^2,3 Radiographs will help assess for Segond fracture indicating an ALL injury or lateral tibial plateau fracture. Moreover, lateral radiographs help determine the patient's posterior tibial slope.

Magnetic resonance imaging helps assess for classic bone bruising to indicate a pivot-shift mechanism of injury. The pivot-shift test in clinic is frequently not feasible given the patient's pain and guarding. Therefore, it is paramount to perform an examination under anesthesia (EUA) to assess the true pivot-shift grade. Finally, it is important to ensure appropriate ACLR tunnel placement to prevent tunnel convergence with LET.

Technique Description

Patients are positioned supine on an operating room table with a lateral leg post or a knee holder. We prefer completing the case under thigh tourniquet for visualization purposes, but it is important to consider concomitant procedures that need to be performed in an expedient manner to limit tourniquet time. An EUA is performed, including a Lachman, a pivot shift, and an assessment of knee hyperextension to help confirm appropriate indications for surgery. Based on the surgeon's preference, the order of whether ACLR or LET is completed first is decided.

Anatomic landmarks are identified and marked. A 5-cm incision is made in line with the IT band from Gerdy's tubercle toward the lateral epicondyle. Initial superficial dissection is completed, and the entire width of the IT band is visualized and confirmed with fibers running longitudinally toward Gerdy's tubercule. Using a ruler, approximately 1 cm from the posterior border of the IT band, a full-thickness graft of 7 to 8 cm in length and 1 cm in width is marked and harvested. It is separated from the continuation of the IT band proximally and then whipstitched using a circular looped suture. A varus stress may be placed on the knee to place tension on the LCL and aid in identification of the ligament. The LCL is palpated and dissected out, and the IT band graft is passed deep to it from distal to proximal with the assistance of a Schnidt forceps or similar instrument. A 2.6-mm all-suture knotless anchor is placed approximately 1 to 2 cm proximal and posterior to the LCL attachment point on the lateral epicondyle. The tunnel is drilled, and an all-suture anchor is placed. As the tunnel is drilled, it is helpful to aim proximally and anteriorly to prevent convergence with the ACL tunnel. The whipstitched graft is passed inside the loop suture and held taught while the loop suture is cinched down with the knee positioned in neutral and at approximately 60° of flexion in a knotless fashion. For enhanced fixation, the needled suture is passed through the graft, and an additional knot is tied over top. The IT band is then repaired using a 0-Vicryl (Ethicon) suture. Subsequently, subcutaneous tissue and skin are closed in standard fashion.

Results and Discussion

LET is a technique that is not without challenge. It is crucial to protect the integrity of the LCL. In our technique, we tunnel the portion of the IT band underneath the LCL after it has been carefully dissected out, and a Schnidt or similar instrument can be used to carefully pass the graft underneath. A varus stress helps identify the LCL. To prevent overtensioning of graft, the IT band is held taught but not firmly while the graft is passed through the suture anchor. Additionally, a hemostat or similar instrument can be passed underneath the IT band graft, while the surgeon pulls the shuttle suture to cinch the graft onto the femur. The hemostat prevents overtightening of the graft.

Tunnel convergence is an important concept, and we use the landmark of the lateral epicondyle with our anchor drilled posterior and proximal to this landmark, approximately 1 to 2 cm.^1,7 Moreover, when drilling, aiming proximally and anteriorly helps prevent convergence. One additional mode of a check is placing the arthroscope back into the knee joint and viewing up the femoral tunnel after the LET tunnel is drilled prior to the ACL graft being passed to ensure the LET anchor is not in the femoral tunnel. Postoperatively, it is important to close the IT band to prevent a hematoma from forming or for muscle to herniate out. Another helpful means of hemostasis is releasing the tourniquet prior to IT band closure to ensure hemostasis and prevent hematoma.

Postoperative protocol is dependent on concomitant procedures performed. Importantly, the LET does not preclude the patient from a weightbearing as tolerated status if otherwise indicated. There is additionally no impact on timing of engagement in physical therapy or return to sport with performance of a concomitant LET.

The STABILITY study is a multicenter randomized controlled trial that included 618 patients aged 14 to 25 years randomized to ACLR with a single-bundle hamstring autograft alone versus ACLR with LET. ⁴ This study found both clinically and statistically significant reductions in clinical failure (40% to 25%) and graft rerupture (11% to 4%) in patients who underwent ACLR plus LET.

Similarly, a meta-analysis that included 6 randomized controlled trials in over a thousand patients who underwent ACLR with single-bundle graft versus ACLR with LET concomitantly performed found similar outcomes to the STABILITY study. ⁵ In summary, lateral extra-articular tenodesis or LET is a surgical technique that is employed to confer additional rotational stability in patients who are considered high risk and aids in reducing ACL rerupture and clinical failure.