Modified Ellison Lateral Extra-articular Tenodesis of the Knee With a Knotless All-Suture Anchor

Abstract

Anterior cruciate ligament reconstruction is a surgical procedure that has largely undergone changes; its techniques have improved over the years to achieve the most appropriate graft choice, preparation, positioning, and fixation, thereby preserving graft survival. Residual rotational instability is largely present in patients who receive only anterior cruciate ligament reconstruction, leading to a higher rerupture rate, especially in higher-risk patients. Lateral extra-articular tenodesis is part of the larger family of lateral extra-articular procedures that aim to lengthen graft life span by protecting it from excessive tibial internal rotation. Various techniques with different implants have been described to perform this reconstruction. This Technical Note presents a modified Ellison technique that obtains fixation through a knotless all-suture anchor. This technique is faster, is less invasive, and provides equally effective results.

Lateral extra-articular tenodesis (LET) is a procedure performed in conjunction with anterior cruciate ligament reconstruction (ACLR) to protect the graft from failure by eliminating the residual rotational instability encountered following isolated ACLR.¹

In 1991, Noyes and Barber² stated the superiority of LET when added to an ACLR, showing encouraging results. This procedure is part of the lateral extra-articular procedures (LEAPs). LEAPs have improved anterolateral rotatory instability and reduced anterior tibial translation and graft failure.³ Two main different LEAP techniques exist: anterolateral ligament (ALL) reconstruction and LET.⁴

One advantage of LEAP procedures with grafts that run deep to the fibular collateral ligament (FCL), as with the iliotibial band (ITB) graft used in LET, is that they provide “desirable” length change patterns, maintaining native knee biomechanics.⁵

Various LET techniques have been described, differing in graft fixation and thus exhibiting similar biomechanical results.⁶ A meta-analysis by Bosco et al. showed no superiority of one approach over the other in terms of patient-reported outcome measures, pivot-shift tests, and reinjury rates.^7,8

LET can also be performed using a “monoloop” single-stranded graft to perform both ACLR and LET.^9,10

This Technical Note presents the LET modified Ellison technique using a 2.6-mm knotless all-suture anchor (FiberTak; Arthrex). This technique offers a minimally invasive incision and significantly reduced operative time (Fig 1).¹¹

Fig 1.

A graphic illustration of a modified Ellison lateral extra-articular tenodesis, identifying principal anatomic landmarks, iliotibial band graft suture placement, and knotless all-suture anchor positioning on right knee.

Surgical Technique

A video presenting this technique is provided (Video 1).

Patient Positioning

The patient is positioned supine on a surgical table after anesthesia and antibiotic prophylaxis (2 g of intravenous cefazolin). A tourniquet is applied to the patient’s thigh, and the knee is flexed at 90° using a roller and 2 holders to stabilize the patient during varus and valgus stress maneuvers. A preoperative physical examination is performed. In this case, positive Lachman and pivot-shift tests are observed. The sterile field is prepared with sterile surgical drapes.

Diagnostic Arthroscopy and ACLR

First, 2 standard arthroscopic portals, anterolateral and anteromedial, are created, and a diagnostic arthroscopy is performed. Any associated lesions should be treated accordingly. ACLR is then performed according to the senior surgeon’s (M.F.) preferred technique: in this case, a standard ACLR with a bone–patellar tendon–bone graft.

Distal ITB Graft Preparation

A sterile marker is used to mark anatomic landmarks: fibular head, Gerdy’s tubercle (GT), and the FCL (Fig 2). A skin incision is made from the GT to the proximal femoral insertion of the FCL in line with the ITB fibers. Subcutaneous dissection is performed to reach the ITB plane. The posterior third of the ITB is incised longitudinally along its fibers. A parallel incision is then performed 8 to 10 mm anterior to the previous one. The incisions are then elongated approximately 2 to 3 cm proximally to the FCL in line with the ITB fibers.

Fig 2.

The anatomic landmarks drawn on right knee skin before surgical incision: Gerdy’s tubercle, fibular head, and fibular collateral ligament. Identification of the incision site directly over the fibular collateral ligament toward Gerdy’s tubercle is fundamental.

The ITB sleeve is then dissected distally off the GT using a sharp blade, and blunt dissection is performed to release the strip of all soft tissue underneath, obtaining a flap free to be tensioned (Fig 3).

Fig 3.

We present the superficial subcutaneous incision and further dissection of a 10-mm-wide iliotibial band stripe for graft setup on a right knee. The graft is bluntly detached from Gerdy’s tubercle toward the proximal aspect of the iliotibial band. Care must be taken in releasing deep fascial adherences.

The strip is then whipstitched with a No. 0 absorbable suture (Vicryl; Ethicon), which serves as a carrier and achieves the desired graft tension. The FCL is then identified by palpation (Fig 4); if this proves to be difficult, placing the knee in a figure-of-4 position can help to identify the ligament. A sharp incision is made distal to the FCL in line with its fibers, and a right-angle forceps is passed beneath it to create the space through which the ITB sleeve shall pass. Care must be taken during this step since sufficient space is required underneath the ITB to allow for graft passage without the graft folding on itself. Excessive dilation of this space, however, can lead to FCL injury. The blunt forceps are then used to grasp the ITB sleeve through the carrier suture (Fig 5).

Fig 4.

Second, after displacing the iliotibial band graft proximally to expose the underlying tissue layers, the right knee fibular collateral ligament is identified by palpation. Patients may be positioned in a figure-of-4 pose to facilitate ligament identification, and then an incision is performed distally, introducing forceps underneath the fibular collateral ligament, taking care not to damage it.

Fig 5.

Forceps are used to enlarge the soft tissue tunnel created on the right knee and to retrieve the iliotibial band graft underneath the fibular collateral ligament in a proximodistal direction through a docking suture. This passage must be as smooth as possible to prevent any graft damage.

Anchor Positioning and Graft Fixation

The knee is then positioned at 30° of flexion with the foot in neutral rotation, and the ITB sleeve is tensioned by pulling on the carrier suture. The anchor position on the tibia is then marked using cautery: typically slightly proximal to the GT. Ideally, the anchor should be placed to achieve proper graft tensioning, leaving approximately 1 cm of residual graft tissue to ensure secure fixation (Fig 6). The periosteum is then removed over the identified point, and a knotless self-punching all-suture anchor (FiberTak; Arthrex) is positioned through its inserter. The anchor is then hammered until the indicator on the handle reaches cortical bone level. The anchor is then set in place with a steady pull on all the sutures and then pulled in a tugging fashion to confirm fixation.

Fig 6.

The anchor positioning landmark is signed with a monopolar electric scalpel directly over right knee Gerdy’s tubercle at 30° of flexion and the foot in neutral rotation. The definitive iliotibial band graft position must be predicted in order for the graft to appropriately adjust to the tibia when tightening the anchor.

The next step is to convert the knotless mechanism by passing the repair suture through the end of the shuttling suture, which shuttles the repair suture through the anchor, creating a loop.

Next, the ITB graft is passed in a proximodistal fashion through the loop, which is tightened with the knee at 30° of flexion and neutral rotation (Fig 7).

Fig 7.

The right knee iliotibial band graft is fixed through an anchor loop by docking the suture through the anchor and tightening it until the desired tension is reached. Care must be taken to avoid graft twisting or mispositioning by accommodating the graft to its bony bed while tightening the anchor loop.

Further reinforcement of the repair is achieved by distally suturing the fascia lata to the anterior and posterior margins of the graft using a No. 0 absorbable suture (Vicryl; Ethicon) (Fig 8). Proximally, the dissected ITB is sutured together to prevent muscle herniation (Fig 9).

Fig 8.

The fascia lata is distally sutured to the graft superior and inferior margin with No. 0 absorbable suture (Vicryl; Ethicon) to reinforce the right knee lateral extra-articular tenodesis, preventing anchor failure.

Fig 9.

The right knee fascia defect is further closed proximally with a No. 0 absorbable suture (Vicryl; Ethicon) to reduce muscle herniation and reduce blood loss.

Correct tensioning is assessed through full knee range of motion, and the resistance to internal tibial rotation is tested. Subcutaneous tissue and skin are then sutured.

Rehabilitation Protocol

Full range of motion and progressive weightbearing with crutches are allowed from day 1 postoperatively. Cryo-compression therapy is highly recommended to all patients and has shown favorable results with pain relief at our center. The rehabilitation protocol has to be adjusted accordingly in cases of associated meniscal repair.

Discussion

Anterior cruciate ligament (ACL) tears can result in both anterior and rotational instability of the knee. While anterior stability is achieved through anatomic ACLR, rotational instability can persist, with a residual high-grade pivot shift. Lagae et al.¹² found that ACLR in ACL- and ALL-deficient knees was not enough to restore rotatory stability at 30° to 100° of flexion.

Residual instability can lead to ACL retear, particularly in high-risk patients. Agarwal et al.¹³ showed that either LET or ALL reconstruction procedures had a lower rerupture rate (4.03% and 1.14%, respectively) than ACLR performed alone (12.59%), restoring native knee biomechanics.¹⁴

Grassi et al.¹⁵ reported good mid-term outcomes for LET associated with ACL revisions, with a 2.6-mm side-to-side difference at arthrometry evaluation, an 80% negative pivot shift, and a 74% return to previous sport; failure rate was reported as 3.6%.

LET, however, introduces further donor site morbidity and some concern about overconstraint on the knee joint. An excessively tight LET could be counterbalanced by the tendency of the graft to loosen over time. Furthermore, Gibbs et al.¹⁶ suggested that the restraint on the anterior tibial translation derived from the tenodesis could be protective of graft healing in the early postoperative period.¹⁷

In a multicenter randomized control trial, Firth et al.¹⁸ investigated predisposing factors for ACLR failure. They found that younger age, greater posterior tibial slope, high-grade knee laxity, and earlier return to sport were correlated with a higher graft rupture rate, but in these patients, adding a LET reduced the asymmetric pivot shift and the odds of graft rupture.

Indeed, patients who have 1 or more of the following characteristics are considered at high risk, and adding an anterolateral procedure is advantageous to their ACLR¹⁹: ACLR revisions,20, 21, 22 pivot-shift test grade ≥2,²³ high-performance athletes, returning to pivoting sports, knee recurvatum >10°, generalized preoperative hyperlaxity, skeletally immature patients, Segond fractures, chronic ACL lesions, and radiographic lateral femoral notch sign.^24,25

LET can be performed using various techniques and with a wide range of implants, or even with just simple sutures. This article describes how to perform LET using a knotless all-suture anchor (FiberTak; Arthrex). There are several advantages to this technique: the knotless anchor mechanism is minimally invasive, resulting in less soft tissue irritation. It provides a faster fixation with minimal blood loss. Its major advantage is that surgeons do not have to worry about tunnel convergence when performing LET following ACLR. Theoretically, this anchor can be deployed even if it converges with one of the tunnels used for ACLR without affecting the knee’s final stability of graft fixation. Finally, it is easier to apply compared to other techniques, which can be an advantage for young surgeons.

However, there are a few disadvantages: first, there is a risk of losing graft fixation by anchor failure, which can be prevented by adding firm sutures superiorly and inferiorly; lastly, this procedure requires added costs compared with other devices or using no devices at all (Table 1, Table 2).

Table 1.

Advantages and Disadvantages of the Modified Ellison Lateral Extra-articular Tenodesis of the Knee With a Knotless All-Suture Anchor

Advantages	Disadvantages
•With the ITB autograft, there is no need for an allograft. •The LET can reduce the pivot shift and stress on the ACL graft. •The knotless anchor mechanism is minimally invasive, with less soft tissue irritation •Using a loop anchor reduces suturing time. •The modified Ellison technique is less invasive than other techniques.	•Further donor site morbidity (an autograft for ACL reconstruction and another one for LET) •Risk of losing graft fixation by failure of the knotless anchor •Increased operating time •Added cost of suture anchor compared with other devices

ACL, anterior cruciate ligament; ITB, iliotibial band; LET, lateral extra-articular tenodesis.

Table 2.

Pearls and Pitfalls of the Modified Ellison Lateral Extra-articular Tenodesis of the Knee With a Knotless All-Suture Anchor

Pearls	Pitfalls
•Identify the correct landmarks to minimize skin incision •Place the knee in a figure-of-4 position to identify the FCL •Perform tibial fixation at 30° of knee flexion and neutral foot rotation •After tibial fixation, suture the fascia layer proximally and distally to the graft to minimize blood loss	•Soft tissue anchor potentially presents lower resistance than metal hardware •Risk of iatrogenic damage to the FCL •Risk of injury to the lateral geniculate vessels •Do not overtension the graft or secure it in external rotation to avoid overconstraint •Failure to close the ITB defect may result in larger blood loss and muscle herniation, causing cosmetic deformity

FCL, fibular collateral ligament.

The modified Ellison technique for LET is a reliable technique to protect the ACL-reconstructed graft, reducing postoperative asymmetric pivot shift and anterior tibial translation. This technique, in our experience, is well tolerated, improves aesthetical results, and remains an easy and quick technique to perform. The adoption of a knotless suture anchor improves operative efficiency, reducing surgical time added by LET procedures and thus lowering surgery morbidity.

Disclosures

All authors (M.A., D.M.A., T.Z.A., P.F., M.F.) declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Supplementary Data

Video 1

This video shows our surgical technique for a modified Ellison lateral extra-articular tenodesis with a knotless all-suture anchor. Surgical technique is described step by step. Preoperative clinical examination shows a positive Lachman test, anterior drawer test, and pivot-shift test. After the anterior cruciate ligament reconstruction is completed through conventional portals and the first surgeon’s preferred technique, the patient is positioned supine on the surgical table, and anatomic landmarks are identified. A straight incision is made directly over the fibular collateral ligament (FCL) toward Gerdy’s tubercle, and accurate dissection is performed. Two straight incisions 1 cm apart are performed on the posterior third of the iliotibial band; the strip is then isolated and detached. A carrier suture is created by whipstitching the graft to control its movement and its tensioning during the procedure. The graft is further released proximally from soft tissue adhesions using blunt scissors. Excessive internal rotation due to the anterolateral complex deficit is evaluated. The FCL is identified by palpation, and then 2 sharp incisions are made distally and proximally to the FCL in line with its fibers. Forceps are then introduced underneath the FCL to dilate the space and allow for graft passage. Next, an insertion point is identified and marked at 30° of flexion. The anchor is inserted into the bone and then set in place with a steady pull on all sutures. Fixation is confirmed. Next, the knotless mechanism is converted, creating a suture loop. The graft is then passed through the loop, which is tightened at 30° of flexion and with the foot in neutral rotation. Further reinforcement of the repair is achieved by distally suturing the ITB to the anterior and posterior margins of the graft. Proximally, the fascia is sutured together, and subcutaneous tissue and skin are closed over the tenodesis.